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Fulltext The Thermoluminescence Response of Ge-Doped Flat Fibers to Gamma Radiation

Nawi SN, Wahib NF, Zulkepely NN, Amin YB, Min UN, Bradley DA, et al.

Sensors (Basel), 2015;15(8):20557-69.
PMID: 26307987 DOI: 10.3390/s150820557

Study has been undertaken of the thermoluminescence (TL) yield of various tailor-made flat cross-section 6 mol% Ge-doped silica fibers, differing only in respect of external dimensions. Key TL dosimetric characteristics have been investigated, including glow curves, dose response, sensitivity, fading and reproducibility. Using a (60)Co source, the samples were irradiated to doses within the range 1 to 10 Gy. Prior to irradiation, the flat fibers were sectioned into 6 mm lengths, weighed, and annealed at 400 °C for 1 h. TL readout was by means of a Harshaw Model 3500 TLD reader, with TLD-100 chips (LiF:Mg, Ti) used as a reference dosimeter to allow the relative response of the fibers to be evaluated. The fibers have been found to provide highly linear dose response and excellent reproducibility over the range of doses investigated, demonstrating high potential as TL-mode detectors in radiation medicine applications. Mass for mass, the results show the greatest TL yield to be provided by fibers of the smallest cross-section, analysis indicating this to be due to minimal light loss in transport of the TL through the bulk of the silica medium.

Matched MeSH terms: Thermoluminescent Dosimetry
Doped silica fibre thermoluminescence measurements of radiation dose in the use of 223Ra

Bradley, Sani SFA, Shafiqah ASS, Collins SM, Hugtenburg RP, Rashid HAA, et al.

Appl Radiat Isot, 2018 Aug;138:65-72.
PMID: 28427834 DOI: 10.1016/j.apradiso.2017.04.019

Using tailor-made sub-mm dimension doped-silica fibres, thermoluminescent dosimetric studies have been performed for α-emitting sources of 223RaCl2 (the basis of the Bayer Healthcare product Xofigo®). The use of 223RaCl2 in the palliative treatment of bone metastases resulting from late-stage castration-resistant prostate cancer focuses on its favourable uptake in metabolically active bone metastases. Such treatment benefits from the high linear energy transfer (LET) and associated short path length (<100µm) of the α-particles emitted by 223Ra and its decay progeny. In seeking to provide for in vitro dosimetry of the α-particles originating from the 223Ra decay series, investigation has been made of the TL yield of various forms of Ge-doped SiO2 fibres, including photonic crystal fibre (PCF) collapsed, PCF uncollapsed, flat and single-mode fibres. Irradiations of the fibres were performed at the UK National Physical Laboratory (NPL). Notable features are the considerable sensitivity of the dosimeters and an effective atomic number Zeff approaching that of bone, the glass fibres offering the added advantage of being able to be placed directly into liquid. The outcome of present research is expected to inform development of doped fibre dosimeters of versatile utility, including for applications as detailed herein.

Matched MeSH terms: Thermoluminescent Dosimetry
Ensuring radiation safety: Evaluating dose and compliance among medical staff at King Faisal Medical Complex, Saudi Arabia

Hassan WB, Osman H, Alosaimi M, AbuRkbah A, AlQurashi A, Elkhader BA, et al.

Appl Radiat Isot, 2024 Sep;211:111386.
PMID: 38870555 DOI: 10.1016/j.apradiso.2024.111386

BACKGROUND: Radiation is an integral part of routine medical practice, but it carries a risk to the health of medical staff. Hence, it should be assessed periodically. The study's goal was to quantify the levels of radiation exposure for medical staff at King Faisal Medical Complex (KFMC), Taif City Saudi Arabia, and to assess their radiation protective procedures in practice.
METHODS: The study looked at the thermoluminescence dosimeters (TLDs) records of 50 medical professionals who were exposed to radiation while working at KFMC from 2019 to 2020 in Taif city, Saudi Arabia. In Riyadh, radiation exposure is read from skin TLDs using Harshaw model 6600 plus detectors. The Excel software was utilized to process the obtained data for calculating effective doses. A questionnaire was also distributed to the medical staff to assess their radiation protection procedures. The Statistical Package for Social Sciences (SPSS) program version 23 was used to analyze the obtained data.
RESULTS: The mean annual effective doses of the medical staff in 2019 and 2020 were determined to be 1.14 mSv and 1.4645 mSv, respectively, with no significant difference in effective doses between males and females in either year. The socio-demographic features of the medical personnel were examined, and the findings revealed that the majority of participants were male radiological technologists. The rate of adherence to radiation protection techniques was 68%, with a normally distributed dispersal. The amount of adherence varied significantly depending on nationality, occupation, and academic qualification.
CONCLUSION: According to the research, the mean annual effective dosage for medical professionals at KFMC was significantly below the recommended level, indicating satisfactory compliance with the ALARA radiation safety concept.

