Verification imaging in prostate MR-only radiotherapy: Are fiducial markers necessary?

IF 2.5 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Radiography Pub Date : 2025-01-01 DOI:10.1016/j.radi.2024.12.010

R.L. Brooks-Pearson , R.A. Pearson , L. O'Connor , K. Skehan , D. Redding , E. Wilkins , S. Taylor , J.J. Wyatt

{"title":"Verification imaging in prostate MR-only radiotherapy: Are fiducial markers necessary?","authors":"R.L. Brooks-Pearson , R.A. Pearson , L. O'Connor , K. Skehan , D. Redding , E. Wilkins , S. Taylor , J.J. Wyatt","doi":"10.1016/j.radi.2024.12.010","DOIUrl":null,"url":null,"abstract":"<div><h3>Purpose/objective</h3><div>MR-only radiotherapy planning exploits the benefits of MRI soft-tissue delineation, whilst negating the registration inaccuracies caused by MRI CT fusion. Fiducial markers have conventionally been used in prostate radiotherapy to reduce on-treatment image matching variability. However, this is an invasive procedure for the patient, and presents technical difficulties in an MR-only pathway as fiducial markers are difficult to visualise on MRI. This study compares MR-CBCT soft-tissue matching to fiducial matching in an MR-only prostate pathway.</div></div><div><h3>Material/methods</h3><div>Four therapeutic radiographers reviewed first fraction CBCTs for 25 patients. The CBCT was compared to the planning MRI, a T2 weighted sequence for the soft-tissue match and compared to a T1 weighted MRI sequence for the fiducial match. Inter-observer variability was quantified using the inter-observer error and 95 % limits of agreement from a modified Bland-Altman analysis. Accuracy of the soft-tissue match was quantified by calculating the difference from the fiducial match.</div></div><div><h3>Results</h3><div>Limits of agreement on the MR soft-tissue match were 1.5 mm, 4.0 mm, 3.5 mm and fiducial match 2.5 mm, 3.6 mm, 2.5 mm (lateral, longitudinal, vertical). Inter-observer error (±standard deviation) on the MR soft-tissue match were 0.6(±0.5) mm, 1.8(±1.1) mm, 1.7(±0.7) mm and fiducial match 0.7(±1.1) mm, 1.1(±1.5) mm, 0.8(±0.7) mm (lateral, longitudinal, vertical). The difference of the soft-tissue match from the fiducial match was 0.3(±1.1) mm, −0.1(±2.7) mm, 0.1(±1.9) mm (lateral, longitudinal, vertical).</div></div><div><h3>Conclusion</h3><div>MR-CBCT soft-tissue matching has similar accuracy and inter-observer variability as fiducial matching. This suggests fiducial markers are not necessary in an MR-only prostate radiotherapy pathway.</div></div><div><h3>Implications for practice</h3><div>MR-only prostate radiotherapy does not require fiducial markers since MR-CBCT soft tissue matching can be used for IGRT.</div></div>","PeriodicalId":47416,"journal":{"name":"Radiography","volume":"31 1","pages":"Pages 333-340"},"PeriodicalIF":2.5000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Radiography","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1078817424003717","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}

引用次数: 0

Abstract

Purpose/objective

MR-only radiotherapy planning exploits the benefits of MRI soft-tissue delineation, whilst negating the registration inaccuracies caused by MRI CT fusion. Fiducial markers have conventionally been used in prostate radiotherapy to reduce on-treatment image matching variability. However, this is an invasive procedure for the patient, and presents technical difficulties in an MR-only pathway as fiducial markers are difficult to visualise on MRI. This study compares MR-CBCT soft-tissue matching to fiducial matching in an MR-only prostate pathway.

Material/methods

Four therapeutic radiographers reviewed first fraction CBCTs for 25 patients. The CBCT was compared to the planning MRI, a T2 weighted sequence for the soft-tissue match and compared to a T1 weighted MRI sequence for the fiducial match. Inter-observer variability was quantified using the inter-observer error and 95 % limits of agreement from a modified Bland-Altman analysis. Accuracy of the soft-tissue match was quantified by calculating the difference from the fiducial match.

Results

Limits of agreement on the MR soft-tissue match were 1.5 mm, 4.0 mm, 3.5 mm and fiducial match 2.5 mm, 3.6 mm, 2.5 mm (lateral, longitudinal, vertical). Inter-observer error (±standard deviation) on the MR soft-tissue match were 0.6(±0.5) mm, 1.8(±1.1) mm, 1.7(±0.7) mm and fiducial match 0.7(±1.1) mm, 1.1(±1.5) mm, 0.8(±0.7) mm (lateral, longitudinal, vertical). The difference of the soft-tissue match from the fiducial match was 0.3(±1.1) mm, −0.1(±2.7) mm, 0.1(±1.9) mm (lateral, longitudinal, vertical).

Conclusion

MR-CBCT soft-tissue matching has similar accuracy and inter-observer variability as fiducial matching. This suggests fiducial markers are not necessary in an MR-only prostate radiotherapy pathway.

Implications for practice

MR-only prostate radiotherapy does not require fiducial markers since MR-CBCT soft tissue matching can be used for IGRT.

查看原文本刊更多论文

前列腺磁共振放射治疗的验证成像：是否需要基准标记？

目的/目的：仅磁共振放射治疗计划利用MRI软组织描绘的优势，同时消除MRI CT融合引起的配准不准确。基准标记通常用于前列腺放射治疗，以减少治疗时图像匹配的可变性。然而，这对患者来说是一种侵入性手术，并且在MRI上很难看到基础标记物，因此在MRI上仅通过mr通道存在技术困难。本研究比较了MR-CBCT软组织匹配和MR-only前列腺通路的基准匹配。材料/方法：四名放射治疗技师回顾了25名患者的一段cbct。将CBCT与计划MRI、软组织匹配的T2加权序列和基准匹配的T1加权MRI序列进行比较。采用改进的Bland-Altman分析的观察者间误差和95%的一致性限制来量化观察者间变异性。通过计算与基准匹配的差值来量化软组织匹配的准确性。结果：MR软组织匹配的一致限为1.5 mm、4.0 mm、3.5 mm，基准匹配的一致限为2.5 mm、3.6 mm、2.5 mm（横向、纵向、纵向）。mri软组织匹配的观察者间误差（±标准差）分别为0.6（±0.5）mm、1.8（±1.1）mm、1.7（±0.7）mm，基准匹配分别为0.7（±1.1）mm、1.1（±1.5）mm、0.8（±0.7）mm（横向、纵向、纵向）。软组织匹配与基准匹配的差值分别为0.3（±1.1）mm、-0.1（±2.7）mm、0.1（±1.9）mm（横向、纵向、纵向）。结论：MR-CBCT软组织匹配与基准匹配具有相似的准确性和观察者间变异性。这表明在仅磁共振前列腺放射治疗途径中，基准标记物是不必要的。实践意义：磁共振前列腺放疗不需要基准标记物，因为磁共振cbct软组织匹配可用于IGRT。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Radiography RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING-

CiteScore

4.70

自引率

34.60%

发文量

169

审稿时长

63 days

期刊介绍： Radiography is an International, English language, peer-reviewed journal of diagnostic imaging and radiation therapy. Radiography is the official professional journal of the College of Radiographers and is published quarterly. Radiography aims to publish the highest quality material, both clinical and scientific, on all aspects of diagnostic imaging and radiation therapy and oncology.