Displaying publications 1 - 20 of 269 in total

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  1. 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: Radiotherapy Dosage
  2. 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*
  3. Abdullah JM, Mutum SS, Nasuha NA, Biswal BM, Ariff AR
    Neurol. Med. Chir. (Tokyo), 2002 Jun;42(6):259-63.
    PMID: 12116532
    A 28-year-old Malay man presented with progressive paraparesis over a period of 6 months. Magnetic resonance imaging of the spine revealed a thoracic intramedullary spinal cord tumor at the T-7 level with homogeneous enhancement following intravenous gadolinium administration. Laminectomy and partial decompression of the tumor was performed. Histological examination of the tumor revealed features of spindle cell hemangioendothelioma. The patient was managed with limited field radiotherapy followed by systemic interferon therapy. Good neurological improvement was seen subsequently. The patient has survived 48 months with growth restraint at the primary site, although residual neurological deficit persists. Immunotherapy should be considered as a treatment modality for intramedullary hemangioendothelioma of the spinal cord after surgery and radiotherapy.
    Matched MeSH terms: Hemangiosarcoma/radiotherapy; Radiotherapy, High-Energy; Spinal Cord Neoplasms/radiotherapy
  4. Abdur Razzaque Mughal, Zakiyah Zain, Nazrina Aziz
    Sains Malaysiana, 2016;45:1763-1772.
    In this study, group acceptance sampling plan (GASP) proposed by Aslam et al. (2011) is redesigned where the lifetime of
    test items are following Pareto distribution of 2nd kind. The optimal plan parameters are found by considering various
    pre-determined designed parameters. The plan parameters were obtained using the optimization solution and it also
    concludes that the proposed plan is more efficient than the existing plan as it requires minimum sample size.
    Matched MeSH terms: Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated
  5. 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*
  6. Aggarwal A, Court LE, Hoskin P, Jacques I, Kroiss M, Laskar S, et al.
    BMJ Open, 2023 Dec 07;13(12):e077253.
    PMID: 38149419 DOI: 10.1136/bmjopen-2023-077253
    INTRODUCTION: Fifty per cent of patients with cancer require radiotherapy during their disease course, however, only 10%-40% of patients in low-income and middle-income countries (LMICs) have access to it. A shortfall in specialised workforce has been identified as the most significant barrier to expanding radiotherapy capacity. Artificial intelligence (AI)-based software has been developed to automate both the delineation of anatomical target structures and the definition of the position, size and shape of the radiation beams. Proposed advantages include improved treatment accuracy, as well as a reduction in the time (from weeks to minutes) and human resources needed to deliver radiotherapy.

    METHODS: ARCHERY is a non-randomised prospective study to evaluate the quality and economic impact of AI-based automated radiotherapy treatment planning for cervical, head and neck, and prostate cancers, which are endemic in LMICs, and for which radiotherapy is the primary curative treatment modality. The sample size of 990 patients (330 for each cancer type) has been calculated based on an estimated 95% treatment plan acceptability rate. Time and cost savings will be analysed as secondary outcome measures using the time-driven activity-based costing model. The 48-month study will take place in six public sector cancer hospitals in India (n=2), Jordan (n=1), Malaysia (n=1) and South Africa (n=2) to support implementation of the software in LMICs.

    ETHICS AND DISSEMINATION: The study has received ethical approval from University College London (UCL) and each of the six study sites. If the study objectives are met, the AI-based software will be offered as a not-for-profit web service to public sector state hospitals in LMICs to support expansion of high quality radiotherapy capacity, improving access to and affordability of this key modality of cancer cure and control. Public and policy engagement plans will involve patients as key partners.

