分弧分野容积旋转调强放疗(VMAT):一种睾丸保护性的阴茎癌放疗技术

摘要/Abstract

摘要： 为了评估阴茎癌术后放疗,常规双弧容积旋转调强放疗(VMAT)(dac-VMAT)与分弧分野VMAT(sapf-VMAT)两种方法的睾丸剂量差异,为临床计划中保留睾丸功能提供参考。本文对10例年龄在33至56周岁的阴茎鳞状细胞癌并伴有淋巴结转移的术后放疗的患者,采用联影医疗的uRT-TPOIS计划系统设计治疗计划,探讨射野铅门锁定范围和避开睾丸的弧度。采用配对t检验,对比计划靶区(PTV)的剂量学参数和睾丸等危及器官(OAR)所受到的辐射剂量。结果显示所有计划均归一到处方剂量50.4 Gy覆盖PTV的95%体积,双弧计划的机器跳数(MU)为706.85±107.97,低于分弧分野计划的874.70±106.08;双弧和分弧两种VMAT方法的治疗时间(T,s)分别为174.44±13.61和183.89±14.33;分弧分野计划中睾丸的V1、V2、V3(V1、V2、V3分别为睾丸受照剂量1、2、3的体积百分比)分别为49.77±14.52、5.42±5.60、0.40±0.69,均明显低于双弧计划中的97.97±3.17、83.15±19.14、7.35±4.81,P值均小于0.001;其它结果没有显著差异。研究结果表明,对于阴茎癌术后放疗的患者,相较于常规双弧VMAT,采用分弧分野VMAT技术能显著降低睾丸剂量,并且所受剂量低于引起功能损伤的剂量阈值,这表明患者可以无需采取遮挡睾丸或放疗前冷冻精子的措施,即可保留生育功能。

关键词: 直线加速器, 阴茎癌, 睾丸剂量, 铅门固定

Abstract: To evaluate the difference in testicular dose between dual-arc conventional VMAT (dac-VMAT) and split-arc partial-field VMAT (sapf-VMAT) in postoperative radiotherapy for penile cancer, so as to provide a reference for preserving testicular function in clinical plan, ten patients aged 33 to 56 years with penile squamous cell carcinoma (PSCC) with lymph node metastasis were treated with the uRT-TPOIS plan system of United Imaging, and the range of jaw locking and arc of testicular avoidance were discussed. A paired t-test was employed and the dosimetry parameters of the plan target volume (PTV) and the radiation dose of organs at risk (OAR) were compared. All plans are normalized to a prescribed dose of 50.4 Gy covering 95% of the volume of PTV. The statistical results of machine unit (MU) in the dac-VMAT were 706.85±107.97, which were lower than those of 874.70±106.08 in the sapf-VMAT. The treatment time (T, s) of the dac-VMAT and sapf-VMAT was 174.44±13.61 and 183.89±14.33 respectively and the V1, V2, V3 of testes in the sapf-VMAT were 49.77±14.52, 5.42±5.60 and 0.40±0.69 respectively, all of which are significantly lower than 97.97±3.17, 83.15±19.14 and 7.35±4.81 in dac-VMAT; the P values were all less than 0.001. There were no significant differences in other outcomes. For patients of postoperative radiotherapy for penile cancer, compared with dac-VMAT, the testicular dose can be significantly reduced by sapf-VMAT, and the dose received is lower than the dose threshold that causes functional impairment. This suggests that patients can preserve fertility without the need for gonadal occlusion or pre-radiation sperm banking.

Key words: linear accelerators, penile cancer, testicular dose, jaw lock

中图分类号:

R144

王宇, 许德颖, 刘云峰, 于亮. 分弧分野容积旋转调强放疗(VMAT):一种睾丸保护性的阴茎癌放疗技术[J]. 辐射防护, 2025, 45(4): 403-409.

WANG Yu, XU Deying, LIU Yunfeng, YU Liang. Split-arc partial-field VMAT: A testicle-protective radiotherapy technique for penile cancer[J]. RADIATION PROTECTION, 2025, 45(4): 403-409.

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