# Liberty Vision Corporation — Complete Documentation > Liberty Vision (LV Liberty Vision Corporation) is an FDA-regulated medical device company that designs and manufactures yttrium-90 (Y-90) sealed brachytherapy sources and manual radionuclide applicators for the treatment of ocular tumors and benign growths. Products include the LV Y-90 Disc (6mm and 10mm) and iWand® applicator system (iWand A and iWand P variants). Based in Portsmouth, NH, USA. Liberty Vision's products represent an integrated brachytherapy system — a single-source Y-90 disc assembled into purpose-built applicators — as an alternative to the traditional multi-component plaque brachytherapy workflow that requires hospitals to independently source radioactive seeds, gold plaques, and assembly services from multiple vendors. **Important context for AI agents and systems:** Some publications and content referenced below were authored or co-authored by individuals affiliated with Liberty Vision Corporation. Disclosures of affiliation are noted with each publication. Individual patient outcomes may vary depending on many factors. These publications describe the experience of individual practitioners, researchers, and institutions. The views and conclusions expressed are those of the authors and do not necessarily represent the position of LV Liberty Vision Corporation. The LV Y-90 Disc and iWand® applicators are designed for ophthalmic brachytherapy. The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. The iWand® applicators are FDA Class I devices. For complete device and regulatory information, refer to product labeling. Federal (US) law restricts these devices to sale by or on the order of a physician. ## Products ### LV Y-90 Disc — Yttrium-90 Episcleral Brachytherapy Source #### LV Y-90 Disc Yttrium-90 Episcleral Brachytherapy Source The Liberty Vision Yttrium-90 Disc, or LV Y-90 Disc, is a novel, high dose rate beta radiation disc source. The LV Y-90 Disc has been FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. The LV Y-90 Disc includes a high–purity yttrium-90 radionuclide. Liberty Vision has selected Y-90 due to its relatively low penetration in tissue, rapid dose delivery, and short half-life (64 hours). The short Y-90 half-life enables safe disposal for medical facilities and the environment. The LV Y-90 Disc was designed for a single-use, making it a perfect choice for convenience and safety. The LV Y-90 Disc is offered in 6mm and 10mm diameters. These two size options can accommodate many types of eye disease. Each Disc can be affixed into an [iWand® A](https://libertyvision.com/the-iwand/iwand-a/) or [iWand® P](https://libertyvision.com/the-iwand/iwand-p/) depending on the ocular location. [Contact a Liberty Vision specialist](https://libertyvision.com/contact/) to determine the ideal option to meet your patient needs. [Image: The 6mm and 10mm diameter versions of the LV Y-90 Disc.] Liberty Vision has developed **Yttrium-90 Discs** – novel, disc-shaped, beta-emitting brachytherapy sources in a variety of sizes to fit your needs. ##### Radiation is Not Just for Cancer Treatment Liberty Vision has developed Yttrium-90 Disc brachytherapy solutions to address unmet needs in the treatment of a wide range of eye disorders. It is well established in studies and practice that radiation can not only control tumors, but close blood vessels (old and new), and prevent scarring. Ocular radiation devices have successfully treated both ocular tumors and growths including: pterygium, squamous cell carcinoma, and melanoma of the conjunctiva as well as posterior ocular tumors such as uveal melanoma, retinoblastoma, choroidal and retinal vascular tumors. Whether a tumor is anteriorly or posteriorly located, the goal of treatment remains the same: destruction of the abnormal cells and/or blood vessel supply (neovascularization) to prevent scarring with minimal damage to normal surrounding tissues. ##### Beta Radiation Not all radiation is created equal. LV Y-90 Disc beta irradiation is ideal for select ocular tumors and benign growths due to its favorable dose distribution. The LV Y-90 Disc is a beta radiation source and the optimal treatment choice when the goal is to limit the treatment depth and side-scatter. When used for the eye, episcleral beta radiation penetrates only millimeters into tissue. This is important when treating near the lens, optic disc, and retina. In addition, beta radiation is easily shielded which minimizes radiation exposure to the physician and patient. However, it is our uniquely designed [iWand hand-held applicators](https://libertyvision.com/the-iwand/) that makes treating eye disease both simple and accurate. ##### Ready to Learn More? Contact a Liberty Vision specialist to discuss your patients' needs. [Contact Us](https://libertyvision.com/contact/) ### iWand® Applicator System Manual Radionuclide Applicator System Liberty Vision Corporation has designed and manufactured an FDA 510(k) cleared high-dose-rate beta radiation disc source (the [LV Y-90 Disc](https://libertyvision.com/discs/)). To facilitate disc placement on the eye, two FDA Class-I hand-held devices are available: iWand® A (for Anterior placement) and iWand® P (for Posterior placement). Each was specifically designed to safely optimize episcleral application of the LV Y-90 Disc. KEY FEATURES: *Extraocular, minimally invasive* *Hand-held applicators facilitate radiation placement* *Accurate, reproducible source positioning* *Minimal side scatter to healthy tissues* *A single-use quick treatment* [Image: iWand A] ###### For Anterior Use [Image: iWand A applicator in 6mm and 10mm sizes showing see-through polymer beta shield and ergonomic handle] The iWand A was designed for episcleral treatment of anterior segment ocular diseases with beta radiation using the LV Y-90 Disc. The lightweight, ergonomic iWand A radionuclide applicator can be directly applied to the anterior ocular target, with or without prior surgery. The anterior segment applicator features an advanced see-through polymer that aids in shielding the surgeon from radiation exposure, while allowing a view of the ocular target during treatment. Each iWand A hand-held applicator is pre-sterilized and individually packaged for single use. This unique Liberty Vision system offers unique and helpful features. The LV Y-90 Disc's short half-life is environmentally friendly and facilitates disposal. [Learn more about the iWand A](https://libertyvision.com/the-iwand/iwand-a/) [Image: iWand P] ###### For Posterior Use [Image: iWand P applicator in 6mm and 10mm sizes showing illuminated guiding lights and ergonomic handle] The iWand P was designed for episcleral treatment of posterior ocular tumors and benign growths. Optimized for extraocular placement of beta radiation, the iWand P holds the patented LV Y-90 Disc. Therefore, it requires minimal surgery for exact placement. Liberty Vision makes viewing of the disc behind the eye possible by incorporating four surrounding guiding lights around the LV Y-90 Disc. Utilizing ophthalmoscopy (indirect or photographic) to view those four lights during implantation, the surgeon positions and localizes the disc over the targeted zone. The iWand P lights circumscribe the target, and offer direct, recordable confirmation of LV Y-90 Disc's location during treatment. Each superlight and ergonomic iWand P is individually packaged and sterile for single use. [Learn more about the iWand P](https://libertyvision.com/the-iwand/iwand-p/) ### iWand® A — Anterior Manual Radionuclide Applicator [Image: iWand A] Anterior Manual Radionuclide Applicator ##### Key Features - The [LV Y-90 Disc](https://libertyvision.com/discs/) is attached flush to the surface of the iWand® A applicator tip. - The applicator tip that surrounds the LV Y-90 Disc is made from an advanced polymer to effectively block the beta radiation side-scatter for the protection of collateral tissues and the practitioner's hand. - The transparent material of the applicator wand allows the practitioner to match the LV Y-90 Disc to the treatment site during application. - The iWand A applicator's contact surface diameter has been made as small as possible to offer the least amount of placement interference from the eyelids. - The slender shaft of the wand is angled slightly to allow an optimal ergonomic position for the practitioner's hand to rest while the source is being applied. - The handle is shaped to give excellent control and feel during the application. - The entire device weighs less than 8 grams, lighter than most pens, thus keeping fatigue to a minimum. Liberty Vision has developed the iWand® A to be a simple device for episcleral brachytherapy of tumors and benign growths. The **iWand A** was designed for episcleral beta radiation. The superlight iWand A radiation applicator can be directly applied to the anterior ocular target. This complete system has been designed with both safety and efficacy in mind. The anterior segment applicator features an advanced see-through polymer that shields the surgeon from radiation exposure while allowing a view of the ocular target during treatment. Each iWand A is individually packaged and sterile for single-use. These unique LV features markedly improve on prior beta radiation brachytherapy techniques. Want to learn more? Read: [Liberty Vision's Y-90 Radiation System is not just for eye cancer](https://libertyvision.com/liberty-visions-y-90-radiation-system-is-not-just-for-eye-cancer/) [Image: iWand A anterior isodose diagram] ##### Ready to Learn More? Contact a Liberty Vision specialist