    Matched MeSH terms: Radiotherapy Planning, Computer-Assisted
  7. Ahmad P, Khandaker MU, Muhammad N, Rehman F, Ullah Z, Khan G, et al.
    Appl Radiat Isot, 2020 Dec;166:109404.
    PMID: 32956924 DOI: 10.1016/j.apradiso.2020.109404
    The shortcomings in Boron neutron capture therapy (BNCT) and Hyperthermia for killing the tumor cell desired for the synthesis of a new kind of material suitable to be first used in BNCT and later on enable the conditions for Hyperthermia to destroy the tumor cell. The desire led to the synthesis of large band gap semiconductor nano-size Boron-10 enriched crystals of hexagonal boron nitride (10BNNCs). The contents of 10BNNCs are analyzed with the help of x-ray photoelectron spectroscopy (XPS) and counter checked with Raman and XRD. The 10B-contents in 10BNNCs produce 7Li and 4He nuclei. A Part of the 7Li and 4He particles released in the cell is allowed to kill the tumor (via BNCT) whereas the rest produce electron-hole pairs in the semiconductor layer of 10BNNCs suggested to work in Hyperthermia with an externally applied field.
    Matched MeSH terms: Neoplasms/radiotherapy
  8. Ahmad, M.B., Hashim, K.B., Mohd Yazid, N., Zainuddin, N.
    MyJurnal
    In this work, hydrogels were prepared from carboxymethyl cellulose (CMC) and 1-vinyl-2-pyrrolidone(VP) by Electron Beam irradiation in the presence of N,N'-methylenebisacrylamide (BIS) as a crosslinkingagent. The parameters studied include stirring time and percentage of crosslinking agent. Hydrogels werecharacterized using Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy(SEM). VP and BIS were found be effective as reinforcement materials to improve the properties ofCMC. Meanwhile, the optimum conditions were 5% BIS and 3 hours of stirring time. The gel fractionincreased when irradiation dose was increased. FTIR confirmed the crosslinking reaction between CMCand VP after the irradiation process by using BIS as the crosslinking agent. TGA thermograms showedchanges in the thermal properties of CMC-VP hydrogels in the presence of different amounts of BIS.
    Matched MeSH terms: Radiotherapy Dosage
  9. 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: Hyperthyroidism/radiotherapy; Thyroid Neoplasms/radiotherapy*
  10. Alashrah S, Kandaiya S, Lum LS, Cheng SK
    Z Med Phys, 2013 Dec;23(4):270-8.
    PMID: 24113373 DOI: 10.1016/j.zemedi.2013.09.001
    One of the factors which influence the spatial resolution of a 2D detector array is the size of the single detector, another the transport of the secondary electrons from the walls into the measuring volume. In this study, the single ion chamber dose response function of an I'mRT MatriXX array was determined by comparison between slit beam dose profiles measured with the array and with EBT2 radiochromic film in a solid water-equivalent phantom at a shallow depth of 0.5cm and at a depth of 5cm beyond the depth dose maximum for a 6 MV photon beam. The dose response functions were obtained using two methods, the best fit method and the deconvolution method. At the shallow depth, a Lorentz function and at 5cm depth a Gaussian function, both with the same FWHM of 7.4mm within limits of uncertainty, were identified as the best suited dose response functions of the 4.5mm diameter single array chamber. These dose response functions were then tested on various dose profiles whose true shape had been determined with EBT2 film and with the IC03 ionization chamber. By convolving these with the Lorentz kernel (at shallow depth) and the Gaussian kernel (at 5cm depth) the signal profiles measured with the I'mRT MatriXX array were closely approximated. Thus, the convolution of TPS-calculated dose profiles with these dose response functions can minimize the differences between calculation and measurement which occur due to the limited spatial resolution of the I'mRT MatriXX detector.
    Matched MeSH terms: Radiotherapy, Conformal/instrumentation*
  11. Alawiah A, Alina MS, Bauk S, Abdul-Rashid HA, Gieszczyk W, Noramaliza MN, et al.
    Appl Radiat Isot, 2015 Apr;98:80-6.
    PMID: 25644081 DOI: 10.1016/j.apradiso.2015.01.016
    The thermoluminescence (TL) glow curves and kinetics parameters of Thulium (Tm) doped silica cylindrical fibers (CF) are presented. A linear accelerator (LINAC) was used to deliver high-energy radiation of 21MeV electrons and 10MV photons. The CFs were irradiated in the dose range of 0.2-10Gy. The experimental glow curve data was reconstructed by using WinREMS. The WinGCF software was used for the kinetic parameters evaluation. The TL sensitivity of Tm-doped silica CF is about 2 times higher as compared to pure silica CF. Tm-doped silica CF seems to be more sensitive to 21MeV electrons than to 10MV photons. Surprisingly, no supralinearity was displayed and a sub-linear response of Tm-doped silica CF was observed within the analyzed dose range for both 21MeV electrons and 10MV photons. The Tm-doped silica CF glow curve consists of 5 individual glow peaks. The Ea of peak 4 and peak 5 was highly dependent on dose when irradiated with photons. We also noticed that the electron radiation (21MeV) caused a shift of glow peak by 7-13°C to the higher temperature region compared with photons radiation (10MV). Our Tm-doped fibers seem to give high TL response after 21MeV electrons, which gives around 2 times higher peak integral as compared with 10MV photon radiation. We concluded that peak 4 is the first-order kinetic peak and can be used as the main dosimetric peak of Tm-doped silica CF.
    Matched MeSH terms: Radiotherapy, High-Energy
  12. Alcantara VS, Lim GH, Lim SH, Sultana R, Lee JA
    J Surg Oncol, 2017 Apr;115(5):523-537.
    PMID: 28168712 DOI: 10.1002/jso.24559
    BACKGROUND AND OBJECTIVES: Triple negative breast cancer (TNBC) carries a worse prognosis compared to the other subtypes. There have been conflicting studies that race may impact the prognosis of TNBC patients. We aim to determine the incidence and prognosis of TNBC among the different ethnic races in Singapore, and to determine its associated risk factors for prognosis.

