Brachytherapy involves the application of a radioactive, source inside or close to a tumor or benign growth.1 During, application, this radiation is delivered continuously, but over a fixed amount of time. Therefore, in radiation, oncology there exist short-term (temporary) implants, and long-term (even permanent) implants. Temporary, brachytherapy implants can be either low-dose rate, (LDR) or high-dose rate (HDR), requiring days or minutes, of application respectively. In radiation oncology,, brachytherapy is used because it is conformal, allowing, irradiation of targeted tissue volume with limited radiation, to nearby healthy tissues.1-3, As early as 1911, Dr. Albert Terson used radium to prevent, pterygium recurrence.4 Since that time, a number of, beta and gamma applicators have been important tools, for delivering radiation within the eye and orbit.2,3 Given, the small size of the eye and proximity of visually significant, structures, precise calculation of the radiation, dose to these vital structures is essential.5,6 However,, there exists scant clinical research comparing the efficacy, of various methods and brachytherapy types. The, closest research includes a 2012 American Association, of Physicists in Medicine (AAPM) comparison of, iodine-125 (125I) versus palladium-103 (103Pd) sources, used in eye plaques which included a review of ophthalmic, brachytherapy.7 Then, in 2014 the American, Brachytherapy Society (ABS) OOTF together with the, AAPM published a 47-person consensus, multicenter,, international OOTF guideline for plaque brachytherapy, of choroidal melanoma and RB.8 We suggest that all, eye cancer specialists obtain these open-access publications, and integrate their recommendations into clinical, practice. Lessons learned from these 2 publications are, presented in this chapter.
Chapter Keyword: retinopathy
Management of Radiation Retinopathy
Radiation therapy for uveal melanoma offers high, local control rates. Radiation therapy has been proven, noninferior to enucleation for the prevention of metastatic, melanoma by the medium-sized melanoma trial, of COMS.1 In 2014, the consensus guidelines produced, by the AJCC-OOTF for the American Brachytherapy, Society (ABS) and American Association of Physicists, in Medicine (AAPM) showed that only a few tumors are, considered untreatable by ophthalmic brachytherapy, plaques.2 This shift to eye-conserving radiation therapy, is supported by patients who prefer to keep vision and, their eye., Recent research has focused on vision preservation., Although radiation-related cataracts are common, surgical, vision rehabilitation by lens replacement is both safe, and effective. In contrast, the macular retina and optic, disc are irreplaceable, leaving retinopathy and optic neuropathy, as the most common, irreversible, sight-limiting, side effects of irradiation. Depending on the dose, dose, rate, and thus treatment modality, up to 50% of patients, with posterior uveal melanoma are at risk.3 In the past,, prior to undergoing radiation therapy, patients with posterior, and select large choroidal melanomas were told to, expect severe radiation-related vision loss.4, However, since 2006, Dr. Finger found that anti-VEGF, therapy slowed or stabilized radiation maculopathy and, optic neuropathy.5-8 This discovery ushered in a new era, where treatment not only provides local cancer control, but also makes long-term vision preservation an attainable, goal.