Proton beam radiotherapy in the management of uveal melanoma: Clinical experience in Scotland

Abstract

Aim: To evaluate proton-beam radiotherapy (PBRT) in the management of uveal melanoma in Scotland.

Methods: A retrospective review was undertaken on all patients receiving PBRT for uveal melanoma (1994-2005). Data obtained included: gender, past ocular/medical history, age, presenting complaint(s), diagnosis, laterality, tumor location/ultrasound characteristics, visual acuity (VA) and intraocular pressure. At post-treatment reviews (3, 6, 12, and 24 months), the following data was obtained: VA, intraocular pressure, tumor appearance and ultrasound characteristics. Mean follow up was 38.8 months.

Results: Seventy-six patients were included. Mean age was 64 years; male to female ratio was 1.1:1. Ninety-seven percent demonstrated initial treatment response; 87% had successful control of tumor growth. Mean pre-treatment tumor height was 6.2 mm v.s. 4.8 mm post-irradiation (p < 0.001). Pre-irradiation VA was <3/60 in 18.5% compared with 74% post-irradiation (p < 0.0001). There was a statistically significant association between adverse events (enucleation, metastasis) and greater maximal basal tumor diameter. Eighteen eyes were enucleated. The median survival time was estimated to be 54 months.

Conclusion: In our experience, PBRT is a precise, reliable and effective treatment in the management of large, and previously treated uveal melanomas. It prevents enucleation in the majority at short term follow-up.

Keywords: enucleation; proton-beam radiotherapy; tumor; uveal melanoma; visual acuity.

Figure 1

Kaplan-Meier estimated cumulative adverse event rate (enucleation or distant metastasis) compared with follow-up time after proton beam irradiation.