Evidence-Based Estimates of Outcome in Patients Irradiated for Intraocular Melanoma

Abstract

Background: Melanoma of the eye is the only potentially fatal ocular malignancy in adults. Until radiation therapy gained wide acceptance in the 1980s, enucleation was the standard treatment for the tumor. Long-term results after proton beam irradiation are now available. Methods:We developed risk score equations to estimate probabilities of the 4 principal treatment outcomeslocal tumor recurrence, death from metastasis, retention of the treated eye, and vision loss-based on an analysis of 2069 patients treated with proton beam radiation for intraocular melanoma between July 10, 1975, and December 31, 1997. Median follow-up in surviving patients was 9.4 years.Results: Tumor regrowth occurred in 60 patients, and 95% of tumors (95% confidence interval, 93%-96%) were controlled locally at 15 years. Risk scores were developed for the other 3 outcomes studied. Overall, the treated eye was retained by 84% of patients (95% confidence interval, 80%-87%) at 15 years. The probabilities for vision loss (visual acuity worse than 20/200) ranged from 100% to 20% at 10 years and for death from tumor metastases from 95% to 35% at 15 years, depending on the risk group.Conclusions: High-dose radiation treatment was highly effective in achieving local control of intraocular melanomas. In most cases, the eye was salvaged, and functional vision was retained in many patients. The mortality rate was high in an identifiable subset of patients who may benefit from adjuvant therapies directed at microscopic liver metastases.

Outcomes of treatment with stereotactic radiosurgery or proton beam therapy for choroidal melanoma

“…This compares to 48% of patients with visual acuity of 20/200 or better at 5 years post-treatment in a study by Gragoudas 3 and 61% with acuity of 6/60 or better reported by Damato et al 4 Distance of the tumour from the optic disc or fovea is a recognised risk factor for poorer outcomes and tumours within 2 disc diameters of both the fovea and optic disc tend to have poorer visual outcomes. 10 Our results confirmed these findings with 91% of cases in which the tumour touched or encircled the optic disc in the SRS group and 73% in the PBT group having a final visual acuity of 6/60 or less. This may be due to differences in the way radiation is delivered to the tumour between the two groups.…”

Radiotherapy for ocular tumours

“…The position of the eye is fixed according to the location of the tumour by fixing the contralateral eye on a specified point. Doses of 60 Gy in four fractions 38,39 and 70 Gy in five fractions 40 have been used. This latter dose has been reduced to 50 Gy also in five fractions, but without any significant difference in either local control or complications.…”

“…39 Local control with protons is about 95% in most series. [38][39][40] Stereotactic RT with a g knife started with 55 Gy in one fraction, reducing slowly over several years of experience to 31 Gy. With a stereotactic linear accelerator, 60-70 Gy in five fractions was given but this was then reduced to 50 Gy.…”

Radiation Techniques in Neuro-Oncology

“…With prices exceeding $100 million per unit, the cost-benefit ratio remains to be accurately described; efficacy data are still maturing. Diseases for which benefits have been seen with charged particles include uveal melanomas, 51 optic pathway gliomas, 52 skull-based tumors, 53 pituitary adenomas, 54 acoustic neuromas, 55 nasopharynx and paranasal sinuses, 56,57 spinal cord tumors, 58,59 prostate cancer, 60,61 lung cancer, [62][63][64][65] gastrointestinal malignancies, [66][67][68] and pediatric cancers. 69 …”