Proton therapy is a promising modality for craniospinal irradiation (CSI), offering dosimetric advantages over conventional treatments. While significant attention has been paid to spine fields, for the brain fields, only dose reduction to the lens of the eye has been reported. Hence, the objective of this study is to assess the potential gains and feasibility of adopting different treatment planning techniques for the entire brain within the CSI target. To this end, eight previously treated CSI patients underwent retrospective replanning using various techniques: (1) intensity modulated proton therapy (IMPT) optimization, (2) the modification/addition of field directions, and (3) the pre-optimization removal of superficially placed spots. The target coverage robustness was evaluated and dose comparisons for lenses, cochleae, and scalp were conducted, considering potential biological dose increases. The target coverage robustness was maintained across all plans, with minor reductions when superficial spot removal was utilized. Single- and multifield optimization showed comparable target coverage robustness and organ-at-risk sparing. A significant scalp sparing was achieved in adults but only limited in pediatric cases. Superficial spot removal contributed to scalp V30 Gy reduction at the expense of lower coverage robustness in specific cases. Lens sparing benefits from multiple field directions, while cochlear sparing remains impractical. Based on the results, all investigated plan types are deemed clinically adoptable.
质子治疗作为颅脊髓照射的创新治疗模式，在剂量学方面较传统疗法具有显著优势。目前研究多聚焦于脊柱照射野，而针对脑部照射野仅见晶状体剂量降低的相关报道。本研究旨在评估颅脊髓靶区内全脑部采用不同治疗计划技术的潜在获益与临床可行性。为此，我们对八例既往接受颅脊髓照射的患者进行回顾性再计划设计，采用以下技术方案：(1) 调强质子治疗优化，(2) 照射野方向调整/增补，(3) 优化前剔除浅表布点。在考量潜在生物剂量增加的前提下，评估靶区覆盖稳健性，并对晶状体、耳蜗及头皮进行剂量对比分析。结果显示所有计划均保持靶区覆盖稳健性，仅浅表布点剔除方案出现轻微下降。单野与多野优化在靶区覆盖稳健性和危及器官保护方面表现相当。成人病例实现显著头皮保护，但儿童病例获益有限。特定情况下浅表布点剔除虽降低头皮V30 Gy受量，但会削弱靶区覆盖稳健性。多野照射方向设计可提升晶状体保护效果，而耳蜗保护仍难以实现。综合研究结果，所有考察的计划类型均具备临床适用性。
肿瘤(癌症)患者之家