Efficacy of palliative low-dose involved-field radiation therapy in advanced lymphoma: a phase II study

To confirm the efficacy of low-dose involved-field radiation therapy (LD-IFRT) as palliative treatment in patients symptomatic from advanced lymphoma.

A total of 36 patients (47 sites), received 4 Gy in 2 fractions to the lymphoma with a 1.5-2-cm margin. Pathology subtypes included 29 (62%) sites with indolent lymphoma and 18 (36%) sites with aggressive lymphoma histology. Bulky disease was seen in 22 (48%) sites and, of these, 6 sites had disease > 10 cm. A median of 3 previous chemotherapy regimens (range, 0 to 9 regimens) preceded LD-IFRT. The primary endpoint of the study was in-field lymphoma control. Patients completed the European Organization for the Research and Treatment of Cancer QLQ-C30 quality of life (QOL) questionnaire before RT and at 3-4 weeks after treatment.

The overall response rate (RR) at 1-3 months after the RT was 75%. A complete remission (CR) was observed in 13 patients (36%) lasting up to a maximum of 31.3 months and ongoing at analysis. A partial remission (PR) was achieved in 14 patients (39%) lasting up to 10 months. The response rate for non-diffuse large B-cell lymphoma (DLBCL) sites was 86%, while it was 50% for sites with DLBCL histology. Median time to local progression for the entire group was 15 months. There was no statistical difference between the QOL before and after LD-IFRT.

LD-IFRT is an effective and easy treatment for patients with advanced lymphoma that can be repeated at previously irradiated sites, a particularly useful attribute because of the relapsing nature, especially of advanced follicular subtypes.