Retrospective dose reconstruction of prostate stereotactic body radiotherapy using cone-beam CT and a log file during VMAT delivery with flattening-filter-free mode
Autor: | Keiichi Nakagawa, Shigeharu Takenaka, Osamu Abe, Wataru Takahashi, Kanabu Nawa, Hideomi Yamashita, Yuichi Watanabe, Akihiro Haga, Toshikazu Imae, Mami Ogita, Takashi Shiraki |
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Rok vydání: | 2020 |
Předmět: |
Male
medicine.medical_treatment Physical Therapy Sports Therapy and Rehabilitation Radiation Dosage Radiosurgery 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Prostate medicine Humans Radiology Nuclear Medicine and imaging Image warping Radiation treatment planning Cone beam ct Aged Retrospective Studies Mathematics Radiation Flattening filter free business.industry Radiotherapy Planning Computer-Assisted Prostatic Neoplasms Isocenter Radiotherapy Dosage General Medicine Cone-Beam Computed Tomography Radiation therapy medicine.anatomical_structure 030220 oncology & carcinogenesis Radiotherapy Intensity-Modulated Nuclear medicine business Stereotactic body radiotherapy |
Zdroj: | Radiological Physics and Technology. 13:238-248 |
ISSN: | 1865-0341 1865-0333 |
Popis: | This study aimed to reconstruct the dose distribution of single fraction of stereotactic body radiotherapy for patients with prostate cancer using cone-beam computed tomography (CBCT) and a log file during volumetric-modulated arc therapy (VMAT) delivery with flattening-filter-free (FFF) mode. Twenty patients with clinically localized prostate cancer were treated with FFF-VMAT, and projection images for in-treatment CBCT (iCBCT) imaging were concomitantly acquired with a log file. A D95 dose of 36.25 Gy in five fractions was prescribed to each planning target volume (PTV) on each treatment planning CT (pCT). Deformed pCT (dCT) was obtained from the iCBCT using a hybrid deformable image registration algorithm. Dose distributions on the dCT were calculated using Pinnacle3 v9.10 by converting the log file data to Pinnacle3 data format using an in-house software. Dose warping was performed by referring to deformation vector fields calculated from pCT and dCT. Reconstructed dose distribution was compared with that of the original plan. Dose differences between the original and reconstructed dose distributions were within 3% at the isocenter and observed in PTV and organ-at-risk (OAR) regions. Differences in OAR regions were relatively larger than those in the PTV, presumably because OARs were more deformed than the PTV. Therefore, our method can be used successfully to reconstruct the dose distributions of one fraction using iCBCT and a log file during FFF-VMAT delivery. |
Databáze: | OpenAIRE |
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