Brachytherapy or enucleation in ring melanoma patients: which is better? Preliminary results of the authors’ own experiences

Introduction
A retrospective evaluation of effectiveness of brachytherapy or enucleation in treatment of rare form of uveal melanoma: ring melanoma.

Material and methods
Analysis comprised 49 patients treated from 2000 to 2019 for ring melanoma involving ciliary body. In 15 patients, primary treatment consisted of brachytherapy (106Ru or 125I), whereas in 34 patients, eyeballs were enucleated. The evaluation concerned differences between analyzed groups relating to the clinical and histopathological features as well as overall survival, cancer-specific overall survival, and disease-free survival.

Results
No significant differences between the analyzed groups were found with regards to clinical and histopathological features, apart from intra-ocular pressure (increased in the enucleation group). Kaplan-Meier analysis did not reveal any significant differences between the group treated with enucleation and the group undergoing brachytherapy, both with regards to overall survival (p = 0.325) and cancer-specific overall survival (p = 0.477). A significant difference was observed in disease-free survival (p = 0.009), which was significantly shorter in the group undergoing brachytherapy. In the analysis of parameters of the applied brachytherapy, no significant differences between patients with and without local recurrence were found. Mean observation period was 350.8 weeks (range, 24-996 weeks, SD = 231.6). A local recurrence occurred in 11 (22.4%) patients, including 3 (6.1%) in enucleation and 8 (16.3%) after brachytherapy groups. Metastasis developed in 11 (22.4%) cases after a mean follow-up of 133 weeks (33.25 months), range 3-655 weeks.

Conclusions
Preliminary observations may suggest that brachytherapy in this rare form of uveal melanoma, such as ring melanoma involving the ciliary body, may be taken into consideration as a useful alternative to enucleation. However, the confirmation of such an approach requires a larger patients’ group to be gathered, and also a longer follow-up period. This is especially important in patients with a good baseline visual acuity in the affected eye, or when the neoplasm is present in the remaining eye with vision.