Yukinori Matsuo1, Dirk Verellen2, Kenneth Poels2, Nobutaka Mukumoto3, Tom Depuydt4, Mami Akimoto3, Mitsuhiro Nakamura3, Nami Ueki3, Benedikt Engels2, Christine Collen2, Masaki Kokubo5, Masahiro Hiraoka3, Mark de Ridder2. 1. Radiotherapy Department, UZ Brussel, Vrije Universiteit Brussel, Belgium; Department of Radiation Oncology and Image-applied Therapy, Kyoto University, Japan. Electronic address: ymatsuo@kuhp.kyoto-u.ac.jp. 2. Radiotherapy Department, UZ Brussel, Vrije Universiteit Brussel, Belgium. 3. Department of Radiation Oncology and Image-applied Therapy, Kyoto University, Japan. 4. Radiotherapy Department, UZ Brussel, Vrije Universiteit Brussel, Belgium; Department of Radiation Oncology, University Hospitals Leuven, Belgium. 5. Division of Radiation Oncology, Institute of Biomedical Research and Innovation; Department of Radiation Oncology, Kobe City Medical Center General Hospital, Japan.
Abstract
PURPOSE: This study aimed to compare procedures for dynamic tumour tracking (DTT) using a gimbal-mounted linac between centres in Japan (KU-IBRI) and Belgium (UZB), to quantify tracking error (TE), and to estimate tumour-fiducial uncertainties and PTV margins. METHODS: Twenty-two patients were evaluated. TE was divided into components originating from the patient, fraction, segment, and residuals. RESULTS: KU-IBRI applied DTT to lung cancer, while UZB treated both the lung and liver. Patients from UZB were younger and had a higher body mass index. DTT procedures differed in the use of body fixation, correction for set-up error, type of fiducial markers, and goodness of fit of correlation model. TE was larger at UZB in the intra-fraction components, whereas the tumour-fiducial uncertainties were estimated to be larger at KU-IBRI. These results ultimately led to similar PTV margins at both centres (2.1, 4.2, and 2.6 mm for KU-IBRI; 2.4, 3.6, and 2.0 mm for UZB in LR, AP, and SI, respectively, for 99% coverage of patients). CONCLUSION: Several differences in procedures and patient characteristics were observed that affected TE and tumour-fiducial uncertainties. This analysis confirmed similar accuracy in DTT delivery and adequate PTV margins in the different centres based on their local specific workflows.
PURPOSE: This study aimed to compare procedures for dynamic tumour tracking (DTT) using a gimbal-mounted linac between centres in Japan (KU-IBRI) and Belgium (UZB), to quantify tracking error (TE), and to estimate tumour-fiducial uncertainties and PTV margins. METHODS: Twenty-two patients were evaluated. TE was divided into components originating from the patient, fraction, segment, and residuals. RESULTS: KU-IBRI applied DTT to lung cancer, while UZB treated both the lung and liver. Patients from UZB were younger and had a higher body mass index. DTT procedures differed in the use of body fixation, correction for set-up error, type of fiducial markers, and goodness of fit of correlation model. TE was larger at UZB in the intra-fraction components, whereas the tumour-fiducial uncertainties were estimated to be larger at KU-IBRI. These results ultimately led to similar PTV margins at both centres (2.1, 4.2, and 2.6 mm for KU-IBRI; 2.4, 3.6, and 2.0 mm for UZB in LR, AP, and SI, respectively, for 99% coverage of patients). CONCLUSION: Several differences in procedures and patient characteristics were observed that affected TE and tumour-fiducial uncertainties. This analysis confirmed similar accuracy in DTT delivery and adequate PTV margins in the different centres based on their local specific workflows.
Authors: Ingo Gulyas; Petra Trnkova; Barbara Knäusl; Joachim Widder; Dietmar Georg; Andreas Renner Journal: Med Phys Date: 2022-06-06 Impact factor: 4.506