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  1. Dosimetric assessment of Gadolinium-159 for hepatic radioembolization: Tomographic images and Monte Carlo simulation
    Musa AS, Abdul Hadi MFR, Hashikin NAA, Ashour NI, Ying CK
    Appl Radiat Isot, 2023 Sep;199:110916.
    PMID: 37393764 DOI: 10.1016/j.apradiso.2023.110916
    A common therapeutic radionuclide used in hepatic radioembolization is yttrium-90 (90Y). However, the absence of gamma emissions makes it difficult to verify the post-treatment distribution of 90Y microspheres. Gadolinium-159 (159Gd) has physical properties that are suitable for therapy and post-treatment imaging in hepatic radioembolization procedures. The current study is innovative for conducting a dosimetric investigation of the use of 159Gd in hepatic radioembolization by simulating tomographic images using the Geant4 application for tomographic emission (GATE) Monte Carlo (MC) simulation. For registration and segmentation, tomographic images of five patients with hepatocellular carcinoma (HCC) who had undergone transarterial radioembolization (TARE) therapy were processed using a 3D slicer. The tomographic images with 159Gd and 90Y separately were simulated using the GATE MC Package. The output of simulation (dose image) was uploaded to 3D slicer to compute the absorbed dose for each organ of interests. 159Gd were able to provide a recommended dose of 120 Gy to the tumour, with normal liver and lungs absorbed doses close to that of 90Y and less than the respective maximum permitted doses of 70 Gy and 30 Gy, respectively. Compared to 90Y, 159Gd requires higher administered activity approximately 4.92 times to achieve a tumour dose of 120 Gy. Thus; this research gives new insights into the use of 159Gd as a theranostic radioisotope, with the potential to be used as a90Y alternative for liver radioembolization.
    Matched MeSH terms: Yttrium Radioisotopes/therapeutic use
  2. Dose perturbation effects by metal hip prosthesis in gynaecological 192Ir HDR brachytherapy
    Ab Shukor NS, Abdullah R, Abdul Aziz MZ, Samson DO, Musarudin M
    Appl Radiat Isot, 2023 Jun;196:110751.
    PMID: 36871495 DOI: 10.1016/j.apradiso.2023.110751
    The present study was conducted to elucidate the effects of hip prostheses in 192Ir HDR brachytherapy and determine dose uncertainties introduced by the treatment planning. A gynaecological phantom irradiated using Nucletron 192Ir microSelectron HDR source was modeled using MCNP5 code. Three hip materials considered in this study were water, bone, and metal prosthesis. According to the obtained results, a dose perturbation was observed within the medium with a higher atomic number, which reduced the dose to the nearby region.
    Matched MeSH terms: Iridium Radioisotopes/therapeutic use
  3. Fulltext Radiation doses to patient's relatives following radioiodine therapy
    Sulaiman BT, Clarke SE
    Med J Malaysia, 1996 Mar;51(1):131-3.
    PMID: 10967992
    A total of 10 volunteers were monitored for radiation doses, whose spouses were given radio-iodine (131I) orally. Nine of the spouses were given radio-iodine for Graves' disease and one for thyroid carcinoma. It was found that the highest radiation dose received by the volunteer was only 13.5% of the annual dose limit for individual members of the public. Hence, patients treated with radio-iodine do not pose a significant radiation hazard to the public.
    Matched MeSH terms: Iodine Radioisotopes/therapeutic use*
  4. Response to radioactive phosphorus treatment of polycythaemia rubra vera in Malaysians: analysis of 8 cases
    Zulkifli A, Chelvam P, Weng Hwa N, Dharmalingam SK
    Med J Malaysia, 1979 Jun;33(4):346-8.
    PMID: 392273
    Matched MeSH terms: Phosphorus Radioisotopes/therapeutic use*
  5. Characterization of MOSkin detector for in vivo dose verification during Cobalt-60 high dose-rate intracavitary brachytherapy
    Jamalludin Z, Jong WL, Abdul Malik R, Rosenfeld A, Ung NM
    Phys Med, 2019 Feb;58:1-7.
