[Risk factors for the recurrence of choroidal melanoma after the Ru-106 brachytherapy]

The aim of the study was to determine factors, which are likely to affect local recurrence of choroidal melanoma after ruthenium-106 brachytherapy with or without adjunctive transpupillary thermotherapy.

We analysed 355 cases of patients with choroidal melanoma treated ruthenium-106 brachytherapy with or without adjunctive transpupillary thermotherapy. These were divided into two groups of patients with confirmed recurrence of choroidal melanoma (97 subjects) and patients without recurrence (control group, 258 subjects).

We found a significant relationship between tumour recurrence and the presence of retinal detachment at the time of diagnosis, tumor shape, its large size and location with the marginal adjacency to the optic disc and with the anterior margin located 1-2 optic disc diameters from the macula. Among other risk factors, the use of COB plaque with supplementary transpupillary thermotherapy, dose to the tumor base, visibility of tumor base shade during transillumination, and uncertainty regarding precise plaque placement showed a significant correlation with tumour recurrence, just as the presence of metastases did.

It seems that large tumour size and its location at the proximity of the optic disc are the key factors to affect the failure of brachytherapy and recurrence in patients with choroidal melanoma.