图像引导近距离放射治疗在子宫颈癌中 192Ir 和 60Co 源的比较。

Image-Guided Brachytherapy a Comparison Between 192Ir and 60Co Sources in Carcinoma Uterine Cervix.

机构信息

Department of Radiation Oncology, Regional Cancer Centre, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry 605006, India.

出版信息

Gulf J Oncolog. 2022 Jan;1(38):7-14.

PMID:35156639

Abstract

INTRODUCTION

Combination of external beam radiotherapy (EBRT) and High Dose Rate (HDR) brachytherapy (BT) with concurrent chemotherapy (Cisplatin 40mg/m2/weekly) is the standard treatment of approach for the carcinoma of uterine cervix. In this study for image based HDR brachytherapy of intracavitary both 192Ir and 60Co sources were used for dosimetry and the dose distribution compared between point doses and volume doses as per the recommendation of ICRU89 and GEC-ESTRO on 3D image based planning. The dosimetry and clinical outcome will decide decisionmaking on choice of radionuclide for HDR brachytherapy of cervix in addition to economic reason.

MATERIALS AND METHODS

The Study conducted for 27 patients of cancer cervix stage IIB or IIIB with vaginal involvement limited to the upper third of vagina. All patients underwent concurrent chemoradiation Cisplatin 40mg/m2 weekly throughout EBRT by 3D conformal therapy 46Gy in 23# followed by two fractions of HDR brachytherapy with 9Gy/1Fr. Post implants 3mm slice selection of pelvic CT scans performed with ring applicator in place followed by T2 weighted paracorpal or paracoronal section of MRI imaging. The solid ring applicator (AL13017000) from library used for applicator reconstruction. Initially all plan calculated with TG-43 formalism using 192Ir radionuclide (Varian, GammaMed HDR Plus source) and then modelled 60Co radionuclide (Eckert < Ziegler BEBIG GmbH, Co0. A86) used for dose computation. ICRU89 recommended points and volumes of targets and OARs evaluated and compared.

RESULTS

The study concludes that 60Co based point-A, BICRU and RICRU doses showed a comparable result with that of 192Ir HDR source based dosimetry. The volume based criterion for the target such as GTV, CTVHR, CTVIR for D90, D98, V150%and V200% are all within 5% dose level comparing two sources.

CONCLUSION

60Co a viable alternate to 192Ir by taking into consideration frequency of source exchange and cost reserve with comparable dosimetry.

摘要

简介

外照射放射治疗（EBRT）与高剂量率（HDR）近距离放射治疗（BT）联合顺铂（40mg/m2/周）同期化疗是治疗宫颈癌的标准方法。在这项研究中，对于腔内 HDR 近距离放射治疗，我们使用 192Ir 和 60Co 源进行剂量学测量，并根据 ICRU89 和 GEC-ESTRO 关于基于 3D 图像的计划的建议，对点剂量和体积剂量进行了比较。剂量学和临床结果将决定选择哪种放射性核素用于宫颈癌的 HDR 近距离放射治疗，除了经济原因外。

材料和方法

这项研究共纳入 27 例阴道受累局限于阴道上三分之一的 IIB 期或 IIIB 期宫颈癌患者。所有患者均接受同期放化疗，EBRT 采用 3D 适形治疗，46Gy，共 23 次，随后进行两次 HDR 近距离放射治疗，每次 9Gy/1Fr。植入后，在原位放置环形施源器后，对盆腔 CT 扫描进行 3mm 层厚选择，随后进行 T2 加权矢状或冠状旁 MRI 成像。使用来自库的实心环形施源器（AL13017000）进行施源器重建。最初，所有计划均使用 TG-43 形式主义，使用 192Ir 放射性核素（瓦里安，伽玛医疗 HDR 加源）进行计算，然后使用 60Co 放射性核素（Eckert < Ziegler BEBIG GmbH，Co0. A86）进行剂量计算。评估并比较了 ICRU89 推荐的靶区和 OAR 靶点和体积。