Reduced-dose Radiation Therapy by the Chemoresponsiveness for the Primary Central Nervous System Lymphoma

Abstract

therapy: one had received 45 Gy with opposed laterals at an outside facility and the other was initially diagnosed as an atypical meningioma and underwent 54 Gy. Both these patients were treated with an additional 60 Gy when they recurred. The 12 other patients received a median of 81 Gy (76.8 82.5). These patients were treated using a hyperfractionated regiment of 1.2 Gy twice daily (BID) to 60 Gy followed by a 21 Gy boost at 1.5 Gy BID. Dosimetry data was not available on one patient. The 11 remaining patients had median max and mean dose to the brainstem of 81 Gy (46.7 85.7) and 38 (6.7 58.1) respectively. The mean target volume was 22 cm (60.5 193.3). LC at 3, 5, and 10 years was 71, 48 and 48% respectively. Cause-specific survival was 89, 63, and 63% respectively with a median follow up of 5 years for the 12 patients. There was a trend for improved survival in patients treated adjuvantly as compared to those treated for recurrent disease. Clinically significant late toxicity occurred in one patient, a 69-year-old man with multiple comorbidities developed progressive hearing loss 7 years after his treatment. Performance status declined in 3 patients after treatment due to disease progression. Conclusions: HD-FSRT can achieve identical doses to proton therapy plans and is a safe and effective treatment in patients with SBC. Preliminary results appear similar to larger series treated with protons. Author Disclosure: A. Sheybani: None. R. Ahmed: None. M.J. Tennapel: None. D.E. Hyer: None. K. Anderson: None. J.M. Buatti: None.