Chen Kaiqiang, Zhuo Yanhong, Li Zirong, Bai Penggang, Chen Jihong, Lin Yibin, Liu Jing, Li Li, Yang Yang, Pan Junping, Song Yanwen, Wu Tianming, Zhang Xiuchun, Xu Qin
Fujian Provincial Cancer Hospital, Jinan District, Fujian Province Fuzhou, 350014 Fuzhou City, China.
Zhangzhou Municipal Hospital of Fujian Province and Zhangzhou Affiliated Hospital of Fujian Medical University, Zhangzhou, Fujian, China.
J Contemp Brachytherapy. 2024 Jun;16(3):219-224. doi: 10.5114/jcb.2024.141169. Epub 2024 Jun 28.
To compare the dosimetric differences in vaginal brachytherapy (VBT) using single-channel vaginal cylinder (SCVC) and free-hand interstitial needles (FIN).
Twenty-two women with malignant gynecologic tumors were prospectively treated with image-guided high-dose-rate (HDR) brachytherapy after surgery and external beam radiation therapy (EBRT). All HDR treatments were delivered using FIN implant technique. For dosimetric comparison purposes only, SCVCs of 2.5 cm diameter were placed in all patients. No sources were dwelled in cylinder applicator during clinical treatment. CT-guided brachytherapy treatment planning was performed according to GEC-ESTRO guidelines, with high-risk clinical target volume (HR-CTV) delineated based on clinical exams and MRI T2 sequences. Dose-volume parameters to HR-CTV and surrounding organs at risk (OARs) from interstitial plans were compared with those achieved from cylinder plans.
Compared with SCVC group, FIN group showed the same HR-CTV coverage. FIN group had higher V and V ( < 0.05). In addition, it had lower HI ( < 0.05). However, doses to the rectum D (538.5 ±119.8 cGy), D (415.4 ±73.3 cGy), D (355.7 ±66.6 cGy), and D (162.8 ±43.7 cGy) as well as the bladder D (516.1 ±85.2 cGy) and D (392.9 ±59.8 cGy) were lower in FIN group than in SCVC group ( < 0.05).
FIN technique can be a dosimetrically preferable alternative to the commonly used SCVC for HDR VBT boost in patients with gynecological malignancies. It provides adequate coverage of target volumes, with minimal radiation dose to surrounding organs at risk.
比较使用单通道阴道柱状施源器（SCVC）和徒手组织间插植针（FIN）进行阴道近距离放疗（VBT）时的剂量学差异。
22例患有妇科恶性肿瘤的女性患者在手术后接受了图像引导下的高剂量率（HDR）近距离放疗，并接受了外照射放疗（EBRT）。所有HDR治疗均采用FIN植入技术。仅为剂量学比较目的，为所有患者放置了直径2.5 cm的SCVC。临床治疗期间施源器内未驻留放射源。根据GEC-ESTRO指南进行CT引导下的近距离放疗治疗计划，基于临床检查和MRI T2序列勾画高危临床靶区（HR-CTV）。将组织间插植计划中HR-CTV和周围危及器官（OARs）的剂量体积参数与柱状施源器计划所获得的参数进行比较。
与SCVC组相比，FIN组的HR-CTV覆盖情况相同。FIN组的V和V更高（<0.05）。此外，其均匀性指数（HI）更低（<0.05）。然而，FIN组直肠的D（538.5±119.8 cGy）、D（415.4±73.3 cGy）、D（355.7±66.6 cGy）和D（162.8±43.7 cGy）以及膀胱的D（516.1±85.2 cGy）和D（392.9±59.8 cGy）均低于SCVC组（<0.05）。
对于妇科恶性肿瘤患者的HDR VBT增量治疗，FIN技术在剂量学上可能是比常用的SCVC更优的选择。它能充分覆盖靶区，同时对周围危及器官的辐射剂量最小。
