A novel system for commissioning brachytherapy applicators
Autor: | Gabriel P. Fonseca, Michiel R Van den Bosch, Frank Verhaegen, R. Voncken, Mark Podesta |
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Přispěvatelé: | RS: GROW - R3 - Innovative Cancer Diagnostics & Therapy, Promovendi ODB, Radiotherapie |
Jazyk: | angličtina |
Rok vydání: | 2017 |
Předmět: |
Photon
Catheters Channel (digital image) Computer science medicine.medical_treatment Brachytherapy brachytherapy HDR Radiation UNCERTAINTIES 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Optics Position (vector) Neoplasms medicine Dosimetry Humans time-resolve commissioning Radiology Nuclear Medicine and imaging RECONSTRUCTION Irradiation Radiological and Ultrasound Technology business.industry Phantoms Imaging Radiotherapy Planning Computer-Assisted Reproducibility of Results imaging panel Radiotherapy Dosage DOSIMETRY PORTAL IMAGING DEVICE 030220 oncology & carcinogenesis Dose rate business Telecommunications Software |
Zdroj: | Physics in Medicine and Biology, 62(21), 8360-8375. IOP Publishing Ltd. |
ISSN: | 1361-6560 0031-9155 |
Popis: | A novel system was developed to improve commissioning and quality assurance of brachytherapy applicators used in high dose rate (HDR). It employs an imaging panel to create reference images and to measure dwell times and dwell positions. As an example: two ring applicators of the same model were evaluated. An applicator was placed on the surface of an imaging panel and a HDR 192Ir source was positioned in an imaging channel above the panel to generate an image of the applicator, using the gamma photons of the brachytherapy source. The applicator projection image was overlaid with the images acquired by capturing the gamma photons emitted by the source dwelling inside the applicator. We verified 0.1, 0.2, 0.5 and 1.0 cm interdwell distances for different offsets, applicator inclinations and transfer tube curvatures. The data analysis was performed using in-house developed software capable of processing the data in real time, defining catheters and creating movies recording the irradiation procedure. One applicator showed up to 0.3 cm difference from the expected position for a specific dwell position. The problem appeared intermittently. The standard deviations of the remaining dwell positions (40 measurements) were less than 0.05 cm. The second ring applicator had a similar reproducibility with absolute coordinate differences from expected values ranging from -0.10 up to 0.18 cm. The curvature of the transfer tube can lead to differences larger than 0.1 cm whilst the inclination of the applicator showed a negligible effect. The proposed method allows the verification of all steps of the irradiation, providing accurate information about dwell positions and dwell times. It allows the verification of small interdwell positions (⩽0.1 cm) and reduces measurement time. In addition, no additional radiation source is necessary since the HDR 192Ir source is used to generate an image of the applicator. |
Databáze: | OpenAIRE |
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