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Fulltext Angiotensin-I converting enzyme (ACE) inhibitory peptides from chicken skin gelatin hydrolysate and its antihypertensive effect in spontaneously hypertensive rats

Sarbon, N.M., Howell, N.K., Wan Ahmad, W.A.N.

International Food Research Journal, 2019;26(3):903-911.
MyJurnal

Chicken skin gelatin hydrolysates and peptides with angiotensin converting enzyme inhibitory (ACEI) activity were produced enzymatically using alcalase, pronase E, and collagenase before fractionation into

Matched MeSH terms: Dose Fractionation
Fulltext LINAC based radiosurgery and radiotherapy for neurosurgical diseases: what have we learnt so far

Zamzuri I, Badrisyah I, Rahman GI, Pal HK, Muzaimi M, Jafri AM, et al.

Med J Malaysia, 2011 Oct;66(4):346-9.
PMID: 22299555 MyJurnal

Stereotactic radiosurgery uses a single fraction high dose radiation while stereotactic radiotherapy uses multifractionated lower dose focused radiation.

Matched MeSH terms: Dose Fractionation*
Numerical simulation of normal and cancer cells' populations with fractional derivative under radiotherapy

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: Dose Fractionation*
Mathematical modeling of radiotherapy cancer treatment using Caputo fractional derivative

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: Dose Fractionation*
Emerging Role of Secondary Bystander Effects Induced by Fractionated Proton Microbeam Radiation

Autsavapromporn N, Liu C, Kobayashi A, Ahmad TAFT, Oikawa M, Dukaew N, et al.

Radiat Res, 2019 02;191(2):211-216.
PMID: 30526323 DOI: 10.1667/RR15155.1

Increased understanding of radiation-induced secondary bystander effect (RISBE) is relevant to radiation therapy since it likely contributes to normal tissue injury and tumor recurrence, subsequently resulting in treatment failure. In this work, we developed a simple method based on proton microbeam radiation and a transwell insert co-culture system to elucidate the RISBE between irradiated human lung cancer cells and nonirradiated human normal cells. A549 lung cancer cells received a single dose or fractionated doses of proton microbeam radiation to generate the primary bystander cells. These cells were then seeded on the top of the insert with secondary bystander WI-38 normal cells growing underneath in the presence or absence of gap junction intercellular communication (GJIC) inhibitor, 18-α-glycyrrhetnic acid (AGA). Cells were co-cultured before harvesting and assayed for micronuclei formation. The results of this work showed that fractionated doses of protons caused less DNA damage in the secondary bystander WI-38 cells compared to a single radiation dose, where the means differ by 20%. However, the damaging effect in the secondary bystander normal cells could be eliminated when treated with AGA. This novel work reflects our effort to demonstrate that GJIC plays a major role in the RISBE generated from the primary bystander cancer cells.

Matched MeSH terms: Dose Fractionation*
Fulltext Split-Course Radiotherapy in Stage IV Head & Neck Cancer

Biswal BM, Ruzman N, Ahmad NM, Zakaria A

Malays J Med Sci, 2000 Jan;7(1):54-9.
PMID: 22844216 MyJurnal

Short course hypo-fractionated radiotherapy is a standard regime for the palliation of stage IV head and neck cancers. However few patients respond favorably and require further radiotherapy in curative intent. We have used split-course radiotherapy technique to find out this conversion rate from palliative to curative intent. This was a prospective study conducted from November 1998 to October 1999; twenty-six (26) patients with stage IV head & neck cancers were treated with a hypofractionated regime of radiotherapy. A tumor dose of 30 Gy in 10 fractions [time dose fraction (TDF) 62] over 2 weeks was delivered using a 6 MV linear accelerator. A conventional 2 field or 3 field technique was used. Patients were assessed for the regression of tumor on fifth day, tenth day of radiotherapy and 4 weeks after the completion of radiotherapy. Patients showing complete response and good partial response were allowed to receive further radiotherapy of 30 Gy in 15 fractions [TDF 49]. There were 21 males and 5 females in the study with a median age of 44 years (range 19-77 years). All patients completed the initial regime. Complete responses were observed among 14 patients (54%); partial response in 6 patients (23%), and no response was seen among 6 patients (23%). Sixteen patients (61%) were suitable for radical radiotherapy after phase-I course of the above schedule. Seventeen patients (65%) showed an improvement in the general well being with a better quality of life. One year actuarial survival was (76%), with a median survival time of 12 months. Split-course technique is a useful radiotherapy treatment in stage IV head and neck cancers to distinguish between the subset of patients who would require curative treatment and who would not.

Matched MeSH terms: Dose Fractionation
Estimating radiotherapy demands in South East Asia countries in 2025 and 2035 using evidence-based optimal radiotherapy fractions

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: Dose Fractionation
Mometasone furoate cream reduces acute radiation dermatitis in patients receiving breast radiation therapy: results of a randomized trial

Hindley A, Zain Z, Wood L, Whitehead A, Sanneh A, Barber D, et al.

Int J Radiat Oncol Biol Phys, 2014 Nov 15;90(4):748-55.
PMID: 25585779 DOI: 10.1016/j.ijrobp.2014.06.033

We wanted to confirm the benefit of mometasone furoate (MF) in preventing acute radiation reactions, as shown in a previous study (Boström et al, Radiother Oncol 2001;59:257-265).

Matched MeSH terms: Dose Fractionation
Multi-institutional Observational Study of Prophylactic Extended-Field Concurrent Chemoradiation Therapy Using Weekly Cisplatin for Patients With Pelvic Node-Positive Cervical Cancer in East and Southeast Asia

Wakatsuki M, Kato S, Ohno T, Banu PA, Hoang NC, Yadamsuren E, et al.

Int J Radiat Oncol Biol Phys, 2019 09 01;105(1):183-189.
PMID: 31125594 DOI: 10.1016/j.ijrobp.2019.04.039

PURPOSE: This multi-institutional observational study conducted among 11 countries in East and Southeast Asia aimed to assess the clinical outcomes of prophylactic extended-field concurrent chemoradiation therapy using weekly cisplatin for patients with locally advanced cervical cancer.
METHODS AND MATERIALS: Between October 2007 and May 2016, 106 patients with untreated squamous cell carcinoma of the cervix were enrolled in the present study. Radiation therapy consisted of pelvic irradiation (total dose, 50 Gy in 25 fractions including central shielding), prophylactic paraortic regional irradiation (36-40 Gy in 20 fractions), and either high- or low-dose-rate intracavitary brachytherapy (ICBT) according to institutional practice. The planned point A dose was 21 to 28 Gy in 3 to 4 fractions for high-dose-rate ICBT and 40 to 41 Gy in 1 to 2 fractions for low-dose-rate ICBT. Five cycles of weekly cisplatin (40 mg/m2) were administered during the radiation therapy course.
RESULTS: A total of 106 patients were enrolled. Of these, 9 had major protocol violations and 2 did not receive treatment because of worsened general condition. Thus, 95 patients were evaluable. The median follow-up was 56 months. Of the 95 patients, 76 (80%) received 4 or 5 cycles of chemotherapy. Acute grade 3 leukopenia was observed in 20 of the patients (21%), and late grade 3 gastrointestinal toxicity was observed in 3%. The 2-year local control, progression-free survival, and overall survival rate for all patients were 96%, 78%, and 90%, respectively.
CONCLUSIONS: The results indicated that prophylactic extended-field concurrent chemoradiation therapy using weekly cisplatin is feasible and effective for patients with locally advanced cervical cancer in East and Southeast Asia.

Matched MeSH terms: Dose Fractionation