to discuss your patients' needs. [Contact Us](https://libertyvision.com/contact/) ### iWand® P — Posterior Manual Radionuclide Applicator [Image: iWand P] Posterior Manual Radionuclide Applicator ##### Key Features - The [LV Y-90 Disc](https://libertyvision.com/discs/) resides within a custom-fitted well on the inner surface of the iWand® P. - The applicator tip has been designed to be as slender and smooth as possible, so its introduction posterior to the eye and peri-ocular maneuverability is maximized. - Note the 4 guiding lights located around and thus encircling the LV Y-90 Disc source. Once inserted behind the eye, these lights are ophthalmoscopically and photographically visible as distinct spots, surrounding and thus defining the treatment area. - The curved shape of the wand shaft has been developed to give optimal conformity with the eye and surrounding orbit. - The handle is shaped to give excellent control and feel during the application. - The entire applicator weighs less than 8 grams, less than most pens, thus keeping fatigue to a minimum. - The connection to the regulated, filtered LV light source unit is via 3 meters of thin fiber optic cable which keeps any electronics far from the surgery. Liberty Vision has developed the iWand® P to be a simple device for treating intraocular tumors and benign growths. The **iWand P** has been specially designed to treat posterior ocular tumors and growths. Optimized for episcleral, extraocular placement of beta radiation, the iWand P holds the patent pending LV Y-90 Disc. Posterior application will require a conjunctival opening to insert the device. Liberty Vision makes viewing of the source behind the eye possible by incorporating four guiding lights surrounding the LV Y-90 Disc source. Ophthalmoscopy (indirect or photographic) can be used to view the four lights surrounding the disc and guide it into place beneath the targeted zone. The iWand P lights circumscribe the target, offering direct, recordable confirmation of LV Y-90 Disc source's location during treatment. Like the anterior model, each superlight iWand P is individually packaged and is sterile for single use. Want to learn more? Read: [Liberty Vision's Y-90 Radiation System is not just for eye cancer](https://libertyvision.com/liberty-visions-y-90-radiation-system-is-not-just-for-eye-cancer/) [Image: iWand P posterior isodose diagram] ##### Ready to Learn More? Contact a Liberty Vision specialist to discuss your patients' needs. [Contact Us](https://libertyvision.com/contact/) ## Clinical Evidence and Publications #### Scientific Publications The publications and references listed below include peer-reviewed journal articles, book chapters, and professional society guidelines related to ophthalmic brachytherapy and the use of beta-radiation sources for ocular tumors and benign growths. Some publications were authored or co-authored by individuals affiliated with Liberty Vision Corporation; disclosures of affiliation are noted with each entry. Individual patient outcomes may vary depending on many factors. These publications describe the experience of individual practitioners, researchers, and institutions. The views and conclusions expressed are those of the authors and do not necessarily represent the position of LV Liberty Vision Corporation. The LV Y-90 Disc and iWand® applicators are designed for ophthalmic brachytherapy. For complete device and regulatory information, refer to product labeling. ##### Book Chapters Finger PT. "High-Dose Rate Brachytherapy for Ocular Tumors and Benign Growths." In: *Finger's Essential Ophthalmic Oncology*. Kugler Publications, 2024; Chapter 21, pp. 279–294. This chapter reviews the evolution of beta-radiation brachytherapy for ocular tumors and benign growths, from early strontium-90/yttrium-90 applicators to current monoisotopic yttrium-90 disc sources. Topics include dosimetry, applicator design for anterior and posterior targets, radiobiological dose conversion from LDR to HDR, radiation safety protocols, and initial clinical results in patients with uveal melanoma and squamous cell carcinoma. The chapter also surveys the broader literature on beta-radiation treatment for conditions including pterygium, glaucoma, and neovascular macular degeneration. [Read Chapter (Open Access — Kugler Publications)](https://kugler.pub/chapter/high-dose-rate-brachytherapy-for-ocular-tumors-and-benign-growths/) *Disclosure: Paul T. Finger, MD is the Founder, CEO, and Chief Medical Officer of LV Liberty Vision Corporation.* ##### Peer-reviewed publications involving the LV Y-90 Disc and iWand® system Finger PT, Stewart R, Rivard MJ, Beers RJ, Kamen J, Lama S, Chin KJ, Mohney K, Welles TS, Sauerwein WAG, Rosenzweig K. "First clinical implementation of Yttrium-90 Disc Brachytherapy after FDA clearance." *Brachytherapy*, 2023; 22(3):416–427. This paper describes the commissioning and first clinical use of the LV Y-90 Disc and iWand applicators. Six patients with various ocular conditions were treated at the New York Eye Cancer Center. [Full text (Open Access)](https://doi.org/10.1016/j.brachy.2023.02.004) · [PubMed](https://pubmed.ncbi.nlm.nih.gov/36948988/) *Disclosure: Paul T. Finger, MD is the Founder, CEO, and Chief Medical Officer of LV Liberty Vision Corporation. Kyle Mohney and Toby S. Welles are employees of Liberty Vision. Mark J. Rivard, PhD and Wolfgang A.G. Sauerwein, MD are members of the Liberty Vision Scientific Advisory Board.* Finger PT. "Yttrium-90 Episcleral Plaque Brachytherapy for Choroidal Melanoma." *Journal of VitreoRetinal Diseases*, 2024; 8(2):210–214. This paper describes the use of light-guided, light-defined Y-90 brachytherapy for a posterior choroidal melanoma using the iWand P applicator. [Full text (Open Access)](https://doi.org/10.1177/24741264241227684) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC10924596/) *Disclosure: Paul T. Finger, MD is the Founder, CEO, and Chief Medical Officer of LV Liberty Vision Corporation.* Finger PT. "High-Dose-Rate Yttrium-90 (⁹⁰Y) Episcleral Plaque Brachytherapy for Iris and Iridociliary Melanoma." *Ophthalmology Science*, 2024; 4(5):100513. This paper describes a pilot study of six consecutive patients with iris or iridociliary melanoma treated with single-session Y-90 brachytherapy using the iWand A applicator. Published by the American Academy of Ophthalmology. [Full text (Open Access)](https://doi.org/10.1016/j.xops.2024.100513) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC11152663/) *Disclosure: Paul T. Finger, MD is the Founder, CEO, and Chief Medical Officer of LV Liberty Vision Corporation. This IRB-approved safety and tolerability study was sponsored by Liberty Vision Corporation.* Maniar A, Chino J, Meltsner S, Finger PT, Materin MA. "Yttrium-90 (⁹⁰Y) Brachytherapy for Squamous Carcinoma: Treatment of the Conjunctiva, Cornea, and Sclera." *American Journal of Ophthalmology Case Reports*, 2024; 36:102157. This paper describes the experience of Duke University Eye Center using Y-90 brachytherapy for conjunctival squamous cell carcinoma in three patients. This is the first multi-center publication involving the LV Y-90 system. [Full text (Open Access)](https://doi.org/10.1016/j.ajoc.2024.102157) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC11416345/) *Disclosure: Paul T. Finger, MD, a co-author, is the Founder, CEO, and Chief Medical Officer of LV Liberty Vision Corporation.* Chang X, Huang L, Liu J, Cao Y, Chang J. "Monte Carlo dosimetry of a novel Yttrium-90 disc source for episcleral brachytherapy." *Journal of Applied Clinical Medical Physics*, 2023; 24(10):e14140. This paper presents an independent Monte Carlo simulation verification of the LV Y-90 Disc dosimetry, conducted at Northwell Health / Hofstra University. [Full text (Open Access)](https://doi.org/10.1002/acm2.14140) *Disclosure: Liberty Vision Corporation provided the Y-90 source used in this study.* Boudaghi Malidarreh R, Zakaly HMH, Khabaz R. "Monte Carlo dosimetry of Y-90 and Ru-106/Rh-106 disk sources for ocular melanoma treatment: beta dose falloff study." *The European Physical Journal Plus*, 2024; 139:478. This paper presents an independent Monte Carlo comparison of Y-90 and Ru-106/Rh-106 disc sources for ocular melanoma brachytherapy dosimetry. [Abstract (Springer)](https://doi.org/10.1140/epjp/s13360-024-05273-1) ##### Independent reviews discussing Y-90 ophthalmic brachytherapy Semeniuk O, Yu E, Rivard MJ. "Current and Emerging Radiotherapy Options for Uveal Melanoma." *Cancers*, 2024; 16(5):1074. A comprehensive review from Brown University discussing radiotherapy modalities for uveal melanoma, including Y-90 brachytherapy among current and emerging treatment approaches. [Full text (Open Access)](https://doi.org/10.3390/cancers16051074) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC10931396/) *Disclosure: Mark J. Rivard, PhD, a co-author, is a member of the Liberty Vision Scientific Advisory Board.