Displaying publications 41 - 60 of 275 in total

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  1. Bhoo-Pathy N, Pignol JP, Verkooijen HM
    Lancet, 2014 Nov 22;384(9957):1846.
    PMID: 25457914 DOI: 10.1016/S0140-6736(14)62239-X
    Matched MeSH terms: Breast Neoplasms/radiotherapy*
  2. Adauwiyah J, Suraiya HH
    Med J Malaysia, 2010 Dec;65(4):297-9.
    PMID: 21901949 MyJurnal
    Psoralen and ultraviolet light A (PUVA) was the mainstay of vitiligo treatment before the introduction of narrowband UVB(NB-UVB). Eighteen patients treated with NB-UVB in Hospital Kuala Lumpur were retrospectively analyzed. Eight patients had Fitzpatrick skin phototype III and 10 with phototype IV. The mean duration of disease was 7.3 +/- 5.4 years, and the mean body surface area affected was 19.3 +/- 16.2%. Mean duration of treatment was 14.3 +/- 9.6 months, number of session 113.5 +/- 88.6 times and cumulative dose 111.7 +/- 108.5 J/ cm2. Concomitant topical steroid was used in 88.9% patients. Repigmentation was moderate in 6 (40%) patients, good in 3 (20%), while 3 (20%) achieved excellent results. One patient (6.6%) showed no response and 2 (13.3%) showed poor repigmentation. Three patients developed side effects. NB-UVB phototherapy results in satisfactory repigmentation in our vitiligo patients and should be offered as a treatment option.
    Matched MeSH terms: Vitiligo/radiotherapy*
  3. Ng KH
    Australas Phys Eng Sci Med, 2008 Jun;31(2):85-9.
    PMID: 18697700
    From the time when Roentgen and other physicists made the discoveries which led to the development of radiology, radiotherapy and nuclear medicine, medical physicists have played a pivotal role in the development of new technologies that have revolutionized the way medicine is practiced today. Medical physicists have been transforming scientific advances in the research laboratories to improving the quality of life for patients; indeed innovations such as computed tomography, positron emission tomography and linear accelerators which collectively have improved the medical outcomes for millions of people. In order for radiation-delivery techniques to improve in targeting accuracy, optimal dose distribution and clinical outcome, convergence of imaging and therapy is the key. It is timely for these two specialties to work closer again. This can be achieved by means of cross-disciplinary research, common conferences and workshops, and collaboration in education and training for all. The current emphasis is on enhancing the specific skill development and competency of a medical physicist at the expense of their future roles and opportunities. This emphasis is largely driven by financial and political pressures for optimizing limited resources in health care. This has raised serious concern on the ability of the next generation of medical physicists to respond to new technologies. In addition in the background loom changes of tsunami proportion. The clearly defined boundaries between the different disciplines in medicine are increasingly blurred and those between diagnosis, therapy and management are also following suit. The use of radioactive particles to treat tumours using catheters, high-intensity focused ultrasound, electromagnetic wave ablation and photodynamic therapy are just some areas challenging the old paradigm. The uncertainty and turf battles will only explode further and medical physicists will not be spared. How would medical physicists fit into this changing scenario? We are in the midst of molecular revolution. Are we prepared to explore the newer technologies such as nanotechnology, drug discovery, pre-clinical imaging, optical imaging and biomedical informatics? How are our curricula adapting to the changing needs? We should remember the late Professor John Cameron who advocated imagination and creativity - these important attributes will make us still relevant in 2020 and beyond. To me the future is clear: "To achieve more, we should imagine together."
    Matched MeSH terms: Radiotherapy/trends*
  4. Abdulla YA, Amin YM, Khoo HB
    J Radiol Prot, 2002 Dec;22(4):417-21.
    PMID: 12546228
