Feasibility study of glass dosimeter postal dosimetry audit of high-energy radiotherapy photon beams.
BACKGROUND
The characteristics of a glass dosimeter were investigated for its potential use as a tool for postal dose audits. Reproducibility, energy dependence, field size and depth dependence were compared to those of a thermoluminescence dosimeter (TLD), which has been the major tool for postal dose audits worldwide.


METHODS
A glass dosimeter, GD-302M (Asahi Techno Glass Co.) and a TLD, TLD-100 chip (Harshaw Co.) were irradiated with gamma-rays from a (60)Co unit and X-rays from a medical linear accelerator (4, 6, 10 and 20 MV).


RESULTS
The dosimetric characteristics of the glass dosimeter were almost equivalent to those of the TLD, in terms of utility for dosimetry under the reference condition, which is a 10 x 10 cm(2) field and 10 cm depth. Because of its reduced fading, compared to the TLD, and easy quality control with the ID number, the glass dosimeter proved to be a suitable tool for postal dose audits. Then, we conducted postal dose surveys of over 100 facilities and got good agreement, with a standard deviation of about 1.3%.


CONCLUSIONS
Based on this study, postal dose audits throughout Japan will be carried out using a glass dosimeter.
Mizuno
Hideyuki
H
Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan. h-mizuno@nirs.go.jp
Kanai
Tatsuaki
T
Kusano
Yohsuke
Y
Ko
Susumu
S
Ono
Mari
M
Fukumura
Akifumi
A
Abe
Kyoko
K
Nishizawa
Kanae
K
Shimbo
Munefumi
M
Sakata
Suoh
S
Ishikura
Satoshi
S
Ikeda
Hiroshi
H
D005240:Feasibility Studies; D005898:Glass; D006801:Humans; D007564:Japan; D017785:Photons; D010865:Pilot Projects; D011177:Postal Service; D011785:Quality Assurance, Health Care; D011874:Radiometry; D015203:Reproducibility of Results; D013819:Thermoluminescent Dosimetry