    PMID: 30824140 DOI: 10.1016/j.ejmp.2019.01.010
    In vivo dosimetry in high dose-rate (HDR) intracavitary brachytherapy (ICBT) is important for assessing the true dose received by surrounding organs at risk during treatment. It also serves as part of the treatment delivery quality assurance and verification program with the use of a suitable dosimeter. Such a dosimeter should be characterized under brachytherapy conditions before clinical application to ensure the accuracy of in vivo measurement. In this study, a MOSFET-based detector, MOSkin, was calibrated and characterized under HDR Cobalt-60 (Co-60) brachytherapy source. MOSkin possessed the major advantages of having small physical and dosimetric sizes of 4.8 × 10-6 mm3 with the ability to provide real-time measurements. Using solid water and polymethyl methacrylate (PMMA) phantom, the detectors' reproducibility, linearity, angular and distance dependency was tested for its suitability as an in vivo detector. Correction factors to account for differences in depth measurements were determined. The MOSkin detector showed a reliable response when tested under Co-60 brachytherapy range of doses with an excellent linearity of R2 = 0.9997 and acceptable reproducibility. A phantom verification study was also conducted to verify the differences between MOSkin responses and treatment planning (TPS) calculated doses. By taking into account several correction factors, deviations ranging between 0.01 and 0.4 Gy were found between MOSkin measured and TPS doses at measurement distance of 20-55 mm. The use of MOSkin as the dosimeter of choice for in vivo dosimetry under Co-60 brachytherapy condition is feasible.
    Matched MeSH terms: Cobalt Radioisotopes/therapeutic use*
  6. 2021 Asia-Pacific Graves' Disease Consortium Survey of Clinical Practice Patterns in the Management of Graves' Disease
    Parameswaran R, de Jong MC, Kit JLW, Sek K, Nam TQ, Thang TV, et al.
    Endocrine, 2023 Jan;79(1):135-142.
    PMID: 36129592 DOI: 10.1007/s12020-022-03193-7
    AIM: Although Graves' disease (GD) is common in endocrine practices worldwide, global differences in diagnosis and management remain. We sought to assess the current practices for GD in countries across Asia and the Pacific (APAC), and to compare these with previously published surveys from North America and Europe.

    METHODS: A web-based survey on GD management was conducted on practicing clinicians. Responses from 542 clinicians were received and subsequently analysed and compared to outcomes from similar surveys from other regions.

    RESULTS: A total of 542 respondents participated in the survey, 515 (95%) of whom completed all sections. Of these, 86% were medical specialists, 11% surgeons, and 3% nuclear medicine physicians. In addition to serum thyroid-stimulating hormone (TSH) and free thyroxine assays, most respondents would request TSH-receptor autoantibody (TRAb) measurement (68%) during initial work-up. Thyroid ultrasound is requested by about half of respondents (53%), while the use of nuclear medicine scans is limited. The preferred first-line treatment is anti-thyroid drug (ATD) therapy (79%) with methimazole (MMI) or carbimazole (CBZ), followed by radioiodine (RAI; 19%) and surgery (2%). In case of surgery, one-third of respondents would opt for a subtotal rather than a total thyroidectomy. In case of mild Graves orbitopathy (GO), ATDs (67%) remains the preferred treatment, but a larger proportion of clinicians prefer surgery (20%). For a patient with intention to conceive, the preferred treatment pattern remained unchanged, although propylthiouracil (PTU) became the preferred ATD-agent during the first trimester. In comparison to European and American practices, marked differences were noted in the relatively infrequent usage of nuclear medicine scans and the overall higher use of a ATDs and β-blockers and adjunctive ATD-treatment during RAI in the APAC-group.

    CONCLUSION: Although regional differences regarding the diagnosis and management of GD are apparent in this first pan-Asia-Pacific survey, this study reveals the overall approach to the management of this disease in Asia-Pacific generally tends to fall between the trends appreciated in the American and European cohorts.

