Displaying all 11 publications

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  1. Banjade DP, Ng BS, Zakir M, Tajuddin AA, Shukri A
    Br J Radiol, 2002 Oct;75(898):812-8.
    PMID: 12381690
    A study of dose mapping techniques to investigate the dose distribution throughout a planned target volume (PTV) in a humanoid breast phantom exposed to a 6 MV photon beam similar to that of treatment conditions is described. For tangential breast irradiation using a 6 MV accelerator beam, the dose is mapped at various locations within the PTV using thermoluminescent dosemeters (TLDs) and radiographic films. An average size perspex breast phantom with the ability to hold the dosemeters was made. TLDs were exposed after packing them in various locations in a particular slice, as planned by the treatment planning system (TPS). To map the dose relative to the isocenter, films were exposed after tightly packing them in between phantom slices, parallel to the central axis of the beam. The dose received at every location was compared with the given dose as generated by the TPS. The mapped dose in each location in the isocentric slice from superficial to deep region was found to be in close agreement with the TPS generated dose to within +/-2%. Doses at greater depths and distant medial and lateral ends, however, were found to be lower by as much as 9.4% at some points. The mapped dose towards the superior region and closest inferior region from the isocenter was found to agree with those for TPS. Conversely, results for the farthest inferior region were found to be significantly different with a variance as much as 17.4% at some points, which is believed to be owing to the variation in size and shape of the contour. Results obtained from films confirmed this, showing similar trends in dose mapping. Considering the importance of accurate doses in radiotherapy, evaluating dose distribution using this technique and tool was found to be useful. This provides the opportunity to choose a technique and plan to provide optimum dose delivery for radiotherapy to the breast.
    Matched MeSH terms: Radiotherapy/methods
  2. Yahya N, Manan HA
    World Neurosurg, 2019 Oct;130:e188-e198.
    PMID: 31326352 DOI: 10.1016/j.wneu.2019.06.027
    BACKGROUND: Diffusion tensor imaging (DTI), which visualizes white matter tracts, can be integrated to optimize intracranial radiation therapy (RT) and radiosurgery (RS) treatment planning. This study aimed to systematically review the integration of DTI for dose optimization in terms of evidence of dose improvement, clinical parameter changes, and clinical outcome in RT/RS treatment planning.

    METHODS: PubMed and Scopus electronic databases were searched based on the guidelines established by PRISMA to obtain studies investigating the integration of DTI in intracranial RT/RS treatment planning. References and citations from Google Scholar were also extracted. Eligible studies were extracted for information on changes in dose distribution, treatment parameters, and outcome after DTI integration.

    RESULTS: Eighteen studies were selected for inclusion with 406 patients (median study size, 19; range: 2-144). Dose distribution, with or without DTI integration, described changes of treatment parameters, and the reported outcome of treatment were compared in 12, 7, and 10 studies, respectively. Dose distributions after DTI integration improved in all studies. Delivery time or monitor unit was higher after integration. In studies with long-term follow-up (median, >12 months), neurologic deficits were significantly fewer in patients with DTI integration.

    CONCLUSIONS: Integrating DTI into RT/RS treatment planning improved dose distribution, with higher treatment delivery time or monitor unit as a potential drawback. Fewer neurologic deficits were found with DTI integration.

    Matched MeSH terms: Radiotherapy/methods*
  3. Jothy SL, Chen Y, Vijayarathna S, Kanwar JR, Sasidharan S
    Curr Gene Ther, 2015;15(1):15-20.
    PMID: 25478696
    Radiotherapy plays an essential primary role in cancer patients. Regardless of its significant advances in treatment options, tumor recurrence and radio-resistance in cancer cells still occur in a high percentage of patients. Furthermore, the over expression of miRNAs accompanies the development of radio-resistant cancer cells. Consequently, miRNAs might serve as therapeutic targets for the treatment of radio-resistance in cancer cells. The findings of the current research also signify that the use of a natural anti-miRNA substance could inhibit specific miRNAs, and, concurrently, these natural remedies could exhibit radioprotective activity against the healthy cells during radiotherapy. Therefore, in this review, we have reported the association of miRNAs with radio-resistance and the potential uses of natural remedies as green gene therapeutic approaches, as well as radioprotectors against the adverse effects of irradiation on healthy cells during radiotherapy.
    Matched MeSH terms: Radiotherapy/methods
  4. Rai NP, Divakar DD, Al Kheraif AA, Ramakrishnaiah R, Mustafa SM, Durgesh BH, et al.
    Asian Pac J Cancer Prev, 2015;16(16):6919-22.
    PMID: 26514468
    BACKGROUND: The treatment selection for the oral squamous cell carcinoma remains controversial. Radiation therapy or surgical excision of the lesion can be applied as the sole treatment or it can be used in combination with other treatment modalities. Radiotherapy is considered to be the safest of all the treatment modalities and can be used in several situations for oral and oropharyngeal cancers. The aim of this study was to evaluate the survival outcome differences in patients treated with radical and palliative radiotherapy as the primary treatment modality.

