Single-center phase 2 trial of response-adapted low-dose radiation therapy for orbital indolent B-cell lymphoma

Radiation therapy doses 24 to 36 Gy is currently used to treat indolent B-cell lymphoma of the ocular adnexa. However, ocular adverse events are common. A phase 2 trial at MD Anderson Cancer Center (Houston, TX) evaluated response-adapted radiation therapy, with 4 Gy in 2 fractions; patients with persistent disease were offered an additional 20 Gy in 10 fraction. Among 50 patients, 45 (90%) experienced a complete response to respons-adapted radiation, including 44 patients with complete response to 4 Gy and one patient after an additional 20 Gy. There were no grade 3 or higher toxic effects. The authors conclude that response-adapted low-dose therapy for indolent orbital B-cell lymphoma resulted in reduced radiation exposure, negligible toxic effects, and excellent disease outcomes.