    Matched MeSH terms: Iodine Radioisotopes/therapeutic use
  7. Development and physicochemical characterization of a biodegradable microspheres formulation loaded with samarium-153 and doxorubicin for chemo-radioembolization of liver tumours
    Alregib AH, Tan HY, Wong YH, Kasbollah A, Wong EH, Abdullah BJJ, et al.
    J Labelled Comp Radiopharm, 2023 Aug;66(10):308-320.
    PMID: 37287213 DOI: 10.1002/jlcr.4046
    Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) are promising treatments for unresectable liver tumours. Some recent studies suggested that combining TACE and TARE in one treatment course might improve treatment efficacy through synergistic cytotoxicity effects. Nonetheless, current formulations do not facilitate a combination of chemo- and radio-embolic agents in one delivery system. Therefore, this study aimed to synthesise a hybrid biodegradable microsphere loaded with both radioactive agent, samarium-153 (153 Sm) and chemotherapeutic drug, doxorubicin (Dox) for potential radio-chemoembolization of advanced liver tumours. 152 Sm and Dox-loaded polyhydroxybutyrate-co-3-hydroxyvalerate (PHBV) microspheres were prepared using water-in-oil-in-water solvent evaporation method. The microspheres were then sent for neutron activation in a neutron flux of 2 × 1012  n/cm2 /s. The physicochemical properties, radioactivity, radionuclide purity, 153 Sm retention efficiency, and Dox release profile of the Dox-153 Sm-PHBV microspheres were analysed. In addition, in vitro cytotoxicity of the formulation was tested using MTT assay on HepG2 cell line at 24 and 72 h. The mean diameter of the Dox-153 Sm-PHBV microspheres was 30.08 ± 2.79 μm. The specific radioactivity was 8.68 ± 0.17 GBq/g, or 177.69 Bq per microsphere. The 153 Sm retention efficiency was more than 99%, tested in phosphate-buffered saline (PBS) and human blood plasma over 26 days. The cumulative release of Dox from the microspheres after 41 days was 65.21 ± 1.96% and 29.96 ± 0.03% in PBS solution of pH 7.4 and pH 5.5, respectively. The Dox-153 Sm-PHBV microspheres achieved a greater in vitro cytotoxicity effect on HepG2 cells (85.73 ± 3.63%) than 153 Sm-PHBV (70.03 ± 5.61%) and Dox-PHBV (74.06 ± 0.78%) microspheres at 300 μg/mL at 72 h. In conclusion, a novel biodegradable microspheres formulation loaded with chemotherapeutic drug (Dox) and radioactive agent (153 Sm) was successfully developed in this study. The formulation fulfilled all the desired physicochemical properties of a chemo-radioembolic agent and achieved better in vitro cytotoxicity on HepG2 cells. Further investigations are needed to evaluate the biosafety, radiation dosimetry, and synergetic anticancer properties of the formulation.
    Matched MeSH terms: Radioisotopes/therapeutic use
  8. Fulltext New-onset Thyroid Eye Disease after COVID-19 Vaccination in a Radioactive Iodine-Treated Graves' Disease Patient: A Case Report and Literature Review
    Im Teoh JH, Mustafa N, Wahab N
    J ASEAN Fed Endocr Soc, 2023;38(1):125-130.
    PMID: 37252417 DOI: 10.15605/jafes.038.01.19
    Autoimmunity associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been well-described as the mechanism of development of thyroid dysfunction following Coronavirus Disease 19 (COVID-19) infection and SARS-CoV-2 vaccination. However, the occurrence of thyroid eye disease (TED) after SARS-CoV-2 vaccination is scarcely described. The postulated mechanisms include immune reactivation, molecular mimicry and the autoimmune/inflammatory syndrome induced by adjuvants (ASIA). We report a case of new-onset TED after receiving the SARS-CoV-2 vaccine.
    Matched MeSH terms: Iodine Radioisotopes/therapeutic use
  9. Fulltext Neutron Activated Samarium-153 Microparticles for Transarterial Radioembolization of Liver Tumour with Post-Procedure Imaging Capabilities
    Hashikin NA, Yeong CH, Abdullah BJ, Ng KH, Chung LY, Dahalan R, et al.
    PLoS One, 2015;10(9):e0138106.
