基于三维 CT 图像的宫颈癌两种高剂量率近距离放疗源（钴和铱）治疗计划中靶区和危及器官的积分剂量估算与比较。

Estimation and comparison of integral dose to target and organs at risk in three-dimensional computed tomography image-based treatment planning of carcinoma uterine cervix with two high-dose-rate brachytherapy sources: Co and Ir.

机构信息

Department of Radiotherapy, Gandhi Medical College, Bhopal; Department of Physics, Rabindranath Tagore University, Raisen, Madhya Pradesh, India.

Department of Radiotherapy, Gandhi Medical College, Bhopal, Madhya Pradesh, India.

出版信息

J Cancer Res Ther. 2021 Jan-Mar;17(1):191-197. doi: 10.4103/jcrt.JCRT_199_19.

DOI:10.4103/jcrt.JCRT_199_19

PMID:33723154

Abstract

BACKGROUND

Iridium-192 (Ir) has been a widely accepted radioisotope for high-dose-rate (HDR) brachytherapy. Recently, Cobalt-60 (Co) radioisotope with a longer half-life (5.26 years) has been gaining popularity due to economic and logistical reasons as compared with the traditional Ir.

AIM

This study aimed to evaluate and compare the integral dose (ID) to the target and organs at risk (OARs) with two HDR brachytherapy sources in brachytherapy treatment of carcinoma uterine cervix to find appropriate HDR radioisotopes for clinical benefit.

MATERIALS AND METHODS

This is a retrospective analysis of 52 computed tomography image-based brachytherapy plans of 52 patients who have received intracavitary treatment with Ir HDR source. For each patient plan, one additional set of plan was created using Co source in place of Ir source keeping the same dwell position, and again dose was optimized. The volume and mean dose for target, OARs, and volume structures of 400%, 200%, 150%, 100%, and 50% were recorded for the estimation and comparison of ID.

RESULTS

The mean ID to high-risk clinical target volume was significantly higher by 5.84% in Co plan than that in Ir plan. For OARs, the mean ID to the rectum was significantly higher by 2.60% in Co plan as compared to Ir plan, whereas for bladder and sigmoid colon, it was lower in Co plan than that in Ir plan. The mean ID of central dose volume structures of 400%, 200%, 150%, 100%, and 50% was higher by 12.97%, 9.77%, 8.16%, 6.10%, and 3.22%, respectively, in Co plan than that of Ir plan.

CONCLUSION

The results of our study concluded that Ir HDR radioisotope should be preferred for intracavitary brachytherapy due to its ideal physical characteristics for better clinical outcomes.

摘要

背景

铱-192（Ir）一直是高剂量率（HDR）近距离放射治疗中广泛接受的放射性同位素。最近，钴-60（Co）放射性同位素由于经济和后勤原因，与传统的 Ir 相比，其半衰期（5.26 年）更长，越来越受欢迎。

目的

本研究旨在评估和比较两种 HDR 近距离放射治疗源在宫颈癌近距离放射治疗中的靶区和危及器官（OARs）的积分剂量（ID），以找到适合临床获益的合适 HDR 放射性同位素。

材料和方法

这是对 52 名接受 Ir HDR 源腔内治疗的宫颈癌患者的 52 例基于 CT 图像的近距离放射治疗计划的回顾性分析。对于每位患者的计划，使用 Co 源代替 Ir 源创建了另一组计划，同时保持相同的驻留位置，并再次进行剂量优化。记录靶区、OARs 和 400%、200%、150%、100%和 50%等体积结构的体积和平均剂量，以估算和比较 ID。

结果

Co 计划中高危临床靶区的平均 ID 比 Ir 计划高 5.84%。对于 OARs，Co 计划中直肠的平均 ID 比 Ir 计划高 2.60%，而膀胱和乙状结肠的 ID 则比 Ir 计划低。Co 计划的中央剂量体积结构的平均 ID 比 Ir 计划高 12.97%、9.77%、8.16%、6.10%和 3.22%，分别为 400%、200%、150%、100%和 50%。