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Patient‐specific quality assurance using machine log files analysis for stereotactic body radiation therapy (SBRT)
- Source :
- Journal of Applied Clinical Medical Physics
- Publication Year :
- 2020
- Publisher :
- John Wiley and Sons Inc., 2020.
-
Abstract
- An in‐house trajectory log analysis program (LOGQA) was developed to evaluate the delivery accuracy of volumetric‐modulated arc therapy (VMAT) for stereotactic body radiation therapy (SBRT). Methods have been established in LOGQA to provide analysis on dose indices, gantry angles, and multi‐leaf collimator (MLC) positions. Between March 2019 and May 2020, 120 VMAT SBRT plans of various treatment sites using flattening filter‐free (FFF) mode were evaluated using both LOGQA and phantom measurements. Gantry angles, dose indices, and MLC positions were extracted from log and compared with each plan. Integrated transient fluence map (ITFM) was reconstructed from log to examine the deviation of delivered fluence against the planned one. Average correlation coefficient of dose index versus gantry angle and ITFM for all patients were 1.0000, indicating that the delivered beam parameters were in good agreement with planned values. Maximum deviation of gantry angles and monitor units (MU) of all patients were less than 0.2 degree and 0.03 % respectively. Regarding MLC positions, maximum and root‐mean‐square (RMS) deviations from planned values were less than 0.6 mm and 0.3 mm respectively, indicating that MLC positions during delivery followed planned values in precise manner. Results of LOGQA were consistent with measurement, where all gamma‐index passing rates were larger than 95 %, with 2 %/2 mm criteria. Three types of intentional errors were introduced to patient plan for software validation. LOGQA was found to recognize the introduced errors of MLC positions, gantry angles, and dose indices with magnitudes of 1 mm, 1 degree, and 5 %, respectively, which were masked in phantom measurement. LOGQA was demonstrated to have the potential to reduce or even replace patient‐specific QA measurements for SBRT plan delivery provided that the frequency and amount of measurement‐based machine‐specific QA can be increased to ensure the log files record real values of machine parameters.
- Subjects :
- Correlation coefficient
Stereotactic body radiation therapy
Maximum deviation
stereotactic body radiation therapy
Radiosurgery
Imaging phantom
030218 nuclear medicine & medical imaging
law.invention
03 medical and health sciences
0302 clinical medicine
law
Arc therapy
Radiation Oncology Physics
Humans
Radiology, Nuclear Medicine and imaging
volumetric‐modulated arc therapy
Instrumentation
Mathematics
Radiation
business.industry
Phantoms, Imaging
Radiotherapy Planning, Computer-Assisted
log file analysis
Collimator
Radiotherapy Dosage
Patient specific
plan delivery accuracy
patient‐specific QA
030220 oncology & carcinogenesis
Radiotherapy, Intensity-Modulated
Particle Accelerators
business
Nuclear medicine
Quality assurance
Subjects
Details
- Language :
- English
- ISSN :
- 15269914
- Volume :
- 21
- Issue :
- 11
- Database :
- OpenAIRE
- Journal :
- Journal of Applied Clinical Medical Physics
- Accession number :
- edsair.doi.dedup.....d79870c80795bd3a016234be9ae3087a