The phase I-II trial for nine patients with chemotherapy-refractory lymphoma evaluated dose escalation in total body irradiation above the previously reported maximum tolerated dose with use of a regimen combining dose-escalated irradiation with autologous peripheral blood stem cell transplantation.

The patients, who had Hodgkin's or non-Hodgkin's lymphoma with primary refractory disease or resistant relapse, received a stem cell transplant and dose-escalated radiation therapy to the entire body. The three levels of dose-escalated irradiation were 1,600 cGy, 1,800 cGy, and 2,000 cGy. Lung blocks were used to reduce transmission dose by 50 percent; the chest wall dose was supplemented to the prescribed dose using electrons. The kidneys were shielded to limit the maximal renal dose to 1,600 cGy.

Although toxicities were associated with the high-dose radiation therapy, six (66 percent) of the patients achieved some type of remission. Four (44 percent) of the patients achieved complete remission, three of which lasted more than one year. Two of the patients (22 percent) achieved partial remission. One of those patients remains disease free more than 5 years after the stem cell transplant. However, another patient died 429 days after transplantation from corticosteroid-induced gastritis and postoperative infection.

"High-dose radiotherapy with autologous stem cell transplantation is an effective and potentially curative therapy for selected patients with chemo-resistant Hodgkin's and non-Hodgkin's lymphoma," said Simon N. Powell, M.D., Ph.D., lead author in the study.