Abstract
Abstract
Background
An accurate assessment of the radiotherapy plans requires an accurate dose to the target and efficient confinement of the doses. However, present indices do not completely cover these aspects in a single framework.
Purpose
To develop a unified, dimensionless metric that integrates geometric conformity and dosimetric efficiency for evaluating stereotactic and fractionated radiotherapy plans aims to reduce QA workload by providing a rapid, quantitative estimate of plan acceptability, allowing early prediction of treatment plan performance.
Methods
In this study, the Nabaa Efficiency Index is introduced and defined as the product of the Conformity Index (CI) and a Dose‐Efficiency Ratio (DER), evaluated at 50% and 90% isodose levels (, ). We analyzed theoretical behavior against normalized dose–volume ratios and compared with established indices of conformity, homogeneity, and the Paddick efficiency index . Clinical validation used 100 plans (50 Gamma Knife, 50 VMAT‐SRS). Statistics included ANOVA, correlations, ROC/AUC, and decision‐curve analysis.
Results
and were monotonic, bounded, and dimensionless. distinguished gradient/halo efficiency between stereotactic and linac plans (
p
Conclusion
unifies geometric and dosimetric assessment across modalities. Its simplicity, physical interpretability, and software‐ready formulation support integration into automated QA and treatment‐planning pipelines.