Prophylactic Scrotal And Contralateral Testicular Radiation Therapy Prevents Local Relapses in Primary Testicular Lymphomas

Abstract

Primary testicular lymphoma is a rare form of extranodal lymphoma typically expressing B-cell markers. The contralateral testis and the central nervous system are common localizations of relapses. The purpose was to evaluate the benefit of prophylactic scrotal radiation therapy (RT). Patients with primary testicular lymphoma were identified from the institutional electronic database, by submitting keywords in a search engine. Eligibility was limited to adults (age > 18 years), and diffuse large B cells subtype. Patient’s clinical data were retrospectively reviewed. Survivals were estimated using the Kaplan-Meier method and compared using log-rank tests. Forty-eight patients were included. The majority of the patients had localized disease (Ann-Arbor stage I-II, 85.4%). Orchiectomy was performed in all cases. Their mean age at diagnosis was 61.4±14.4 years. Median follow-up was 67.7 months (range 5.6-317.2). No patient presented with B symptoms and no central nervous system involvement was documented at diagnosis. International prognostic indexes were 0 in 31.3% of the patients, 1 in 45.8%, 2 or 3 in 10.4% and 4 in one patient (2.1%). Anthracycline-based chemotherapy was administered to 81% of patients, 29.1% had rituximab associated. Prophylactic intrathecal injections of methotrexate were administered to 48% of patients. Scrotal irradiation was given to 37.5% of patients, following chemotherapy. The target volumes comprised the scrotum and contralateral testis. The mean dose was 33.3±.2.9 Gy (range: 30-36). No local relapse was reported among the patients who received scrotal radiotherapy whereas 8 failures (16.7%) where observed in those who did not. The 5-year local control rates were 100% and 81.9% respectively, in the groups of patients with and without prophylactic RT (n=30, and n=18, P=0.034). In the subgroup of patients with stage I-II diseases (n=41), 5-year local control rates were 100% in those who received RT (n=15) and 80.4% in the remaining ones (n=26, P=0.05). Prophylactic scrotal and contralateral testicular RT is effective in preventing local relapses in primary testicular lymphoma.