Displaying publications 61 - 80 of 275 in total

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  1. Prepageran N, Raman R
    Med J Malaysia, 2005 Aug;60(3):377-8.
    PMID: 16379198
    Radiotherapy is the accepted treatment for early laryngeal carcinomas with the advantage of voice preservation. It is however, not without complications. We report a case of bilateral vocal cord immobility 15 years after radiotherapy. This appears to be due to ankylosis of cricoarytenoid joint and fibrosis of the larynx.
    Matched MeSH terms: Laryngeal Neoplasms/radiotherapy*; Radiotherapy/adverse effects*
  2. Mustafa IS, Kamari HM, Yusoff WM, Aziz SA, Rahman AA
    Int J Mol Sci, 2013;14(2):3201-14.
    PMID: 23380963 DOI: 10.3390/ijms14023201
    Spectrophotometric studies of lead borotellurite glasses were carried out before and after gamma irradiation exposure. The increasing peak on the TeO(4) bi-pyramidal arrangement and TeO(3+1) (or distorted TeO(4)) is due to augmentation of irradiation dose which is attributed to an increase in degree of disorder of the amorphous phase. The structures of lead tellurate contain Pb(3)TeO(6) consisting of TeO(3) trigonal pyramid connected by PbO(4) tetragonal forming a three-dimensional network. The decrease of glass rigidity is due to irradiation process which is supported by the XRD diffractograms results. The decreasing values of absorption edge indicate that red shift effect occur after irradiation processes. A shift in the optical absorption edge attributed to an increase of the conjugation length. The values of optical band gap, E(opt) were calculated and found to be dependent on the glass composition and radiation exposure. Generally, an increase and decrease in Urbach's energy can be considered as being due to an increase in defects within glass network.
    Matched MeSH terms: Radiotherapy Dosage
  3. Banjade DP, Shrestha SL, Shukri A, Tajuddin AA, Bhat M
    Australas Phys Eng Sci Med, 2002 Sep;25(3):110-8.
    PMID: 12416587
    This is a study using LiF:Mg;Ti thermoluminescent dosimeter (TLD) rods in phantoms to investigate the effect of lack of backscatter on exit dose. Comparing the measured dose with anticipated dose calculated using tissue maximum ratio (TMR) or percentage depth dose (PDD) gives rise to a correction factor. This correction factor may be applied to in-vivo dosimetry results to derive true dose to a point within the patient. Measurements in a specially designed humanoid breast phantom as well as patients undergoing radiotherapy treatment were also been done. TLDs with reproducibility of within +/- 3% (1 SD) are irradiated in a series of measurements for 6 and 10 MV photon beams from a medical linear accelerator. The measured exit doses for the different phantom thickness for 6 MV beams are found to be lowered by 10.9 to 14.0% compared to the dose derived from theoretical estimation (normalized dose at dmax). The same measurements for 10 MV beams are lowered by 9.0 to 13.5%. The variations of measured exit dose for different field sizes are found to be within 2.5%. The exit doses with added backscatter material from 2 mm up to 15 cm, shows gradual increase and the saturated values agreed within 1.5% with the expected results for both beams. The measured exit doses in humanoid breast phantom as well as in the clinical trial on patients undergoing radiotherapy also agreed with the predicted results based on phantom measurements. The authors' viewpoint is that this technique provides sufficient information to design exit surface bolus to restore build down effect in cases where part of the exit surface is being considered as a target volume. It indicates that the technique could be translated for in vivo dose measurements, which may be a conspicuous step of quality assurance in clinical practice.
