Ruthenium plaque radiation therapy for iris and iridociliary melanomas

Abstract

ABSTRACT.Purpose: To determine the long-term effects of ruthenium-106 plaque radiation therapy for iris and iridociliary melanomas in terms of tumour regression and complications. Methods: Between 1 November 1997 and 31 December 2007, 36 patients with an iris or iridociliary melanoma were treated with Ruthenium-106 (Ru-106) ophthalmic plaque radiation therapy. The median follow-up was 6.5 years with a range of 2-11 years. The mean tumour apex dose was 151.5 Gy. Main outcome measures were local tumour control and radiation-related ocular complications. Results: The mean age of the patients at the time of treatment was 54 years (range 14-82). The tumours had a median largest basal dimension of 4.8 mm (range 3-11) and a prominence of 2.3 mm (range 0.8-5), with a median involvement of three clock hours (range 1-6). The tumours were confined to the iris in 14 patients (39%), extended into the anterior ciliary body in 12 (33%), while the anterior ciliary body tumour extended into the iris in ten patients (28%). Tumours regressed in all patients (100%) with a mean regression of 80% of the original tumour size at 7 years of follow-up. Radiation-related complications included corneal erosions on the first postoperative day in nine patients (25%), cataract in four of 11 patients free of cataract before treatment (36%) and postradiation glaucoma in one patient (3%). Visual acuity of 20 ⁄ 200 or worse was present in one of 20 patients (5%) at 6 years of follow-up. Local recurrences occurred in two patients (5%), 2 and 5 years after the radiation therapy respectively, and both underwent enucleation. Distant metastases occurred in one of these enucleated patients (3%) 2 years after treatment. Conclusion: Ru-106 plaque radiation therapy for iris and iridociliary melanoma resulted in good local tumour control and preservation of visual acuity with few and treatable side-effects.

Ruthenium-106 brachytherapy for iris and iridociliary melanomas

“…Before treatment, all patients underwent complete ophthalmic examination consisting of1 best-corrected VA (Snellen),2 slit-lamp examination, measurement of tumour dimensions,3 intraocular pressure (IOP) measured by Goldmann tonometer,4 ophthalmoscopy,5 gonioscopy,6 serial photographic documentation of the lesions and7 UBM (50 MHz) to determine tumour dimensions, structure and extension.…”

“…Melanoma diagnosis was made by experienced specialised ophthalmologists using the aforementioned clinical examinations and specific diagnostic criteria 4. Tumour type (iris vs iridociliary) was determined by the location of the larger part of the tumour, which was assessed using UBM.…”

Small incision guarded hydroaspiration of iris lesions

“…In general, iris neoplasms can be managed by observation and forms of radiation therapy such as brachytherapy26 27 and proton beam radiation28 29 as an alternative to surgical excision based on the size, location and suspected clinical diagnosis 30 31. It must be emphasised that the cases included in this series were carefully selected by the author wherein the tumours were small (LBD of 3.0 mm (range 1.5–5.0 mm; median 3.0 mm) and mean thickness of 1.3 mm (range 0.5–2.5 mm; median 1.0 mm)) and circumscribed with peripheral iris clearing of at least 2 mm.…”

Proton beam radiotherapy of diffuse iris melanoma in 54 patients

“…Iodine-125 plaque treatment delivers a higher dose to the cornea, which is even higher in palladium-103 and ruthenium-106 brachytherapy 11 12. Brachytherapy generally exposes the patient to surgery and in-patient treatment, which is not needed in PBR.…”

“…Recurrence in posterior uveal melanoma can often be managed by additional focal destructive measures but recurrence in iris melanoma is often diffuse and enucleation was the management in all recurrent iris melanomas after irradiation treatment in several series 7 9 10 12 13. Most patients will need glaucoma treatment during follow-up and this often includes surgical therapy.…”