Radiotherapy for early and advanced stages Follicular Lymphoma

To evaluate the results of radiotherapy (RT) for follicular lymphoma (FL) under different management scenarios.

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.

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.

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.