Efficacy and toxicity of infradiaphragmal radiotherapy fields in lymphoma patients: a single-centre experience.

Purpose: Data on efficacy and toxicity of infradiaphragmal radiotherapy fields in lymphoma patients are scarce. We therefore performed this retrospective study to analyse our experience with radiotherapy exclusively to infradiaphragmal fields.
Materials and Methods: we retrospectively evaluated 101 patients treated between 2003 and 2014. Median dose was 36 Gy, range 4 to 54 Gy. Medium dose per fraction was 2 Gy, range 1.5 to 7 Gy.
Results: After a median follow-up of 66 months (range 1-211 months), we observed lymphoma recurrence in 38 patients (38%), five in the RT field and 33 out-of-field. Recurrences were significantly more frequent in the salvage group (17 out-of-field and 4 in-field in 31 patients) than in adjuvant group (16 out-of-field and 1 in-field in 70 patients; p < 0.001). The 2-, 5- and 10-year event-free survival (EFS) rates were 62%, 56% and 54%. The 2-, 5- and 10-year overall survival (OS) rates for the entire group of patients are 73%, 60% and 54%, respectively. Acute side effects occurred in 43 (43%) patients, most frequent gastrointestinal in 26 (26%) patients. Late side effects occurred in 12 (12%) of all patients, 6 of 23 (26%) followed up for more than 10 years. Six patients developed secondary cancers, four gastrointestinal disturbances, two diabetes mellitus and three renal failure.
Conclusion: Radiotherapy is an effective and safe treatment option for patients with infradiaphragmatic lymphoma providing excellent local disease control with minimal late toxicity. Infradiaphragmatic lymphoma localization should not be regarded as a contraindication for use of radiotherapy. However, patients should be monitored for a secondary malignancy.
(© 2023. Italian Society of Medical Radiology.)