    MATERIALS AND METHODS: The study included a total of 47 patients with oral cancer reporting to our hospital between years 2009 to 2010. The age group for the selected patients was more than 65 years, treated with radical and palliative radiotherapy with no prior surgical interventions. Patients were evaluated till Dec 2013 for overall survival time.

    RESULTS: Twenty nine patients were treated with radical radiotherapy as main stay of treatment, out of which 21 died during the follow up time with median survival of 352 ± 281.7 days with 8 patients alive. All the 16 patients were dead who received palliative radiotherapy with a median survival time of 112 ± 144.0 days.

    CONCLUSIONS: This retrospective study showed improved overall survival time, loco regional control rates and reduced morbidity in patients treated with radical radiotherapy when compared to patients treated with palliative radiotherapy.

    Matched MeSH terms: Radiotherapy/methods
  5. Banjade DP, Tajuddin AA, Shukri A
    Appl Radiat Isot, 2001 Aug;55(2):235-43.
    PMID: 11393765
    Protocols developed for high-energy dosimetry IAEA (Technical Reports Series No. 277, 1997), AAPM (Med. Phys. 10 (1983) 741: Med. Phys. 18 (1991) 73: Med. Phys. 21 (1994) 1251), IPEMB (Phys. Med. Biol. 41 (1996) 2557), and HPA (Phys. Med. Biol. 28 (1983) 1097) have continued to enhance precision in dose measurements and the optimization of radiotherapy procedures. While recent dosimetry protocols, including those due to the IAEA and IPEMB, have made a number of improvements compared with previous protocols, it is further desirable to develop absolute dosimetry methods of dose measurements. Measurements based on careful implementation of procedures contained within the various protocols have been carried out in an effort to determine the extent to which discrepancies exist among the protocols. Dose in water at dmax was measured using cylindrical and parallel-plate ionization chambers for 6 MV photon beams and 5 and 12 MeV electron beams. Results obtained from the use of the AAPM and HPA protocols for 6 MV photon beams were found to be 0.9% larger and 0.1% smaller, respectively, than those measured following the IAEA protocol. Calibration dose measurements for 5 and 12 MeV electron beams in water phantoms were found to agree to within 1%, this being well within recommendations from the ICRU and other sources regarding the accuracy of dose delivery.
    Matched MeSH terms: Radiotherapy/methods*
  6. Farayola MF, Shafie S, Mohd Siam F, Khan I
    Comput Methods Programs Biomed, 2020 Apr;187:105202.
    PMID: 31835107 DOI: 10.1016/j.cmpb.2019.105202
    Background This paper presents a numerical simulation of normal and cancer cells' population dynamics during radiotherapy. The model used for the simulation was the improved cancer treatment model with radiotherapy. The model simulated the population changes during a fractionated cancer treatment process. The results gave the final populations of the cells, which provided the final volumes of the tumor and normal cells. Method The improved model was obtained by integrating the previous cancer treatment model with the Caputo fractional derivative. In addition, the cells' population decay due to radiation was accounted for by coupling the linear-quadratic model into the improved model. The simulation of the treatment process was done with numerical variables, numerical parameters, and radiation parameters. The numerical variables include the populations of the cells and the time of treatment. The numerical parameters were the model factors which included the proliferation rates of cells, competition coefficients of cells, and perturbation constant for normal cells. The radiation parameters were clinical data based on the treatment procedure. The numerical parameters were obtained from the previous literature while the numerical variables and radiation parameters, which were clinical data, were obtained from reported data of four cancer patients treated with radiotherapy. The four cancer patients had tumor volumes of 28.4 cm3, 18.8 cm3, 30.6 cm3, and 12.6 cm3 and were treated with different treatment plans and a fractionated dose of 1.8 Gy each. The initial populations of cells were obtained by using the tumor volumes. The computer simulations were done with MATLAB. Results The final volumes of the tumors, from the results of the simulations, were 5.67 cm3, 4.36 cm3, 5.74 cm3, and 6.15 cm3 while the normal cells' volumes were 28.17 cm3, 18.68 cm3, 30.34 cm3, and 12.54 cm3. The powers of the derivatives were 0.16774, 0.16557, 0.16835, and 0.16. A variance-based sensitivity analysis was done to corroborate the model with the clinical data. The result showed that the most sensitive factors were the power of the derivative and the cancer cells' proliferation rate. Conclusion The model provided information concerning the status of treatments and can also predict outcomes of other treatment plans.
    Matched MeSH terms: Radiotherapy/methods*
  7. Jong WL, Ung NM, Vannyat A, Rosenfeld AB, Wong JHD
    Phys Med, 2017 Oct;42:39-46.
    PMID: 29173919 DOI: 10.1016/j.ejmp.2017.08.011
    Challenges in treating lung tumours are related to the respiratory-induced tumour motion and the accuracy of dose calculation in charged particle disequilibrium condition. The dosimetric characteristics near the interface of lung and Perspex media in a moving phantom during respiratory-gated and non-gated radiotherapy were investigated using Gafchromic EBT2 and the MOSkin detector. The MOSkin detectors showed good agreement with the EBT2 films during static and gated radiotherapy. In static radiotherapy, the penumbral widths were found to be 3.66mm and 7.22mm in Perspex and lung media, respectively. In non-gated (moving) radiotherapy with 40mm respiratory amplitude, dose smearing effect was observed and the penumbral widths were increased to 28.81mm and 26.40mm, respectively. This has been reduced to 6.85mm and 9.81mm, respectively, in gated radiotherapy with 25% gating window. There were still some dose discrepancies as compared to static radiotherapy due to the residual motion. This should be taken into account in the margin generation for the target tumour.
    Matched MeSH terms: Radiotherapy/methods*
  8. Entezam A, Khandaker MU, Amin YM, Ung NM, Bradley DA, Maah J, et al.
    PLoS One, 2016;11(5):e0153913.
    PMID: 27149115 DOI: 10.1371/journal.pone.0153913
    Study has been made of the thermoluminescence (TL) response of silica-based Ge-doped cylindrical, flat and photonic crystal fibres (referred to herein as PCF-collapsed) to electron (6, 12 and 20 MeV) and photon (6, 10 MV) irradiation and 1.25 MeV γ-rays, for doses from 0.1 Gy to 100 Gy. The electron and photon irradiations were delivered through use of a Varian Model 2100C linear accelerator located at the University of Malaya Medical Centre and γ-rays delivered from a 60Co irradiator located at the Secondary Standard Dosimetry Laboratory (SSDL), Malaysian Nuclear Agency. Tailor-made to be of various dimensions and dopant concentrations (6-10% Ge), the fibres were observed to provide TL yield linear with radiation dose, reproducibility being within 1-5%, with insensitivity to energy and angular variation. The sensitivity dependency of both detectors with respect to field size follows the dependency of the output factors. For flat fibres exposed to 6 MV X-rays, the 6% Ge-doped fibre provided the greatest TL yield while PCF-collapsed showed a response 2.4 times greater than that of the 6% Ge-doped flat fibres. The response of cylindrical fibres increased with core size. The fibres offer uniform response, high spatial resolution and sensitivity, providing the basis of promising TL systems for radiotherapy applications.
    Matched MeSH terms: Radiotherapy/methods
  9. Yang Y, Swierczak A, Ibahim M, Paiva P, Cann L, Stevenson AW, et al.
    Radiother Oncol, 2019 04;133:93-99.
    PMID: 30935588 DOI: 10.1016/j.radonc.2019.01.006
    BACKGROUND: Synchrotron microbeam radiation therapy (MRT) is a new, evolving form of radiotherapy that has potential for clinical application. Several studies have shown in preclinical models that synchrotron MRT achieves equivalent tumor control to conventional radiotherapy (CRT) but with significantly reduced normal tissue damage.