    PMID: 26382059 DOI: 10.1371/journal.pone.0138106
    Samarium-153 (153Sm) styrene divinylbenzene microparticles were developed as a surrogate for Yttrium-90 (90Y) microspheres in liver radioembolization therapy. Unlike the pure beta emitter 90Y, 153Sm possess both therapeutic beta and diagnostic gamma radiations, making it possible for post-procedure imaging following therapy.
    Matched MeSH terms: Radioisotopes/therapeutic use*; Yttrium Radioisotopes/therapeutic use
  10. Fulltext Therapeutic radionuclides in nuclear medicine: current and future prospects
    Yeong CH, Cheng MH, Ng KH
    J Zhejiang Univ Sci B, 2014 Oct;15(10):845-63.
    PMID: 25294374 DOI: 10.1631/jzus.B1400131
    The potential use of radionuclides in therapy has been recognized for many decades. A number of radionuclides, such as iodine-131 ((131)I), phosphorous-32 ((32)P), strontium-90 ((90)Sr), and yttrium-90 ((90)Y), have been used successfully for the treatment of many benign and malignant disorders. Recently, the rapid growth of this branch of nuclear medicine has been stimulated by the introduction of a number of new radionuclides and radiopharmaceuticals for the treatment of metastatic bone pain and neuroendocrine and other malignant or non-malignant tumours. Today, the field of radionuclide therapy is enjoying an exciting phase and is poised for greater growth and development in the coming years. For example, in Asia, the high prevalence of thyroid and liver diseases has prompted many novel developments and clinical trials using targeted radionuclide therapy. This paper reviews the characteristics and clinical applications of the commonly available therapeutic radionuclides, as well as the problems and issues involved in translating novel radionuclides into clinical therapies.
    Matched MeSH terms: Radioisotopes/therapeutic use*
  11. Accurate measurement of exposure rate from a 60Co teletherapy source: deviations from the inverse-square law
    Samat SB, Evans CJ, Kadni T, Dolah MT
    Br J Radiol, 2000 Aug;73(872):867-77.
    PMID: 11026863
    A cylindrical gamma-ray 60Co source of activity alpha is predicted to produce an exposure rate X at a distance d in vacuum, given by X = gamma(T)(alpha/d2), where gamma(T) is the specific gamma-ray constant. It has been documented that this formula may be used to approximate X with an accuracy of 1% from a source of length l, provided that d/l > or = 5. It is shown that the formula is accurate to 0.1% under these conditions, provided that the distance is measured from the centre of the source. When absorption in the source and scattering in the collimator are considered, the position of the origin d = 0 can shift by a distance of the order of centimetres. Absorption in air between the source and the ionization chamber adds an exponential factor to the formula. It is shown that even when these modifications are included the discrepancy in the results, although generally less than 1%, is still large compared with the measurement errors. Some suggestions are made for the origin of this discrepancy.
    Matched MeSH terms: Cobalt Radioisotopes/therapeutic use*
  12. Fulltext Results of long-term follow-up after compensated fixed-dose therapy for thyrotoxicosis
    Zaini A, Khir A, Doi SA, Chan SP, Paramsothy M, Khoo BH
    J Int Med Res, 1992 Jun;20(3):279-88.
    PMID: 1397673
    To evaluate the effects of simple compensated fixed-dose iodine-131 therapy for thyrotoxicosis, the long-term results for 74 patients treated with a fixed dose of iodine-131 ranging from 5 to 12 mCi (185 to 444 MBq) were evaluated in the first 2 years of a trial. The dose selected was loosely based on the gross size of the thyroid gland. Routine antithyroid drug therapy was given for a minimum of 3 months after iodine-131 therapy. The mean (+/- SD) duration of follow-up was 74.5 +/- 42 months. The results indicated that roughly 25% of patients treated in this way will become hypothyroid after 5 years and that 85% are cured (need no further therapy during the follow-up period) using a single dose of iodine-131. Of those cured using a single iodine-131 dose, 81% were no longer receiving drugs after 6 months and 85% after 1 year. Such a regimen seems currently to be among the best available where prolonged periods of medication-free euthyroidism after therapy are sought.
