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 ( = .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 < .001). The minimum PTV dose of IMPT was higher than that of PSPT ( = .01). The inhomogeneity index of IMPT was lower than that of PSPT ( = .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.