Palliation by low-dose local radiation therapy for indolent non-Hodgkin lymphoma.

Purpose: The purpose of this study was to assess the efficacy of a 2×2 Gy (total dose, 4 Gy) palliative radiation therapy (RT) regimen for treating patients with indolent non-Hodgkin lymphoma (NHL) in terms of response rate, response duration, and symptom relief.

Methods And Materials: A retrospective chart review was conducted. Between 2003 and 2007, 54 patients with NHL were treated to 85 anatomical sites with a 2×2 Gy palliative regimen. Local response was assessed by clinical and/or radiographic data. Symptoms before and after treatment for each site treated were obtained from clinical notes in patient medical records. Median follow-up time was 1.3 years.

Results: For the 54 patients, the median age at time of treatment was 71.1 years old, and 57% of them were male. Of the 85 disease sites treated, 56% of sites had indolent histology, 28% of sites were diagnosed with chronic lymphocytic leukemia (CLL), 13% of sites had aggressive histology, and 2% of sites were shown to have other histology. Overall response rate (ORR) was 81% (49% complete response [CR], 32% partial response [PR]). The 2-year rate for freedom from local progression was 50% (95% CI, 37%-61%). The ORR for follicular lymphoma, Mucosa associated lymphoid tissue (MALT), and marginal zone lymphoma (MZL) histology was 88%, compared with a 59% rate for CLL histology (p=0.005). While the ORR was similar for tumors of different sizes, the CR rate for patients with tumors<5 cm tended to be higher than those with tumors>10 cm (CR rate of 57% vs. 27%, respectively; p=0.06). For the 48 sites with clearly documented symptoms at pretreatment, 92% of sites improved after low-dose RT.

Conclusions: Short-course low-dose palliative radiotherapy (2×2 Gy) is an effective treatment that results in high response rates for indolent non-Hodgkin lymphoma. This treatment regimen provides effective symptomatic relief for tumor bulk of all sizes.