    Matched MeSH terms: Neoplasms/radiotherapy*; Radiotherapy Dosage*
  4. Lim Kok Hooi A
    Gan To Kagaku Ryoho, 1992 Jul;19(8 Suppl):1233-5.
    PMID: 1514837
    Matched MeSH terms: Colonic Neoplasms/radiotherapy*; Radiotherapy Dosage; Rectal Neoplasms/radiotherapy*
  5. Rejab E, Said H, Saim L, Thim L
    J Laryngol Otol, 1991 Nov;105(11):959-60.
    PMID: 1761955
    A case of sphenoid sinus mucocoele following radiotherapy in a patient with nasopharyngeal carcinoma is reported. Diagnosis was made by radiological investigation and confirmed at surgery performed via a sublabial transeptal approach. Its content was completely removed and continuous drainage of the sinus was maintained by an indwelling tube. It is felt that the sphenoid mucocoele developed as a result of occlusion of the sinus ostium by scarred mucosa following radiotherapy.
    Matched MeSH terms: Nasopharyngeal Neoplasms/radiotherapy*; Radiotherapy/adverse effects
  6. Banjade DP, Raj TA, Ng BS, Xavier S, Tajuddin AA, Shukri A
    Med Dosim, 2003;28(2):73-8.
    PMID: 12804703
    Verification of tumor dose for patients undergoing external beam radiotherapy is an important part of quality assurance programs in radiation oncology. Among the various methods available, entrance dose in vivo is one reliable method used to verify the tumor dose delivered to a patient. In this work, entrance dose measurements using LiF:Mg;Ti and LiF:Mg;Cu;P thermoluminescent dosimeters (TLDs) without buildup cap was carried out. The TLDs were calibrated at the surface of a water equivalent phantom against the maximum dose, using 6- and 10-MV photon and 9-MeV electron beams. The calibration geometry was such that the TLDs were placed on the surface of the "solid-water" phantom and a calibrated ionization chamber was positioned inside the phantom at calibration depth. The calibrated TLDs were then utilized to measure the entrance dose during the treatment of actual patients. Measurements were also carried out in the same phantom simultaneously to check the stability of the system. The dose measured in the phantom using the TLDs calibrated for entrance dose to 6-and 10-MV photon beams was found to be close to the dose determined by the treatment planning system (TPS) with discrepancies of not more than 4.1% (mean 1.3%). Consequently, the measured entrance dose during dose delivery to the actual patients with a prescribed geometry was found to be compatible with a maximum discrepancy of 5.7% (mean 2.2%) when comparison was made with the dose determined by the TPS. Likewise, the measured entrance dose for electron beams in the phantom and in actual patients using the calibrated TLDs were also found to be close, with maximum discrepancies of 3.2% (mean 2.0%) and 4.8% (mean 2.3%), respectively. Careful implementation of this technique provides vital information with an ability to confidently accept treatment algorithms derived by the TPS or to re-evaluate the parameters when necessary.
    Matched MeSH terms: Pelvic Neoplasms/radiotherapy*; Radiotherapy Dosage; Thoracic Neoplasms/radiotherapy*
  7. Farayola MF, Shafie S, Siam FM, Khan I
    Comput Methods Programs Biomed, 2020 May;188:105306.
    PMID: 31901851 DOI: 10.1016/j.cmpb.2019.105306
    BACKGROUND: This paper presents a mathematical model that simulates a radiotherapy cancer treatment process. The model takes into consideration two important radiobiological factors, which are repair and repopulation of cells. The model was used to simulate the fractionated treatment process of six patients. The results gave the population changes in the cells and the final volumes of the normal and cancer cells.

