[Optimization of the craniospinal radiation technique by synthesizing multiple advanced radiation techniques].

Craniospinal radiation is one of essential components in the treatment flow for a number of central nervous system malignancies. Meticulous attention to technique and dosimetry is required to produce optimum tumor control. In this paper, an optimized treatment regimen was proposed based on multiple techniques. The CT images for a 17-year-old male patient in need of craniospinal radiation were acquired for 3D conformal treatment planning. The split-beam technique, the extended penumbra fields matching technique, and the multiple leaf collimator segments and extended SSD technique were synthesized in the treatment regimen so as to work out an optimized treatment plan. The added few segments improved the dose homogeneity in spinal cord. The maximal point dose was decreased from 124% to 108% of the prescribed dose in it. Comparative study on the anthropomorphic phantom showed that the data collected by thermoluminescent detectors and the data obtained by calculation were basically coincident. These results suggest that the proposed technique be clinically acceptable.