Whole-abdomen radiotherapy for non-Hodgkin’s lymphoma using twice-daily fractionation

Abstract

To report the tolerability and efficacy of twice-daily whole-abdomen irradiation (WAI) for non-Hodgkin's lymphoma (NHL). Of 123 patients treated for NHL with WAI, 37% received previous chemotherapy, 28% received WAI as part of comprehensive lymphatic irradiation (CLI), and 32% received WAI for palliation. The median dose to the whole abdomen was 25.0 Gy, followed by a median tumor boost of 9.8 Gy in 58 patients. Fractionation was 1.0 Gy once daily (54%) or 0.8 Gy twice daily (46%). Blood counts were measured weekly. At a median follow-up of 4.3 years, local control was 72% and overall survival was 55% at 5 years. Median time of WAI was 42 days for once-daily treatment and 32 days for twice-daily treatment. Patients receiving twice-daily WAI did not have a significantly higher rate of acute side effects (e.g., nausea, diarrhea, platelet or red blood cell toxicity). Overall, acute thrombocytopenia was the most frequent side effect of treatment; 24 of 96 patients (25%) with available hematologic data had Grade 3+ toxicity. There was no acute Grade 3 gastrointestinal toxicity and no late small bowel obstruction. Multiple regression indicated that patients with four or less involved sites and disease size < or =6 cm had improved local control and overall survival. Twice-daily WAI using 0.8 Gy/fraction does not appear to have any greater toxicity compared with once-daily treatment using 1 Gy/fraction. Small doses per fraction (0.8-1 Gy/fx) are effective, tolerated well in the acute setting, and associated with a low rate of late toxicity.