Abstract: ObjectiveTo explore the efficacy， side effects and dosimetry advantage of tomotherapy on medulloblastoma. Methods Four patients with medulloblastoma were treated with tomoth erapy from February 2011 to October 2011. CTV1 was the tumor bed after operation， and the prescription dose was 50.4Gy （for 28 times, 1.8Gy for each time，5 times／week）. CTV2was the whole brain and spinal cord，and the prescription dose was 30.6Gy （for 17 times，1.8Gy for each time，5 times／week）.
ResultsThe therapy plans demonstrated excellent target coverage with low dose on key organs. The treating time was less 15min. Four patients were followedup， the median duration of follow-up was 9 months （4-15 months）， and no recurrence occurred. The side effects included marrow suppression and digestive reaction with good tolerance. Conclusion Tomotherapy shows good efficacy and excellent target coverage on medulloblastoma，and creates a new stage on the treatment of medulloblastoma.