[en] The reference condition established to determine the absorbed dose in water of a linear accelerator, according to TRS-398, depends on some electro-mechanics parameters. Furthermore, in principle, uncertainties in the parameters settings may results in dosimetry variations. The goal of this study is to analyze the influence in quality control parameters changes, which tolerance limits are established by TECDOC-1151, in the dosimetry result of photon beam. For this, some parameters (gantry and collimator angle, field size and source to surface distance) and chamber position were changed. The results of these changes were evaluated. For the variation range of quality control items (that went beyond the tolerance limits established by TECDOC-1151), the deviations got less than 1 % of reference for all analyzed parameters; the deviations for the ionization chamber position variation were less than 0,2 % for lateral and longitudinal variations although almost got to 3 % for depth alterations. (author)
Source
Associacao Brasileira de Fisica Medica (ABFM), Sao Paulo, SP (Brazil); [vp.]; ISBN 978-85-85205-94-2; 
; 2009; [3 p.]; 14. Brazilian congress on medical physics; 14. Congresso brasileiro de fisica medica; Sao Paulo, SP (Brazil); 8-12 Jul 2009; 4. Symposium on instrumentation and medical imaging; 4. Simposio de instrumentacao e imagens medicas; Sao Paulo, SP (Brazil); 8-12 Jul 2009
; 2009; [3 p.]; 14. Brazilian congress on medical physics; 14. Congresso brasileiro de fisica medica; Sao Paulo, SP (Brazil); 8-12 Jul 2009; 4. Symposium on instrumentation and medical imaging; 4. Simposio de instrumentacao e imagens medicas; Sao Paulo, SP (Brazil); 8-12 Jul 2009
No abstract available
Journal
Brazilian Journal of Oncology; ISSN 1806-6054; ; v. 13(suppl.1); p. 375
; v. 13(suppl.1); p. 375
No abstract available
Journal
Brazilian Journal of Oncology; ISSN 1806-6054; ; v. 13(suppl.1); p. 330-331
; v. 13(suppl.1); p. 330-331