Background: The proton irradiation modality has transitioned from passive scattering (PS) to pencil beam scanning. Nevertheless, the documented outcomes predominantly rely on PS. Methods: Thirty patients diagnosed with prostate cancer were selected to assess treatment planning across line scanning (LS), PS, and volumetric modulated arc therapy (VMAT). Dose constraints encompassed clinical target volume (CTV) D98 ≥ 73.0 Gy (RBE), rectal wall V65 < 17% and V40 < 35%, and bladder wall V65 < 25% and V40 < 50%. The CTV, rectal wall, and bladder wall dose volumes were calculated and evaluated using the Freidman test. Results: The LS technique adhered to all dose limitations. For the rectal and bladder walls, 10 (33.3%) and 21 (70.0%) patients in the PS method and 5 (16.7%) and 1 (3.3%) patients in VMAT, respectively, failed to meet the stipulated requirements. The wide ranges of the rectal and bladder wall volumes (V10-70) were lower with LS than with PS and VMAT. LS outperformed VMAT across all dose–volume rectal and bladder wall indices. Conclusion: The LS method demonstrated a reduction in rectal and bladder doses relative to PS and VMAT, thereby suggesting the potential for mitigating toxicities.
背景：质子放射治疗模式已从被动散射（PS）过渡到笔形束扫描。然而，现有文献报道的治疗结果主要基于被动散射技术。方法：本研究选取30例前列腺癌患者，评估线扫描（LS）、被动散射和容积旋转调强放疗（VMAT）三种技术的治疗计划。剂量约束条件包括：临床靶区（CTV）D98 ≥ 73.0 Gy（相对生物效应值），直肠壁V65 < 17%且V40 < 35%，膀胱壁V65 < 25%且V40 < 50%。通过计算CTV、直肠壁和膀胱壁的剂量体积参数，并采用弗里德曼检验进行统计分析。结果：线扫描技术满足所有剂量限制条件。在被动散射组中，分别有10例（33.3%）和21例（70.0%）患者的直肠壁和膀胱壁未达到限定标准；而VMAT组中分别为5例（16.7%）和1例（3.3%）。线扫描技术在直肠壁和膀胱壁的宽范围剂量体积参数（V10-70）上均低于被动散射和VMAT。在所有直肠壁和膀胱壁的剂量-体积指标比较中，线扫描技术均优于VMAT。结论：相较于被动散射和VMAT，线扫描技术能够降低直肠和膀胱的受照剂量，这表明该技术具有降低放射毒性的潜在优势。
肿瘤(癌症)患者之家