Proton Teletherapy of Uveal Melanoma

Abstract

The optimal treatment of uveal melanoma would destroy the intraocular tumor, retain good vision, and avoid the development of metastatic disease. Unfortunately, inherent limitations make the development of such an optimal therapy unlikely in the near future. 1 One, approximately two thirds of choroidal melanomas examined in most ophthalmic oncologic practices are within 3 mm of the optic nerve or fovea. Even with a very focused type of treatment-delivery system, to avoid a marginal miss, usually such eyes have significant long-term visual damage. Two, whereas only 1% of patients present with simultaneously detectable metastases and a newly discovered uveal melanoma, the majority of patients who metastasize have already developed micrometastatic disease before the detection of their intraocular lesion. At present, there is no effective treatment of liver metastases from uveal melanomas. Three, in approximately 20% to 35% of patients, at the initial presentation, the tumor is too large for treatment with current eye salvage techniques, and these eyes are treated with primary enucleation.In this issue, several different radiation delivery systems are presented, including those that rely on brachytherapy (radioactive plaques) as well as teletherapy (protons, intensity-modulated conformal therapy, and cyberknife). Over 10,000 patients with uveal melanoma have been treated around the world with charged particles (helium ions and protons).There are 4 theoretical advantages of proton radiation. One, because of the inherent Bragg peak, the lateral and distal falloff with this form of treatment results in more focused radiation delivery than any other form of ionizing radiation. In most proton facilities, the lateral and distal falloff 41

Robotic radiosurgery for the treatment of medium and large uveal melanoma

“…Interestingly, their patient cohort was similar to the patients analyzed in the current study with mostly challenging-to-treat medium to large uveal melanomas (medium to large size, 97%) with worse prognoses. Most other proton series involve a higher number of small tumors that are more amenable to treatment [21,22]. Our eye retention rate was 86.7% at a mean time of 36 months and the disease-specific survival rate was 84.8% at 3 years and, therefore, almost identical to the McDonald series.…”

Current status of radiotherapy with proton and light ion beams

“…With current techniques and appropriate patient selection a >98% local control rate can be expected. 24 On the other hand, long-term results of brachytherapy for intraocular melanomas suggest that this modality may provide equally satisfactory outcomes to particle therapy. 26 …”

“…23 Local control at 10 years was reported at 95.4.% and considered comparable to that achievable with protons. 24 A large retrospective analysis from the Paul Scherrer Institut (PSI) reported excellent eye-retention outcomes, with an overall rate of 83.7 at 15 years. 25 After optimization of the treatment technique the 5-year eye-retention rate was raised from 97.1% to 100% in small tumors, from 86.7% to 99.7% in medium, and from 71.1% to 89.5% in large tumors.…”

Self-Shielding Gyroscopic Radiosurgery for Uveal Melanoma: A First Case Report

“…The goal of radiotherapy in treating uveal melanoma is to achieve tumor control and ocular preservation [1,7,8]. A variety of radiation devices have been used to reach this goal.…”