    METHOD: The model was formulated by integrating the Caputo fractional derivative with the previous cancer treatment model. Thereafter, the linear-quadratic with the repopulation model was coupled into the model to account for the cells' population decay due to radiation. The treatment process was then simulated with numerical variables, numerical parameters, and radiation parameters. The numerical parameters which included the proliferation coefficients of the cells, competition coefficients of the cells, and the perturbation constant of the normal cells were obtained from previous literature. The radiation and numerical parameters were obtained from reported clinical data of six patients treated with radiotherapy. The patients had tumor volumes of 24.1cm3, 17.4cm3, 28.4cm3, 18.8cm3, 30.6cm3, and 12.6cm3 with fractionated doses of 2 Gy for the first two patients and 1.8 Gy for the other four. The initial tumor volumes were used to obtain initial populations of cells after which the treatment process was simulated in MATLAB. Subsequently, a global sensitivity analysis was done to corroborate the model with clinical data. Finally, 96 radiation protocols were simulated by using the biologically effective dose formula. These protocols were used to obtain a regression equation connecting the value of the Caputo fractional derivative with the fractionated dose.

    RESULTS: The final tumor volumes, from the results of the simulations, were 3.58cm3, 8.61cm3, 5.68cm3, 4.36cm3, 5.75cm3, and 6.12cm3, while those of the normal cells were 23.87cm3, 17.29cm3, 28.17cm3, 18.68cm3, 30.33cm3, and 12.55cm3. The sensitivity analysis showed that the most sensitive model factors were the value of the Caputo fractional derivative and the proliferation coefficient of the cancer cells. Lastly, the obtained regression equation accounted for 99.14% of the prediction.

    CONCLUSION: The model can simulate a cancer treatment process and predict the results of other radiation protocols.

    Matched MeSH terms: Neoplasms/radiotherapy*; Radiotherapy Planning, Computer-Assisted*
  8. Sulieman A, Mayhoub FH, Salah H, Al-Mohammed HI, Alkhorayef M, Moftah B, et al.
    Appl Radiat Isot, 2020 Oct;164:109240.
    PMID: 32819499 DOI: 10.1016/j.apradiso.2020.109240
    Lutetium-177 (DOTATATE) (177Lu; T1/2 6.7 days), a labelled β- and Auger-electron emitter, is widely used in treatment of neuroendocrine tumours. During performance of the procedure, staff and other patients can potentially receive significant doses in interception of the gamma emissions [113 keV (6.4%) and 208 keV (11%)] that are associated with the particle decays. While radiation protection and safety assessment are required in seeking to ensure practices comply with international guidelines, only limited published studies are available. The objectives of present study are to evaluate patient and occupational exposures, measuring ambient doses and estimating the radiation risk. The results, obtained from studies carried out in Riyadh over an 11 month period, at King Faisal Specialist Hospital and Research Center, concerned a total of 33 177Lu therapy patients. Patient exposures were estimated using a calibrated Victoreen 451P survey meter (Fluke Biomedical), for separations of 30 cm, 100 cm and 300 cm, also behind a bed shield that was used during hospitalization of the therapy patients. Occupational and ambient doses were also measured through use of calibrated thermoluminescent dosimeters and an automatic TLD reader (Harshaw 6600). The mean and range of administered activity (in MBq)) was 7115.2 ± 917.2 (4329-7955). The ambient dose at corridors outside of therapy isolation rooms was 1.2 mSv over the 11 month period, that at the nursing station was below the limit of detection and annual occupational doses were below the annual dose limit of 20 mSv. Special concern needs to be paid to comforters (carers) and family members during the early stage of radioisotope administration.
    Matched MeSH terms: Meningeal Neoplasms/radiotherapy*; Meningioma/radiotherapy*; Radiotherapy Dosage
  9. Yahya N, Roslan N
    Asia Pac J Clin Oncol, 2018 Oct;14(5):e543-e547.
    PMID: 29316293 DOI: 10.1111/ajco.12831
    BACKGROUND AND PURPOSE: As about 50% of cancer patients may require radiotherapy, the demand of radiotherapy as the main treatment to treat cancer is likely to rise due to rising cancer incidence. This study aims to quantify the radiotherapy demand in countries in Southeast Asia (SEA) in 2025 and 2035 using evidence-based optimal radiotherapy fractions.

    MATERIALS AND METHODS: SEA country-specific cancer incidence by tumor site for 2015, 2025 and 2035 was extracted from the GLOBOCAN database. We utilized the optimal radiotherapy utilization rate model by Wong et al. (2016) to calculate the optimal number of fractions for all tumor sites in each SEA country. The available machines (LINAC & Co-60) were extracted from the IAEA's Directory of Radiotherapy Centres (DIRAC) from which the number of available fractions was calculated.

    RESULTS: The incidence of cancers in SEA countries are expected to be 1.1 mil cases (2025) and 1.4 mil (2035) compared to 0.9 mil (2015). The number of radiotherapy fractions needed in 2025 and 2035 are 11.1 and 14.1 mil, respectively, compared to 7.6 mil in 2015. In 2015, the radiotherapy fulfillment rate (RFR; required fractions/available fractions) varied between countries with Brunei, Singapore and Malaysia are highest (RFR > 1.0 - available fractions > required fractions), whereas Cambodia, Indonesia, Laos, Myanmar, Philippines, Timor-Leste and Vietnam have RFR 

    Matched MeSH terms: Neoplasms/radiotherapy*; Radiotherapy*
  10. Suneja G, Brown D, Chang A, Erickson B, Fidarova E, Grover S, et al.
    Brachytherapy, 2017 Jan-Feb;16(1):85-94.
    PMID: 27919654 DOI: 10.1016/j.brachy.2016.10.007
    PURPOSE: Most cervix cancer cases occur in low-income and middle-income countries (LMIC), and outcomes are suboptimal, even for early stage disease. Brachytherapy plays a central role in the treatment paradigm, improving both local control and overall survival. The American Brachytherapy Society (ABS) aims to provide guidelines for brachytherapy delivery in resource-limited settings.

