Beyond Gamma Analysis: An Accessibility-oriented Framework for Comparative Evaluation of Patient-specific Radiotherapy Quality Assurance.

BACKGROUND

Patient-specific quality assurance (QA) in radiotherapy is traditionally performed using measurement-based systems that require dedicated hardware, machine time, and manpower. Although software-based QA approaches have emerged as efficient alternatives, their comparative accessibility and operational performance remain insufficiently investigated. This study evaluated conventional and software-based QA methodologies using integrated dosimetric, temporal, and economic metrics.

MATERIALS AND

METHODS

A total of 90 clinically approved treatment plans, including head-and-neck, pelvis, and lung volumetric modulated arc therapy/stereotactic body radiotherapy cases, were retrospectively analysed. All plans were generated in Eclipse TPS v15.6 and evaluated using ArcCHECK phantom-based QA, electronic portal imaging device (EPID)-based QA, and log file-based QA. Gamma analysis was performed using 3%/2 mm criteria with a 10% dose threshold. Workflow time and relative cost burden were recorded for each method. Three composite indices were defined: QA Cost Efficiency Index (QCEI), QA Efficiency Index (QEI), and QA Accessibility Index (QAI). Statistical comparisons were performed using paired analysis with Bonferroni correction.

RESULTS

All QA methods achieved clinically acceptable gamma passing rates. Log file-based QA demonstrated the highest median gamma passing rate; however, the absolute differences between methodologies were small, and all approaches exceeded the predefined clinical acceptance criterion (≥95%). ArcCHECK showed the greatest workflow time and cost burden, whereas log file-based QA demonstrated the highest QCEI, QEI, and QAI values. EPID-based QA showed intermediate performance. All pairwise differences in accessibility metrics were statistically significant (P < 0.05).

CONCLUSION

Software-based QA approaches significantly improved operational efficiency and accessibility while maintaining clinically acceptable dosimetric agreement. However, further prospective, multi-institutional validation of the proposed accessibility framework is warranted.