    METHODS: Patients diagnosed with invasive breast cancer (BC) from 2005 to 2013 at our tertiary institution were included and divided according to race and subtypes. Demographic and clinical information of non-metastatic TNBC patients were analyzed. Log-rank test, univariate and multivariate Cox proportional hazard regression models were used to find associated risk factors related with overall survival (OS) and disease-free survival (DFS).

    RESULTS: Among 1227 BC patients, 129 (10.5%) had TNBC. TNBC patients had the worst OS (P: 0.0005) and DFS (P: 0.0016) among the subtypes. However, variations in race did not have any difference in OS or DFS among TNBC patients. Axillary lymph node involvement, invasive lobular histology, larger tumor size, and the presence of lymphovascular invasion (LVI) were factors associated with both poor DFS and OS among TNBC patients.

    CONCLUSIONS: Racial variation did not have any impact on the prognosis of the TNBC.

    Matched MeSH terms: Radiotherapy, Adjuvant
  13. 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: Breast Neoplasms/radiotherapy*; Radiotherapy Dosage; Radiotherapy, Conformal/adverse effects
  14. Aminah M, Ng KH, Abdullah BJ, Jamal N
    Australas Phys Eng Sci Med, 2010 Dec;33(4):329-34.
    PMID: 20938762 DOI: 10.1007/s13246-010-0035-3
    The performance of a digital mammography system (Siemens Mammomat Novation) using different target/filter combinations and tube voltage has been assessed. The objective of this study is to optimize beam quality selection based on contrast-to-noise ratio (CNR) and mean glandular dose (MGD). Three composition of breast were studied with composition of glandular/adipose of 30/70, 50/50, and 70/30. CNR was measured using 2, 4 and 6 cm-thick simulated breast phantoms with an aluminium sheet of 0.1 mm thickness placed on top of the phantom. Three target/filter combinations, namely molybdenum/molybdenum (Mo/Mo), molybdenum/rhodium (Mo/Rh) and tungsten/rhodium (W/Rh) with various tube voltage and mAs were tested. MGD was measured for each exposure. For 50/50 breast composition, Mo/Rh combination with tube voltage 26 kVp is optimal for 2 cm-thick breast. W/Rh combination with tube voltage 27 and 28 kVp are optimal for 4 and 6 cm-thick breast, respectively. For both 30/70 and 70/30 breast composition, W/Rh combination is optimal with tube voltage 25, 26 and 27 kVp, respectively. From our study it was shown that there are potential of dose reduction up to 11% for a set CNR of 3.0 by using beam quality other than that are determined by AEC selection. Under the constraint of lowest MGD, for a particular breast composition, calcification detection is optimized by using a softer X-ray beam for thin breast and harder X-ray beam for thick breast. These experimental results also indicate that for breast with high fibroglandular tissues (70/30), the use of higher beam quality does not always increase calcification detection due to additional structured noise caused by the fibroglandular tissues itself.
    Matched MeSH terms: Radiotherapy Planning, Computer-Assisted/methods*
  15. Aminordin Sabri AH, Mohamad Tajudin S, Abdul Aziz MZ, Furuta T
    Radiol Phys Technol, 2023 Mar;16(1):109-117.
    PMID: 36729272 DOI: 10.1007/s12194-023-00703-8
    In a brachytherapy room irradiated with an Iridium-192 (192Ir) source, the spatial distributions of photon dose rates were measured and calculated for the dose distribution both inside and outside the room. The spatial distributions were measured using a thermoluminescent dosimeter (LiF-100) on the surfaces of the concrete walls and barriers of the irradiation room. The calculations were performed using the particle and heavy ion transport code system (PHITS) by considering the detailed model of the brachytherapy room and the radiation source used in the measurements. The measured and calculated doses exhibited a similar distribution pattern within and outside the brachytherapy room. To reduce the edge effect at the entrance door, the addition of a 3-mm thick lead layer on the surface of the concrete wall on the left doorstop is recommended. For the 60Co source, with the existing walls and lead door thickness, the dose at the control console and in front of the entrance maze increased by a factor of approximately 60.
    Matched MeSH terms: Radiotherapy Dosage
  16. Ariza M, Rafaee T, Adeeb N, Muhaizan WM, Isa MR
    Med J Malaysia, 1999 Sep;54(3):371-3.
    PMID: 11045067
    A 14 year old girl presented in 1986 with a huge perineal swelling which was progressively increasing in size and associated with loss of weight and loss of appetite. Biopsy from the mass revealed rhabdomyosarcoma of the vulva. She was treated with chemotherapy and radium implant. She responded well to the regime. Fibrosis of the vulva and vagina caused difficulty in consummation. Once it was corrected, she conceived easily and proceeded to a normal pregnancy and delivery.
    Matched MeSH terms: Rhabdomyosarcoma/radiotherapy*; Vulvar Neoplasms/radiotherapy*
  17. Atieno OM, Opanga S, Martin A, Kurdi A, Godman B
    J Med Econ, 2018 Sep;21(9):878-887.
    PMID: 29860920 DOI: 10.1080/13696998.2018.1484372
    BACKGROUND: Currently the majority of cancer deaths occur in low- and middle-income countries, where there are appreciable funding concerns. In Kenya, most patients currently pay out of pocket for treatment, and those who are insured are generally not covered for the full costs of treatment. This places a considerable burden on households if family members develop cancer. However, the actual cost of cancer treatment in Kenya is unknown. Such an analysis is essential to better allocate resources as Kenya strives towards universal healthcare.

