Purpose
To report out experience with a novel radiation brachytherapy technique used in treatment of orbital melanoma secondary to extrascleral extension of uveal melanoma. Further, to compare the dose deposition versus external beam radiation therapy.
Methods
A clinical case series of patients received high dose rate iridium-192 interstitial orbital radiation therapy. Tumors were staged according to the American Joint Committee on Cancer system as T1c, T2c, T2d, T3d, (three) T4c, (two) T4d and one R2. Typically 8-10 orbital catheters were surgically placed into the orbit. Then a target dose of 32.85 Gy was delivered in 9-10 twice daily fractions over 5 consecutive days.
Results
Ten patients were entered into the study. Nine successfully underwent high dose rate therapy. With a mean follow up 18 months (range 1 to 62) there has been no orbital recurrence. Cosmetic results were invariably better than our experience with 6MV photon external beam radiation therapy with almost no eyelash or eyebrow loss nor retracted sockets. All were able to maintain ocular prostheses.
Conclusions
High dose rate, interstitialiridium-192 brachytherapy can be considered as an alternative to external beam radiation treatment for post-enucleation extrascleral extension. This series reports complete local control, few side effects and excellent cosmetic results.
Keywords: 671 radiation therapy •
631 orbit •
589 melanoma