Outcome of hyperfractionated radiotherapy in chemotherapy-resistant non-Hodgkin's lymphoma

Patients with chemotherapy-resistant lymphoma have rapidly progressive disease and a poor prognosis. Local symptoms are treated with radiotherapy (RT) for local control. We have reviewed local control and toxicity in patients treated with hyperfractionated accelerated RT.

A total of 34 patients received hyperfractionated RT between 1997 and 2003. The radiation dose was 39.9-40.5 Gy in 30 fractions. The median treatment time was 22 days with twice-daily involved-field RT. The median follow-up was 4.4 years. Response was assessed <3 months after RT and was classified as a complete response, a complete response-unconfirmed, a partial response, or no response. Local control was defined as maintenance of local complete response, complete response-unconfirmed, or lack of local progression with a partial response. Recurrence or progression outside the RT volume was regarded as distant disease.

The median age was 53 years; 20 patients were men and 14 were women. The initial diagnosis was Stage I-II in 56% and Stage III-IV in 44%. The disease bulk was > or =10 cm in 35% (n = 12). The histologic features at diagnosis were follicular in 11 (Grade 1 in 4, Grade 2 in 3, and Grade 3 in 4), diffuse large B-cell in 14, peripheral T-cell lymphoma in 2, Burkitt-like in 1, mantle cell in 2, natural killer cell in 2, plasmacytoma/lymphoma in 1, and T-cell lymphoblastic in 1. The initial treatment was chemotherapy in 32 patients (94%); 71% were refractory to initial chemotherapy and 29% developed a relapse after an initial response. The RT response was complete in 24% (n = 8), complete, unconfirmed in 26% (n = 9), partial in 47% (n = 16), and none in 3% (n = 1). The local control rate was 73% at 1, 2, and 3 years. Grade 1 dermatitis was the most common side effect.

Hyperfractionated RT provided good local control and was well tolerated. This encouraging result requires additional study with comparison to conventional fractionation regimens.