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The hypofractionated radiotherapy modality was established to reduce treatment durations and enhance therapeutic efficiency, as compared to conventional fractionation treatment. However, this modality is challenging because of rigid dosimetric constraints. This study aimed to assess the impact of multi-leaf collimator (MLC) widths (10 mm and 5 mm) on plan quality during the treatment of prostate cancer. Additionally, this study aimed to investigate the impact of the MLC mode of energy on the Agility flattening filter (FF), MLC Agility-free flattening filter (FFF), and MLCi2 for patients receiving hypofractionated radiotherapy. Two radiotherapy techniques; Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Radiotherapy (VMAT), were used in this research. In the present study, computed tomography simulations of ten patients (six plans per patient) with localized prostate adenocarcinoma were analyzed. Various dosimetric parameters were assessed, including monitor units, treatment delivery times, conformity, and homogeneity indices. To evaluate the plan quality, dose-volume histograms (DVHs) were estimated for each technique. The results demonstrated that the determined dosimetric parameters of planning target volume (PTV)p (such as D mean, conformity, and homogeneity index) showed greater improvement with MLC Agility FF and MLC Agility FFF than with MLCi2. Additionally, the treatment delivery time was reduced in the MLC Agility FF (by 31%) and MLC Agility FFF (by 10.8%) groups compared to the MLCi2 group. It is concluded that for both the VMAT and IMRT techniques, the smaller width (5 mm) MLCs revealed better planning target volume coverage, improved the dosimetric parameters for PTV, reduced the treatment time, and met the constraints for OARs. It is therefore recommended to use 5 mm MLCs for hypofractionated prostate cancer treatment due to better target coverage and better protection of OARs.

To provide means for calculating the dose received by various tissues of the patient, calculate lung shield, and verify received dose using a phantom as a tool for quality assurance for a planned Total Body Irradiation (TBI) procedure in radiotherapy.Using Microsoft Visual Basic, MATLAB, and Python, a program for Total Body Irradiation Calculation in Radiotherapy (TBICR) is constructed. It uses patient translation and beam zone method for total body irradiation calculations to compute the proper dose received by the patient and determine the lung shield thickness. There are three main user-friendly interfaces in the application. The first one allows the user to upload the TBI topography and estimate the distances needed for TBI calculations. The second one enables the user to count the number of beam zones needed for each point and estimate the effective area (AThe TBICR software has been successfully validated by reproducing all of the manual calculations in an exact and timely manner. TBICR generated more accurate results and confirmed the absorbed dose to patient through measurements on Anderson phantom.A computer program for the calculation of total body irradiation (TBI) is described in full. The dose received at each point on the patient, the calculation of lung shield and the determination of the velocity and time required for the couch movement are all made possible using the software. The ease of use, precision, data storage and printing are some important features of the present software.

Prominence of radionuclide myocardial perfusion imaging (MPI) using single photon emission computed tomography (SPECT) has been investigated and shown to have high precision and predictive value. Improvement of the quality care for patients could be obtained by decreasing the radiation dose and increasing the image quality. The objective of this work is quantitative evaluation of the injected dose in MPI. 32 patients were categorized into 4 groups; each group received a different radiant dose. Image quality indices (Heart/Background (H/B), Heart/Lung (H/P) and Heart/Liver (H/L)) ratios and cardiac ejection fraction (EF%) were determined. It was observed from the images, that there is no substantial alteration in image quality among the groups. It was concluded that the most optimal dose providing the best image is the lowest one.

Electrical Pulsed Field (PEF), of pulse duration in 4 milliseconds, effect on mosquito larvae (

