Current status of cranio-spinal irradiation: Based on a questionnaire survey by the Japan Children’s Cancer Group Brain Tumor Committee

Abstract

In recent years, intensity-modulated radiation therapy and proton beam therapy have been increasingly applied to cranio-spinal irradiation, necessitating precise target considerations. Therefore, we conducted a questionnaire survey on cranio-spinal irradiation to clarify the current treatment landscape at each facility.

We invited 100 facilities affiliated to the Brain Tumor Committee to participate in the survey via e-mail, and received responses from 54 facilities (54%). Of these, 46 utilized photon beam therapy, while 8 employed proton beam therapy. Over a 3-year period, photon beam therapy facilities treated varying number of cases: less than 3 at 24 facilities (52%), 9 at 10 (22%), 18 at 7 (13%), and more than 18 at 2 (4%). In contrast, proton beam therapy facilities treated 1 (13%), 2 (25%), 5 (63%), and 1 (13%) cases, respectively. Eight of the photon beam therapy facilities treated patients with intensity-modulated radiation therapy, and six of these facilities applied tomotherapy. An inquiry into the clinical target volume of cranio-spinal irradiation in proton beam therapy facilities revealed that a few included the cranial nerves, including the optic nerve.

The survey suggests a potential trend towards the increased adoption of high-precision treatments such as intensity-modulated radiation therapy and proton beam therapy. This rising trend necessitates a more detailed definition of the target volume.