    METHODS AND MATERIALS: A panel of clinicians and physicists with expertise in brachytherapy administration in LMIC was convened. A survey was developed to identify practice patterns at the authors' institutions and was also extended to participants of the Cervix Cancer Research Network. The scientific literature was reviewed to identify consensus papers or review articles with a focus on treatment of locally advanced, unresected cervical cancer in LMIC.

    RESULTS: Of the 40 participants invited to respond to the survey, 32 responded (response rate 80%). Participants were practicing in 14 different countries including both high-income (China, Singapore, Taiwan, United Kingdom, and United States) and low-income or middle-income countries (Bangladesh, Botswana, Brazil, India, Malaysia, Pakistan, Philippines, Thailand, and Vietnam). Recommendations for modifications to existing ABS guidelines were reviewed by the panel members and are highlighted in this article.

    CONCLUSIONS: Recommendations for treatment of locally advanced, unresectable cervical cancer in LMIC are presented. The guidelines comment on staging, external beam radiotherapy, use of concurrent chemotherapy, overall treatment duration, use of anesthesia, applicator choice and placement verification, brachytherapy treatment planning including dose and prescription point, recommended reporting and documentation, physics support, and follow-up.
    Matched MeSH terms: Uterine Cervical Neoplasms/radiotherapy*; Radiotherapy; Radiotherapy Dosage
  11. Kasthoori JJ, Wastie ML
    Singapore Med J, 2006 Oct;47(10):907-9.
    PMID: 16990970
    Radiation-induced sarcomas are well-known though uncommon potential late sequelae of radiation therapy. We report irradiation-induced osteosarcoma involving the maxilla following treatment of nasopharyngeal carcinoma in a 44-year-old man who presented with painful cheek swelling. Radiographs and computed tomography showed a large destructive lesion of the left maxilla. Diagnosis of osteosarcoma was confirmed by excision biopsy.
    Matched MeSH terms: Nasopharyngeal Neoplasms/radiotherapy*; Radiotherapy/adverse effects
  12. Loh ZH, Mohamad S, Gan BC, Zakaria Z, Mohamad I
    Med J Malaysia, 2023 Mar;78(2):197-201.
    PMID: 36988530
    INTRODUCTION: Nasopharyngeal carcinoma (NPC) is among the most common malignancy in Malaysia. Radiationinduced hypothyroidism has been reported in other countries. However, in Malaysia, no studies were ever done to determine the effect of radiation on hypothyroidism. The objective of this study is to evaluate the practice of taking thyroid function test (TFT) and determine hypothyroidism post-radiation in patients with NPC.

    MATERIALS AND METHODS: A retrospective study on the symptoms and results of TFT according to the dosage of intensity-modulated radiotherapy (IMRT) given to patients with NPC. Data were traced and analysed.

    RESULTS: A total of 78 patients were identified. All patients received IMRT with 33-35 fractions of radiotherapy (RT) with total dosage of 66-70 Gray given. Not all patients had their thyroid function status measured routinely. Twelve patients did have symptoms of hypothyroidism. TFT were obtained in this group but the results were normal. No correlation was found between RT and hypothyroidism.

    CONCLUSION: There was no correlation between IMRT and the development of hypothyroidism. A prospective study with better control of inclusion and exclusion criteria, and longer follow-up period with TFT, is needed to demonstrate the consistency of these findings.

    Matched MeSH terms: Radiotherapy Dosage
  13. Rasmussen ME, Akbarov K, Titovich E, Nijkamp JA, Van Elmpt W, Primdahl H, et al.
    JCO Glob Oncol, 2024 Aug;10:e2400173.
    PMID: 39236283 DOI: 10.1200/GO.24.00173
    PURPOSE: Most research on artificial intelligence-based auto-contouring as template (AI-assisted contouring) for organs-at-risk (OARs) stem from high-income countries. The effect and safety are, however, likely to depend on local factors. This study aimed to investigate the effects of AI-assisted contouring and teaching on contouring time and contour quality among radiation oncologists (ROs) working in low- and middle-income countries (LMICs).