For localized prostatic adenocarcinoma, hypo fractionated radiation has been shown to minimize treatment times while producing results that are similar to those of conventionally fractionated radiotherapy; therefore, volumetric modulated arc therapy (VMAT) plans face a real challenge in achieving the dosimetric parameters for planning target volumes (PTVs) and organs at risk (OARs).The aim of this study was to compare the plan quality and dosimetric effects of two different types of multi-leaf collimators (MLCs) on simultaneous integrated boost (SIB) hypo fractionated prostate cancer treatment using VMAT. Using the VMAT procedure, ten patients with prostate cancer were re-planned with two separate MLCs. For each patient, two treatment plans were carried out. The dose volume histogram (DVH) for PTVs and OARs, as well as the conformity index (CI) and homogeneity index (HI) with 5mm vs. 10mm MLC width, were used to examine the dosimetric parameters. The prescribed doses for the prostate gland (PTVp) and the pelvic nodes (PTVn) are 60 Gy/20fractions and 44 Gy/20fractions, respectively. In plans for Agility to MLCi2, HI and CI were improved. For Agility MLC, the p-values for HI and CI were 0.017 and 0.008, respectively. When compared to MLCi2, the dose distribution for PTVs was improved with Agility MLC. When compared to MLCi2, the delivery time with Agility MLC was reduced by 31%. With Agility MLC, the smallest leaf width results in a dosimetric benefit for PTV.

Silver nanoparticles (AgNPs) have a wide range of industrial and biomedical applications. The aim of the present study was to determine the cytotoxic and genotoxic effects of AgNPs on Ehrlich carcinoma-bearing mice. AgNPs were characterized by ultraviolet-visible absorption spectroscopy, dynamic light scattering, and transmission electron microscopy (TEM). Furthermore, the cytotoxicity and genotoxicity of AgNPs were evaluated using a series of assays: superoxide dismutase (SOD) enzyme activity, malondialdehyde (MDA) levels, DNA damage (comet assay), and histopathological examination of tissues and tumor size in Ehrlich carcinoma-bearing mice. Treatment of Ehrlich carcinoma-bearing mice with various concentrations of AgNPs (6, 24, and 48 mg/kg) injected intra peritoneal (IP) and intra tumor (IT) revealed that AgNPs significantly elevated the levels (0.5- to 5-fold) of MDA and reduced the activity (32-64%) of SOD. Furthermore, AgNPs caused a 2- to 3-fold increase in comet parameters such as percent tail DNA. Additionally, AgNPs inhibit the promotion of Ehrlich carcinoma by masses of necrotic and fragmented tumor cells. Consequently, the volume of tumor reduced by about 31-95% compared to control one. The results indicate that AgNPs possess cytotoxic and genotoxic effects against Ehrlich tumor and confirm the antitumor properties of AgNPs.

The radioprotective and antioxidant activities of melanin nanoparticles (MNP) were investigated in Chinese hamster ovary (CHO) cells in vitro and BALB/C mice in vivo. The endpoints measured were cell viability, superoxide dismutase (SOD) enzyme activity, malondialdehyde (MDA) levels, DNA damage (comet assay), and histopathological examination of tissues. Irradiated groups showed decreased SOD activity and increased MDA levels. Irradiation caused a 3-10-fold increase in comet parameters such as % tail DNA. Treatment with MNP protected cells from DNA damage and death, restored SOD activity, and decreased MDA production. Synthetic MNPs have both antioxidant and radioprotective activities.

Urinary tract infections (UTI) due to Proteus mirabilis strains represented nearly 90% of Urinary tract infection cases. In this study the effect of applying extremely low frequency square magnetic pulses ELF-SMP on P. mirabilis was investigated. While, it interferes with the bioelectric signals generated during the cell division process. Also, the effect of exposure on bacterial antibiotic susceptibility and morphological cellular structure was studied. The results indicated that there was a significant inhibition effect for P. mirabilis exposed to 0.6 Hz SMP for one hour and significant increase in antibiotic susceptibility to DNA, proteins, β-lactamase enzyme and cell-wall synthesis inhibitors. Additionally, results of dielectric relaxation and TEM indicated molecular and morphological changes. According to these aforementioned results, it was concluded that treatment of P. mirabilis cells with SMP at mentioned frequency acts on its cellular activity and structure of the bacteria which can make this method is a promising one in further in vivo applications.

