[Therapy of radiation resistant malignant uveal melanoma with endoresection by pars plana vitrectomy in two patients].

BACKGROUND

Since introduction of brachytherapy using (106)ruthenium plaque therapy for treating malignant choroidal melanomas a number of comparative studies have shown that survival rates are equal between patients who underwent radiation or enucleation. When radiation treatment fails, the patient might be determined to choose removal of the tumor by pars plana vitrectomy.

PATIENTS AND METHODS

Between 1995 and 1998 a total number of 48 patients underwent (106)ruthenium plaque irradiation. In 9 patients tumor regression was not sufficient. Two of these nine patients decided explicitly against enucleation and choose to have the tumor removed from within the eye employing pars plana vitrectomy.

RESULTS

Intraoperatively, the previously radiated melanoma was easily removed with the vitrectomy cutter without significant bleeding. Postoperative recovery was without complications. Silicone oil removal was carried out in one patient after one year. Vision 9 months and 2.5 years after surgery was 0.2 and 0.02, respectively. The cosmetic results with parallel axis of the globes were very good and one patient gained binocular vision. No recurrent tumor growth was seen so far. Histologically, no mitotic figures were found.

CONCLUSION

Malignant choroidal melanomas can be safely removed by pars plana vitrectomy with stable intraocular pressure. Previous radiation therapy alters the tumor, inducing fibrous tissue growth and necrosis of tumor cells. These tissue types are not prone to bleed when they are resected by the vitrectomy cutter. Long time studies have to elucidate the difference in survival rates between patients undergoing enucleation of the eye and patients who chose endoresection of the melanoma by pars plana vitrectomy.