    Percentage depth doses for 6 and 10 MV x-ray beams from a linear accelerator were measured using approximately 1 cm long (approximately 0.3 mg) Ge-doped optical fibre as a thermoluminescence dosimeter for two field sizes, 5 x 5 and 10 x 10 cm2. The results indicate that the Ge-doped optical fibre dosimeter is in good agreement with the results from a PTW 30001 cylindrical ionisation chamber and TLD-100. For 6 MV x-ray beams we observe that the depth of maximum dose d(max) is 1.5 and 2 cm for field sizes of 5 x 5 and 10 x 10 cm2 respectively. For 10 MV d(max) is 2 cm for a field size of 5 x 5 cm2 and 2.5 cm for a 10 x 10 cm2 field.
    Matched MeSH terms: Radiotherapy, High-Energy*
  5. Chong ZX, Yeap SK, Ho WY
    Int J Radiat Biol, 2021;97(3):289-301.
    PMID: 33356761 DOI: 10.1080/09553002.2021.1864048
    Breast cancer is the most common type of cancer that affects females globally. Radiotherapy is a standard treatment option for breast cancer, where one of its most significant limitations is radioresistance development. MicroRNAs (miRNAs) are small, non-protein-coding RNAs that have been widely studied for their roles as disease biomarkers. To date, several in vitro, in vivo, and clinical studies have reported the roles of miRNAs in regulating radiosensitivity and radioresistance in breast cancer cells. This article reviews the roles of miRNAs in regulating treatment response toward radiotherapy and the associating cellular pathways. We identified 36 miRNAs that play a role in mediating radio-responses; 22 were radiosensitizing, 12 were radioresistance-promoting, and two miRNAs were reported to promote both effects. A brief overview of breast cancer therapy options, mechanism of action of radiation, and molecular mechanism of radioresistance was provided in this article. A summary of the latest clinical researches involving miRNAs in breast cancer radiotherapy was also included.
    Matched MeSH terms: Breast Neoplasms/radiotherapy*
  6. Gaffney D, Small B, Kitchener H, Young Ryu S, Viswanathan A, Trimble T, et al.
    Int. J. Gynecol. Cancer, 2016 11;26(9):1690-1693.
    PMID: 27779548
    Eighty-seven percent of cervix cancer occurs in less-developed regions of the world, and there is up to an 18-fold difference in mortality rate for cervix cancer depending on the region of the world. The Cervix Cancer Research Network (CCRN) was founded through the Gynecologic Cancer InterGroup with the aim of improving access to clinical trials in cervix cancer worldwide, and in so doing improving standards of care. The CCRN recently held its first international educational symposium in Bangkok. Sixty-two participants attended from 16 different countries including Pakistan, India, Bangladesh, Thailand, Malaysia, Singapore, Philippines, Taiwan, China, Vietnam, Korea, Japan, Columbia, Brazil, Canada, and the United States. The focus of this symposium was to evaluate progress, to promote new clinical trials for the CCRN, and to provide education regarding the role of brachytherapy in the treatment of cervical cancer.
    Matched MeSH terms: Uterine Cervical Neoplasms/radiotherapy*
  7. CHESTERMAN JN
    Med J Malaysia, 1963 Jun;17:263-8.
    PMID: 14060502
    Matched MeSH terms: Neoplasms/radiotherapy*
  8. Bradley DA, Ng KH, Aziz YB
    Int J Rad Appl Instrum A, 1988;39(5):439-40.
    PMID: 2840420
    The utility of a phantom material, based on SMR(L) [Standard Malaysian Rubber] grade natural rubber and a formulation used for the proprietary rubber phantom-material, Temex, has been examined for the 1-MeV photon-Measurement has also been performed with 60-keV photons using the radionuclide 241Am. At photon-therapy energy levels the measured response, when compared with tabulated central-axis percentage depth doses for the defined measuring conditions, produces everywhere (in the range 1-19 cm depth) better than 2% deviation. The favourable measured response characteristics combined with the ease of processing and casting the phantom material provide the basis for useful radiotherapy machine calibration and anthropomorphic dosimetry measurements. The measured mass-attenuation coefficient, at 60keV, of 0.204 cm2 g-1 (+/- 3%) is in close agreement with tabulated values for water (0.2055 cm2 g-1).
    Matched MeSH terms: Radiotherapy Dosage*
