Radiotherapy of indolent orbital lymphomas

Abstract

The aim of this work was to retrospectively analyze efficacy, toxicity, and relapse rates of conventional (CRT) and low-dose radiotherapy (LDRT) in patients with indolent orbital lymphomas. From 1987-2014, 45patients (median age 64years) with 52lesions of indolent orbital lymphomas were treated with CRT (median dose 36Gy, range 26-46Gy) and 7patients (median age 75years) with 8lesions were treated with LDRT (2 fractions of 2.0Gy). Median follow-up was 133months (range 2-329 months) in the CRT group and 25months (range 10-41 months) in the LDRT group. Overall response rates were 97.7 % (CRT) and 100 % (LDRT). The 2‑ and 5‑year local progression-free survival (PFS) rates were 93.5 and 88.6 %, distant PFS 95.0 and 89.9 %, and overall survival 100 and 85.6 % after CRT. In the LDRT group, 2‑year local PFS and overall survival remained 100 %, respectively, and distant PFS 68.6 %. Acute radiotherapy-related complications (grades 1-2) were detected in virtually all eyes treated with CRT. Cataracts developed in only patients who were irradiated with more than 34Gy. LDRT was well tolerated with only mild acute and late complications. Primary radiotherapy of indolent orbital lymphomas is an effective treatment with high response rates and excellent local control in CRT and LDRT. In combination with close follow-up, LDRT may be an attractive alternative since re-irradiation even with conventional doses is still feasible.