Study of target volume effect on efficiency index and paddick comformty index for arteriovenous malformation treatment plans by gamma knife

Abstract

Background: Since energy is the product of volume times dosage, volumes are given a weighting that is proportionate to the dose that they have received. This is a result that energy is a measure of how much substance has been absorbed. Aim of the study: The current study aimed to study the fluctuation of the efficiency index and Paddick with differences in the target volume. Method The efficiency index and conformance index data were computed for each of the thirty scheduled clinical treatments using the Leksell Gamma Knife® Icon™ version (11.1) and compared to the target volume. Data analysis was carried out using the available statistical package for Social Sciences. Result The value of efficiency index (ƞ50% ) for the 30 clinical stereotactic radiosurgery treatment plans ranged from 44% to 84% with a mean value of 63%.and value of conformity was 47% to 82% with a mean value of 60.6%, The study also showed a strong relationship between target volume and this indexes. Conclusion: Volumes are given a weighting that is proportional to the dose that they have absorbed because energy is the product of volume times dose, where there would be a correlation between efficiency and conformance improvements and an increase in the target volume

Keywords

• radiotherapy , comformity , efficiency index , plan quality , stereotactic radiosurgery