Purpose: Quality Assurance (QA) is crucial in the delivery of radiation therapy to assure safety and accuracy for best outcomes. Several commercially available systems readily assist in this aspect, but the affordability remains a major problem in low- and middle-income countries (LMICs) especially sub-Saharan Africa. In this work, we developed and tested a simple and cost-effective system for application in patient pre-delivery and weekly QA and suitable for use in LMIC. Indeed, our platform works by analyzing and comparing DICOM-RT files generated after each treatment with the initial plan parameters to ensure that patient treatment parameters were as expected.
Methods: Our QA platform was based on Varian logfile analysis with dynalog files extracted from the MLC control computer console via simple input commands. The data analysis was performed using a DynaLog Analysis Package for MATLAB and Octave consisting of a series of pre-written functions and code which were then modified and adjusted in-house as needed. For patient-specific QA, the clinically approved plan is first delivered, and the associated log file extracted and compared with the planned(expected) distribution. For weekly QA, logfiles for all treatments delivered during the week were compared with the initial. Our comparisons were between planned fluence map versus delivered fluence map and a resulting gamma analysis.
Results: Based on an evaluation of twelve (n=12) delivery cases treated for Head and Neck (H&N) cancer at our department, we tested our platform and observed an average gamma passing of 97.6% ± 0.5% (Range: 97 – 98%) using the 3%/3mm and 10% threshold criteria.
Conclusion: We have successfully developed and tested a simple and cost-effective platform that extracts and analyzes Varian log files as a suitable system for patient specific QA and weekly QA. Such a system is suitable for use in LMICs where affordability remains a major problem.
Treatment Verification, Quality Assurance