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SU‐FF‐T‐241: Evaluation of EBT GafChromic Film for External Beam Dose Verification
Author(s) -
Todorovic M,
Fischer M,
Cremers F,
Schmidt R
Publication year - 2005
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.1997969
Subject(s) - imaging phantom , materials science , dosimetry , linear particle accelerator , scanner , nuclear medicine , beam (structure) , irradiation , optics , medical physics , physics , nuclear physics , medicine
Purpose: Radiochromic Films are a widely accepted method to measure dose distributions for brachytherapy. Compared to radiographic films they offer a variety of advantages. They are self developing, almost tissue‐equivalent and insensitive to daylight. The films mainly used so far had the disadvantage of a low sensitivity to radiation. The new GafChromic EBT film offers a solution to this problem. The purpose of this paper is to prove the application of this new film for verification measurements concerning IMRT and stereotactic radiotherapy (SRT), Method and Materials: In order to establish a precise and reliable dosimetric measuring device, it was necessary to investigate the relevant features of the film. After this the films could be applied for dosimetric measurements with 6 MV x‐rays using a Siemens Primus linear accelerator. The verification measurements (IMRT and SRT) were done using a μMLC manufactured by 3D Line in combination with the Primus. The films were placed in our multi‐purpose Phantom (EasyCube). After irradiation they were scanned using a flat‐bed scanner (MicroTek) and compared with the data provided by the treatment planning system Ergo++ using selfwritten MatLab routines. Results: The general properties of the film were determined (eg. response, post‐irradiation growth of the OD, energy dependence) and compared with the GafChromic HS and radiographic Kodak EDR‐2 films. The response of the EBT is 10‐times higher than the response of the HS, which so far was the GafChromic film with the highest sensitivity, and 3‐times higher than the response of the EDR‐2. The measured dose distributions (IMRT and SRT) were in good agreement with the data from the planning system. Conclusion: The results of our investigations prove that the EBT is a successful approach for making the advantages of the GafChromic films applicable for external beam radiotherapy.