Evaluation of Two Thermoluminescent Detection Systems for Medical Imaging Environments

Abstract

Thermoluminescent detectors (TLDs) can provide accurate and precise measurements for both patient and personnel dosimetry in the medical imaging environment. They have the advantages of tissue equivalency, an excellent dynamic range, and dose rate independence. In the work reported here, experiments with planar x-ray, fluoroscopy, and a 57Co source were conducted to test the repeatability and energy dependence of an LiF TL ribbon/automatic reader system and a four-element CaSO2 and Li2B4O7 badge/automatic reader system for diagnostic radiology and nuclear medicine dosimetry. The results indicate the usefulness and appropriateness of the TLD systems tested for both personnel and patient dosimetry in the medical diagnostic environment.

Monte Carlo Simulation of TLD Response Function: Scatterd Radiation Application

“…It has been shown by Mobit et al (1998), that the quality dependence factor for LiF-TLD in kilovoltage x-rays relative to 60 C 0 gamma-rays ranges from 1.36 for 50 kV x-rays to 1.03 for 300 kV which are comparable with our results [10]. Kearfott et al (1990) observed an quality dependence factor of LiF TL ribbon from 1.045 (50 keV) to 1.353 (100 keV) [12]. Study of Kron et al (1998) has also shown the quality dependence factor of 1.47 at 27 keV from synchrotron radiation [4].…”

Mixed field dosimetry using focused and unfocused laser heating of thermoluminescent materials

“…Numerous studies have discussed The heating and glow curve characteristics obtained when laser heat sources are used for local and positional heating of TLDs for both unfocused [Grupen-Shemansky, 19891 and focused lasers [Braunlich et al, 1984;Abtahi et al, 1985;Moreau et al, 1986;Abtahi et al, 1986 b;Kelly et al, 1987;Grupen-Shemansky, 1989;Young et al, 1989;Zangaro et al, 19901. Several applications and practical systems have used lasers to heat TLDs Kearfott et al, 1990 b;Kearfott et al, 1990 c]. Abtahi [Abtahi et al, 1986 b;Kelly et al, 19871 recommends heating the TLD with a laser beam of uniform intensity profile for accurate and sensitive personnel and environmental dosimetry.…”

Investigation of TLD-700 energy response to low energy x-ray encountered in diagnostic radiology

“…Mobit et al [11] performed Monte Carlo study of the quality dependence of LiF TLD in kilovoltage photon beams for radiotherapy dosimetry studies. Kearfott et al [12] observed an energy response of LiF TL ribbon for low energy x-rays. Kron et al [6], studied energy response of LiF for low energy synchrotron radiation.…”

“…The majority of these studies has concerned the LiF in di erent forms (chips, rods or ribbon) with monoenergetic x-ray beams, and only a few studies involved broad x-ray spectra like those encountered in diagnostic radiology [12,15]. However, only few works were published concerning TLD-700 energy response.…”