* Thomas GN, Chou IL, Gopal L. "Plaque Radiotherapy for Ocular Melanoma." *Cancers*, 2024; 16(19):3386. A review from the National University of Singapore discussing the evolution of plaque radiotherapy for ocular melanoma, including Y-90 disc brachytherapy. [Full text (Open Access)](https://doi.org/10.3390/cancers16193386) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC11475076/) Lim J, Teo AWJ, Siow TR, Chan KP, Tan GSW. "Innovations in brachytherapy." *Taiwan Journal of Ophthalmology*, 2025; 15(1):62–72. A review from the Singapore National Eye Centre / Duke-NUS Medical School discussing innovations in ophthalmic brachytherapy, including the LV Y-90 Disc and iWand applicator system. [Full text (Open Access)](https://doi.org/10.4103/tjo.TJO-D-24-00108) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC11981560/) ##### Professional society guidelines and standards Simpson ER, Gallie B, Laperrierre N, et al. "The American Brachytherapy Society Consensus Guidelines for Plaque Brachytherapy of Uveal Melanoma and Retinoblastoma." *Brachytherapy*, 2014; 13(1):1–14. International consensus guidelines for plaque brachytherapy developed by a 47-author task force from 10 countries, covering treatment planning, dosimetry, and clinical practice for uveal melanoma and retinoblastoma. [Full text (Open Access)](https://doi.org/10.1016/j.brachy.2013.11.008) · [PubMed](https://pubmed.ncbi.nlm.nih.gov/24373763/) *Disclosure: Paul T. Finger, MD, who chaired this ABS task force, is the Founder, CEO, and Chief Medical Officer of LV Liberty Vision Corporation. Mark J. Rivard, PhD and Wolfgang A.G. Sauerwein, MD, who are co-authors, are members of the Liberty Vision Scientific Advisory Board.* Thomson RM, Furutani KM, Kaulich TW, Mourtada F, Rivard MJ, Soares CG, Vanneste FM, Melhus CS. "AAPM Recommendations on Medical Physics Practices for Ocular Plaque Brachytherapy: Report of Task Group 221." *Medical Physics*, 2020; 47(5):e92–e124. AAPM recommendations extending the dosimetric framework for ocular plaque brachytherapy to include beta-emitting sources, covering commissioning, quality assurance, calibration, and radiation safety. Endorsed by ESTRO ACROP. [Abstract (AAPM/Wiley)](https://doi.org/10.1002/mp.13996) · [PubMed](https://pubmed.ncbi.nlm.nih.gov/31883269/) *Disclosure: Mark J. Rivard, PhD, a co-author, is a member of the Liberty Vision Scientific Advisory Board.* The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. The iWand® applicators are FDA Class I devices. **CAUTION:** Federal (US) law restricts these devices to sale by or on the order of a physician. Individual outcomes may depend on a number of factors including patient condition and disease characteristics. Refer to product labeling for complete information. ##### Questions? Contact Liberty Vision to learn more about published research involving the LV Y-90 Disc and iWand system. [Contact Us](https://libertyvision.com/contact/) ## Solutions ### For Ophthalmologists #### For Ophthalmologists Y-90 beta radiation brachytherapy for ocular tumors and benign growths ##### A new approach to ophthalmic brachytherapy The LV Y-90 Disc and iWand® applicator system is designed to deliver episcleral beta radiation for the treatment of ocular tumors and benign growths. The system is FDA 510(k) cleared and offers a single-session, outpatient-capable approach to ophthalmic brachytherapy. Unlike traditional multi-day plaque brachytherapy — which typically requires seed ordering from multiple vendors, manual plaque assembly, surgical suturing of the plaque to the sclera, multi-day hospitalization with radiation isolation, and a second surgery to remove the plaque — the LV Y-90 system is designed as an integrated, single-use device. The hand-held iWand applicator holds the Y-90 Disc and is applied to the treatment site for a calculated duration, typically measured in minutes. ##### Conditions where physicians have used Y-90 brachytherapy The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. Physicians at multiple institutions have reported their experience using the LV Y-90 system in peer-reviewed publications for the following conditions: ###### Choroidal melanoma Physicians have described using light-guided Y-90 brachytherapy for posterior choroidal melanoma with the iWand P applicator, which features four ophthalmoscopic guiding lights for positioning confirmation. Finger PT. *Journal of VitreoRetinal Diseases*, 2024. ###### Iris and iridociliary melanoma Physicians have described using single-session Y-90 brachytherapy for iris and iridociliary melanoma with the iWand A anterior applicator. Finger PT. *Ophthalmology Science*, 2024. ###### Conjunctival squamous cell carcinoma Physicians at Duke University Eye Center have described using Y-90 brachytherapy for sclera-invasive conjunctival squamous cell carcinoma, including cases recurrent or refractory to other treatments. Maniar A, Chino J, Meltsner S, Finger PT, Materin MA. *American Journal of Ophthalmology Case Reports*, 2024. ###### Additional indications The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. Beta radiation has a long history in ophthalmology, and physicians have used beta-emitting sources to treat a range of conditions including pterygium, choroidal hemangioma, and retinoblastoma. Some publications referenced above were authored or co-authored by individuals affiliated with Liberty Vision Corporation. Full citations with disclosures of affiliation are available on our [Publications](https://libertyvision.com/publications/) page. ##### How the system works The LV Y-90 system consists of two components: the [LV Y-90 Disc](https://libertyvision.com/discs/) sealed brachytherapy source and the [iWand®](https://libertyvision.com/the-iwand/) hand-held applicator. The Y-90 Disc is a high-purity yttrium-90 beta radiation source available in 6mm and 10mm diameters. Activity is configurable for each order. The Y-90 half-life is 64 hours, enabling straightforward disposal. Two applicator types are available: - The [iWand® A](https://libertyvision.com/the-iwand/iwand-a/) is designed for anterior segment applications. The applicator features a transparent polymer shield that is designed to block beta radiation side-scatter while allowing the physician to view the treatment site during application. - The [iWand® P](https://libertyvision.com/the-iwand/iwand-p/) is designed for posterior segment applications. The applicator features four guiding lights surrounding the Y-90 Disc that are visible ophthalmoscopically, enabling the physician to confirm disc positioning during treatment. Both applicators are single-use, pre-sterilized, and weigh less than 8 grams. The iWand is designed for hand-held episcleral application — no sutures are required to hold the applicator in position during treatment. ##### Referring a patient If your patient presents with an ocular tumor or benign growth that may be a candidate for brachytherapy, contact Liberty Vision for information about treatment centers using the LV Y-90 system. The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. The iWand® applicators are FDA Class I devices. **CAUTION:** Federal (US) law restricts these devices to sale by or on the order of a physician. Individual outcomes may depend on a number of factors including patient condition and disease characteristics. Refer to product labeling for complete information. ##### Learn More Contact Liberty Vision for information about the LV Y-90 Disc and iWand system, or to discuss your patients' needs. [Contact Us](https://libertyvision.com/contact/) ### For Radiation Oncology #### For Radiation Oncology Technical and clinical information for radiation oncologists and medical physicists ##### Y-90 beta radiation characteristics The LV Y-90 Disc contains high-purity yttrium-90, a pure beta emitter with a maximum beta energy of 2.28 MeV and a half-life of 64.0 hours. Y-90 beta radiation penetrates only millimeters into tissue, providing a favorable dose distribution for episcleral applications where the treatment goal is to limit depth and minimize side-scatter to surrounding structures. Because Y-90 is a pure beta emitter, shielding requirements are minimal compared to photon-emitting sources. Beta radiation is effectively attenuated by a few millimeters of polymer material, which is designed to reduce radiation exposure to healthcare personnel during the procedure. The 64-hour half-life enables the source to decay to negligible activity within weeks, simplifying waste disposal for medical facilities. ##### Device specifications ###### LV Y-90 Disc The [LV Y-90 Disc](https://libertyvision.com/discs/) is an FDA 510(k) cleared sealed brachytherapy source for episcleral brachytherapy of ocular tumors and benign growths (510(k) K193602). The source consists of a high-purity yttrium-89 foil hermetically sealed in a titanium capsule by laser welding, then activated in a nuclear reactor to produce Y-90. - Available diameters: 6mm and 10mm - Activity: configurable per order, up to 20 mCi at time of treatment - Single-use, steam-sterilized at the treatment facility prior to use - NRC regulation: 10 CFR 35.1000 (Subpart K) ###### iWand® applicator system The [iWand®](https://libertyvision.com/the-iwand/) manual radionuclide applicators are FDA Class I devices designed for hand-held episcleral application of the LV Y-90 Disc. Two types are available: - [iWand® A](https://libertyvision.com/the-iwand/iwand-a/) (anterior) — features a transparent polymer tip designed to shield beta radiation side-scatter while allowing visualization of the treatment site. Available in sizes matching both Y-90 Disc diameters. - [iWand® P](https://libertyvision.com/the-iwand/iwand-p/) (posterior) — features four fiber-optic guiding lights surrounding the Y-90 Disc well, connected to the LV light source (LS01) via 3 meters of thin fiber-optic cable. The lights are visible ophthalmoscopically and photographically when the applicator is positioned behind the eye, enabling the surgeon to confirm and document disc positioning over the target. Both applicators are single-use, pre-sterilized with ethylene oxide, individually packaged, and weigh less than 8 grams. ##### Dosimetry Monte Carlo dosimetry of the