Matched MeSH terms: Thermoluminescent Dosimetry
Fulltext Radiation exposure to operating theatre personnel during fluoroscopic-assisted orthopaedic surgery

Radhi AM, Masbah O, Shukur MH, Shahril Y, Taiman K

Med J Malaysia, 2006 Feb;61 Suppl A:50-2.
PMID: 17042230

Orthopaedic procedures especially dynamic hip screw (DHS) fixation, interlocking nailing (ILN) of the tibia and femur require fluoroscopic assistance. Frequent exposure to radiation is a major concern to members of the orthopaedic surgical team. This study was undertaken to measure shallow (skin) dose to the operating team personnel and deep (whole body) dose to the surgeon during such procedures in view to provide guidelines to the operating team members regarding the number of procedures allowable for them to perform or assist annually. Skin dose for the operating personnel and whole body dose for the operating surgeon during 25 procedures; ten cases of DHS, seven and six cases of ILN of the tibia and femur respectively, was measured using Thermoluminescent Dosimeter (TLD) chips. The shallow radiation dose for theatre personnel ranged from 0.19 mSy to 0.61 per case while the deep dose for the surgeon was 0.28, 0.55 and 0.81 mSy for seven cases of tibial ILN, ten cases of DHS and six cases of femur ILN respectively. The surgeon has the highest radiation exposure than other theatre personnel and the whole body exposure for DHS was higher than that of for ILN. However, the estimated cumulative dose was still far below the permissible annual dose limit.

Matched MeSH terms: Thermoluminescent Dosimetry*
Fulltext Occupational exposure and radiobiological risk from thyroid radioiodine therapy in Saudi Arabia

Al-Mohammed HI, Sulieman A, Mayhoub FH, Salah H, Lagarde C, Alkhorayef M, et al.

Sci Rep, 2021 Jul 15;11(1):14557.
PMID: 34267237 DOI: 10.1038/s41598-021-93342-1

Worldwide, thyroid cancer accounts for some 10% of total cancer incidence, most markedly for females. Thyroid cancer radiotherapy, typically using 131I (T1/2 8.02 days; β- max energy 606 keV, branching ratio 89.9%), is widely adopted as an adjunct to surgery or to treat inoperable cancer and hyperthyroidism. With staff potentially receiving significant doses during source preparation and administration, radiation protection and safety assessment are required in ensuring practice complies with international guidelines. The present study, concerning a total of 206 patient radioiodine therapies carried out at King Faisal Specialist Hospital and Research Center over a 6-month period, seeks to evaluate patient and occupational exposures during hospitalization, measuring ambient doses and estimating radiation risk. Using calibrated survey meters, patient exposure dose-rate estimates were obtained at a distance of 30-, 100- and 300 cm from the neck region of each patient. Occupational and ambient doses were measured using calibrated thermoluminescent dosimeters. The mean and range of administered activity (AA, in MBq) for the thyroid cancer and hyperthyroidism treatment groups were 4244 ± 2021 (1669-8066), 1507.9 ± 324.1 (977.9-1836.9), respectively. The mean annual occupational doses were 1.2 mSv, that for ambient doses outside of the isolation room corridors were found to be 0.2 mSv, while ambient doses at the nursing station were below the lower limit of detection. Exposures to staff from patients being treated for thyroid cancer were less compared to hyperthyroidism patients. With a well-defined protocol, also complying with international safety requirements, occupational exposures were found to be relatively high, greater than most reported in previous studies.

