Evaluation of S Values for Beta-ray Emitters within the Urinary Bladder

Abstract

S values to the urinary bladder wall for several beta-ray emitters such as 14C, 24Na, 32P, ^Co, 89Sr, ^Sr, 90Y, 91Y, 137Cs, 147Pm and 204Tl have been evaluated using the Monte Carlo simulation. The S values evaluations were made on the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine Pamphlet No. 5 type phantoms (MIRD 5 type phantoms) and the Japanese adult voxel phantoms developed at the Japan Atomic Energy Research Institute (JAERI). It was found that the absorbed dose to the urinary bladder wall for those radionuclides are not one-half of the absorbed dose in the bladder contents and largely depend on the mass of the urinary bladder wall. The S values derived from the simple assumption that the dose at the surface of the contents is one-half of the dose within the contents were found to be conservative for the dose evaluation of beta-ray emitters within the urinary bladder.