Combined plaque radiotherapy and transpupillary thermotherapy in choroidal melanoma: 5 years' experience

To evaluate the results of combined plaque radiotherapy and transpupillary thermotherapy (TTT) in 50 consecutive patients 5 years after treatment.

50 adult patients with choroidal melanoma were treated with ruthenium-106 ((106)Ru) plaque radiotherapy combined with TTT. A flat scar was the preferred end point of treatment. The mean tumour thickness was 3.9 mm (range 1.5-8.0 mm), the mean tumour diameter was 11.3 mm (range 5.8-15.0 mm). TTT was performed with an infrared diode laser at 810 nm, a beam diameter of 2-3 mm, and 1 minute exposures. Tumours >5 mm thick received an episcleral contact dose of 800 Gy (106)Ru; tumours

Complete tumour regression was obtained in 45 patients. It required one, two, or three TTT sessions in 32, 11, and two patients, respectively. In tumours 3 mm thick (log rank test p = 0.01). Eight melanomas were amelanotic, seven of which required multiple TTT sessions. In one patient the tumour recurred at the central margin of the treated area; this eye was enucleated. In one patient the tumour failed to regress 6 months after treatment and enucleation was performed at the patient's request. Three eyes developed severe proliferative retinopathy. Radiation maculopathy caused a loss of the best corrected visual acuity: before treatment 31 patients had a best corrected visual acuity of 20/60 or better but in only 12 patients did it remain in this range 5 years after treatment. Three patients developed distant metastasis to the liver.

The 5 year results for combined plaque radiotherapy and TTT as treatment for choroidal melanoma are favourable in terms of complete tumour regression and low rate of recurrences; however, there was considerable loss of visual acuity as a result of radiation maculopathy.