Validity of reduced radiation dose for localized diffuse large B-cell lymphoma showing a good response to chemotherapy.

To evaluate the validity of a decrease in the radiation dose for patients who were good responders to chemotherapy for localized diffuse large B-cell lymphoma (DLBCL), 91 patients with localized DLBCL who underwent radiotherapy after multi-agent chemotherapy from 1988-2008 were reviewed. Exclusion criteria were as follows: central nervous system or nasal cavity primary site, or Stage II with bulky tumor (≥10 cm). Of these patients, 62 were identified as good responders to chemotherapy. They were divided into two groups receiving either a higher or a lower radiation dose (32-50.4 Gy or 15-30.6 Gy, respectively). There were no statistically significant differences between the lower and higher dose groups in progression-free survival, locoregional progression-free survival or overall survival. Adaptation of decreased radiation dose may be valid for localized DLBCL patients who show a good response to chemotherapy.