Single Center Results With SRS And FSRT In Uveal Melanoma

Abstract

To assess the results of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) in patients with uveal melanoma. Data of 417 patients treated with SRS/FSRT between September 2007 and November 2019 in our center were retrospectively evaluated. All treatments were applied via CyberKnife®. Median age of patients was 56 years. 201 (48%) patients were female and 216 (52%) were male. One patient had bilateral tumors, so the number of treated tumors was 418. 77% of tumors were T2-3, and 13% had ciliary body invasion. Total SRS/FSRT dose was <45 Gy in 100 (25%), and ≥45 Gy in 313 (75%) patients, respectively. Median tumor basal diameter was 8 mm (1.5-23 mm) and depth 8 mm (1-21 mm). Median tumor volume was 594 mm3 (23-9.158 mm3). Visual acuity was measured in 298 patients at the time of diagnosis. Other tumor and treatment characteristics are given in Table 1. Median follow-up was 48 months (0-263 months). The rate of 2-, 5-, and 10-year overall survival (OS) was 95%, 83%, and 68%, and distant metastasis-free survival (DMFS) was 91%, 77%, and 63%, respectively. Enucleation was performed in 92 patients; due to tumor progression in 59, and RT complication in 21 patients, respectively. The 2-, 5-, and 10-year enucleation-free survival (EFS) in all patients was 80%, 61%, and 50%, respectively. In univariate analysis, the rates of OS and DMFS were similar with ≥45 Gy and <45 Gy but 2- and 5-year EFS rates were significantly higher with ≥45 Gy (82% and 66% vs. 76% and 50% with <45 Gy, p = 0.006). The rates of OS, DMFS, and EFS were significantly lower in patients with a tumor diameter ≥8 mm. In patients with a tumor depth ≥8 mm, the rates of DMFS and EFS were significantly lower. In patients with a tumor volume <600 mm3, the rates of OS, DMFS, and EFS were significantly higher. Among patients that received ≥45 Gy, the ones with a tumor volume <600 cm3 had significantly higher rates of DMFS and EFS but OS was similar. In multivariate analysis, no prognostic factors were found for DMFS. However, for OS and EFS >8 mm basal tumor diameter (relative risk [RR] = 1.6, 95% confidence interval [CI] = 1.92-3.12, p = 0.09; and RR = 1.8, 95% CI = 1.15-2.81, p = 0.01), for EFS >8 mm depth (RR = 1.6, 95% CI = 1.03-2.4, p = 0.03), and ≤45 Gy dose (RR = 1.4, 95% CI = 0.9-2.08, p = 0.06) were negative prognostic factors. SRS/FSRT-related late toxicity was significantly higher in patients with a basal tumor diameter >8 mm and depth >8 mm (p = 0.001 and p = 0.04, respectively). Total SRS/FSRT dose and tumor diameter and depth were found prognostic factors for EFS. Toxicity rate was higher in patients with a higher tumor depth and basal diameter.Abstract 3685; TableCharacteristicNumber of patients (%)Tumor location • Anterior• Posterior52 (12)366 (88)T stage • T1• T2• T3• T4• Unknown88 (21)159 (37)142 (34)20 (5)9 (3)COMS • Small• Medium• Large• Unknown38 (9)257 (62)118 (28)5 (1)Visual acuity at diagnosis (in 298 patients) • Full loss• p-eh• mps- 0.1• 1- 0.4• 4- 0.6• 0.7 and higher1 (1)59 (20)62 (21)61 (20)62 (21)53 (17) Open table in a new tab