    Matched MeSH terms: Iodine Radioisotopes/therapeutic use*
  13. Fulltext Transient hypothyroidism following I131 treatment for thyrotoxicosis
    Zaini A, Ngan A, Paramsothy M, Khoo BH, Ch'ng SL
    Med J Malaysia, 1983 Dec;38(4):331-3.
    PMID: 6599994
    Matched MeSH terms: Iodine Radioisotopes/therapeutic use
  14. Systematic investigation on the validity of partition model dosimetry for90Y radioembolization using Monte Carlo simulation
    Hashikin NAA, Yeong CH, Guatelli S, Abdullah BJJ, Ng KH, Malaroda A, et al.
    Phys Med Biol, 2017 Aug 22;62(18):7342-7356.
    PMID: 28686171 DOI: 10.1088/1361-6560/aa7e5b
    We aimed to investigate the validity of the partition model (PM) in estimating the absorbed doses to liver tumour ([Formula: see text]), normal liver tissue ([Formula: see text]) and lungs ([Formula: see text]), when cross-fire irradiations between these compartments are being considered. MIRD-5 phantom incorporated with various treatment parameters, i.e. tumour involvement (TI), tumour-to-normal liver uptake ratio (T/N) and lung shunting (LS), were simulated using the Geant4 Monte Carlo (MC) toolkit. 108track histories were generated for each combination of the three parameters to obtain the absorbed dose per activity uptake in each compartment ([Formula: see text], [Formula: see text], and [Formula: see text]). The administered activities, A were estimated using PM, so as to achieve either limiting doses to normal liver, [Formula: see text] or lungs, [Formula: see text] (70 or 30 Gy, respectively). Using these administered activities, the activity uptake in each compartment ([Formula: see text], [Formula: see text], and [Formula: see text]) was estimated and multiplied with the absorbed dose per activity uptake attained using the MC simulations, to obtain the actual dose received by each compartment. PM overestimated [Formula: see text] by 11.7% in all cases, due to the escaped particles from the lungs. [Formula: see text] and [Formula: see text] by MC were largely affected by T/N, which were not considered by PM due to cross-fire exclusion at the tumour-normal liver boundary. These have resulted in the overestimation of [Formula: see text] by up to 8% and underestimation of [Formula: see text] by as high as  -78%, by PM. When [Formula: see text] was estimated via PM, the MC simulations showed significantly higher [Formula: see text] for cases with higher T/N, and LS  ⩽  10%. All [Formula: see text] and [Formula: see text] by MC were overestimated by PM, thus [Formula: see text] were never exceeded. PM leads to inaccurate dose estimations due to the exclusion of cross-fire irradiation, i.e. between the tumour and normal liver tissue. Caution should be taken for cases with higher TI and T/N, and lower LS, as they contribute to major underestimation of [Formula: see text]. For [Formula: see text], a different correction factor for dose calculation may be used for improved accuracy.
    Matched MeSH terms: Yttrium Radioisotopes/therapeutic use*
  15. Monte Carlo simulations and analysis of transmitted gamma ray spectra through various tissue phantoms
    Moradi F, Khandaker MU, Alrefae T, Ramazanian H, Bradley DA
    Appl Radiat Isot, 2019 Apr;146:120-126.
    PMID: 30769172 DOI: 10.1016/j.apradiso.2019.01.031
    Studies of radiation interactions with tissue equivalent material find importance in efforts that seek to avoid unjustifiable dose to patients, also in ensuring quality control of for instance nuclear medicine imaging equipment. Use of the Monte Carlo (MC) simulation tool in such characterization processes allows for the avoidance of costly experiments involving transmitted X- and γ-ray spectrometry. Present work investigates MC simulations of γ-ray transmission through tissue equivalent solid phantoms. Use has been made of a range of radionuclide gamma ray sources, 99mTc, 131I, 137Cs, 60Co (offering photons in the energy range from a few keV up to low MeV), popularly applied in medicine and in some cases for gauging in industry, obtaining the transmission spectra following their interaction with various phantom materials and thicknesses. In validation of the model, the simulated values of mass attenuation coefficients (μ/ρ) for different phantom materials and thicknesses were found to be in good agreement with reference values (NIST, 2004) to within 1.1% for all material compositions. For all of the primary photon energies and medium thicknesses of interest herein, results show that multiple scattering peaks are generally located at energies lower than 100 keV, although for the larger phantom thicknesses it is more difficult to distinguish single, double and multiple scattering in the gamma spectra. Transmitted photon spectra investigated for water, soft tissue, breast, brain and lung tissue slab phantoms are demonstrated to be practically independent of the phantom material, while a significant difference is observed for the spectra transmitted through bone that was proved to be due to the density effect and not material composition.