  9. Begum M, Rahman AKMM, Abdul-Rashid HA, Yusoff Z, Mat Nawi SN, Khandaker MU, et al.
    Appl Radiat Isot, 2021 Aug;174:109771.
    PMID: 34048992 DOI: 10.1016/j.apradiso.2021.109771
    Present study concerns the key thermoluminescence (TL) properties of photonic crystal fibres (PCFs), seeking development of alternatively structured TL materials that are able to offer a advantages over existing passive dosimeters. In terms of their internal structure and light guiding properties the PCFs, collapsed and structured, differ significantly from that of conventional optical fibres. To investigate the dosimetric parameters of the PCFs use was made of a linear accelerator producing a 6 MV photon beam, delivering doses ranging from 0.5 Gy to 8 Gy. The parameters studied included TL response, linearity index, glow curves, relative sensitivity and TL signal fading, the results being compared against those obtained using TLD-100 chips. At 4 Gy photon dose the Ge-doped collapsed PCFs were found to provide a response 27 × that of structured PCF, also giving a TL yield similar to that of standard TLD-100 chips. Over post-irradiation periods of 15 and 30 days collapsed PCF TL signal fading were 8% and 17% respectively, with corresponding values of 37% and 64% for the structured PCF. Trapping parameters including the order of kinetics (b), activation energy (E) and frequency factor (s-1) were assessed with Chen's peak shape method. Lifetime of trapping centre was found to be (2.36 E+03) s and (9.03 E +01) s regarding the collapsed and structured PCF respectively with 6 Gy of photon beam. For the Ge-doped collapsed PCF, the high TL yield, sensitivity and low fading provide the basis of a highly promising system of TLD for radiotherapy applications.
    Matched MeSH terms: Radiotherapy Dosage*
  10. Tsapaki V, Ibbott G, Krisanachinda A, Ng KH, Suh TS, Tabakov S, et al.
    Phys Med, 2017 Dec;44:196-198.
    PMID: 29221890 DOI: 10.1016/j.ejmp.2017.11.022
    As medical technology evolves and patient needs increase, the need for well-trained and highly professional medical physicists (MPs) becomes even more urgent. The roles and responsibilities of MPs in various departments within the hospital are diverse and demanding. It is obvious that training, continuing education and professional development of MPs have become essential. One of the ways for an MP to advance his or her knowledge is to participate in conferences and congresses. Last year, the 22nd International Conference of Medical Physics (ICMP 2016) took place in Bangkok, Thailand. The event attracted 584 delegates with most of the participants coming from Asia. It attracted also delegates from 42 countries. The largest delegations were from Thailand, Japan and South Korea. ICMP 2016 included 367 oral presentations and e-posters, most of these being in the fields of Radiation Therapy, Medical Imaging and Radiation Safety. All abstracts were published as an e-book of Abstracts in a supplement to the official IOMP Journal. Many companies had exhibition stands at ICMP2016, thus allowing the participants to see the latest developments in the medical physics-related industry. The conference included 42 mini-symposia, part of the first "IOMP School" activity, covering various topics of importance for the profession and this special issue follows from the success of the conference.
    Matched MeSH terms: Neoplasms/radiotherapy
  11. Khoo FY
    Singapore Med J, 1972 Feb;13(1):65-73.
    PMID: 4555689
    Matched MeSH terms: Radiotherapy/history
  12. Okonogi N, Kono S, Karasawa K, Banu PA, Xu X, Erawati D, et al.
    Clin Oncol (R Coll Radiol), 2023 Jul;35(7):463-471.
    PMID: 37179216 DOI: 10.1016/j.clon.2023.04.007
    AIMS: There is a need for the adequate distribution of healthcare resources in Southeast Asia. Many countries in the region have more patients with advanced breast cancer who are eligible for postmastectomy radiotherapy (PMRT). Therefore, it is critical that hypofractionated PMRT is effective in most of these patients. This study investigated the significance of postoperative hypofractionated radiotherapy in patients with breast cancer, including advanced breast cancer, in these countries.

