Extrascleral extension of choroidal melanoma: Post-enucleation high-dose-rate interstitial brachytherapy of the orbit

Abstract Purpose To investigate if orbital extension of uveal melanoma can be treated with high-dose-rate (HDR) brachytherapy. Methods and Materials This study is a retrospective analysis of the results of a clinical case series was performed on 10 patients. Each underwent primary enucleation for uveal melanoma, was discovered to have orbital extension, and consented for HDR brachytherapy. By American Joint Committee on Cancer (AJCC) initial tumor grading, there was one each (T1c, T2c, T2d, and T3d, three T4c, and two T4d-staged uveal melanomas. One was AJCC–staged R2 due to orbital recurrence presenting 16 months after enucleation.192 Ir HDR brachytherapy involved transcutaneous circumferential orbital incisions allowing for evenly spaced brachytherapy catheters into the orbit. A target dose of 32.85 Gy (range, 32.85–34 Gy) was delivered in 9–10 twice-daily fractions (range, 3.4–3.65 Gy per fraction) over 5 consecutive days. Data analysis included but was not limited to radiation therapy methods, local tumor control, side effects, and metastatic rate. Results In the 9 patients who tolerated treatment, there has been no orbital recurrence at a median follow-up of 18 months (range, 1–62 months). Four patients died of metastatic disease (one presented with a treated solitary liver metastasis before brachytherapy). There was no significant eyelash or eyebrow loss. There was no radiation-induced eyelid erythema, orbital infection, or contracted sockets. All orbits accepted and maintained ocular prostheses. Conclusions Brachytherapy was used as an alternative to external beam radiation treatment for postenucleation orbital melanoma. This series reports complete local control, few side effects, and excellent cosmetic results.