Abstract:
In this work, the dose distribution of high-energy photon beams was measured
using thermoluminescence (TL) dosimeters. The purpose of this work was to
introduce the TLDs in clinical dose measurements, which are normally done with
ion chamber dosimeter. For this, the rod of 1 x 1 x 6 mm3 size of TLD was used.
Most of the measurements were carried out for the photon beams of energies 4.0
& 10MV. The reliability of the detector was tested by comparison with an ionchamber
and a Markus chamber dosimeter.
Chapter 1 describes the scope and aim of the studies. Here, the quality of the
high-energy photon beams, which comprises the prime conditions of
radiotherapy treatment, is also discussed.
In chapter 2, 3 and 4, the review of some related works, theoretical aspects of
thermoluminescence including glow curve theory and some necessary
equipment have been discussed.
In chapter 5 and 6, the reproducibility of the TLDs via the thermal treatment in
four-step application cycle of TLD, the sensitivity factor and calibration of the
TLDs have been discussed. Detail studies with the practical problems including
those associated with the annealing, storage, handling, irradiation, readout and
calibration have also been discussed.
In chapter 7 and 8, the technique of dose accuracy has been established through
some homogeneous and inhomogeneous measurements. Here, the independent
characteristics of field sizes, depths of phantom for TL-dosimeter like ionchamber
dosimetry were obtained through those measurements.
Chapter 9 describes the uses of TLDs in invivo dosimetry by following a new
methodology. The entrance and exit dose was measured using TLDs. The
method provides more accurate target dose (within 0.17% variation from the
direct target dose value).
Chapter 10 describes the development of a new PC program for treatment of
cancer using multiple asymmetric fields and its experimental verification.
Chapter 11 describes the use of TLDs for measuring dose during whole body
irradiation with high-energy photon beams.
Finally, in Chapter 12, the findings of the experiments are discussed.
