Kouhen Fadila, Chahid Malak, Gouache Hanae El, Errafiy Nadia, Maghous Abdelhak
Mohammed 6 Faculty of Medicine, Rabat, Mohammed VI University of Sciences and Health; Radiotherapy Department, International University Hospital Sheikh Khalifa, Morocco; Laboratory of Neuro-Oncology, Onco-Genetics and Precision Medicine, UM6SS, Morocco.
Mohammed 6 Faculty of Medicine, Rabat, Mohammed VI University of Sciences and Health; Radiotherapy Department, International University Hospital Sheikh Khalifa, Morocco.
Cancer Treat Res Commun. 2025;45:100983. doi: 10.1016/j.ctarc.2025.100983. Epub 2025 Aug 26.
Nasopharyngeal carcinoma (NPC) is located near critical structures like the hippocampus, essential for memory and cognitive function. While Volumetric Modulated Arc Therapy (VMAT) has improved dose conformity in NPC treatment, the integration of hippocampal-sparing (HS) approaches remains underexplored. This study evaluates the dosimetric feasibility and effectiveness of hippocampal-sparing VMAT (HS-VMAT) in NPC, focusing on reducing radiation exposure to the hippocampus while maintaining target volume coverage.
We conducted a retrospective cohort study of 20 NPC patients treated at Cheikh Khalifa International University Hospital between 2020 and 2023. Each patient underwent two radiotherapy plans: one with hippocampal sparing and one without. Dosimetric parameters for planning target volumes (PTVs) and organs at risk (OARs) were analyzed. Independent samples t-tests were used for statistical analysis with a significance level of p < 0.05.
For the high-risk PTV (PTV HR), there were no significant differences in maximum dose (D2 %) between HS and non-HS groups (71.71 ± 0.23 Gy vs. 71.65 ± 0.11 Gy; p = 0.298). The minimum doses (D95 %, D98 %) and mean dose (Dmean) were slightly lower in the HS group, though not statistically significant. For intermediate- and low-risk PTVs, dose metrics remained similar across groups. Hippocampal sparing significantly reduced doses to the hippocampus. The minimum dose (Dmin) decreased from 5.87 ± 2.06 Gy to 3.93 ± 0.45 Gy (p = 0.001), and the maximum dose (Dmax) decreased from 10.73 ± 3.62 Gy to 7.40 ± 1.25 Gy (p = 0.001). Radiation doses to critical structures were also reduced. The brainstem Dmax decreased from 35.68 ± 5.31 Gy to 30.12 ± 4.71 Gy (p = 0.001), and the left parotid gland Dmoy decreased from 21.38 ± 5.38 Gy to 18.32 ± 2.53 Gy (p = 0.029).
HS-VMAT for NPC effectively reduces hippocampal and critical structure radiation doses without compromising target volume coverage. This technique offers a feasible approach to minimize neurocognitive risks while maintaining treatment efficacy.
鼻咽癌（NPC）位于海马体等对记忆和认知功能至关重要的关键结构附近。虽然容积调强弧形放疗（VMAT）已改善了鼻咽癌治疗中的剂量适形性，但海马体保护（HS）方法的整合仍未得到充分探索。本研究评估了海马体保护VMAT（HS-VMAT）在鼻咽癌治疗中的剂量学可行性和有效性，重点是在保持靶区覆盖的同时减少对海马体的辐射暴露。
我们对2020年至2023年期间在谢赫·哈利法国际大学医院接受治疗的20例鼻咽癌患者进行了一项回顾性队列研究。每位患者都接受了两个放疗计划：一个采用海马体保护，另一个不采用。分析了计划靶区（PTV）和危及器官（OAR）的剂量学参数。采用独立样本t检验进行统计分析，显著性水平为p < 0.05。
对于高危PTV（PTV HR），HS组和非HS组之间的最大剂量（D2%）无显著差异（71.71±0.23 Gy对71.65±0.11 Gy；p = 0.298）。HS组的最小剂量（D95%、D98%）和平均剂量（Dmean）略低，但无统计学意义。对于中危和低危PTV，各组之间的剂量指标相似。海马体保护显著降低了海马体的剂量。最小剂量（Dmin）从5.87±2.06 Gy降至3.93±0.45 Gy（p = 0.001），最大剂量（Dmax）从10.73±3.62 Gy降至7.40±1.25 Gy（p = 0.001）。对关键结构的辐射剂量也有所降低。脑干Dmax从35.68±5.31 Gy降至30.12±4.71 Gy（p = 0.001），左腮腺Dmoy从21.38±5.38 Gy降至18.32±2.53 Gy（p = 0.029）。
鼻咽癌的HS-VMAT可有效降低海马体和关键结构的辐射剂量，同时不影响靶区覆盖。该技术提供了一种可行的方法，可在保持治疗效果的同时将神经认知风险降至最低。