    MATERIALS AND METHODS: Ninety-seven ROs were randomly assigned to either manual or AI-assisted contouring of eight OARs for two head-and-neck cancer cases with an in-between teaching session on contouring guidelines. Thereby, the effect of teaching (yes/no) and AI-assisted contouring (yes/no) was quantified. Second, ROs completed short-term and long-term follow-up cases all using AI assistance. Contour quality was quantified with Dice Similarity Coefficient (DSC) between ROs' contours and expert consensus contours. Groups were compared using absolute differences in medians with 95% CIs.

    RESULTS: AI-assisted contouring without previous teaching increased absolute DSC for optic nerve (by 0.05 [0.01; 0.10]), oral cavity (0.10 [0.06; 0.13]), parotid (0.07 [0.05; 0.12]), spinal cord (0.04 [0.01; 0.06]), and mandible (0.02 [0.01; 0.03]). Contouring time decreased for brain stem (-1.41 [-2.44; -0.25]), mandible (-6.60 [-8.09; -3.35]), optic nerve (-0.19 [-0.47; -0.02]), parotid (-1.80 [-2.66; -0.32]), and thyroid (-1.03 [-2.18; -0.05]). Without AI-assisted contouring, teaching increased DSC for oral cavity (0.05 [0.01; 0.09]) and thyroid (0.04 [0.02; 0.07]), and contouring time increased for mandible (2.36 [-0.51; 5.14]), oral cavity (1.42 [-0.08; 4.14]), and thyroid (1.60 [-0.04; 2.22]).

    CONCLUSION: The study suggested that AI-assisted contouring is safe and beneficial to ROs working in LMICs. Prospective clinical trials on AI-assisted contouring should, however, be conducted upon clinical implementation to confirm the effects.

    Matched MeSH terms: Head and Neck Neoplasms/radiotherapy; Radiotherapy Planning, Computer-Assisted/methods
  14. Biswal BM, Kumaraswamy N, Mukhtar F
    PMID: 15691157
    Between July 1999 to November 2000, 115 patients undergoing radiotherapy were evaluated for the development of treatment-related fatigue, using a modified Piper's fatigue scale. The above scale determines 4 dimensions of fatigue ie behavioral severity (6 items), affective meaning (5 items), sensory (5 items), and cognitive mood (6 items). Radiotherapy was delivered to the head and neck, breast, pelvis, and miscellaneous sub-sites. The area of the radiation field ranged from 25 to 480 cm2 (median 156 cm2). Forty-three percent of patients experienced significant fatigue, which altered their work environment. The individual components of fatigue were behavioral severity 25%, affective meaning 21%, sensory 18%, and cognitive mood 16%. Significant radiotherapy-related fatigue was higher in patients treated with advanced-stage disease, large radiotherapy field area, and low pre-radiotherapy hemoglobin level.
    Matched MeSH terms: Neoplasms/radiotherapy*; Radiotherapy/adverse effects*
  15. 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: Uterine Cervical Neoplasms/radiotherapy*; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted/methods
  16. 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
  17. Sothy K, Mafauzy M, Mohamad WB, Mustaffa BE
    Med J Malaysia, 1991 Sep;46(3):212-7.
    PMID: 1839914
    The clinical, biochemical and pathological features of 31 patients with thyroid carcinoma managed at Hospital Universiti Sains Málaysia, Kubang Kerian from 1985 to 1989 were analyzed. There were 25 females and 6 males. The types of carcinoma were: papillary-17 cases; follicular-10 cases; medullary-2 cases and anaplastic-2 cases. For papillary carcinoma the mean age of the patients was 52.9 years. For follicular carcinoma the mean age was 48.3 years, for medullary carcinoma, 48.5 years and for anaplastic, 74.5 years. All patients had pre-existing goitre except for 2 and most presented with advanced disease. The mean duration of symptoms for papillary carcinoma was 3.7 years, follicular carcinoma 1.6 years, medullary carcinoma 13.5 years and anaplastic carcinoma 6 months. 12 patients presented with goitre of increasing size; 9 had compression symptoms; 4 presented with cervical lymph node enlargement and 6 presented with bony pains of whom 2 had paraplegia. None of the patients were ever thyrotoxic or hypothyroid. Treatment in general was unsatisfactory because of patients' non-acceptance of surgery and/or radioactive iodine.
    Matched MeSH terms: Adenocarcinoma/radiotherapy; Carcinoma/radiotherapy; Carcinoma, Papillary/radiotherapy; Thyroid Neoplasms/radiotherapy
  18. Syadwa AS, Anita ZB
    Med J Malaysia, 2018 08;73(4):190-196.
    PMID: 30121680 MyJurnal
    AIM: Symptomatic relief following palliative radiotherapy for advanced cancers may take a few weeks up to a few months to achieve. Thus, accurate prognostication is important to avoid harm to these patients with limited lifespan. We conducted a retrospective cohort study to determine the median survival and 30-day mortality (30-DM) and factors associated with these parameters in our centre.