    Matched MeSH terms: Radioisotopes/therapeutic use
  16. Concurrent Benign Iodine-Avid Thymic and Liver Cysts Mimicking Metastatic Disease on 131I Whole-Body Scintigraphy
    Kamarulzaman K, Mohd Rohani MF, Mat Nawi N, Amir Hassan SZ
    Clin Nucl Med, 2024 Mar 01;49(3):250-252.
    PMID: 38306377 DOI: 10.1097/RLU.0000000000005037
    A 57-year-old woman received radioiodine therapy post total thyroidectomy for pT3aNxMx follicular thyroid carcinoma. Posttherapy 131I whole-body scan showed 131I concentration in the chest, mediastinum, and left upper thigh with stimulated thyroglobulin (Tg) of 89 μg/L. Subsequent radioiodine therapies showed persistent 131I accumulation in the anterior mediastinal soft tissue lesions and a hypodense segment VII liver lesion visualized on SPECT/CT, suggestive of iodine-avid metastatic disease despite the undetectable serum Tg (<1.0 μg/L) with no Tg antibody interference. Biopsy of the liver lesion revealed liver cyst, and consequent removal of the mediastinal lesions showed benign thymic cysts.
    Matched MeSH terms: Iodine Radioisotopes/therapeutic use
  17. Comparison of planned and measured rectal dose in-vivo during high dose rate Cobalt-60 brachytherapy of cervical cancer
    Zaman ZK, Ung NM, Malik RA, Ho GF, Phua VC, Jamalludin Z, et al.
    Phys Med, 2014 Dec;30(8):980-4.
    PMID: 25086486 DOI: 10.1016/j.ejmp.2014.07.002
    Cobalt-60 (Co-60) is a relatively new source for the application of high-dose rate (HDR) brachytherapy. Radiation dose to the rectum is often a limiting factor in achieving the full prescribed dose to the target during brachytherapy of cervical cancer. The aim of this study was to measure radiation doses to the rectum in-vivo during HDR Co-60 brachytherapy. A total of eleven HDR brachytherapy treatments of cervical cancer were recruited in this study. A series of diodes incorporated in a rectal probe was inserted into the patient's rectum during each brachytherapy procedure. Real-time measured rectal doses were compared to calculated doses by the treatment planning system (TPS). The differences between calculated and measured dose ranged from 8.5% to 41.2%. This corresponds to absolute dose differences ranging from 0.3 Gy to 1.5 Gy. A linear relationship was observed between calculated and measured doses with linear regression R(2) value of 0.88, indicating close association between the measured and calculated doses. In general, absorbed doses for the rectum as calculated by TPS were observed to be higher than the doses measured using the diode probe. In-vivo dosimetry is an important quality assurance method for HDR brachytherapy of cervical cancer. It provides information that can contribute to the reduction of errors and discrepancies in dose delivery. Our study has shown that in-vivo dosimetry is feasible and can be performed to estimate the dose to the rectum during HDR brachytherapy using Co-60.
    Matched MeSH terms: Cobalt Radioisotopes/therapeutic use*
  18. Thyroid eye disease--medical or surgical therapy?
    Khalid BA, Ng ML
    Ann Acad Med Singap, 1991 Mar;20(2):273-6.
