Williamson Aoife, Houston Peter, Paterson Jennifer, Chalmers Anthony J, McLoone Philip, Fullerton Natasha, Foo Sin Yee, James Allan, Nowicki Stefan
Department of Clinical Oncology, Beatson West of Scotland Cancer Centre, Glasgow, UK.
School of Cancer Sciences, University of Glasgow, Glasgow, UK.
Neurooncol Adv. 2024 Aug 6;6(1):vdae131. doi: 10.1093/noajnl/vdae131. eCollection 2024 Jan-Dec.
Radiotherapy (RT) plays an integral role in the management of low-grade gliomas (LGG). Late toxicity from RT can cause progressive neurocognitive dysfunction. Radiation-induced damage to the hippocampus (HCP) plays a considerable role in memory decline. Advancements in photon planning software have resulted in the development of multi-criteria optimization (MCO) and HyperArc technologies which may improve HCP sparing while maintaining planning target volume (PTV) target coverage.
Three planning methods for hippocampal sparing (HS) were compared, volumetric modulated arc therapy (VMAT) without HS (VMAT_noHS), VMAT with HS (VMAT_HS), MCO with HS (MCO_HS), and HyperArc with HS (HyperArc_HS).
Twenty-five patients were identified. The contralateral HCP was spared in 16 patients and bilateral HCP in 9 patients with superiorly located tumors. All 3 HS planning techniques showed significant reductions in dose to the spared HCP in contralateral cases but only VMAT_HS and MCO_HS achieved this in bilateral cases ( < .008). Only MCO_HS was superior to VMAT_HS in lowering the dose to both contralateral HCP and bilateral HCP in all measured metrics ( < .008). PTV and OAR (organ at risk) dose constraints were achieved for all plans.
This retrospective dosimetric study demonstrated the feasibility of HS for low-grade glioma. All 3 HS planning techniques achieved significant dose reductions to the spared contralateral hippocampus, but only MCO_HS and VMAT_HS achieved this in bilateral cases. MCO was superior to other planning techniques for sparing both bilateral and contralateral hippocampi.
放射治疗（RT）在低级别胶质瘤（LGG）的治疗中起着不可或缺的作用。放疗的晚期毒性可导致进行性神经认知功能障碍。辐射诱导的海马体损伤（HCP）在记忆衰退中起重要作用。光子治疗计划软件的进步导致了多标准优化（MCO）和HyperArc技术的发展，这可能在维持计划靶体积（PTV）靶区覆盖的同时改善对海马体的保护。
比较了三种海马体保护（HS）的治疗计划方法，即无海马体保护的容积调强弧形放疗（VMAT_noHS）、有海马体保护的VMAT（VMAT_HS）、有海马体保护的MCO（MCO_HS）和有海马体保护的HyperArc（HyperArc_HS）。
共纳入25例患者。16例患者的对侧海马体得到保护，9例肿瘤位置较高的患者双侧海马体均得到保护。在对侧病例中，所有三种海马体保护计划技术均显示对未受照射的海马体的剂量显著降低，但在双侧病例中只有VMAT_HS和MCO_HS做到了这一点（P<0.008）。在所有测量指标中，只有MCO_HS在降低对侧和双侧海马体剂量方面优于VMAT_HS（P<0.008）。所有计划均达到了PTV和危及器官（OAR）的剂量限制。
这项回顾性剂量学研究证明了低级别胶质瘤海马体保护的可行性。所有三种海马体保护计划技术均显著降低了未受照射的对侧海马体的剂量，但在双侧病例中只有MCO_HS和VMAT_HS做到了这一点。在保护双侧和对侧海马体方面，MCO优于其他计划技术。
