Intra-operative Echographic Localization for Radioactive Ophthalmic Plaques in Choroidal Melanoma
The objectives were to evaluate the beneficial effect of intra-operative echographic plaque site localization and to assess the rate of complications of postplaque insertion. This paper is a descriptive study of 48 patients with choroidal melanoma who underwent iodine-125 (I125) or ruthenium-106 (Ru106) plaque radiotherapy with intra-operative echographic confirmation of plaque placement with the aid of a nonradioactive plaque (dummy) at McGill University Health Centre from 1997 to 2003. Patients' mean age was 63.7 years; 52% (25/48) male, 48% (23/48) female. Twenty-seven percent (13/48) of the tumors were confined to the right eye and 73% (35/48) to the left eye. Forty-eight percent (23/48) of the tumors were located posterior to the equator, 14.6% (7/48) were anterior to the equator, 18.7% (9/48) in posterior pole, and 18.7% (9/48) at equator. Sixty-nine percent (33/48) received I125 and 31% (15/48) had Ru106 treatment. Ninety percent of the dummy plaques were initially positioned suboptimally and required repositioning under echographic guidance. At mean follow-up of 18.8 months, there was no tumor-related death or metastasis, but one patient required enucleation. The dummy plaque technique under echographic visualization resulted in reduction of radioactive exposure time during surgery of up to 50%. Intra-operative echographic utilization has the ability to localize precisely the tumorplaque relationship, thereby optimizing the radiation delivered to the choroidal melanoma, while minimizing the surgeon's exposure time.
choroidal melanoma echography radioactive plaque