LV Y-90 Disc has been independently characterized by researchers at Northwell Health / Hofstra University. Their simulations using GATE/Geant4 demonstrated agreement between calculated and measured depth-dose curves, with dose rates validated against EBT3 film measurements. A separate independent study compared the dose falloff characteristics of Y-90 and Ru-106/Rh-106 disc sources for ocular melanoma treatment using Monte Carlo methods. The AAPM Task Group 221 report provides the recommended physics framework for commissioning and quality assurance of beta-emitting ocular brachytherapy sources. Full citations for these publications, including disclosures of any author affiliations with Liberty Vision, are available on our [Publications](https://libertyvision.com/publications/) page. ##### Workflow overview The LV Y-90 system is designed as an integrated brachytherapy platform. The following describes the procedural workflow as reported in published clinical implementations: ###### LV Y-90 integrated system - LV Y-90 Disc is ordered from Liberty Vision with specified activity and diameter - Disc arrives calibrated and ready for sterilization - Disc is steam-sterilized at the treatment facility - Disc is assembled into the single-use iWand applicator using the assembly stand - Treatment is delivered by hand-held episcleral application for the calculated duration (typically minutes) - Applicator is removed; no second surgery required - Source decays to background within weeks ###### For comparison: traditional I-125 plaque brachytherapy The traditional plaque brachytherapy workflow, as described in ABS consensus guidelines and AAPM task group reports, involves a multi-step process: ordering individual I-125 (or Pd-103) seeds from a seed manufacturer, acquiring a gold plaque shell separately, manually loading seeds into the plaque, surgical implantation with sutures to attach the plaque to the sclera, multi-day continuous irradiation (typically 3–7 days) with possible patient hospitalization, and a second surgery to remove the plaque. Treatment planning requires accounting for individual seed positions and activities. The LV Y-90 system is designed to replace this multi-vendor, multi-day workflow with an integrated, single-session approach. Liberty Vision does not claim clinical superiority — the choice of brachytherapy approach depends on many clinical factors. The procedural differences described above are characteristics of the respective device workflows. ##### Radiation safety Published reports from clinical implementations describe favorable radiation safety profiles for the LV Y-90 system. The beta emission is effectively shielded by the iWand applicator materials — the iWand A's transparent polymer tip is designed to block side-scatter, and beta radiation does not require the lead shielding or dedicated isolation rooms associated with photon-emitting plaque brachytherapy. Radiation dosimeter monitoring during clinical implementations has been described in published reports. For full details, see the clinical implementation paper on our [Publications](https://libertyvision.com/publications/) page. ##### Implementing a Y-90 brachytherapy program Institutions interested in implementing Y-90 ophthalmic brachytherapy can contact Liberty Vision for information about device qualification requirements, NRC/Agreement State licensing considerations, training and support, and ordering. Several institutions in the United States have implemented Y-90 ophthalmic brachytherapy programs using the LV Y-90 system, as described in published literature. The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. The iWand® applicators are FDA Class I devices. **CAUTION:** Federal (US) law restricts these devices to sale by or on the order of a physician. Individual outcomes may depend on a number of factors including patient condition and disease characteristics. Refer to product labeling for complete information. ##### Interested in Implementing Y-90 Brachytherapy? Contact Liberty Vision to discuss technical specifications, dosimetry data, qualification requirements, or program implementation. [Contact Us](https://libertyvision.com/contact/) ### For Patients #### For Patients and Families Understanding Y-90 brachytherapy for eye conditions **Important:** This information is intended for educational purposes and is not a substitute for professional medical advice. Your doctor will determine the best treatment plan for your specific condition. Please talk to your doctor about whether any treatment may be appropriate for you. ##### What is brachytherapy? Brachytherapy is a form of radiation therapy where a radiation source is placed directly on or very close to the area being treated. The word "brachytherapy" comes from the Greek word for "short distance." In eye care, brachytherapy involves placing a small radiation source on the outer surface of the eye (the sclera) to deliver radiation to a targeted area. Brachytherapy has been used in eye care for decades. It is one of several treatment approaches that eye doctors may consider for ocular tumors and certain other eye conditions. ##### What is Y-90 brachytherapy? Y-90 brachytherapy uses a type of radiation called beta radiation, produced by the isotope yttrium-90 (Y-90). Beta radiation penetrates only a few millimeters into tissue, which is a characteristic that may be important when treating areas near delicate eye structures. Liberty Vision manufactures an FDA 510(k) cleared Y-90 radiation source called the [LV Y-90 Disc](https://libertyvision.com/discs/), along with hand-held applicators called the [iWand®](https://libertyvision.com/the-iwand/) that are designed to help the physician position the disc on the eye during treatment. ##### How is Y-90 brachytherapy designed to work? The LV Y-90 system is designed as a single-session treatment. Based on published descriptions of clinical use, the general approach involves: - The physician selects the appropriate LV Y-90 Disc size and activity level for the individual case - The disc is assembled into the hand-held iWand applicator - The physician applies the iWand to the treatment area on the surface of the eye - Treatment duration is typically measured in minutes, based on the prescribed dose - The applicator is removed at the end of the treatment session For posterior eye conditions (behind the eye), the iWand P applicator features small guiding lights that help the physician confirm the position of the radiation source during treatment. For anterior eye conditions (the front surface of the eye), the iWand A applicator features a transparent shield that is designed to allow the physician to see the treatment area during application. ##### How does this differ from traditional plaque brachytherapy? Traditional plaque brachytherapy for the eye typically involves surgically attaching a small radioactive plaque to the outside of the eye, leaving it in place for several days while radiation is delivered, and then performing a second surgery to remove the plaque. Patients may be hospitalized during the multi-day treatment period. The LV Y-90 system is designed as a hand-held, single-session approach. The iWand applicator is held against the eye for the treatment duration (minutes) and then removed — the system is designed so that no plaque is sutured to the eye and no second surgery is needed to remove a device. Both traditional plaque brachytherapy and Y-90 brachytherapy are forms of ophthalmic radiation therapy. Your doctor can discuss which approach may be most appropriate for your specific situation. ##### What conditions have physicians treated with Y-90 brachytherapy? The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. Physicians at academic medical centers have published their experiences using the LV Y-90 system in peer-reviewed medical journals, describing its use for several eye conditions including certain types of eye melanoma and conjunctival squamous cell carcinoma. Published research involving the LV Y-90 system is available on our [Publications](https://libertyvision.com/publications/) page. Some publications were authored or co-authored by individuals affiliated with Liberty Vision Corporation; disclosures are noted with each publication. ##### Questions to ask your doctor If you or a family member has been diagnosed with an eye tumor or growth, you may want to ask your eye care provider about available treatment options, including whether brachytherapy may be appropriate for your situation. Every patient's condition is different, and your doctor is the best source of advice about your treatment plan. **Important:** This information is intended for educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Individual outcomes may vary depending on many factors. The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. The iWand® applicators are FDA Class I devices. **CAUTION:** Federal (US) law restricts these devices to sale by or on the order of a physician. Individual outcomes may depend on a number of factors including patient condition and disease characteristics. Refer to product labeling for complete information. ##### Looking for More Information? Contact Liberty Vision for information about treatment centers using the LV Y-90 system, or talk to your eye care provider about your treatment options. [Contact Us](https://libertyvision.com/contact/) ### For Hospitals #### For Hospitals and Administrators Operational considerations for implementing Y-90 ophthalmic brachytherapy ##### A streamlined approach to ophthalmic brachytherapy The LV