    METHODS: To explore differences between these two modalities, we assessed the immune cell infiltrate into EMT6.5 mammary tumors after CRT and MRT.

    RESULTS: CRT induced marked increases in tumor-associated macrophages and neutrophils while there were no increases in these populations following MRT. In contrast, there were higher numbers of T cells in the MRT treated tumors. There were also increased levels of CCL2 by immunohistochemistry in tumors subjected to CRT, but not to MRT. Conversely, we found that MRT induced higher levels of pro-inflammatory genes in tumors than CRT.

    CONCLUSION: Our data are the first to demonstrate substantial differences in macrophage, neutrophil and T cell numbers in tumors following MRT versus CRT, providing support for the concept that MRT evokes a different immunomodulatory response in tumors compared to CRT.

    Matched MeSH terms: Radiotherapy/methods
  10. Yahya N, Ebert MA, Bulsara M, House MJ, Kennedy A, Joseph DJ, et al.
    Med Phys, 2016 May;43(5):2040.
    PMID: 27147316 DOI: 10.1118/1.4944738
    Given the paucity of available data concerning radiotherapy-induced urinary toxicity, it is important to ensure derivation of the most robust models with superior predictive performance. This work explores multiple statistical-learning strategies for prediction of urinary symptoms following external beam radiotherapy of the prostate.
    Matched MeSH terms: Radiotherapy/methods
  11. 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/methods
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