1991 Volume 3 Issue 2 Pages 101-109
A thermoluminescence [TL] sheet and its spatial readout system for in vivo measurement of spatial dose distribution around sources has been newly developed for intracavitary high dose-rate radiation therapy. The TL sheet (40cm×50cm×200μm), which is composed of teflon mixed with BaSO4 (Eu doped) powder, has a linear response with a very wide dynamic range from at least 0.002cGy to 5000cGy for 60Co sources. Phantom test of the TL sheet readout system demonstrated that absorbed dose with TL sheet and that with ionization chamber as standard dosimeter agreed well. For clinical application, TL sheet was attached on an applicator of intracavitary radiation therapy for rectal cancer. After irradiation with high dose-rate 60Co sources, the in vivo dose distribution on the surface of the rectum was determined. The TL sheet was suggested to provide a convenient means of measuring the dosedistribution around 60Co sources in intracavitary radiation therapy.