Matched MeSH terms: Thermoluminescent Dosimetry/methods
A thermoluminescent dosimetry postal dose inter-comparison of radiation therapy centres in Malaysia

Rassiah P, Ng KH, DeWerd LA, Kunugi K

Australas Phys Eng Sci Med, 2004 Mar;27(1):25-9.
PMID: 15156705

A thermoluminescent dosimetry (TLD) postal dose inter-comparison was carried out amongst radiotherapy centres in Malaysia. The aim of this TLD inter-comparison was to compare the uniformity involved in the measurement of absorbed dose among the participating centres. A set of 5 TLD chips placed within acrylic trays were mailed to all participating centres for irradiation to an absorbed dose to water of 2 Gy. Measurements were made for 6 MV and 60Co photon beams. Results show an agreement of +/- 5% for all but three radiotherapy centres. The ratios of the TLD readings to that of the reference centre are comparable with other national/regional dose inter-comparisons. The importance of a proper ongoing quality assurance program is essential in maintaining the consistency and uniformity of doses delivered.

Matched MeSH terms: Thermoluminescent Dosimetry/standards*
Fulltext Radiation exposure to the surgeon during femoral interlocking nailing under fluoroscopic imaging

Muzaffar TST, Imran Y, Iskandar MA, Zakaria A

Med J Malaysia, 2005 Jul;60 Suppl C:26-9.
PMID: 16381279

Femoral interlocking nailing requires fluoroscopic assistance for insertion of the nail and distal screws. In this study, scattered radiation to the eye and hand of the operating surgeon was measured during the procedure. Thermo-luminescent dosimeter (TLD) was used to quantify the dose received by the surgeon. The mean radiation exposure time during the procedure was 3.89 minutes. The mean scattered radiation doses to the hand and eye were 0.27 mSv and 0.09 mSv per procedure respectively. These very low doses have made a surgeon very unlikely to receive more than the recommended annual dose limit set by the National Council on Radiological Protection.

Matched MeSH terms: Thermoluminescent Dosimetry
Computed and conventional chest radiography: a comparison of image quality and radiation dose

Ramli K, Abdullah BJ, Ng KH, Mahmud R, Hussain AF

Australas Radiol, 2005 Dec;49(6):460-6.
PMID: 16351609

The aim of this study was to compare the image quality and entrance skin dose (ESD) for film-screen and computed chest radiography. Analysis of the image quality and dose on chest radiography was carried out on a conventional X-ray unit using film-screen, storage phosphor plates and selenium drum direct chest radiography. For each receptor, ESD was measured in 60 patients using thermoluminescent dosemeters. Images were printed on 35 x 43 cm films. Image quality was assessed subjectively by evaluation of anatomic features and estimation of the image quality, following the guidelines established by the protocols of the Commission of the European Communities. There was no statistically significant difference noted between the computed and conventional images (Wilcoxon rank sum test, P > 0.05). Imaging of the mediastinum and peripheral lung structures were better visualized with the storage phosphor and selenium drum technique than with the film-screen combination. The patients' mean ESD for chest radiography using the storage phosphor, film-screen combination and selenium drum was 0.20, 0.20 and 0.25 mGy, respectively, with no statistically significant difference with P > 0.05 (chi(2) tests).

Matched MeSH terms: Thermoluminescent Dosimetry
Contralateral breast dose from chest wall and breast irradiation: local experience

Alzoubi AS, Kandaiya S, Shukri A, Elsherbieny E

Australas Phys Eng Sci Med, 2010 Jun;33(2):137-44.
PMID: 20309667 DOI: 10.1007/s13246-010-0011-y

Second cancer induction in the contralateral breast (CB) is an issue of some concern in breast radiotherapy especially for women under the age of 45 years at the time of treatment. The CB dose from 2-field and 3-field techniques in post-mastectomy chest wall irradiations in an anthropomorphic phantom as well as in patients were measured using thermoluminescent dosimeters (TLDs) at the local radiotherapy center. Breast and chest wall radiotherapy treatments were planned conformally (3D-CRT) and delivered using 6-MV photons. The measured CB dose at the surface fell sharply with distance from the field edge. However, the average ratio of the measured to the calculated CB dose using the pencil beam algorithm at the surface was approximately 53%. The mean and median measured internal dose at the posterior border of CB in a phantom was 5.47+/-0.22 cGy and 5.44 cGy, respectively. The internal CB dose was relatively independent of depth. In the present study the internal CB dose is 2.1-4.1% of the prescribed dose which is comparable to the values reported by other authors.

Matched MeSH terms: Thermoluminescent Dosimetry