The use of thermoluminescent dosimeters for In-vivo dosimetry in a fast neutron therapy beam

Thermoluminescent detectors (TLD-700) have been investigated for absorbed dose measurements in a p(66)/Be neutron therapy beam at the National Accelerator Centre. Chips were selected based on their reproducibility and chip individual neutron calibration factors were derived. The dose non-linearity was determined in peak 5 and peak 6 and dose non-linearity corrections were performed. The sensitivity of TLD-700 chips with depth and off-axis distance was determined. In-vivo dose measurements were performed on seven patients (9 fields). In the entrance in-vivo dose measurements, a maximal deviation of 3.2 % was detected and a systematic difference of 1.7 % was observed. On the exit side, a maximal deviation of -7.3 % was detected and a systematic difference of -5.1 % was observed. The glow curve peak 6/5 ratio was investigated and found to correlate with the qualitative variations of the average LET in the neutron beam.

Grantor dc:publisher.institution

Division of Medical Physics

Year dc:date.issued

2000

Author dc:creator

• Bhengu, Khumbulani John

Advisors dc:contributor.advisor

• Jones, Dan T L
• Langen, Katja M

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/2799

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/2799