    MATERIALS AND METHODS: Eighteen facilities in 10 Asian countries participated in this prospective, interventional, single-arm study. The study included two independent regimens: hypofractionated whole-breast irradiation (WBI) for patients who had undergone breast-conserving surgery and hypofractionated PMRT for patients who had undergone total mastectomy at a dose of 43.2 Gy in 16 fractions. In the hypofractionated WBI group, patients with high-grade factors received additional 8.1 Gy boost irradiation sessions for the tumour bed in three fractions.

    RESULTS: Between February 2013 and October 2019, 227 and 222 patients were enrolled in the hypofractionated WBI and hypofractionated PMRT groups, respectively. The median follow-up periods in the hypofractionated WBI and hypofractionated PMRT groups were 61 and 60 months, respectively. The 5-year locoregional control rates were 98.9% (95% confidence interval 97.4-100.0) and 96.3% (95% confidence interval 93.2-99.4) in the hypofractionated WBI and hypofractionated PMRT groups, respectively. Regarding adverse events, grade 3 acute dermatitis was observed in 2.2% and 4.9% of patients in the hypofractionated WBI and hypofractionated PMRT groups, respectively. However, no other adverse events were observed.

    CONCLUSION: Although further follow-up is required, hypofractionated radiotherapy regimens for postoperative patients with breast cancer in East and Southeast Asian countries are effective and safe. In particular, the proven efficacy of hypofractionated PMRT indicates that more patients with advanced breast cancer can receive appropriate care in these countries. Hypofractionated WBI and hypofractionated PMRT are reasonable approaches that can contain cancer care costs in these countries. Long-term observation is required to validate our findings.

    Matched MeSH terms: Radiotherapy, Adjuvant/adverse effects
  13. Tan HY, Wong YH, Kasbollah A, Md Shah MN, Abdullah BJJ, Perkins AC, et al.
    Nucl Med Commun, 2022 Apr 01;43(4):410-422.
    PMID: 35045548 DOI: 10.1097/MNM.0000000000001529
    PURPOSE: Hepatic radioembolization is an effective minimally invasive treatment for primary and metastatic liver cancers. Yttrium-90 [90Y]-labelled resin or glass beads are typically used as the radioembolic agent for this treatment; however, these are not readily available in many countries. In this study, novel samarium-153 oxide-loaded polystyrene ([153Sm]Sm2O3-PS) microspheres were developed as a potential alternative to 90Y microspheres for hepatic radioembolization.

    METHODS: The [152Sm]Sm2O3-PS microspheres were synthesized using solid-in-oil-in-water solvent evaporation. The microspheres underwent neutron activation using a 1 MW open-pool research reactor to produce radioactive [153Sm]Sm2O3-PS microspheres via 152Sm(n,γ)153Sm reaction. Physicochemical characterization, gamma spectroscopy and in-vitro radionuclide retention efficiency were carried out to evaluate the properties and stability of the microspheres before and after neutron activation.

    RESULTS: The [153Sm]Sm2O3-PS microspheres achieved specific activity of 5.04 ± 0.52 GBq·g-1 after a 6 h neutron activation. Scanning electron microscopy and particle size analysis showed that the microspheres remained spherical with an average diameter of ~33 μm before and after neutron activation. No long half-life radionuclide and elemental impurities were found in the samples. The radionuclide retention efficiencies of the [153Sm]Sm2O3-PS microspheres at 550 h were 99.64 ± 0.07 and 98.76 ± 1.10% when tested in saline solution and human blood plasma, respectively.

    CONCLUSIONS: A neutron-activated [153Sm]Sm2O3-PS microsphere formulation was successfully developed for potential application as a theranostic agent for liver radioembolization. The microspheres achieved suitable physical properties for radioembolization and demonstrated high radionuclide retention efficiency in saline solution and human blood plasma.

