title: Exposure rate constants for filtered 192Ir sources.
abstract: The exposure rate constant, gamma delta was recently calculated to be 4.69 +/- 0.05 R cm2h-1mCi-1 (9.09 x 10(-19) C kg-1m2s-1 Bq-1) for an unfiltered point sources of 192Ir. Using that same nuclear spectroscopy data filtered exposure rates constants have been calculated for encapsulated sources produced by two commercial manufacturers. For a 0.3 mm diam. spherical source with a 0.1 mm core of 25% Ir and 75% Pt encased in a sheath of 0.1mm 100% Pt, the calculated filtered exposure rate constant is 4.30 +/- 0.10 R cm2h-1mCi-1 (8.33 x 10(-19) C kg-1m2s-1 Bq-1). For a 0.5 mm diam. spherical source with 0.1 mm diam. core of 25% Ir and 75% Pt encapsulated in 0.2 mm stainless steel, the calculated filtered exposure rate constant is 4.45 +/- 0.10 R cm2h-1mCi-1 (8.62 x 10(-19) C kg-1m2s-1 Bq-1). Calculational details are presented.
mesh_terms: D001918:Brachytherapy; D005374:Filtration; D006801:Humans; D007495:Iridium / Q000008:administration & dosage*; D011868:Radioisotopes / Q000008:administration & dosage*; D011879:Radiotherapy Dosage
chemical_list: D011868:Radioisotopes; D007495:Iridium