    PMID: 1883189
    Thyroid eye disease is autoimmune in nature and associated with Graves' Disease. Autoantibodies to the 64 kDa antigen in thyroid membranes cross-react to the 64 kDa proteins in human eye muscle membranes. Antibody dependent cell mediated cytotoxicity against eye muscle cells are also found in patients with thyroid eye disease. The purpose of this paper is to review the treatment available and to share the authors' experience using cyclosporin A. In the majority of cases, thyroid eye disease is mild, manifest only as bilateral or unilateral proptosis, with/without grittiness of the eyes. This is usually treated conservatively with eye drops. If proptosis is more severe and there is incomplete closure of eyelids, epiphora and conjunctival injection, then lateral tarrsorrhaphy is usually effective, combined with use of eye pads and eye drops. The problem of diplopia can be treated conservatively with special lenses, or with surgical correction of tethered muscles. However when proptosis is severe, with raised intraocular pressure, severe chemosis and danger of blindness, then the choice of therapy is controversial: rapid decompression by surgical means or use of high doses of prednisolone. Most prefer prednisolone therapy initially, surgical decompression if it fails. Various other methods have been tried, aimed at the immunological nature of the disease, namely plasmapheresis, radiotherapy and immunosuppressive drugs such as cyclosporin, with variable success. Our experience with cyclosporin had been mixed and inconclusive.
    Matched MeSH terms: Iodine Radioisotopes/therapeutic use
  19. Fulltext Synergetic Influence of Bismuth Oxide Nanoparticles, Cisplatin and Baicalein-Rich Fraction on Reactive Oxygen Species Generation and Radiosensitization Effects for Clinical Radiotherapy Beams
    Talik Sisin NN, Abdul Razak K, Zainal Abidin S, Che Mat NF, Abdullah R, Ab Rashid R, et al.
    Int J Nanomedicine, 2020;15:7805-7823.
    PMID: 33116502 DOI: 10.2147/IJN.S269214
    Purpose: This study aimed to quantify synergetic effects induced by bismuth oxide nanoparticles (BiONPs), cisplatin (Cis) and baicalein-rich fraction (BRF) natural-based agent on the reactive oxygen species (ROS) generation and radiosensitization effects under irradiation of clinical radiotherapy beams of photon, electron and HDR-brachytherapy. The combined therapeutic responses of each compound and clinical radiotherapy beam were evaluated on breast cancer and normal fibroblast cell line.

    Methods: In this study, individual BiONPs, Cis, and BRF, as well as combinations of BiONPs-Cis (BC), BiONPs-BRF (BB) and BiONPs-Cis-BRF (BCB) were treated to the cells before irradiation using HDR brachytherapy with 0.38 MeV iridium-192 source, 6 MV photon beam and 6 MeV electron beam. The individual or synergetic effects from the application of the treatment components during the radiotherapy were elucidated by quantifying the ROS generation and radiosensitization effects on MCF-7 and MDA-MB-231 breast cancer cell lines as well as NIH/3T3 normal cell line.

    Results: The ROS generated in the presence of Cis stimulated the most substantial amount of ROS compared to the BiONPs and BRF. Meanwhile, the combination of the components had induced the higher ROS levels for photon beam than the brachytherapy and electron beam. The highest ROS enhancement relative to the control is attributable to the presence of BC combination in MDA-MB-231 cells, in comparison to the BB and BCB combinations. The radiosensitization effects which were quantified using the sensitization enhancement ratio (SER) indicate the highest value by BC in MCF-7 cells, followed by BCB and BB treatment. The radiosensitization effects are found to be more prominent for brachytherapy in comparison to photon and electron beam.

    Conclusion: The BiONPs, Cis and BRF are the potential radiosensitizers that could improve the efficiency of radiotherapy to eradicate the cancer cells. The combination of these potent radiosensitizers might produce multiple effects when applied in radiotherapy. The BC combination is found to have the highest SER, followed by the BCB combination. This study is also the first to investigate the effect of BRF in combination with BiONPs (BB) and BC (BCB) treatments.

    Matched MeSH terms: Iridium Radioisotopes/therapeutic use
  20. 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: Iodine Radioisotopes/therapeutic use*
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