The implementation of an in-vivo diode for dose verification of the intensity-modulated radiotherapy (IMRT) during the actual treatment being rare. This work aims to implement in-vivo and in-vitro diode dosimetry for the IMRT technique to verify the accuracy of the dose delivered to the patients undergoing radiation treatment. In total, 279 fields have been investigated for dose verification from 33 cases, including head and neck, prostate, bladder, and breast cancer patients. Additionally, these fields were compared with in-vitro measurements on a perspex phantom. Beforehand, the measurements were tested for an Alderson Rando phantom. In-vivo measurements revealed that 87.1% of the measured doses were within ±5% of the calculated doses. Of the other 12.9%, about 11.1% were more than ±5% and less ±10% and only 1.8% were outside the ±10% of the calculated doses. The corresponding fields for in-vitro measurements show that 96.1% of the measured doses within ±5% and only 3.9% were outside the ±5% of the calculated doses. The results in this study indicated that in-vivo diode dosimetry for IMRT is reliable as a quality assurance (QA) tool in the radiotherapy departments. Moreover, measurements with diodes are a real-time readout during actual treatment compared to the verification tools that have been used for routine IMRT QA. Additionally, the measurements were carried out comfortably and well tolerated by the patients.

Isolated Agrobacterium tumefaciens was exposed to different extremely low frequencies of square amplitude modulated waves (QAMW) from two generators to determine the resonance frequency that causes growth inhibition. The carrier was 10 MHz sine wave with amplitude ±10 Vpp which was modulated by a second wave generator with a modulation depth of ± 2Vpp and constant field strength of 200 V/m at 28 °C. The exposure of A. tumefaciens to 1.0 Hz QAMW for 90 min inhibited the bacterial growth by 49.2%. In addition, the tested antibiotics became more effective against A. tumefaciens after the exposure. Furthermore, results of DNA, dielectric relaxation and TEM showed highly significant molecular and morphological changes due to the exposure to 1.0 Hz QAMW for 90 min. An in-vivo study has been carried out on healthy tomato plants to test the pathogenicity of A. tumefaciens before and after the exposure to QAMW at the inhibiting frequency. Symptoms of crown gall and all pathological symptoms were more aggressive in tomato plants treated with non-exposed bacteria, comparing with those treated with exposed bacteria. We concluded that, the exposure of A. tumefaciens to 1.0 Hz QAMW for 90 min modified its cellular activity and DNA structure, which inhibited the growth and affected the microbe pathogenicity.

To evaluate the relationship between oxidative stress, DNA damage, and suppression of tumor growth induced by lipoic acid free and nano-capsule. Lipoic acid nano-capsule was assessed by transmission electron microscopy (TEM). The antitumor activity of lipoic acid free and nano-capsule was investigated in Ehrlich solid tumor bearing mice. The endpoints measured were superoxide dismutase (SOD) enzyme activity, malondialdehyde (MDA) levels, DNA damage (comet assay), histopathological examination of tissues and tumor growth volume. Treatment with α-lipoic acid (A-LA) free and nano-capsule (1.2, 2.4 mg/kg) showed a significant depression (67–28%) in MDA levels and elevated (38–98%) in SOD activity. Additionally, A-LA free and nano-capsule caused a 3-10-fold increase in comet parameters such as % tail DNA and suppressed Ehrlich solid tumor growth in mice. In conclusion, the present study revealed that A-LA free and nano-capsule have antitumor activity. This might be possible via its redox activity.

