Background: To evaluate the effectiveness of transpupillary thermotherapy (TTT) as an adjunct to ruthenium brachytherapy for treatment of choroidal melanoma with reduced radioactive dose.
Patients and methods: In a prospective nonrandomised analysis 15 eyes with primary malignant melanoma of the choroid (posterior to the equator, thickness </= 4.5 and base </= 12 mm) were treated with TTT (diode laser at 810 nm, spot size 2 - 3 mm, energy 0.3 - 0.9 watt, exposure time 21 - 45 minutes) in conjunction with an attenuated ruthenium plaque (radioactive dose to the tumour apex 100 Gy). Follow-up was at least 12 months.
Results: The mean tumour thickness before therapy was 3.2 mm (1.2 - 4.5 mm), the mean tumour regression 3 months postoperatively 2.1 mm (0.5 - 4.5 mm). 12 months postoperatively all tumours were regressed through a completely flattened chorioretinal scar. In 5 eyes visual acuity improved. The main reason for visual decrease in 7 eyes was subfoveal tumour location in 4 eyes, development of macular oedema in 2 eyes and epiretinal gliosis in one eye. Neither occlusion of retinal vessels nor radiation retinopathy/optic neuropathy were observed. Despite complete tumour regression clinically and fluoresceinangiographically, ICG-angiography revealed persistence of choriocapillary vessels especially at the posterior margin of the treatment zone in all eyes. No tumour regrowth or metastatic disease were recorded.
Conclusions: Our 12-month results of TTT complementary to ruthenium brachytherapy with an attenuated tumour apex dose of 100 Gy for posterior choroidal melanoma with thickness </= 4.5 mm are comparable to findings after TTT alone, especially in regard to regression course, low rate of sideeffects and visual results. ICG angiography might be a useful tool to monitor an eventual tumour regrowth in the choriocapillary layer. For evaluation of sideeffects of brachytherapy a postradiation follow-up of at least 2 - 5 years is mandatory.