Effect of Bilirubin concentration on radiation absorbed dose equivalent using LiF (TLD-100)

Abstract

The effect of bilirubin concentration on dose equivalent of absorbed radiation was investigated in vitro in this study. Different concentrations of bilirubin were exposed to a fixed dose equivalent x-ray irradiation from an R501 x-ray generator. The fraction of radiation transmitted and the fraction absorbed were measured using LiF (TLD 100) chips as detectors, and the radiation absorbed by bilirubin was computed. Results indicate that at low concentrations (25 mol/L to 76 mol/L) absorbed doses decreased with increase in bilirubin concentration. At higher bilirubin concentrations (76 mol/L to 460 mol/L) and beyond, there was an increase in absorption with a strong positive correlation (r = 0.92) between dose absorbed and bilirubin concentration. The possible applications of this property of bilirubin as a modifier at high concentrations--- to enhance radiation effect on diseased tissue during radiotherapy, and the danger inherent presenting neonates for radiodiagnostic examinations are discussed.

Global Journal of Pure and Applied Sciences Volume , No 1 January (2001) pp. 143-146



KEY WORDS:

Bilirubin, radiation, absorption, radiotherapy, modifier.