Impact of endorectal filling on interobserver variability of MRI based rectal primary tumor delineation.

Autor:	Lo Russo M; Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany., Nachbar M; Section for Biomedical Physics, Department of Radiation Oncology, University Hospital Tübingen, Germany., Barry A; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada., Bhide S; Radiotherapy and Imaging, The Royal Marsden NHS Foundation Trust and the Institute of Cancer Research, London, United Kingdom., Chang A; Hong Kong Sanatorium and Hospital, Hong Kong, China., Hall W; Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA., Intven M; Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands., Marijnen C; Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands., Peters F; Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands., Minsky B; Department of Gastrointestinal Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA., Romesser PB; Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Sarkar R; Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Tan A; GenesisCare, Australia., Boeke S; Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany., Wegener D; Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany., Butzer S; Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany., Boldt J; Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany., Gatidis S; Department of Radiology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany., Nikolaou K; Department of Radiology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany., Thorwarth D; Section for Biomedical Physics, Department of Radiation Oncology, University Hospital Tübingen, Germany.; German Cancer Research Center (DKFZ) Heidelberg and German Consortium for Translational Cancer Research (DKTK), Partner Site Tübingen, Tübingen, Germany., Zips D; Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany.; German Cancer Research Center (DKFZ) Heidelberg and German Consortium for Translational Cancer Research (DKTK), Partner Site Tübingen, Tübingen, Germany., Gani C; Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Germany.; German Cancer Research Center (DKFZ) Heidelberg and German Consortium for Translational Cancer Research (DKTK), Partner Site Tübingen, Tübingen, Germany.
Jazyk:	angličtina
Zdroj:	Clinical and translational radiation oncology [Clin Transl Radiat Oncol] 2022 Sep 21; Vol. 38, pp. 1-5. Date of Electronic Publication: 2022 Sep 21 (Print Publication: 2023).
DOI:	10.1016/j.ctro.2022.09.002
Abstrakt:	Background: Online adaptive MR-guided radiotherapy allows for the reduction of safety margins in dose escalated treatment of rectal tumors. With the use of smaller margins, precise tumor delineation becomes more critical. In the present study we investigated the impact of rectal ultrasound gel filling on interobserver variability in delineation of primary rectal tumor volumes. Methods: Six patients with locally advanced rectal cancer were scanned on a 1.5 T MRI-Linac without (MRI_e) and with application of 100 cc of ultrasound gel transanally (MRI_f). Eight international radiation oncologists expert in the treatment of gastrointestinal cancers delineated the gross tumor volume (GTV) on both MRI scans. MRI_f scans were provided to the participating centers after MRI_e scans had been returned. Interobserver variability was analyzed by either comparing the observers' delineations with a reference delineation (approach 1) and by building all possible pairs between observers (approach 2). Dice Similarity Index (DICE) and 95 % Hausdorff-Distance (95 %HD) were calculated. Results: Rectal ultrasound gel filling was well tolerated by all patients. Overall, interobserver agreement was superior in MRI_f scans based on median DICE (0.81 vs 0.74, p < 0.005 for approach 1 and 0.76 vs 0.64, p < 0.0001 for approach 2) and 95 %HD (6.9 mm vs 4.2 mm for approach 1, p = 0.04 and 8.9 mm vs 6.1 mm, p = 0.04 for approach 2). Delineated median tumor volumes and inter-quartile ranges were 26.99 cc [18.01-50.34 cc] in MRI_e and 44.20 [19.72-61.59 cc] in MRI_f scans respectively, p = 0.012. Conclusions: Although limited by the small number of patients, in this study the application of rectal ultrasound gel resulted in higher interobserver agreement in rectal GTV delineation. The endorectal gel filling might be a useful tool for future dose escalation strategies. Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The Department of Radiation Oncology Tübingen (SB, CG, DT, DZ) receives within the frame of research agreements financial and technical support as well as sponsoring for travels and scientific symposia from: Elekta AB (Stockholm, Sweden), Philips GmbH, Siemens, PTW Freiburg Physikalisch-Technische Werkstätten Dr. Pychlau GmbH. SB: Honoraria for talks by Elekta. AT: Travel and speaking funding by Elekta. from Elekta. PBR is supported by an NIH/NCI grant (K08CA255574), the Memorial Sloan Kettering Cancer Center, an NIH Loan Repayment Program (LRP) award. PBR and RS are supported in part by a National Institutes of Health/National Cancer Institute (NIH/NCI) Memorial Sloan Kettering Cancer Center (MSK) Support Grant (P30 CA008748). (© 2022 The Author(s).)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu