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Clinical Implementation of a Model-Based In Vivo Dose Verification System for Stereotactic Body Radiation Therapy-Volumetric Modulated Arc Therapy Treatments Using the Electronic Portal Imaging Device.
Clinical Implementation of a Model-Based In Vivo Dose Verification System for Stereotactic Body Radiation Therapy-Volumetric Modulated Arc Therapy Treatments Using the Electronic Portal Imaging Device.
- Source :
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International Journal of Radiation Oncology, Biology, Physics . Apr2017, Vol. 97 Issue 5, p1077-1084. 8p. - Publication Year :
- 2017
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Abstract
- <bold>Purpose: </bold>To report findings from an in vivo dosimetry program implemented for all stereotactic body radiation therapy patients over a 31-month period and discuss the value and challenges of utilizing in vivo electronic portal imaging device (EPID) dosimetry clinically.<bold>Methods and Materials: </bold>From December 2013 to July 2016, 117 stereotactic body radiation therapy-volumetric modulated arc therapy patients (100 lung, 15 spine, and 2 liver) underwent 602 EPID-based in vivo dose verification events. A developed model-based dose reconstruction algorithm calculates the 3-dimensional dose distribution to the patient by back-projecting the primary fluence measured by the EPID during treatment. The EPID frame-averaging was optimized in June 2015. For each treatment, a 3%/3-mm γ comparison between our EPID-derived dose and the Eclipse AcurosXB-predicted dose to the planning target volume (PTV) and the ≥20% isodose volume were performed. Alert levels were defined as γ pass rates <85% (lung and liver) and <80% (spine). Investigations were carried out for all fractions exceeding the alert level and were classified as follows: EPID-related, algorithmic, patient setup, anatomic change, or unknown/unidentified errors.<bold>Results: </bold>The percentages of fractions exceeding the alert levels were 22.6% for lung before frame-average optimization and 8.0% for lung, 20.0% for spine, and 10.0% for liver after frame-average optimization. Overall, mean (± standard deviation) planning target volume γ pass rates were 90.7% ± 9.2%, 87.0% ± 9.3%, and 91.2% ± 3.4% for the lung, spine, and liver patients, respectively.<bold>Conclusions: </bold>Results from the clinical implementation of our model-based in vivo dose verification method using on-treatment EPID images is reported. The method is demonstrated to be valuable for routine clinical use for verifying delivered dose as well as for detecting errors. [ABSTRACT FROM AUTHOR]
- Subjects :
- *STEREOTACTIC radiotherapy
*VOLUMETRIC-modulated arc therapy
*RADIATION dosimetry
*ISODOSE curves
*LUNG physiology
*RADIOSURGERY
*TUMOR diagnosis
*RADIATION therapy equipment
*BIOLOGICAL models
*CLINICAL trials
*COMPARATIVE studies
*COMPUTER simulation
*DIAGNOSTIC imaging
*LONGITUDINAL method
*RESEARCH methodology
*MEDICAL cooperation
*COMPUTERS in medicine
*RADIATION doses
*RADIATION measurements
*RADIOTHERAPY
*RESEARCH
*TUMORS
*PRODUCT design
*EVALUATION research
*MEDICAL equipment reliability
*EQUIPMENT & supplies
RESEARCH evaluation
Subjects
Details
- Language :
- English
- ISSN :
- 03603016
- Volume :
- 97
- Issue :
- 5
- Database :
- Academic Search Index
- Journal :
- International Journal of Radiation Oncology, Biology, Physics
- Publication Type :
- Academic Journal
- Accession number :
- 121781304
- Full Text :
- https://doi.org/10.1016/j.ijrobp.2017.01.227