Radiotherapy for early and advanced stages Follicular Lymphoma

OBJECTIVES: To evaluate the results of radiotherapy (RT) for follicular lymphoma (FL) under different management scenarios. METHODS: We retrospectively assessed consecutive patients with FL who had undergone irradiation between 2010 and 2018. All patients had biopsy-proven FL and were positron emission tomography-staged, although some (35.3%) were reassessed with computed tomography after treatment alone. Rituximab was only available to FL patients after 2016. RESULTS: Thirty-four patients were selected, with a mean age at diagnosis of 61.6 years (34-89 years). The median follow-up duration was 49.4 months. Most patients were female (58.8%) and showed good performance on the Eastern Cooperative Oncology Group (ECOG) scale (ECOG 0-55.9%). The mean overall survival (OS) and progression-free survival were 48.7 and 33.6 months, respectively, with four deaths reported. OS rates at 2 and 3 years were 94.1% and 91.2%, respectively. Four patients showed transformation into aggressive lymphomas and underwent rituximab-based systemic treatment. Transformation-free survival was 47.8 months, and all patients with transformed disease were alive at assessment. Five patients had in-field relapse, all of them also relapsed elsewhere, and the mean relapse-free survival time was 40.3 months. No median end points were reached on assessment. CONCLUSION: FL is an indolent disease. Our findings show good outcomes for patients treated with radiation, with a low transformation rate and excellent management of relapsed disease. RT is an important part of these results.