Small field dosimetry formalism implemented using various detectors on several linear accelerators

Abstract

The use of small photon fields is now an established practice in radiotherapy and output factors (OF) need to be determined for small photon fields in the commissioning of a new Linear accelerator (LINAC). However, the dosimetry of small photon fields has been challenging due to several perturbation effects which differ among detectors yielding inconsistent readings [1]. A new code of practice (CoP) devoted to small fields has been introduced by the International Atomic Energy Agency (IAEA) in the technical report series no. 483 (TRS-483) [2]. The objective of this project was to implement the new CoP on six LINACs using various detectors. Another objective was to compare small field output variation between different LINACs of the same model.