Abstract
Purpose: :
To examine the need for optimal alignment of the Ruthenium-106 brachytherapy plaque in respect to tumor margins in treating choroidal melanomas.
Methods: :
Medical files and wide angled retinal photography images (Panoret, Medibell, Israel) of 292 uveal melanoma patients treated by Ru-106 brachytherapy in the Ocular Oncology Service at Hadassah Medical Center, Jerusalem Israel between 1986-2007, which were documented by wide angle photography since 2003, were reviewed. We excluded patients that did not have retinal images of adequate quality (poor visibility of the full contour of the plaque’s scar or the tumor). Patients with less than 6 months follow-up after brachytherapy as well as patients that were enucleated soon after brachytherapy or received multiple brachytherapy treatments were also excluded. 195 patients were included and their survival, metastasis and local recurrence rates were calculated, comparing tumors fully covered by the brachytherapy plaque with tumors reaching the plaque margin.
Results: :
In 130 patients (mean age 60.6±14.6, 42% males, mean follow-up: 92.2±51.2, range 25-271 months) the whole tumor was covered by the plaque (covered group), while in 65 patients (mean age 56.0±15.5, 50.8% males, mean follow-up: 94.2±49.0, range 31-259 months) one side of the tumor reached the plaque's scar margins - the exposed group.During the follow-up period 8 (6.2%) patients in the covered group died compared with 1 (1.5%) in the exposed group (p=0.26). Kaplan-Meier survival analysis did not show a statistically significant difference in mortality between the covered and exposed groups (hazard ratio= 4.3 for the covered group, p=0.13, log rank test). 3 patients in each group experienced local recurrence (2.3% in the covered group and 4.6% in the exposed group, P = 0.66). Kaplan-Meier survival analysis did not show a statistically significant difference in local recurrence between the covered and exposed groups (hazard ratio= 0.5 for the covered group, p=0.39, log rank test).
Conclusions: :
Excentric Ru-106 plaque application does not increase the risk of local recurrence, metastases or mortality and does not require re-operation. These findings can enable us to keep the Ru-106 plaque away from essential structures in the posterior pole.
Keywords: melanoma • tumors • radiation therapy