    OBJECTIVES: To evaluate the economic burden of treating cancer patients.

    METHOD: Descriptive cross-sectional cost of illness study in the leading teaching and referral hospital in Kenya, with data collected from the hospital files of sampled adult patients for treatment during 2016.

    RESULTS: In total, 412 patient files were reviewed, of which 63.4% (n = 261) were female and 36.6% (n = 151) male. The cost of cancer care is highly dependent on the modality. Most reviewed patients had surgery, chemotherapy and palliative care. The cost of cancer therapy varied with the type of cancer. Patients on chemotherapy alone cost an average of KES 138,207 (USD 1364.3); while those treated with surgery cost an average of KES 128,207 (1265.6), and those on radiotherapy KES 119,036 (1175.1). Some patients had a combination of all three, costing, on average, KES 333,462 (3291.8) per patient during the year.

    CONCLUSION: The cost of cancer treatment in Kenya depends on the type of cancer, the modality, cost of medicines and the type of inpatient admission. The greatest contributors are currently the cost of medicines and inpatient admissions. This pilot study can inform future initiatives among the government as well as private and public insurance companies to increase available resources, and better allocate available resources, to more effectively treat patients with cancer in Kenya. The authors will be monitoring developments and conducting further research.

    Matched MeSH terms: Radiotherapy/economics; Radiotherapy/methods
  18. Azhar T, Kamada T, Lopez F, Harun R, Nor I, Lim A
    Med J Malaysia, 1991 Jun;46(2):123-8.
    PMID: 1839415
    One hundred patients with carcinoma of the cervix stages 1B to 4A were treated with intracavitary high dose rate radiation using a linear cobalt source. All cases have received external beam pelvic irradiation to 4500cGy mid plane in twenty fractions over four weeks. The results in terms of patient compliance and convenience were good while acute and late morbidities were comparable to standard Manchester technique of low dose rate intracavitary therapy as practised in the Institute of Radiotherapy and Oncology General Hospital Kuala Lumpur. The four year actuarial survival rate is 76% for stage II and 48% for stage III. All three stage IV patients died within 1 year. Four out of seven stage I patients are alive (minimum follow-up 18 months, longest 43 months). One died of systemic spread at 33 months while one is lost to follow up.
    Matched MeSH terms: Uterine Cervical Neoplasms/radiotherapy*; Radiotherapy Dosage; Radiotherapy, High-Energy
  19. Azhar T, Lopez F
    Med J Malaysia, 1989 Jun;44(2):104-10.
    PMID: 2626118
    One thousand consecutive cases of carcinoma of the uterine cervix treated in the General Hospital Kuala Lumpur between January 1977 to December 1979 were studied. Epidemiological breakdown by race, age, parity, occupation, stage and histology of the disease were obtained. Treatment complications in survivors available for follow-up were analysed. The Chinese had the highest incidence, followed by the Indians and the Malays. Ninety six percent were squamous cell cancers, the remaining were adenocarcinomas. Eighty percent of patients were seen at an advanced stage (Stage IIB-IV). Late radiation complications were mainly proctitis, cystitis and fistula; (5%, 7.2% and 1.4% respectively). These figures are comparable to many centres but the incidence of cystitis is relatively higher. This is believed to be related to irradiation techniques in these cases.
    Matched MeSH terms: Carcinoma, Squamous Cell/radiotherapy*; Uterine Cervical Neoplasms/radiotherapy*; Radiotherapy/adverse effects*
  20. Azhar T, Singh P
    Med J Malaysia, 1988 Mar;43(1):40-3.
    PMID: 2468988
    Matched MeSH terms: Carcinoma, Squamous Cell/radiotherapy; Head and Neck Neoplasms/radiotherapy
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