Premium
Monte Carlo simulations and radiation dosimetry measurements of peripherally applied HDR I 192 r breast brachytherapy D‐shaped applicators
Author(s) -
Yang Yun,
Rivard Mark J.
Publication year - 2009
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 - 10.1118/1.3075818
Subject(s) - dosimetry , brachytherapy , monte carlo method , ionization chamber , materials science , nuclear medicine , thermoluminescent dosimetry , dose profile , optics , biomedical engineering , radiation therapy , thermoluminescent dosimeter , medicine , physics , ionization , dosimeter , radiology , ion , mathematics , statistics , quantum mechanics
Conformal dose coverage for accelerated partial breast irradiation or radiotherapy boost can be obtained with AccuBoost® D‐shaped brachytherapy applicators using a flattened surface positioned near the patient. Three D‐shaped applicators (D45/D53/D60) were dosimetrically characterized using Monte Carlo methods (MCNP5), air ionization chambers (Farmer and Markus), and radiochromic film (GafChromic EBT) in polystyrene and ICRU 44 breast tissue. HDRI192 r source dwell times were either constant or optimized to improve skin dose uniformity. Scatter dose decreased as depth decreased. 10 mm beyond the applicator aperture, dose reductions of 90% and 51% were observed at depths of 0 and 30 mm, respectively. Similarly, planar dose uniformity improved as depth decreased and was also due to scatter and applicator geometry. Dose uniformity inside the applicator aperture was approximately 11% and 15% for all three applicators at the skin and 30 mm deep, respectively. Depth dose measurements in polystyrene using ion chamber and radiochromic film agreed with Monte Carlo results within 2%. Discrepancies between film and Monte Carlo dose profiles at 30 mm depth were within 1%.