    Matched MeSH terms: Liver Neoplasms/radiotherapy
  14. 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: Neoplasms/radiotherapy*; Radiotherapy/trends*
  15. Tan SH, Chong AW, Nazarina AR, Prepageran N
    Otolaryngol Pol, 2014 Sep-Oct;68(5):268-70.
    PMID: 25283325 DOI: 10.1016/j.otpol.2013.09.003
    We describe a rare case of BSCC in the retromolar trigone with only 3 other cases in the literature and also compare the differences between 2 cases of BSCC in terms of presentation and progression. The first patient had a markedly slower progression with painful retromolar trigone swelling over 4 months without nodal metastases. In contrast, the second patient gave a 2-week history of neck swelling with nodal involvement, indicating extremely rapid progression. Our management was tailored accordingly with the first patient undergoing intraoral excision of tumour and adjuvant radiotherapy while the other had bilateral neck dissection with postoperative chemoradiotherapy. Both patients achieved good outcome and are free from disease.
    Matched MeSH terms: Radiotherapy, Adjuvant
  16. Gokula K, Earnest A, Wong LC
    Radiat Oncol, 2013;8:268.
    PMID: 24229418 DOI: 10.1186/1748-717X-8-268
    This meta-analysis aims to ascertain the significance of early lung toxicity with 3-Dimensional (3D) conformal irradiation for breast carcinomas and identify the sub-groups of patients with increased risk.
    Matched MeSH terms: Breast Neoplasms/radiotherapy*; Radiotherapy, Conformal/adverse effects*
  17. Phua CE, Tan BS, Tan AL, Eng KY, Ng BS, Malik RA, et al.
    Asian Pac J Cancer Prev, 2012;13(7):3287-92.
    PMID: 22994749
    PURPOSE: To study the overall treatment time (OTT) and acute toxicity of intensity-modulated radiotherapy (IMRT) treatment for nasopharyngeal carcinoma (NPC).

    METHODS: This retrospective study covered all NPC patients who underwent radical IMRT treatment at the Penang General Hospital from June 2011 to February 2012. Patients of any age and stage of disease with histologically proven diagnosis were included. Information was collected on patient demographics, clinical stage, treatment received, including any neoadjuvant and/or concurrent chemotherapy, acute toxity and completion of IMRT within the OTT.

    RESULTS: A total of 26 NPC patients were treated with IMRT during the study period; 88.5% had stage III/IV disease. 45.2% received neo-adjuvant chemotherapy while 50.0% were given concurrent chemo-irradiation. All patients completed the treatment and 92.3% within the 7 weeks OTT. Xerostomia was present in all patients with 92.3% having grade 2. Severe grade III/IV acute toxicity occurred in 73.1% of patients, the commonest of which was oral mucositis (57.6%). This was followed by dysphagia which occurred in 53.8%, skin reactions in 42.3% and weight loss in 19.2%. However, haematological toxicity was mild with only one patient having leucopaenia.

    CONCLUSION: IMRT treatment for NPC is feasible in our center. More importantly, it can be delivered within the 7 weeks OTT in the majority of patients. Severe grade 3/4 toxicity is very common (73.1%) and thus maximal nutritional and analgesic support is required throughout the treatment.

    Matched MeSH terms: Nasopharyngeal Neoplasms/radiotherapy*; Radiotherapy Dosage; Radiotherapy, Intensity-Modulated
  18. Norhafizah M, Mustafa WM, Sabariah AR, Shiran MS, Pathmanathan R
    Med J Malaysia, 2010 Sep;65(3):218-20.
    PMID: 21939172
    Mucosal malignant melanoma (MMM) is an aggressive tumour occurring in the upper respiratory tract. It is rare compared to malignant melanoma of the skin. We report a case of a 53-year-old man with left paranasal swelling. A biopsy showed high-grade spindle cell tumour. Subsequently a subtotal maxillectomy was performed. Histopathological examination revealed a hypercellular tumour composed of mixed spindle and epitheloid cells with very occasional intracytoplasmic melanin pigment. The malignant cells were immunopositive for vimentin, S-100 protein and HMB-45. It was diagnosed as mucosal malignant melanoma (MMM). This article illustrates a rare case of MMM where the diagnosis may be missed or delayed without proper histopathological examination that include meticulous search for melanin pigment and appropriate immunohistochemical stains to confirm the diagnosis. Malignant melanoma can mimic many other types of high-grade malignancy and should be considered as a differential diagnosis in many of these instances.
    Matched MeSH terms: Maxillary Sinus Neoplasms/radiotherapy; Melanoma/radiotherapy; Radiotherapy, Adjuvant
  19. Marina MB, Gendeh BS
    Med J Malaysia, 2006 Mar;61(1):94-6.
    PMID: 16708742
    Reported cases of acquired posterior choanal atresia are very few in the English literature. A case of acquired posterior choanal atresia post radiotherapy is reported which was treated by endonasal endoscopic repair using microdebrider with untoward effect.
    Matched MeSH terms: Nasopharyngeal Neoplasms/radiotherapy; Radiotherapy/adverse effects*
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