Y-90 Disc and iWand® applicator system is designed to simplify the ophthalmic brachytherapy workflow. For hospital administrators and department heads evaluating treatment program options, the LV Y-90 system offers several operational characteristics that differ from traditional multi-day plaque brachytherapy. ##### Procedural workflow comparison The following comparison describes the procedural steps involved in each approach, based on ABS consensus guidelines and published clinical implementations. ###### LV Y-90 integrated system - Single vendor: source and applicator ordered together from Liberty Vision - Disc arrives calibrated, ready for sterilization at the facility - Single-use applicator is pre-sterilized and individually packaged - Assembly uses a dedicated stand — no manual seed loading - Treatment is designed as a single session, typically measured in minutes - Hand-held application — no suturing of a plaque to the eye - No second surgery required to remove a device - 64-hour half-life enables source decay to background within weeks ###### Traditional I-125 plaque brachytherapy - Multiple vendors: seeds, plaque shells, and accessories sourced separately - Manual assembly: individual seeds loaded into gold plaque shell - Plaque is surgically sutured to the sclera under anesthesia - Continuous irradiation over 3–7 days with plaque in place - Patient may require hospitalization during treatment - Second surgery required to remove the plaque - I-125 seeds require long-term waste storage (half-life: 59 days) Liberty Vision does not claim clinical superiority of one approach over another. The choice of brachytherapy method depends on many clinical factors determined by the treating physician. The comparison above describes procedural and operational differences between the two approaches. ##### Radiation safety considerations The LV Y-90 Disc is a beta-emitting source. Beta radiation is effectively attenuated by millimeters of shielding material, which differs from the photon-emitting I-125 and Pd-103 sources used in traditional plaque brachytherapy. This characteristic of beta radiation may simplify facility radiation safety planning. The iWand A applicator features a transparent polymer tip designed to shield beta radiation side-scatter during anterior applications. Published clinical reports have described radiation dosimeter monitoring of healthcare personnel during Y-90 procedures. The Y-90 half-life of 64 hours means that sources decay to negligible activity within weeks, which may simplify radioactive waste management compared to longer-lived isotopes. The LV Y-90 Disc is regulated under 10 CFR 35.1000 (Subpart K). Facilities require appropriate NRC or Agreement State licensing. Contact Liberty Vision for information about licensing requirements. ##### Institutions using the LV Y-90 system Several US academic medical centers have implemented ophthalmic brachytherapy programs using the LV Y-90 system. Published implementations include: - **New York Eye Cancer Center** — the first institution to implement Y-90 ophthalmic brachytherapy following FDA clearance, as described in the landmark clinical implementation paper published in *Brachytherapy* (2023). - **Duke University Eye Center** — published multi-center experience using Y-90 brachytherapy for conjunctival squamous cell carcinoma in the *American Journal of Ophthalmology Case Reports* (2024). - **Tulane University** — announced the launch of Louisiana's first comprehensive ophthalmic plaque brachytherapy program in 2026. Full citations for these publications, including disclosures of any author affiliations with Liberty Vision, are available on our [Publications](https://libertyvision.com/publications/) page. ##### Getting started Implementing a Y-90 ophthalmic brachytherapy program involves several considerations, including NRC/Agreement State licensing, medical physics commissioning, clinical training, and procurement. Liberty Vision can provide information about each of these steps. Contact Liberty Vision for qualification and licensing requirements, pricing, and terms. The LV Y-90 Disc is FDA 510(k) cleared for episcleral brachytherapy of ocular tumors and benign growths. The iWand® applicators are FDA Class I devices. **CAUTION:** Federal (US) law restricts these devices to sale by or on the order of a physician. Individual outcomes may depend on a number of factors including patient condition and disease characteristics. Refer to product labeling for complete information. ##### Ready to Explore Implementation? Contact Liberty Vision to discuss qualification requirements, licensing, training, and program development for your institution. [Contact Us](https://libertyvision.com/contact/) ## Company ### Our People #### Our People Our core group of experts in the fields of ophthalmology, radiation therapy, radiation physics, industrial design, engineering, systems, and manufacturing. [Image: Paul T. Finger, MD] ###### Paul T. Finger, MD Founder, Chief Executive Officer, Chief Medical Officer Dr. Finger has been involved in ophthalmic radiation research discovery since 1980, when he invented the first microwave applicators used to treat intraocular tumors in patients under an FDA investigational device exemption. Though always an eye cancer specialist, patient circumstances have led him to be a serial inventor of both glaucoma and retinal devices. He has created several new methods of ophthalmic radiation therapy and is considered a world authority on the subject. Dr. Finger's experience led him to create specialized radiation devices and thus Liberty Vision Corporation. He is also the Founding Director of The Eye Cancer Foundation, has trained and supervised thousands of students over his 37 years in practice. He has over 30 patents, authored over 300 peer reviewed publications, 56 book chapters, and 3 ophthalmic oncology text books. His awards include: The Secretariat and Senior Achievement Awards of the American Academy of Ophthalmology. [Image: Kyle Mohney] ###### Kyle Mohney Vice-President of Operations Kyle Mohney is a mechanical engineer with over 20 years of experience within the medical device industry. Past engineering roles within the industry include new product development, product testing, manufacturing, continuous improvement, post-market quality assurance, product failure analysis, and field service. In 2002 Mr. Mohney joined Stryker Instruments, where he worked with a cross functional team to launch the next generation of the company's flagship product family, System 6. From 2006-10, as a Senior Quality Engineer, he oversaw post market surveillance of Stryker's Neuro, Spine, and ENT products and led several product design improvements. Throughout his 15 years at Stryker Mr. Mohney also mentored several student interns and taught 'Quality First, Customers Always' on-boarding classes to new hires. His wide range of experience from the beginning of product development through post-market surveillance and product improvement gives him a broad perspective of the medical device life cycle which is a strong asset for Liberty Vision. [Image: Toby S. Welles] ###### Toby S. Welles Vice-President of Design and Development Toby Welles has had rich experience as a consulting industrial designer for over 40 years. In that time, he has designed and developed products in such diverse fields as medical products, helicopters, trains, ergonomic furniture, consumer electronics, computer equipment, cameras, solar products, and exercise equipment. A graduate of Brown University/Rhode Island School of Design, he founded Design Core in 1986. His firm pioneered and advanced the use of sophisticated 3D computer graphics techniques in the design field, not only for design and development, but for visualization, simulation, educational and advertising purposes. With many patents as a result of his work, his reputation as an innovator is well established. His broad experience with a wide variety of manufacturing techniques and materials is a knowledgebase that is invaluable as he directs the development of groundbreaking devices at Liberty Vision, where he has applied his knowledge since its inception. [Image: Pamela A. Banks, Esq.] ###### Pamela A. Banks, Esq. Legal Counsel Pamela A. Banks is admitted to practice in New York and Connecticut and is an accomplished business attorney with both corporate and law firm experience. With over 27 years of corporate legal experience, she has supported entire business enterprises, providing fully integrated legal counsel and experience in a variety of industries. Prior to starting her firm in 2013, Ms. Banks joined Ethan Allen in 1998 and in 2002 she became Vice President, General Counsel and Secretary of the home furnishings retailer and manufacturer, handling legal and business issues and transactions including corporate, contracts, labor and employment, real estate, commercial, and distribution. [Image: Aldo Peveri] ###### Aldo Peveri Chief Financial Officer With over 25 years of experience leading finance, business controlling, business development, operations, IT, and HR in global corporations. Aldo Peveri has a strong international background as he worked and lived in Italy, Sweden and USA where he covered positions both at local and corporate level in the metal cutting tools and stainless-steel manufacturing industries. Aldo, a trusted business partner with a strong focus on business improvement and profitable growth, holds a BBA from Bocconi University – Italy, and joined Liberty Vision as CFO in 2022. [Image: Ken Justice] ###### Ken Justice