We have located links that may give you full text access.
SU-F-T-286: Calculation-Based Patient Specific IMRT QA Detects Potential Errors That Measurement-Based QA Does Not.
Medical Physics 2016 June
PURPOSE: Calculation-based patient-specific IMRT/VMAT QA, as a DICOM-RT-based plan verification system, has been commissioned and is currently being used at our institution. We report our investigation of IMRT/VMAT plan verification failures/warnings out of more than 1,000 plans verified over an 18-month period.
METHODS: Seven patients with QA failures/warnings from our calculation-based IMRT/VMAT QA were selected. Dose to 95% of PTV volume (D95%) and mean PTV dose with a difference of greater than 3%, a global gamma passing rate of less than 95%, and a mean dose difference to organ at risk (OAR) larger than 5% were set as the failure/warning criteria. The treatment sites of the selected patients included pelvis, leg, head and neck, brain, and breast. Measurement-based IMRT/VMAT QA was done on each patient using MapCHECK2. Root cause analysis (RCA) was performed on all patients to investigate the IMRT/VMAT failures/warnings.
RESULTS: All seven patients' plans passed measurement-based IMRT/VMAT QA with a gamma passing rate of more than 95%. Our RCA of patients showed the IMRT/VMAT QA failures detected by the calculation-based method were mainly due to inclusion of the skin in PTV, and tissue heterogeneity effects particularly at tissue-air and tissue-bone interfaces.
CONCLUSION: Calculation-based IMRT/VMAT QA can detect potential failures which cannot be detected by standard measurement-based QA.
METHODS: Seven patients with QA failures/warnings from our calculation-based IMRT/VMAT QA were selected. Dose to 95% of PTV volume (D95%) and mean PTV dose with a difference of greater than 3%, a global gamma passing rate of less than 95%, and a mean dose difference to organ at risk (OAR) larger than 5% were set as the failure/warning criteria. The treatment sites of the selected patients included pelvis, leg, head and neck, brain, and breast. Measurement-based IMRT/VMAT QA was done on each patient using MapCHECK2. Root cause analysis (RCA) was performed on all patients to investigate the IMRT/VMAT failures/warnings.
RESULTS: All seven patients' plans passed measurement-based IMRT/VMAT QA with a gamma passing rate of more than 95%. Our RCA of patients showed the IMRT/VMAT QA failures detected by the calculation-based method were mainly due to inclusion of the skin in PTV, and tissue heterogeneity effects particularly at tissue-air and tissue-bone interfaces.
CONCLUSION: Calculation-based IMRT/VMAT QA can detect potential failures which cannot be detected by standard measurement-based QA.
Full text links
Related Resources
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app