TY - JOUR
T1 - Impact of log file source and data frequency on accuracy of log file-based patient specific quality assurance
AU - Azzi, Akbar
AU - Heilemann, Gerd
AU - Georg, Dietmar
AU - Ardjo Pawiro, Supriyanto
AU - Mart, Terry
AU - Lechner, Wolfgang
N1 - Funding Information:
This study was supported by PUTI Research Grant with contract number NKB-664/UN2.RST/HKP.05.00/2022 and Asea-uninet PhD sandwich scholarship from OeAD. The authors would like to thank Elekta AB for providing the Elekta Treatment Recorder Converter Tool used in this work.
Funding Information:
This study was supported by PUTI Research Grant with contract number NKB-664/UN2.RST/HKP.05.00/2022 and Asea-uninet PhD sandwich scholarship from OeAD. The authors would like to thank Elekta AB for providing the Elekta Treatment Recorder Converter Tool used in this work.
Publisher Copyright:
© 2023 The Author(s)
PY - 2023
Y1 - 2023
N2 - Performing phantom measurements for patient-specific quality assurance (PSQA) adds a significant amount of time to the adaptive radiotherapy procedure. Log file based PSQA can be used to increase the efficiency of this process. This study compared the dosimetric accuracy of high-frequency linear accelerator (Linac) log files and low-frequency log data stored in the oncology information system (OIS). Thirty patients were included, that were recently treated in the head and neck (HN), brain, and prostate region with volumetric modulated arc therapy (VMAT) and an additional ten patients treated using stereotactic body radiation therapy (SBRT) with 3D-conformal radiotherapy (3D-CRT) technique. Log data containing a single fraction were used to calculate the dose distributions. The dosimetric differences between Linac log files and OIS logs were evaluated with a gamma analysis with 2%/2 mm criterion and dose threshold of 30%. The original treatment plan was used as a reference. Moreover, DVH parameters of D98%, D50%, and D2% of the planning-target volume (PTV) and dose to several organs at risk (OARs) were reported. Significant differences in dose distributions between the two log types and the original dose were observed for PTV D98% and D2% (r < 0.001) for HN cases, PTV D98% (r = 0.005) for brain cases, and PTV D50% (r = 0.015) for prostate cases. No significant differences were found between the two log types with respect to D50%. The root mean square (RMS) error of the leaf positions of the OIS log was approximately twice the RMS error of the Linac log file for VMAT plans, but identical for 3D-CRT plans. The relationship between the gamma pass rate and the RMS error showed a moderate correlation for the Linac log files (r = −0.58, p < 0.001) and strong correlation for OIS logs (r = −0.71, p < 0.001). Furthermore, all doses calculated using Linac log files and OIS log data had a GPR >90% for an RMS error < 3.3 mm. Based on these findings, a tolerance limit of RMS error of 3.3 mm for considering OIS log based PSQA was established. Nevertheless, the OIS log data quality should be improved to achieve adequate PSQA.
AB - Performing phantom measurements for patient-specific quality assurance (PSQA) adds a significant amount of time to the adaptive radiotherapy procedure. Log file based PSQA can be used to increase the efficiency of this process. This study compared the dosimetric accuracy of high-frequency linear accelerator (Linac) log files and low-frequency log data stored in the oncology information system (OIS). Thirty patients were included, that were recently treated in the head and neck (HN), brain, and prostate region with volumetric modulated arc therapy (VMAT) and an additional ten patients treated using stereotactic body radiation therapy (SBRT) with 3D-conformal radiotherapy (3D-CRT) technique. Log data containing a single fraction were used to calculate the dose distributions. The dosimetric differences between Linac log files and OIS logs were evaluated with a gamma analysis with 2%/2 mm criterion and dose threshold of 30%. The original treatment plan was used as a reference. Moreover, DVH parameters of D98%, D50%, and D2% of the planning-target volume (PTV) and dose to several organs at risk (OARs) were reported. Significant differences in dose distributions between the two log types and the original dose were observed for PTV D98% and D2% (r < 0.001) for HN cases, PTV D98% (r = 0.005) for brain cases, and PTV D50% (r = 0.015) for prostate cases. No significant differences were found between the two log types with respect to D50%. The root mean square (RMS) error of the leaf positions of the OIS log was approximately twice the RMS error of the Linac log file for VMAT plans, but identical for 3D-CRT plans. The relationship between the gamma pass rate and the RMS error showed a moderate correlation for the Linac log files (r = −0.58, p < 0.001) and strong correlation for OIS logs (r = −0.71, p < 0.001). Furthermore, all doses calculated using Linac log files and OIS log data had a GPR >90% for an RMS error < 3.3 mm. Based on these findings, a tolerance limit of RMS error of 3.3 mm for considering OIS log based PSQA was established. Nevertheless, the OIS log data quality should be improved to achieve adequate PSQA.
KW - Log file
KW - Oncology information system
KW - Patient specific quality assurance
UR - http://www.scopus.com/inward/record.url?scp=85162870268&partnerID=8YFLogxK
U2 - 10.1016/j.zemedi.2023.05.006
DO - 10.1016/j.zemedi.2023.05.006
M3 - Article
AN - SCOPUS:85162870268
SN - 0939-3889
JO - Zeitschrift fur Medizinische Physik
JF - Zeitschrift fur Medizinische Physik
ER -