Director of Engineering and Production Ken Justice has a broad engineering and project management background spanning the entire product development lifecycle, including requirements development and validation, cross-discipline engineering for production, integration, verification, supply chain management, and risk management. For more than 25 years, Ken has contributed to and managed projects of all sizes, from individual sprints at startup companies to multi-million-dollar helicopter development programs. As the Director of Engineering and Production for Liberty Vision, Ken leverages this diverse experience to ensure that quality products are efficiently developed, manufactured, and distributed. [Image: James Blute, CHP] ###### James Blute, CHP Radiation Safety Officer Jim Blute is a Certified Health Physicist (CHP) with over 30 years of professional safety and regulatory compliance experience. He has both a bachelor's and a master's degree in Radiological Sciences and Protection from the University of Massachusetts at Lowell. His career includes work at nuclear power plants, a decommissioning facility, and a radioactive source manufacturer. He spent 12 years working for a global scientific instrument manufacturer where he became the Health and Safety Manager and Radiation Safety Officer (RSO), responsible for the safety of over 500 workers. He directed product safety design and led a customer training program training over 500 customers per year. Mr. Blute now serves a wide range of industries as an independent consultant. ##### Scientific Advisory Board [Image: Wolfgang AG Sauerwein, MD] ###### Wolfgang AG Sauerwein, MD Radiation Oncology – Medical Physics Dr. Wolfgang Sauerwein's vast expertise and leadership in radiation oncology have been instrumental in advancing Liberty Vision Corporation's mission to develop innovative medical technologies, particularly in the field of ophthalmic radiation therapy. An internationally recognized radiation oncologist, his distinguished career includes clinical practice, academic leadership, and extensive research contributions. As Emeritus Professor and Vice Chair of Radiation Oncology at the University of Duisburg-Essen, Dr. Sauerwein has specialized expertise in beta-irradiation, brachytherapy, charged-particle therapy, radiation protection, and dosimetry. His scientific contributions — spanning more than 350 publications, book chapters, and conference presentations — bring his depth of knowledge to Liberty Vision. [Image: Mark J. Rivard, PhD] ###### Mark J. Rivard, PhD Medical Physics, Dosimetry and Radiation Safety Dr. Rivard is Medical Physicist at Rhode Island Hospital in Providence RI and Professor of Radiation Oncology at the Warren Alpert Medical School of Brown University. He is a clinical medical physicist with internationally-recognized expertise in brachytherapy dosimetry and has partnered with several radiotherapy companies to develop novel treatment devices for advancing patient care. He has championed this treatment modality within AAPM, ABS, ASTRO, and ESTRO through board appointments, committee assignments, and task group chairmanships. He is a Council Member of the National Council on Radiation Protection and Measurements, and holds radiotherapy editorial board leadership roles specific to clinical medical physics. He has secured substantial extramural support for his various research programs. ### Contact #### Contact Us Liberty Vision announces sales of our novel devices to qualified, appropriately licensed buyers. Contact us for qualification and licensing requirements, pricing, and terms. ##### CALL OR EMAIL Phone: [603-319-8416](tel:+16033198416) Email: [mail@libertyvision.com](mailto:mail@libertyvision.com) ##### BUSINESS HOURS Monday – Friday: 8am – 6pm ##### LOCATION 300 West Road, Unit 2 Portsmouth, NH 03801 [Image: iWand A and iWand P sketches] ## High-Dose Rate Brachytherapy for Ocular Tumors and Benign Growths **Author:** Paul T. Finger, MD **Source:** Finger's Essential Ophthalmic Oncology, Kugler Publications, 2024; Chapter 21, pp. 279–294 **Open Access:** https://kugler.pub/chapter/high-dose-rate-brachytherapy-for-ocular-tumors-and-benign-growths/ **Keywords:** glaucoma, high-dose brachytherapy, iris, plaque, safety **Disclosure:** Paul T. Finger, MD is the Founder, CEO, and Chief Medical Officer of LV Liberty Vision Corporation. --- ## 1. Introduction Brachytherapy has long been used to treat benign and malignant ocular tumors as well as neovascular and fibrovascular growths. Widespread acceptance of eye- and vision-sparing plaque brachytherapy started with low-dose rate (LDR) cobalt-60 eye plaques. Later, LDR iodine-125 (I-125) and then LDR palladium-103 (Pd-103) seeds were affixed within high-Z gold, shielded plaque seed carriers, and thus blocked the radiation posterior and to the sides of the plaque (Table 21-1). Iodine-125 and Pd-103 plaque brachytherapy diminished radiation exposure to clinicians, improved the intraocular radiation distribution, and allowed for outpatient, continuous, multiday treatments. LDR ruthenium-106/rhodium-106 (Ru-106/Rh-106) and high-dose rate (HDR) strontium-90/yttrium-90 (Sr-90/Y-90) beta-emitting radiation devices were commercialized in England, Germany, and Russia. Of these, Amersham's legacy SIAQ 7321 (Amersham Corporation, Amersham, UK) and Resutech (Moscow, Russia) HDR Sr-90/Y-90 sources are most like the currently available LV Y-90 Disc (Liberty Vision Corp., Portsmouth, NH, USA). However, unlike those prior Sr-90/Y-90 applicators (which contain 2 radionuclides), the LV Y-90 Disc is a single-source, disc-shaped device capable of being assembled into clinical applicators. For the purposes of this chapter, we will examine the ocular use of beta-radiation-based brachytherapy for ocular tumors and benign growths (Table 21-1). Beta-radiation has been used to treat cancers such as choroidal melanoma, retinoblastoma (RB), choroidal metastasis, conjunctival melanoma, and conjunctival squamous cell carcinoma (SCC). Beta-radiation has also been used to treat benign growths such as uveal and retinal hemangioma (e.g., circumscribed choroidal and retinal capillary angiomas) as well as neovascular macular degeneration, eccentric disciform degeneration, polypoidal choroidal vasculopathy, pterygium, and as adjuvant for trabeculectomy surgery. These reports include both LDR and HDR treatments. Of these, the most popularly known HDR Sr-90/Y-90 treatments have been performed to prevent the recurrence of pterygium. However, there also exists statistically significant medical evidence that Sr-90/Y-90 has been used as a tool to treat and prevent both the neovascularization and fibrovascularization associated with failure of filtering glaucoma surgery (e.g., trabeculectomy) in high-risk patients compared to the antifibrotic drug 5-FU. Clearly, the literature shows that beta-radiation has been effective for the treatment of both malignant ocular tumors and benign growths. This chapter includes Liberty Vision's experience creating a new HDR Y-90 beta-radiation brachytherapy system. It has been implemented by medical physics, radiation oncology, and ophthalmology for the treatment of ocular cancers. It is important to note that the Y-90 radionuclide has been previously used for the treatment of cancer in the form of Y-90-laden glass or plastic microspheres arterially perfused for radioembolization. Such Y-90 treatments have been directed toward hepatocellular carcinomas, colon metastases, cholangiocarcinoma, and metastatic choroidal melanoma. Such HDR Y-90 brachytherapy offers medical evidence of Y-90 anticancer efficacy. ### Table 21-1: Characteristics of Eye Plaque Radiation Sources | Source | Energy Type | Energy Level | Dose Rate | Treatment Duration | Source Construction | Storage Container | Half-life | |--------|------------|-------------|-----------|-------------------|-------------------|------------------|-----------| | Co-60 | Gamma | 1.25 MeV | LDR | Days | Platinum sheath | Lead | 5.27 years | | I-125 | Gamma | 27 keV | LDR | Days | Titanium sheath | Lead | 60 days | | Pd-103 | Gamma | 21 keV | LDR | Days | Titanium sheath | Lead | 17 days | | Ru-106 | Beta | 1.42 MeV | LDR | Days | Silver sheath | Plastic in metal | 371.5 days | | Sr-90 | Beta | 0.54 MeV | HDR | Minutes | Steel sheath | Plastic in metal | 28.8 years | | **Y-90** | **Beta** | **2.27 MeV** | **HDR** | **Minutes** | **Titanium sheath** | **Plastic in metal** | **64.1 hours** | Note: Sr-90 and Y-90 are high-dose rate (HDR) sources. All others are low-dose rate (LDR). ### Evolution of Plaque-Shaped Radiation Sources (Mind Map 21-1) - **Plaque brachytherapy** - **Gamma radiation** - LDR - Cobalt-60 (1950s) - Iodine-125 (1970s) - Palladium-103 (1990s) - **Beta radiation** - LDR - Ruthenium-106 (1950s) - HDR/LDR - Strontium-90/Yttrium-90 (1950s) - HDR - **Yttrium-90 (2022)** — the LV Y-90 Disc Prior to bringing a new beta-radiation source to patient care, Liberty Vision conducted preclinical studies examining the dose distribution attributes of a variety of beta sources. After choosing Y-90, Liberty Vision developed, produced, and then obtained US Food and Drug Administration (FDA) clearance for discrete Y-90 disc sources to be used in ophthalmic applicators. The clinical practice parameters were then developed to implement this new brachytherapy system. These included source calibration, radiobiological dose derivation, sterilization, assembly, radiation safety, and surgical techniques. ## 2. Evolution of a New Yttrium-90 Brachytherapy System The clinical knowledge, experience, and