Ruthenium-106 versus iodine-125 plaque brachytherapy of 571 choroidal melanomas with a thickness of ≥5.5 mm

Abstract

BackgroundEpiscleral brachytherapy is the most common eye-preserving treatment for medium-sized choroidal melanomas. γ-emitting iodine-125 (125I) and β-emitting ruthenium-106 (106Ru) are widely used. The latter is however generally reserved for thinner tumours (<6 mm). In this study, we compare ocular and patient survival in thicker tumours treated with the respective radioisotope.MethodsAll patients with ≥5.5 mm thick choroidal melanomas who were treated with plaque brachytherapy at a single institution between 1 November 1979 and 31 December 2015 were included (n=571). Size-controlled Cox regression HRs for postbrachytherapy enucleation, repeated brachytherapy and melanoma-related mortality were calculated, as well as Kaplan-Meier disease-specific survival and relative 10-year survival in matched subgroups.Results317 patients were treated with 106Ru and 254 with 125I. The rate of repeated brachytherapy was significantly higher among patients treated with 106Ru (8%) than with 125I (1%, p<0.001). Size-controlled Cox regression HRs for postbrachytherapy enucleation (125I vs 106Ru 0.7, p=0.083) and melanoma-related mortality were not significant (125I vs 106Ru 1.1, p=0.63). Similarly, Kaplan-Meier disease-specific and relative 10-year survival was comparable in matched groups of 5.5–7.4 mm (relative survival 106Ru 59%, 125I 56%) and ≥7.5 mm thick tumours (relative survival 106Ru 46%, 125I 44%).ConclusionsRates of repeated brachytherapy were significantly higher among patients treated with 106Ru versus 125I for thick choroidal melanomas. There were, however, no significant differences in rates of enucleation or patient survival.

Forty-year prognosis after plaque brachytherapy of uveal melanoma

“…Starting in the year 2000, Iodine-125 plaques were introduced as the first option for tumors with an apical height of 6 to 10 mm. Previous studies have shown that ocular outcomes and patient survival are similar after Ruthenium-106 and Iodine-125 plaque brachytherapy of both thinner and thicker tumors 20,21 . Standardized A-and B-scan ultrasonography was used preoperatively to measure tumor thickness and diameter.…”

Clinical determinants of long-term survival in metastatic uveal melanoma

“…The mean age-adjusted incidence is 5.2 per million [1] and shows a north-to-south decreasing gradient in Europe [2], with the highest current mean incidence of 9.5 per million in Ireland [3]. The treatment approach of the primary tumor depends on the tumor size, patient preference, and tumor localization, most commonly by brachytherapy or enucleation [4,5]. The most important risk factor for the development of metastases is monosomy 3, and at least 40-50% of patients will develop metastases, predominantly to the liver [6,7].…”

Radiation Retinopathy: Detection and Management Strategies

“… 35 , 36 However, when compared to Iodine-125, rates RR have been seen to be similar between the two, 37 although a few studies have reported slightly higher rates for Iodine-125. 35 , 36 Considering the slight advantage of Iodine-125 in certain cases in terms of tumor control, 37 , 38 the choice of plaque can be individualised on a case-to-case basis. The risk of RR following proton beam irradiation has been reported to be higher, with rates ranging between 85% and 90%.…”