Purpose: LAP has recently developed a novel end-to-end solution for all Patient Specific QA in a single shop platform within RadCalc. Highlighted by a True Composite EPID based in vivo dosimetry solution, by reconstructing the delivered volume dose in the patient’s anatomy to evaluate against the TPS intended dose. RadCalc also includes a full 3D secondary calculation using CC/MC and a pre-treatment solution for EPID based patient specific QA. Using anthropomorphic phantoms, we have simulated, planned, QA’d and treated intracranial SRS and SBRT lung. The results of our current clinical and QA workflows are to be compared to the solution within RadCalc.
Methods: IMT’s MaxHD anthropomorphic head phantom and the CIRS Dynamic Thorax phantom were simulated to mimic that of a patient SRS and Lung SBRT.All plans were delivered for PSQA using current clinical workflow. RadCalc’s pre-treatment QA dose volume reconstruction used the same measurements from the clinical workflow. A pin-point ion chamber was inserted into the phantoms and the plans were delivered with the imager out. The same dosimetry imaging template was used from the pre-treatment measurements to provide a chamber comparison to RadCalc’s EPID in vivo results.
Results: The new single shop solution by RadCalc has produced results in agreement with our existing secondary MU calculation and pre-treatment QA measurements.
Conclusion: The benefits of using a suite like RadCalc go beyond the convenience of a single integrated solution. As per recommendation from AAPM TG-219, a full 3D secondary MU calculation is more robust than a single calc point and allows you to view the isodose lines in 3D. The 3D QA and in vivo solution utilizing EPID dosimetry goes beyond traditional OSLD or Diode readings by demonstrating what was truly delivered on your 3D data set thus providing confidence for a full patient specific end-to-end QA solution.
Funding Support, Disclosures, and Conflict of Interest: Research & authors sponsored by LAP, developer of RadCalc software.
In Vivo Dosimetry, 3D, Quality Assurance
TH- External Beam- Photons: portal dosimetry, in-vivo dosimetry and dose reconstruction