The Improvement For Craniospinal RadiotherapyQI Wei-hua, WANG Jun-liang, ZHOU Zhen-shan, SHEN Ge, YANG Hai-yan, YANG Gang, SUN Hun-ru(Department of Radiation Therapy, Affiliated Hospital of Academy of Military Medical Sciences, Beijing 100071,China)Abstract:Objective: To introduce a new method for craniospinal radiotherapy.Methods: The patients were were treated in thesupine position on the whole positioning plate and fixed by the neck-shoulder and body thermoplastic mask, and then they wereCT scanned. The CT images of patients were transferred to the Treatment Planning System (TPS) for a 3D reconstruction.Drawing target region and making treatment plan. The patients had a CBCT scanning before treatment for verfying the positonson line.Results:We could directly see the dose distribution on the TPS,and adjusted the treatment plan that there were not any"hot"or "cold" spots and fulfilled the QA criteria.Conclusions: The supine position and thermoplastic mask were morecomfortable for craniospinal radiotherapy , The supine position was easy to maintain in the treatment process and ensured theaccurate of treatment. Compared with the traditional simulator, CT simulation was more easy and accurate.Using TPS couldmake the dose distribution more homogeneous and without "hot"or "cold" spots.Key Words: craniospinal radiotherapy; supine position; CT simulation