Comparison of Craniospinal Irradiation Using Proton Beams According to Irradiation Method and Initial Experience Treating Pediatric Patients.

Purpose: This study compared craniospinal irradiation using proton beam therapy (PBT) according to irradiation method and investigated the initial effects.
Methods and Materials: Twenty-four pediatric patients (1-24 years old) who received proton craniospinal irradiation were examined. Passive scattered PBT (PSPT) and intensity modulated PBT (IMPT) were used in 8 and 16 patients, respectively. The whole vertebral body technique was used for 13 patients <10 years old, and the vertebral body sparing (VBS) technique was used for the remaining 11 patients aged ≥10 years. The follow-up period was 17 to 44 (median, 27) months. Organ-at-risk and planning target volume (PTV) doses and other clinical data were examined.
Results: The maximum lens dose using IMPT was lower than that using PSPT ( P  = .008). The mean thyroid, lung, esophagus, and kidney doses were lower in patients treated using the VBS technique compared with the whole vertebral body technique (all P < .001). The minimum PTV dose of IMPT was higher than that of PSPT ( P  = .01). The inhomogeneity index of IMPT was lower than that of PSPT ( P  = .004).
Conclusions: IMPT is better than PSPT at reducing the dose to the lens. The VBS technique can decrease the doses to neck-chest-abdomen organs. The PTV coverage of IMPT is superior to that of PSPT.
(© 2023 Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.)