Dosimetría de campos pequeños según el TRS-483 usando el micro-colimador APEX montado en el acelerador lineal Elekta de la Unidad de Radioterapia del Hospital de Especialidades Carlos Andrade Marín, IESS-Quito.

Abstract

The present of titling work aims to determine the output factors using small fields dosimetry, according to the TRS-483 methodology and compare them with the Daisy Chainning correction method for field sizes of 0.49 cm2, 0.98 cm2, 1.48 cm2, 1.97 cm2, 2.95 cm2, 4.92 cm2, 6.89 cm2 and 9.84 cm2. A Synergy-Elekta linear accelerator with 6 MV energy with an Apex micro-collimator, two ionization chambers models CC01 and CC13, and an IBA dosimetric equipment were used. The reference parameters were: 10 cm deep and a surface source distance of 90 cm. It was obtained as a result that with the Daisy Chainning correction method has a standard error of 0.06% in the eight different field sizes, while with the methodology of technical report 483, a standard error of 0.03% was obtained for the same field sizes where correction factors were used. It is concluded that in small fields, the Daisy Channing correction method did not offer significant corrections in the determination of output factors and it is recommended that for better results in small field dosimetry a micro-type detector is used Diamond.