In the current study, radiation dose-reduction factor (DRF) of nanoceria or cerium oxide nanoparticles (CONPs) in MRC-5 Human Lung Fibroblastic Cells and MCF-7 Breast-Cancer Cells was estimated. Characterization of CONPs was determined using scanner electron microscope (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and spectrophotometer. Then, six plans were designed with different radiation dose values on planning target value. The obtained MRC-5 and MCF-7 cells were treated with non-toxic concentrations of CONPs and then exposed. Finally, cell viability (%) of the cell lines was determined using MTT assay. The findings showed that CONPs have no significant radioprotective effect against 10 cGy radiation dose value. Nevertheless, 70 lM CONPs resulted in a significant radioprotection against 100, 200, 300, 400 and 500 cGy radiation dose values compared with the control group in MRC-5 cells. For all radiation dose values, mean cell viability (%) of MCF-7 had not increased significantly at the presence of nanoceria compared with control group. According to the findings, it was revealed that the use of CONPs have a significant radioprotective effect on normal lung cells, while they do not provide any protection for MCF-7 cancer cells. These properties can help to increase therapeutic ratio of radiotherapy.
Background:Medical use of ionizing radiation has direct/indirect undesirable effects on normal tissues. In this study, the radioprotective effect of arbutin in megavoltage therapeutic x-irradiated mice was investigated using serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), and asparate amniotransferase (AST) activity measurements.
Material and Methods: In this analytical and experimental lab study, sixty mice (12 identical groups) were irradiated with 6 MV x-ray beam (2 and 4 Gy in one fraction). Arbutin concentrations were chosen 50, 100, and 200 mg/kg and injected intraperitoneal 2 hours before irradiation. Samples of peripheral blood cells were collected and serum was separated on the 1, 3, and 7 days post-x-radiation; in addition, the level of ALP, ALT, and AST were measured. Data were analyzed using one-way ANOVA, and Tukey HSD test.
Results: X-radiation (2 and 4 Gy) increased the ALT and AST activity levels on the 1, 3, and 7 days post- irradiation, but the ALP level significantly increased on the 1 and 7 days and decreased on the third day compared to the control group (P< 0.001). ALP, ALT and AST activity levels in “2 and 4 Gy x irradiation + distilled water” groups were significantly higher than “2 and 4 Gy irradiation + 50, 100, and 200 mg/kg arbutin” groups on the first and seventh day post-irradiation (P< 0.001).
Conclusion:Arbutin is a strong radioprotector for reducing the radiation effect on the whole-body tissues by measuring ALP, ALT and AST enzyme activity levels. Furthermore, the concentration of 50 mg/kg arbutin showed higher radioprotective effect.
In this work, a novel planar four-port microstrip triplexer is designed and analyzed to operate at 1.9 GHz, 2.5 GHz, and 3.35 GHz for wireless communication applications. The proposed structure consists of a compact patch and spiral cells. The main advantage of this triplexer is its very compact size, with a cross size of only 15 mm × 15 mm (0.017λ 2 g). Sharp frequency response at the edges of all passbands, low insertion losses (0.25 dB, 0.4 dB and 0.11 dB), and high return losses (45 dB, 54 dB and 40 dB) in all channels are the other advantages of the designed triplexer. Additionally, the triplexer has reasonable isolations (S 23 , S 24 , S 34), better than 20 dB. To verify the design method, both EM simulation and measurement results are obtained. The comparison shows that the measured and simulated results are in good agreement, which proves the feasibility of this work.
Background
Dose painting planning would be more complicated due to different levels of prescribed doses and more complex evaluation with conventional plan quality indices considering uniform dose prescription. Therefore, we tried to introduce new indices for evaluating the dose distribution conformity and homogeneity of treatment volumes based on the tumoral cell density and relative volumes of each lesion in prostate IMRT.
Methods
CT and MRI scans of 20 male patients having local prostate cancer were used for IMRT DP planning. Apparent diffusion coefficient (ADC) images were imported to a MATLAB program to identify lesion regions based on ADC values automatically. Regions with ADC values lower than 750 mm2/s and regions with ADC values higher than 750 and less than 1500 mm2/s were considered CTV70Gy (clinical tumor volume with 70 Gy prescribed dose), and CTV60Gy, respectively. Other regions of the prostate were considered as CTV53Gy. New plan evaluation indices based on evaluating the homogeneity (IOE(H)), and conformity (IOE(C)) were introduced, considering the relative volume of each lesion and cellular density obtained from ADC images. These indices were compared with conventional homogeneity and conformity indices and IOEs without considering cellular density. Furthermore, tumor control probability (TCP) was calculated for each patient, and the relationship of the assessed indices were evaluated with TCP values.
Results
IOE (H) and IOE (C) with considering cellular density had significantly lower values compared to conventional indices and IOEs without considering cellular density. (P < 0.05). TCP values had a stronger relationship with IOE(H) considering cell density (R2 = -0.415), and IOE(C) without considering cell density (R2 = 0.624).
Conclusion
IOE plan evaluation indices proposed in this study can be used for evaluating prostate IMRT dose painting plans. We suggested to consider cell densities in the IOE(H) calculation formula and it’s appropriate to calculate IOE(C) without considering cell density values.
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