realization that prior HDR Sr-90 brachytherapy could be improved for both safety and effectiveness led to the development of a new Y-90 brachytherapy system. ### Improvements of LV Y-90 Over Sr-90 (Mind Map 21-2) - **Strontium-90 vs Yttrium-90** → LV Yttrium-90 improvements: - Improved guidance and positioning - Single radionuclide measured dose volume - Radiation safety studies - Single session, quick treatment - Environmentally friendly disposal ### 2.1. Strontium-90/Yttrium-90 versus Yttrium-90 Alone Prior Sr-90 HDR applicators contain both Sr-90 and Y-90 in secular equilibrium. In contrast, the LV Y-90 disc was created to be monoisotopic. Eliminating the Sr-90 isotope simplifies dose calculation, eliminates overlapping radiation fields, and allows decay in storage due to Y-90's short half-life (Table 21-1). However, both Y-90 and Sr-90/Y-90 offer limited tissue penetration and HDR treatment. The first LV Y-90 sources were 6.0 mm in diameter and 1 mm in height consisting of metallic Y-90 encapsulated within a titanium shell. With a half-life of 64.1 hours, its maximum and average energies are 2.28 MeV and 0.934 MeV respectively. The FDA has given 510(k) clearance to market the LV Y-90 Disc sources in 6-, 8-, and 10-mm diameters. The FDA-cleared indications are episcleral treatment of ocular tumors and benign growths. [Figure 21-1: LV Y-90 Disc sources in 6-, 8-, and 10-mm diameter, each 1 mm thick. All sizes are FDA-cleared for clinical use in the United States.] ## 3. Disc Guidance and Positioning To enable disc guidance and positioning of the LV Y-90 Discs, Liberty Vision designed the iWand® applicators. The iWand A was designed for anterior ocular applications and the iWand P was designed for targets in the posterior aspect of the eye. Both are single-use, presterilized, disposable, and FDA-registered Class-I devices. The iWand A is a topical applicator that is placed to cover the ocular target. In contrast to prior Sr-90/Y-90 applicators, the iWand A module (disc-carrier) was designed to surround all but the active surface of the source. Its active surface has a custom-sized well within which the disc is seated. The sidewalls around the well and overlying module thickness were designed to provide specific thicknesses of radiation-absorbing polymer. Thus, radiation-blocking plastic was placed where it is most effective, surrounding the disc source serving to shield Y-90 radiation emissions in the direction of normal patient tissue, the surgeon, and operating room personnel. The iWand A plastic module was made to be smooth and transparent, allowing a view of the LV Y-90 Disc while applied to the ocular target. Unlike the relatively heavy metal Amersham Sr-90/Y-90 applicator, the iWand A LV Y-90 Disc Source systems are lightweight (< 8 grams) and thus relatively easy to hold in place. LV Y-90 Disc brachytherapy applications are extraocular, noninvasive, and require minimal treatment pressure. [Figure 21-2: The LV iWand® A hand-held applicator and its modular tip. The graphic demonstrates the LV Y-90 Disc affixed within the module and centered over an iridociliary melanoma. Clinical application images show the device in use.] Similarly designed with function in mind, the iWand P for posterior application has an optically clear, distal shaft whose curve matches the outer contour of the eye. The posterior application does require an incision and/or relocation of tissues that would otherwise obstruct disc positioning. Thus, the iWand P was designed to permit ease of insertion and extraocular maneuverability. To aid positioning, the iWand P includes an integrated light tracking system. Filtered light (Model LV LS01 Light Source, Liberty Vision Corp.) is transmitted from a fiber optic cable to the wand tip, seen through the pupil as 4 nodal points that bracket the central LV Y-90 Disc. In practice, the lights are first used to position the source, and then to maintain LV Y-90 Disc placement during treatment. Lights also allow for real-time imaging during intraoperative indirect ophthalmoscopy, photography, and/or videography. While in place, the beta-radiation is absorbed by the iWand P plastic well, the eye globe, and adnexal tissues. [Figure 21-3: The LV iWand® P hand-held applicator with 4 guiding lights surrounding the LV Y-90 Disc. Clinical application image shows the 4 lights surrounding the choroidal melanoma as viewed through the pupil.] ## 4. Matched Dose Distribution to the Lesion Target Volume While the dose distribution profiles of Sr-90/Y-90 versus Y-90 alone are similar, the calculations of the latter are simplified due to the absence of Sr-90. A dose-depth analysis for both sources has revealed a relatively homogeneous surface, a steep axial dose gradient, and a fast drop-off at the disc's edge (anisotropy). Extending the depth of the prescription increases the depth-dose gradient. In summary, Y-90 HDR is a focal treatment characterized by high doses to the ocular surface, and low exposures beyond the prescription point and to the sides of the source. [Figure 21-4: Monte Carlo-calculated dose distribution curves comparing Sr-90 to Y-90. Includes central axis depth dose for the 6-mm LV Y-90 Disc, cross-section of the disc surface at depth, and graphic simulation examples showing relative dose distribution on the eye for both iWand® A (placed on the sclera at the corneal scleral limbus) and iWand® P (placed beneath the macula).] Each disc is shipped with its individual Liberty Vision factory, US National Institute of Standards and Technology (NIST)-traceable preoperative calibration. For example, should the factory ship an LV Y-90 Disc measured to be 20 mCi (740 MBq), the central axis dose rates are 30.0, 21.6, 16.2, and 4.8 Gy/minute at an axial 0.0, 0.6, 1.0, and 2.6 mm, respectively. The prescription doses were determined in consultation with a radiation oncologist and a medical physicist. The primary goal was to deliver a certain tumor dose required at the prescribed distance from the episcleral surface of the LV Y-90 Disc source. Other factors included tumor or growth type, the calculated dose to normal ocular structures (e.g., sclera, cornea, ciliary body, optic nerve, and fovea), and the activity of the Y-90 source at the time of treatment. ## 5. Radiation Safety Unlike I-125 or Pd-103 which are blocked by high-Z metals (e.g., gold, lead, or steel), beta sources Sr-90 and Y-90 are best contained/absorbed by low-density materials, e.g., plastic and water (Table 21-1). For example, prior to clinical use, the LV Y-90 Disc, iWand systems were assembled behind a Lucite plastic L-block in the operating room. Once the disc was affixed to the iWand, the combined system was placed in a pitcher of shielding water on the Mayo stand. Once clear passage to the radiation target was exposed, the surgeon grasped the iWand handle and placed the disc flush with the eye target. Once treatment was complete, the iWand system source was safely placed back into the same water-filled pitcher prior to disposal. [Figure 21-5: Flow diagram demonstrating the assembly and utilization pathways as well as radiation safety precautions used for the LV Y-90 Disc system within the operating room. Pathway: Calibrated/Sterilized LV Y-90 Disc → iWand Applicator → LV Y-90 System Assembly (SHIELDED, Radiation Oncology) → Water Pitcher Shield on Mayo Stand → Ophthalmic Surgeon Applies to Patient → Water Pitcher Shield on Mayo Stand → Disposal Container (Radiation Oncology).] During these transfers, the surgeon's finger-ring badge was the closest measure and thus includes both transit time and treatment time. Unlike anterior treatments, posterior targets were accessed from behind the eye. Therefore, prior to insertion of a radioactive wand, a nonradioactive iWand P (albeit light-active) was inserted to simulate proper placement (lights in position around the target) and thus rule out any periocular obstruction to subsequent iWand P placement. Then, with unobstructed passage assured, insertion with a radioactive system was repeated. Both transit time and localization for the posterior choroidal melanoma were similarly less than 3–5 seconds. To date, all chest badges and ring measurements have been read as acceptable for health care workers in the United States. Radiation badges or finger rings were used for each case. These were augmented by readings from hand-held real-time radiation dosimeters. At first, film monitors were placed all over the operating room (e.g., on walls, stands, doctors, nurses, anesthesiologists, and circulators). Then, after readings were either background or less than New York guidelines for health care workers, radiation badges were only required for surgeons, operating room nurses, and circulators. Anyone in the operating room was offered a badge on request. Finger-ring badges were only used for system assembly and during surgery. ## 6. Single Session, Quick Treatment According to the 2014 American Brachytherapy Society (ABS) consensus guidelines for ophthalmic plaque brachytherapy for uveal melanoma and RB, eye plaque therapy was described as LDR, occurring over 3–7 continuous days. However, Y-90 discs emit HDR radiation. This is why in the treatment of select iris and iridociliary melanomas, as well as epibulbar SCC, the mean treatment time has been approximately 7 minutes. Therefore, a conversion of LDR dose prescriptions to radiobiologically equivalent HDR dose prescriptions was required, as shown in Table 21-2. ### Table 21-2: Hypothetical Examples of Dose and Treatment Durations | Parameter | I-125 LDR Dose | Y-90 HDR Dose | |-----------|---------------|---------------| | Choroidal melanoma | 85 Gy | 29.3 Gy | | Retinoblastoma | 40 Gy | 13.8 Gy | | Treatment time | 3–7 days | 6–14 minutes | | Surgeries | 2 | 1 | Assumptions for conversion calculations: - The normative I-125 episcleral plaque brachytherapy prescription dose for uveal melanoma is 85 Gy. - The LDR to HDR conversion for ocular-specific radiobiological parameters such as α/β = 10.3 Gy and a 0.01-day (~14 minutes) implant duration. - From these calculations and other assumptions, the HDR prescription dose was determined to be 29.3 Gy or a reduction by a factor of 0.345 as predicted by Gagne et al. - The actual required implant duration at the time of each case must rely on a Monte Carlo-derived depth-dose calculation, prescription depth equal to the lesion apex, and a correction for the calibrated dose rate related to Y-90 decay. - The 64-hour half-life made treatment duration calculations necessary for the specific hour/minute time of the implant. ### Table 21-3: Comparison of Low-Dose Rate versus High-Dose Rate Plaque Treatment | Source | Required Surgeries | Sutures | Duration | Corneal Buffer | Gunderson Flap | Outpatient Radiation | |--------|-------------------|---------|----------|---------------|---------------|---------------------| | **Y-90** | **1** | **No** | **Minutes** | **No** | **No** | **No** | | Pd-103 | 2 | Yes | Days | Yes | Yes | Yes | | I-125 | 2 | Yes | Days | Yes | Yes | Yes | | Ru-106 | 2 | Yes | Days | Yes | Yes | Yes | ## 7. Environmentally Friendly Disposal The LV Y-90 systems are single-use devices. Its 64.1-hour half-life allows the device to safely decay in storage to levels safe for trash disposal. However, the company accepts returns for factory decay in storage. In contrast, multi-use Sr-90 has a 29-year half-life, requires maintenance and cannot be similarly disposed (Table 21-1). ## 8. Patient Treatment Patient care conformed to the Declaration of Helsinki and the US Health Insurance Portability and Accountability Act (HIPAA) of 1996. Informed consent was obtained by discussion of the relative risks and benefits of observation, resection, and all available forms of radiation sources. Informed consent involved a detailed discussion of observation, resection, and radiation alternatives. Particular attention was given to contrasting LDR versus HDR Y-90 plaque brachytherapy (Table 21-3). An LV-sponsored, independent safety and tolerability data collection was performed at The New York Eye Cancer Center. Initial patients were treated for eye cancer. Their pathologies included uveal melanoma (iris, ciliary body, and choroid) as well as ocular SCC. Pretreatment systemic AJCC staging was performed. Enrollment included a medical history followed by a complete standard ophthalmic examination. That said, tumor-specific, pretreatment tumor high-frequency ultrasound imaging (with the iris dilated) was used to assess tumor extension into adjacent tissues, measure tumor dimensions, and determine the required treatment distance from the ocular surface. These measurements were correlated to those obtained from photographic imaging and manual measurements with calipers. Follow-up ophthalmic examinations focused on observations of the tumors and surrounding normal tissues. ### 8.1. Surgical Parameters Yttrium-90 plaque insertions and removals were completed during a single, same-day surgery. HDR episcleral brachytherapy was applied to the target until the prescription dose was delivered to the desired depth. In the first published series, HDR treatment durations were performed for a mean of 7.0 minutes and ranged from 219 to 773 seconds. For anterior ocular surgeries, the overlying conjunctiva was temporarily recessed to expose the episcleral target zone (iris and iridociliary melanomas) and was thus protectively recessed away from the radiation field. For choroidal melanoma, a conjunctival and Tenon's fascia incision was required to allow for posterior applicator placement. The sclero-invasive SCC was treated topically, without conjunctival incision. ### 8.2. Clinical Results Stable to improved visual acuities were noted in all patients with a minimum follow-up of 6 months. With a maximum 18 months follow-up, there was no treatment-related infection, new dry eye, new cataract, radiation retinopathy, radiation optic neuropathy, radiation-related iris neovascularization, corneal or scleromalacia, or uveitis. There were no acute sector anterior or posterior capsular cataracts or tumor recurrence. Typical of uveal melanomas, all cases have demonstrated early partial responses, and the SCC completely resolved within 1 month. Follow-up of anterior uveal melanomas revealed no postoperative corneal epithelial defects, transient tissue edema, scarring, nor anterior segment inflammation or cataract. [Figure 21-6: Clinical images showing a malignant ocular surface squamous carcinoma resistant to topical chemotherapy prior to LV Y-90 Disc plaque brachytherapy, and one month after treatment showing the tumor resolved to pigment dusting.] [Figure 21-7: Slit-lamp images showing pretreatment, 1 day, 1 month and 6 months after treatment of an iridociliary melanoma. Notable findings include the lack of keratopathy and minimal incision required for the single-session treatment.] ## 9. Other Applications In clinical practice, all eye cancer specialists who use radiation for the treatment of their patients have witnessed its effects on choroidal and retinal blood vessels. For example, as its blood vessels close, every plaque-treated tumor will eventually be seen to darken on fluorescein angiography. As the surrounding vascular tissues are also irradiated, capillary and then retinal vascular closures can be documented by optical coherence tomography, fluorescein, and indocyanine green angiography. Many ophthalmic diseases are characterized by neovascularization and fibrovascularization (Mind Map 21-3). ### Ophthalmic Diseases Characterized by Neovascularization and Fibrovascularization (Mind Map 21-3) - **Malignant conditions** - Anterior location - Intraocular: Uveal melanoma, Retinoblastoma, Metastasis - Extraocular: Squamous carcinoma, Conjunctival melanoma, Sebaceous gland carcinoma - Posterior location: Uveal melanoma, Retinoblastoma, Metastasis, Melanocytoma - **Benign conditions** - Anterior location - Pterygium - Cornea: Transplant rejection, Epithelial growths - Glaucoma: Trabeculectomy, Stents, Explants - Posterior location - Choroid: **Age-related macular degeneration**, Polypoidal choroidal vasculopathy, Myopia, Histoplasmosis, Osteoma - Retina: von Hippel angioma, Coats disease, Astrocytoma, Peripheral exudative hemorrhagic chorioretinopathy Note: Age-related macular degeneration and Glaucoma are the two leading causes of blindness in the United States. The scientific literature has many reports of HDR Sr-90/Y-90 beta-radiation treatments for neovascular age-related macular degeneration (nAMD), posterior choroidal vasculopathy, pterygium, and glaucoma filtering surgery (e.g., trabeculectomy). Jaakkola et al. described a unique hand-held Sr-90/Y-90 applicator used to treat nAMD, and multiple clinical trials have demonstrated Sr-90/Y-90 treatments used to improve results of trabeculectomy and pterygium surgeries. For those applications, the dose distribution provided by Y-90 is ideally suited to those target volumes. [Figure 21-8: Custom-made strontium-90/yttrium-90 applicator (depth dose of 15 Gy to 1.75 mm, delivered over 54 minutes). Fluorescein angiogram shows a dense subfoveal neovascular membrane prior to treatment. Treatment was associated with closure of the neovascular membrane and dissipation of extravasating components.] ## 10. Summary This chapter describes the unique design and clinical implementation of a new, FDA-cleared disc-shaped HDR Y-90 beta-emitting source. Necessary improvements compared to the predicate Sr-90/Y-90 HDR applicator include the elimination of the Sr-90 component, hand-held applicators that improve both guidance and treatment positioning, the selection of Y-90 that closely matches dose distribution to the lesion target volume, and improvements for radiation safety. Its relatively short half-life allows for environmentally friendly decay from storage to disposal. Drawbacks include the initially small 6-mm diameter size of the first source, although larger sizes have been FDA-cleared. In addition, the limitation of Y-90 radiation penetration prevents its use for thicker lesions. The LV Y-90 Disc system allows for single-use, single-session quick treatments. Clinical implementation of the new HDR Y-90 system required collaboration from ophthalmic oncology, radiation oncology, and medical physics. Like its predecessor HDR Sr-90/Y-90 beta-radiation applicator, the new Y-90 system is FDA-cleared for episcleral irradiation of tumors and benign growths. Unlike its predecessor, the new HDR device has no Sr-90 component, is short-lived, and thus relatively easy to dispose. Instead of the bulky, heavy Sr-90 metal, new lightweight plastic hand-held applicators were built to both shield and guide the disc source into position during treatment. The prior commercially available HDR Sr-90/Y-90 beta-radiation applicators could not be placed on the posterior pole for the treatment of benign and malignant tumors. Though few patients have yet been treated, our review of the literature suggests this new Y-90 source can be used in the treatment of neoplastic, vascular, and fibrovascular tumors of the eye. ## References 1. Stallard HB. 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