    METHODS: Data from 585 eligible patients who received palliative radiotherapy between January 2012 and December 2014 were analysed. Median overall survival was calculated from the commencement of first fraction of the last course of radiotherapy to date of death or when censored. 30-DM was calculated as the proportion of patients who died within 30 days from treatment start date. Kaplan-Meier survival analysis was used to estimate survival. Chi-square test and logistic regression was used to assess the impact of potential prognostic factors on median survival and 30-DM.

    RESULTS: The most common diagnoses were lung and breast cancers and most common irradiated sites were bone and brain. Median survival and 30-DM were 97 days and 22.7% respectively. Primary cancer, age, treatment course, performance status, systemic treatment post radiotherapy and intended radiotherapy treatment completed had an impact on median survival whereas mainly the latter three factors had an impact on 30-DM.

    CONCLUSION: Median survival and factors affecting both survival and 30-DM in our study are comparable to others. However, a 30-DM rate of 22.7% is significantly higher compared to the literature. We need to better select patients who will benefit from palliative radiotherapy in our centre.

    Matched MeSH terms: Breast Neoplasms/radiotherapy; Lung Neoplasms/radiotherapy; Neoplasms/radiotherapy*; Radiotherapy Dosage
  19. Jamalludin Z, Jong WL, Malik RA, Rosenfeld AB, Ung NM
    Phys Med, 2020 Jan;69:52-60.
    PMID: 31830631 DOI: 10.1016/j.ejmp.2019.11.025
    PURPOSE: Dose to the rectum during brachytherapy treatment may differ from an approved treatment plan which can be quantified with in vivo dosimetry (IVD). This study compares the planned with in vivo doses measured with MOSkin and PTW 9112 rectal probe in patients undergoing CT based HDR cervical brachytherapy with Co-60 source.

    METHODS: Dose measurement of a standard pear-shaped plan carried out in phantom to verify the MOSkin dose measurement accuracy. With MOSkin attached to the third diode, RP3 of the PTW 9112, both detectors were inserted into patients' rectum. The RP3 and MOSkin measured doses in 18 sessions as well as the maximum measured doses from PTW 9112, RPmax in 48 sessions were compared to the planned doses.

    RESULTS: Percentage dose differences ΔD (%) in phantom study for two MOSkin found to be 2.22 ± 0.07% and 2.5 ± 0.07%. IVD of 18 sessions resulted in ΔD(%) of -16.3% to 14.9% with MOSkin and ΔD(%) of -35.7% to -2.1% with RP3. In 48 sessions, RPmax recorded ΔD(%) of -37.1% to 11.0%. MOSkin_measured doses were higher in 44.4% (8/18) sessions, while RP3_measured were lower than planned doses in all sessions. RPmax_measured were lower in 87.5% of applications (42/47).

    CONCLUSIONS: The delivered doses proven to deviate from planned doses due to unavoidable shift between imaging and treatment as measured with MOSkin and PTW 9112 detectors. The integration of MOSkin on commercial PTW 9112 surface found to be feasible for rectal dose IVD during cervical HDR ICBT.

    Matched MeSH terms: Uterine Cervical Neoplasms/radiotherapy*; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted/methods
  20. 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: Mammary Neoplasms, Experimental/radiotherapy*; Radiotherapy/instrumentation; Radiotherapy/methods
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