Long-term follow-up after uveal melanoma charged particle therapy.

PURPOSE

To examine the results of helium ion irradiation in 218 uveal melanoma patients treated more than 10 years ago.

METHODS

Retrospective review of 218 eyes treated with helium ion radiation for uveal melanoma between 1978 and 1984. Several parametric and non-parametric statistical analysis techniques were used.

RESULTS

In 218 eyes treated with helium ion radiation for uveal melanoma, the mean dimension for largest basal diameter was 11.9 mm (range 5 mm to 24 mm). The mean tumor thickness was 6.7 mm (range 1.3 mm to 14.2 mm). Following helium ion radiation 208 (95.4%) of 218 eyes had local tumor control. At 10 years after radiation 46 (22.4%) of 218 eyes were enucleated; the majority (37 of 46) of enucleations were due to anterior ocular segment complications. At 10 years after radiation 102 (46.8%) of the 218 patients were dead; half had non-tumor related deaths and 51 died from metastatic melanoma. Best corrected visual acuity after radiation was > or = 20/40 in 21 of 93 eyes of patients that were alive and retained their eyes 10 or more years after treatment. In patients with tumors that were less than 6 mm in height and more than 3 mm away from the nerve or the fovea, 13 of 18 (72%) retained > or = 20/40. In contrast, only 11% of the patients with either thicker tumors or those close to the nerve or fovea retained that level of acuity. The actuarial enucleation rate at 5 years was 17.2% (2.7% S.E.) and at 10 years this was 22.4% (3.1% S.E). The recurrence tumor control rate at both 5 and 10 years was 5.3% (S.E 1.7%).

CONCLUSIONS

Helium ion radiation of uveal melanoma is associated with good local tumor control and reasonable retention of the treated eye 10 years after treatment. In tumors that are less than 6 mm in thickness and greater than 3 mm from the optic nerve and fovea, many retain excellent vision. Approximately one-half of the deaths 10 years after treatment were due to non-tumor-related causes.