An enhanced sector integration model for output and dose distribution calculation of irregular concave shaped electron beams

Abstract

A comprehensive method of output factor and dose distribution calculation for electron beams has been developed. It allows one to calculate the output factors and isodose distributions in water of arbitrary shaped electron fields with excellent accuracy even for the cases of concaved, small, elongated beams, and extended source to surface distances (SSDs). The method requires two sets of data: Depth dose distribution per monitor unit for circular cutouts and depth dose distributions per monitor unit for circular blocks (plugs), both for two SSDs, one reference of 100 cm and second extended one. The method has been extensively tested using a combination of different irregular cutouts and various SSDs for the 6 and 9 MeV electron beams. The calculated values agreed with the measured data well within 1% for output factors and below 1 for gamma (gamma test) for isodose distributions. The computer program has been developed to facilitate the method for practical application. The method has been used for almost 8 years considerably cutting workload in the department.