High-Risk Clinical Target Volume Deformation in MRI-Guided HDR Brachytherapy for Cervical Cancer

IF 2.3 4区医学 Q1 MEDICINE, GENERAL & INTERNAL

Journal of the National Medical Association Pub Date : 2025-09-01 DOI:10.1016/j.jnma.2025.08.074

Ulysses G. Gardner MD, MBA, Gayoung Kim PhD, Khadija Sheikh PhD, Majd Antaki ME, Ehud Schmidt PhD, Michael Roumeliotis PhD, Junghoon Lee PhD, Akila Viswanathan MD

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引用次数: 0

Abstract

Purpose

This study quantitatively evaluates high-risk clinical target volume (HR-CTV) deformation using magnetic resonance imaging (MRI) done before and after applicator placement, in order to consider the reliability of pre-brachytherapy MR imaging to reflect tumor volume and shape at the time of treatment.

Materials & Methods

A retrospective analysis of 54 cervical cancer patients who underwent MRI-guided HDR brachytherapy between January 2019 and December 2023 was conducted under an institutional review board–approved protocol. All patients received tandem/ring or tandem/ring/interstitial applicator insertions and underwent same-day pre- and post-applicator placement T2-weighted MRI in a dedicated 1.5T MR simulator (Siemens Sola). HR-CTVs were segmented, and quantitative shape descriptors—including elongation, flatness and roundness—were analyzed using 3D Slicer (v5.6.2). Paired Student’s t-tests (α < 0.05) were performed to assess statistically significant changes in tumor morphology.

Results

Analysis revealed a significant increase in MR HR-CTV volume from 53.1 cm³ pre-insertion to 62.8 cm³ post-insertion (p=0.048), with a Pearson correlation coefficient (r=0.72) indicating a strong volumetric relationship. However, shape descriptor analysis demonstrated statistically significant geometric changes, including differences in roundness (p=0.002), flatness (p=0.047), and elongation (p=0.002), suggesting that applicator placement induces substantial tumor deformation beyond simple volumetric expansion.

Conclusion

This study provides the first quantitative evidence that pre-brachytherapy MRI alone may not adequately represent HR-CTV geometry at the time of treatment. The significant post-insertion deformation underscores the critical need for post-applicator insertion MRI to ensure accurate target delineation and optimal dose delivery. These findings challenge conventional imaging workflows and highlight the necessity of adaptive treatment planning strategies in MRI-guided brachytherapy to improve clinical outcomes for cervical cancer patients.

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mri引导下HDR近距离治疗宫颈癌的高危靶体积变形

目的：本研究利用磁共振成像（MRI）技术，定量评估贴片放置前后的高危临床靶体积（HR-CTV）变形，以考虑近距离治疗前MR成像在治疗时反映肿瘤体积和形状的可靠性。材料和方法根据机构审查委员会批准的方案，对2019年1月至2023年12月期间接受mri引导HDR近距离治疗的54例宫颈癌患者进行回顾性分析。所有患者均接受串联/环形或串联/环形/间质放置器插入，并在专用的1.5T MR模拟器（西门子Sola）中进行当日放置前后的t2加权MRI检查。对hr - ctv进行分割，并使用3D切片器（v5.6.2）对定量形状描述符（包括伸长率、平整度和圆度）进行分析。采用配对学生t检验（α < 0.05）评估肿瘤形态变化的统计学意义。结果分析显示，MR HR-CTV体积从插入前的53.1 cm³显著增加到插入后的62.8 cm³（p=0.048）， Pearson相关系数（r=0.72）表明体积关系很强。然而，形状描述符分析显示了统计学上显著的几何变化，包括圆度（p=0.002）、平面度（p=0.047）和伸长率（p=0.002）的差异，这表明涂抹器的放置导致了大量的肿瘤变形，而不仅仅是简单的体积扩张。本研究提供了第一个定量证据，证明仅靠近距离治疗前的MRI可能不能充分代表治疗时的HR-CTV几何形状。明显的植入后变形强调了对植入后MRI的迫切需要，以确保准确的目标描绘和最佳剂量递送。这些发现挑战了传统的成像工作流程，并强调了在mri引导下近距离放疗中适应性治疗计划策略的必要性，以改善宫颈癌患者的临床结果。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of the National Medical Association 医学-医学：内科

CiteScore

4.80

自引率

3.00%

发文量

139

审稿时长

98 days

期刊介绍： Journal of the National Medical Association, the official journal of the National Medical Association, is a peer-reviewed publication whose purpose is to address medical care disparities of persons of African descent. The Journal of the National Medical Association is focused on specialized clinical research activities related to the health problems of African Americans and other minority groups. Special emphasis is placed on the application of medical science to improve the healthcare of underserved populations both in the United States and abroad. The Journal has the following objectives: (1) to expand the base of original peer-reviewed literature and the quality of that research on the topic of minority health; (2) to provide greater dissemination of this research; (3) to offer appropriate and timely recognition of the significant contributions of physicians who serve these populations; and (4) to promote engagement by member and non-member physicians in the overall goals and objectives of the National Medical Association.