Background SPECT MPI (Single photon emission computed tomography myocardial perfusion imaging) is an essential tool for diagnosis of cardiovascular disease, but it also involves considerable exposure to ionizing radiation. Objective To determine the radioprotective potential of lipoic acid free and nano-capsule against 99mTc-MIBI-induced injury in cardiovascular tissue. Methods The radioprotective ability was assessed by blood count, histopathology and heart enzymes in different groups of mice. Hearts of mice from all groups were dissected and prepared for oxidative stress analysis of superoxide dismutase (SOD) and malondialdehyde (MDA). Furthermore, levels of DNA damage in heart and bone marrow cells were evaluated by alkaline comet assay technique. The same measurements were estimated after treating the mice with lipoic acid. Results Comparing mice injected by radiopharmaceutics with control group showed a significant depression in the count of white blood cells (WBC) by about 40 % at 24 &72 hrs post-radiopharmaceutical administration. Moreover, platelets count was decreased by 27% at 72 hrs post-radiopharmaceutical administration. Radiation also dropped in super oxide dismutase (SOD) and increased in activity of heart enzymes and level of MDA (Malondialdehyde). Additionally, histopathological observation was characterized by focal necrosis of cardiac myocytes. 99mTc-MIBI induced DNA damage had significant increase. Nevertheless, pretreatment with free and lipoic acid nano-capsules (LANC's) prevented the reduction induced in WBCs and platelets, and improved their counts significantly. Conversely pre-treatment with lipoic acid free and nano-capsule significantly increased the activity of SOD and decreased the level of MDA and therefore protected the cardiovascular tissues and reduced DNA strand-break, consequently and enhanced the body weight of the mice. Conclusions These findings highlight the efficacy of lipoic acid free and nano-capsule as a radio protector.

The main aim of this research is to assess the variation in phototherapy radiometer responsivities toward the optical power of the phototherapeutic devices and hence estimate the spectral mismatch correction factor f1′. Two conventional phototherapy devices were studied to verify their spectral irradiance and three different phototherapy radiometers were studied for their responsivity at the range 400–500 nm. The results show the dependence of total irradiance measurement of phototherapy sources on matching between phototherapy radiometer band responsivity and spectral irradiance of the phototherapy sources. The spectral mismatch values vary from 13% to 47% of the total measured irradiance for the three radiometers. These mismatch values could be added to the measured irradiance as a correction.

Background P. aeruginosa considered as a notoriously difficult organism to be controlled by antibiotics or disinfectants. The potential use of alternative means as an aid to avoid the wide use of antibiotics against bacteria pathogen has been recently arisen remarkably. Objective Effect of extremely low frequency positive electric pulse with different duty cycles on Pseudomonas aeruginosa (ATCC: 27853) growth by constructed and implemented exposure device was investigated in this study. Methods The exposure device was applied to give extremely low frequency in the range of 0.1 up to 20 Hz with the capability to control the duty cycle of each pulse with variation from 10% up to 100%. Growth curves of Pseudomonas aeruginosa were investigated before and after exposure to different frequencies (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 Hz) through measuring the optical density and cell count. Exposures to selected frequencies in the whole ranges of duty cycles were done. These studies were followed by DNA fragmentation, transmission electron microscope (TEM), antibiotic susceptibility tests, and dielectric measurements. Results Findings revealed inhibition effect by 48.56% and 47.4% together with change in the DNA structural properties for samples exposed to 0.5 Hz and 0.7 Hz respectively. Moreover the data indicated important role of duty cycle on the inhibition mechanism. Conclusion It is concluded that there are two different mechanisms of interaction between positive electric pulse and microorganism occurred; 0.5 Hz caused rupture in cell wall while 0.7 Hz caused denaturation of the inner consistent of the cell.

BACKGROUND: Myocardial perfusion imaging (MPI) can provide the valuable cardiac functions.Image quality in nuclear medicine tomography is critically dependent on the activity administered into patients. OBJECTIVE: This study was designed to evaluate the optimum injected dose of 99mTc-MIBI for quantitative assessment of image quality as compared with standard injected dose used for that purpose. METHODS: The image quality parameters (Contrast, relative noise and contrast to noise ratio) were determined in 32 patients (21 male, 11 female, age 45–60 y) with weight 60 ± 15 kg. Patients were classified into four groups; each one consisted of 8 patients. The first group received 370 MBq, the second one received 555 MBq, the third group received 740 MBq and the last group received 925 MBq. RESULTS:Qualitative assessments of the images revealed equivalent scintigraphic patterns in all patients. There was a significant difference in the image contrast. The image contrast in the 370 MBq group was greater than other groups. The image noise between the four groups was significantly different. It increased with injected dose reduction. Contrast to noise ratio (CNR) was significantly different between 370 MBq and other groups. CONCLUSION: It is concluded that results from the first group which received 370 MBq are sufficiently similar to those of the fourth group (standard group) which received 925 MBq. Consequently,accurate estimations of differential cardiac functions are possible with the 370 MBq dose.

