Positioning error and expanding margins of planning target volume with kilovoltage cone beam computed tomography for prostate cancer radiotherapy

Autor:	Yi-Qun Liu, Gang Wang, Yinxiang Hu, Hongmin Dong, Wenling Wang
Rok vydání:	2018
Předmět:	Kilovoltage Cone Beam Computed Tomography Supine position medicine.medical_treatment Planning target volume positioning error OncoTargets and Therapy 030218 nuclear medicine & medical imaging 03 medical and health sciences Prostate cancer 0302 clinical medicine medicine Pharmacology (medical) Original Research Image-guided radiation therapy business.industry Significant difference image-guided radiotherapy Radical radiotherapy prostate cancer medicine.disease Radiation therapy kilovoltage cone beam CT planning target volume Oncology 030220 oncology & carcinogenesis business Nuclear medicine
Zdroj:	OncoTargets and therapy
ISSN:	1178-6930
DOI:	10.2147/ott.s152915
Popis:	Gang Wang, Wen-Ling Wang, Yi-Qun Liu, Hong-Min Dong, Yin-Xiang Hu Department of Abdominal Oncology, Affiliated Hospital of Guizhou Medical University, Guizhou Cancer Hospital, Guiyang, People’s Republic of China Objective: In this study, prostate cancer patients were treated with image-guided radiotherapy (IGRT). The translational positioning errors were discussed to provide the basis for determining margins of the planning target volume (PTV). Methods: Thirty prostate cancer patients were treated with radical radiotherapy using the IGRT system. Patients were placed in the supine position and underwent kilovoltage cone beam computed tomography (KVCBCT) scans before radiotherapy. A total of 447 images were acquired. The translational positioning errors were obtained in three linear directions which were X (left-to-right), Y (superior-to-inferior) and Z (anterior-to-posterior) axes (denoted as Lx, Ly and Lz) through the contrast between images adjusted with gray and manual registrations and the planning CT images. Rotational errors were denoted as Rx, Ry and Rz. Results: Uncorrected translational errors Lx, Ly and Lz in the 251 positioning images were all higher than those after correction, and the differences were all statistically significant (P=0.000, 0.037 and 0.004, respectively). For rotational errors Rx, Ry and Rz, only Rx had a significant difference before and after correction (P=0.044). Before correction, PTV margins in the X, Y and Z directions were 0.61, 0.78 and 0.41cm, respectively; after correction, these were 0.17, 0.12 and 0.17cm, respectively. Conclusion: KVCBCT can be applied to measure positioning errors in prostate cancer radiotherapy and correct these errors in real time through the 6° robotic patient positioning system, in order to improve patient positioning accuracy. The application of IGRT with KVCBCT may reduce PTV margins. Keywords: prostate cancer, image-guided radiotherapy, kilovoltage cone beam CT, positioning error, planning target volume
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c047668144d34501fdbfa5fb0caae160 https://doi.org/10.2147/ott.s152915 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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