%0 Journal Article
%A Höfel, Sebastian
%A Liebig, Pauline
%A Fix, Michael K
%A Drescher, Malte
%A Zwicker, Felix
%T Adapting a practical EPR dosimetry protocol to measure output factors in small fields with alanine.
%J Journal of applied clinical medical physics
%V 24
%N 12
%@ 1526-9914
%C Reston, Va.
%I ACMP
%M DKFZ-2023-02258
%P e14191
%D 2023
%Z #LA:E055# / 2023 Dec;24(12):e14191
%X Modern radiotherapy techniques often deliver small radiation fields. In this work, a practical Electron Paramagnetic Resonance (EPR) dosimetry protocol is adapted and applied to measure output factors (OF) in small fields of a 6 MV radiotherapy system. Correction factors and uncertainties are presented and OFs are compared to the values obtained by following TRS-483 using an ionization chamber (IC).Irradiations were performed at 10 cm depth inside a water phantom positioned at 90 cm source to surface distance with a 6 MV flattening filter free photon beam of a Halcyon radiotherapy system. OFs for different nominal field sizes (1 × 1, 2 × 2, 3 × 3, 4 × 4, normalized to 10 × 10 cm2 ) were determined with a PinPoint 3D (PTW 31022) IC following TRS-483 as well as with alanine pellets with a diameter of 4 mm and a height of 2.4 mm. EPR readout was performed with a benchtop X-band spectrometer. Correction factors due to volume averaging and due to positional uncertainties were derived from 2D film measurements.OFs obtained from both dosimeter types agreed within 0.7
%K EPR dosimetry (Other)
%K alanine (Other)
%K density effect (Other)
%K output factor (Other)
%K small field (Other)
%K volume effect (Other)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:37922380
%R 10.1002/acm2.14191
%U https://inrepo02.dkfz.de/record/285223