Evaluation of S values for beta-ray emitters within the urinary bladder

Kinase, Sakae   ; Zankl, M.*; Funabiki, Jun*; Noguchi, Hiroshi; Saito, Kimiaki  

The present study was performed to evaluate S values to the urinary bladder wall for several beta-ray emitters such as C, Na, P, Co, Sr, Sr, Y, Y, Cs, Pm and Tl for a MIRD 5 type phantom using Monte Carlo simulation. S values were also evaluated on the adult voxel phantoms developed at JAERI and were compared with those for the MIRD 5 type phantom. Furthermore, each of the S values was compared with those derived from the simple assumption (ICRP 30). Consequently, it was found that the absorbed dose to the urinary bladder wall for those radionuclides are not one-half of the absorbed dose in bladder content and largely depend on the mass of the urinary bladder wall. S values derived from the simple assumption were found to be conservative for beta-ray emitters within the urinary bladder.