Department of Radiation Oncology, Kobe Proton Center, 1-6-8, Minatojima-Minamimachi, Kobe, 650-0047, Japan.
Department of Anesthesiology, Kobe Proton Center, Kobe, Japan.
Jpn J Radiol. 2024 Feb;42(2):182-189. doi: 10.1007/s11604-023-01499-8. Epub 2023 Oct 24.
To investigate the dose stability of craniospinal irradiation based on irradiation method of proton beam therapy (PBT).
Twenty-four pediatric and young adult brain tumor patients (age: 1-24 years) were examined. Treatment method was passive-scattered PBT (PSPT) in 8 patients and intensity-modulated PBT (IMPT) in 16 patients. The whole vertebral body (WVB) technique was used in 13 patients whose ages were younger than 10, and vertebral body sparing (VBS) technique was used for the remaining 11 patients aged 10 and above. Dose stability of planning target volume (PTV) against set-up error was investigated.
The minimum dose (D) of IMPT was higher than that of PSPT (p = 0.01). Inhomogeneity index (INH) of IMPT was lower than that of PSPT (p = 0.004). When the irradiation field of the cervical spinal cord level (C level) was shifted, the maximum dose (D) was lower in IMPT, and mean dose (D) was higher than PSPT as movement became greater to the cranial-caudal direction (p = 0.000-0.043). D was higher and INH was lower in IMPT in all directions (p = 0.000-0.034). When the irradiation field of the lumber spinal cord level (L level) was shifted, D was lower in IMPT as movement became greater to the cranial direction (p = 0.000-0.028). D was higher and INH was lower in IMPT in all directions (p = 0.000-0.022).
The PTV doses of IMPT and PSPT are robust and stable in both anterior-posterior and lateral directions at both C level and L level, but IMPT is more robust and stable than PSPT for cranial-caudal movements.
Clinical Trial Registration number: No. 04-03.
基于质子束治疗（PBT）的放射方法，研究颅脊髓照射的剂量稳定性。
对 24 名儿科和年轻成人脑肿瘤患者（年龄：1-24 岁）进行了检查。治疗方法为 8 例患者采用被动散射质子束治疗（PSPT），16 例患者采用强度调制质子束治疗（IMPT）。13 名年龄小于 10 岁的患者采用全椎体（WVB）技术，11 名年龄大于等于 10 岁的患者采用椎体 sparing（VBS）技术。研究了计划靶区（PTV）对摆位误差的剂量稳定性。
IMPT 的最小剂量（D）高于 PSPT（p=0.01）。IMPT 的不均匀性指数（INH）低于 PSPT（p=0.004）。当颈脊髓水平（C 水平）照射野发生偏移时，随着向头尾方向的运动增大，IMPT 的最大剂量（D）较低，平均剂量（D）高于 PSPT（p=0.000-0.043）。在各个方向上，IMPT 的 D 较高，INH 较低（p=0.000-0.034）。当腰脊髓水平（L 水平）照射野发生偏移时，随着向头侧的运动增大，IMPT 的 D 较低（p=0.000-0.028）。在各个方向上，IMPT 的 D 较高，INH 较低（p=0.000-0.022）。
在 C 水平和 L 水平的前后和左右方向上，IMPT 和 PSPT 的 PTV 剂量都具有很强的稳定性，但在头尾方向的运动中，IMPT 比 PSPT 更具稳定性。
No. 04-03。
