Comparison of 18F-FET-PET- and MRI-based target definition for re-irradiation treatment of recurrent diffuse glioma

IF 2.7 3区医学 Q3 ONCOLOGY Clinical and Translational Radiation Oncology Pub Date : 2025-02-11 DOI:10.1016/j.ctro.2025.100931

Albert Everard , Daniel Versnel , Veerle Ruijters , Nelleke Tolboom , Marielle Philippens , Tom Snijders , Joost Verhoeff , Szabolcs David , Casper Beijst

{"title":"Comparison of 18F-FET-PET- and MRI-based target definition for re-irradiation treatment of recurrent diffuse glioma","authors":"Albert Everard , Daniel Versnel , Veerle Ruijters , Nelleke Tolboom , Marielle Philippens , Tom Snijders , Joost Verhoeff , Szabolcs David , Casper Beijst","doi":"10.1016/j.ctro.2025.100931","DOIUrl":null,"url":null,"abstract":"<div><h3>Background and purpose</h3><div>The target area definition for re-irradiation of recurrent glioma typically relies on T1-weighted gadolinium-enhanced MRI (T1Gd), but T1Gd fails to capture glioma infiltration. While T2 FLAIR and CTV margins can address this limitation, their extend in re-irradiation remains debated to minimize toxicity. In contrast, <sup>18</sup>F-FET-PET imaging can better visualize infiltrative components, improving target definition. This study investigates the role of <sup>18</sup>F-FET-PET in target definition by analyzing shape differences and gray-white matter tissue composition.</div></div><div><h3>Material and methods</h3><div>Retrospective data from 36 patients with recurrent glioma were used. These patients underwent <sup>18</sup>F-FET-PET, on which Biological Tumor Volume (BTV<sub>PET</sub>) was delineated, and T1Gd, on which Gross Tumor Volume (GTV<sub>MRI</sub>) and Clinical tumor volume (CTV<sub>MRI</sub>) were delineated. Lesion volume, shape (Hausdorff distance (HD) and Center of Mass Distance (CoM-D)), tissue composition and re-recurrence volume were compared between the delineations.</div></div><div><h3>Results</h3><div>BTV<sub>PET</sub> and the non-overlapping BTV<sub>PET</sub>-GTV<sub>MRI</sub> volumes were significantly larger than GTV<sub>MRI</sub> and non-overlapping GTV<sub>MRI</sub>-BTV<sub>PET</sub> (P < 0.001), but significantly smaller than the CTV<sub>MRI</sub> (P < 0.001). The median HD and CoM-D were 19 mm and 6 mm. A correlation was found between the white matter (WM) ratio in GTV<sub>MRI</sub> and WM in non-overlapping BTV<sub>PET</sub> (slope = 0.36, R<sup>2</sup> = 0.36;P < 0.001) and a correlation with gray matter (GM) in non-overlapping BTV<sub>PET</sub> (slope = -0.15, R<sup>2</sup> = 0.11;P < 0.05). Recurrence after reirradiation was significantly higher within BTV<sub>PET</sub> than GTV<sub>MRI</sub> (P < 0.001). The ratio of the GTV<sub>MRI</sub> which recurred was significantly higher than the non-overlapping BTV<sub>PET</sub> (P < 0.001).</div></div><div><h3>Conclusion</h3><div>Our results suggest that <sup>18</sup>F-FET-PET reveals a more complete extent of glioma’s infiltration, suggesting that the current practice of using isotropic CTV margins around the T1Gd-GTV should be reconsidered in favor of anisotropic CTV based on <sup>18</sup>F-FET-PET.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"52 ","pages":"Article 100931"},"PeriodicalIF":2.7000,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Clinical and Translational Radiation Oncology","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2405630825000217","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ONCOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Background and purpose

The target area definition for re-irradiation of recurrent glioma typically relies on T1-weighted gadolinium-enhanced MRI (T1Gd), but T1Gd fails to capture glioma infiltration. While T2 FLAIR and CTV margins can address this limitation, their extend in re-irradiation remains debated to minimize toxicity. In contrast, ¹⁸F-FET-PET imaging can better visualize infiltrative components, improving target definition. This study investigates the role of ¹⁸F-FET-PET in target definition by analyzing shape differences and gray-white matter tissue composition.

Material and methods

Retrospective data from 36 patients with recurrent glioma were used. These patients underwent ¹⁸F-FET-PET, on which Biological Tumor Volume (BTV_PET) was delineated, and T1Gd, on which Gross Tumor Volume (GTV_MRI) and Clinical tumor volume (CTV_MRI) were delineated. Lesion volume, shape (Hausdorff distance (HD) and Center of Mass Distance (CoM-D)), tissue composition and re-recurrence volume were compared between the delineations.

Results

BTV_PET and the non-overlapping BTV_PET-GTV_MRI volumes were significantly larger than GTV_MRI and non-overlapping GTV_MRI-BTV_PET (P < 0.001), but significantly smaller than the CTV_MRI (P < 0.001). The median HD and CoM-D were 19 mm and 6 mm. A correlation was found between the white matter (WM) ratio in GTV_MRI and WM in non-overlapping BTV_PET (slope = 0.36, R² = 0.36;P < 0.001) and a correlation with gray matter (GM) in non-overlapping BTV_PET (slope = -0.15, R² = 0.11;P < 0.05). Recurrence after reirradiation was significantly higher within BTV_PET than GTV_MRI (P < 0.001). The ratio of the GTV_MRI which recurred was significantly higher than the non-overlapping BTV_PET (P < 0.001).

Conclusion

Our results suggest that ¹⁸F-FET-PET reveals a more complete extent of glioma’s infiltration, suggesting that the current practice of using isotropic CTV margins around the T1Gd-GTV should be reconsidered in favor of anisotropic CTV based on ¹⁸F-FET-PET.

查看原文