Referable to the limited response of the current available cancer treatment modalities, new effective cancer fighting treatments are needed. This work investigates the efficiency of intratumoural injection of Pseudomonas aeruginosa bacteria combined with a local tumour exposure to extremely low frequency square pulsed magnetic field (ELF SPMF) in the mouse Ehrlich tumour. 64 Ehrlich ascites tumour-implanted female albino BALB/C mice were equally split up into 4 groups. Group 1 (GP1) was the positive control group. Group 2 (GP2) received a single intratumoural injection of P. aeruginosa bacteria. Group 3 (GP3) was exposed to ELF SPMF for tumour local exposure. Group 4 (GP4) was treated with P. aeruginosa intratumoural injection followed by local exposure of the tumour to ELF SPMF. Treatment monitoring was evaluated using ultrastructural examination, flow cytometry analysis in addition to the measurement of tumour dielectric properties. Tumour cell apoptosis was obvious in GP2 and GP4, but, with higher severity and percentages in GP2. Tumour biophysical properties revealed a significant increase in static conductivity σS of GP2, and decreases in dielectric increment Δɛ´of both GP2 and GP4 compared to the GP1. Unfortunately, GP2 mice showed severe signs of toxicity. We advocate the utilization of the combination of P. aeruginosa and SPMF to yield the most effective antitumour agent with less bacteria-related toxicity.

The present study aimed to evaluate the association between whole body exposure to extremely low frequency magnetic field (ELF-MF) and genotoxic , cytotoxic hazards in brain and bone marrow cells of newborn rats. Newborn rats (10 days after delivery) were exposed continuously to 50 Hz, 0.5 mT for 30 days. The control group was treated as the exposed one with the sole difference that the rats were not exposed to magnetic field. Comet assay was used to quantify the level of DNA damage in isolated brain cells. Also bone marrow cells were flushed out to assess micronucleus induction and mitotic index. Spectrophotometric methods were used to measure the level of malondialdehyde (MDA) and the activity of glutathione (GSH) and superoxide dismutase (SOD). The results showed a significant increase in the mean tail moment indicating DNA damage in exposed group (P<0.01,0.001,0.0001). Moreover ELF-MF exposure induced a significant (P<0.01,0.001) four folds increase in the induction of micronucleus and about three folds increase in mitotic index (P<0.0001). Additionally newborn rats exposed to ELF-MF showed significant higher levels of MDA and SOD (P<0.05). Meanwhile ELF-MF failed to alter the activity of GSH. In conclusion, the present study suggests an association between DNA damage and ELF-MF exposure in newborn rats.

Background There are various physical factors that limit the quality of the Single Photon Emission Computed Tomography (SPECT) images such as number of frames per projection, number of projections per scan and time per projection in gated myocardial SPECT scan. Objective The aim of the present work was to evaluate physical acquisition parameters affecting the cardiac imaging to optimize the patient's examination time and image quality that are acquired with the gamma camera and workers radiation protection (through reducing time of radiation exposure) in cardiac SPECT facility. Cardiac functional parameters like ejection fraction (EF), end diastole volume (EDV), end systole volume (ESV) and total perfusion defect (TPD) were evaluated. Methods Thirty patients were divided into three groups as follows: 1- Group (1): contains two sub-groups, one scanned with 8 frames per projection, the other with 16 frames per projection. 2- Group (2): contains two sub-groups, one scanned with 32 projections per scan, the other with 16 projections per scan. 3- Group (3): contains two sub-groups, one scanned at a time per projection of 20 s and the other scanned at 10 s per projection. Parameters such as the Ejection Fraction (EF), End Diastole Volume (EDV), End Systole Volume (ESV) and Total Perfusion Defect (TPD) in SPECT were compared for each group. Results There was insignificant difference in the EF, EDV, ESV and TPD between the different groups concerning the number of frames per projection, number of projections per scan and time per projection. Conclusion The reduction of scan time to half or the number of projections per scan to half or increasing the number of frames per scan from 8 to 16 at the same duration has insignificant effect in the cardiac functional parameters used with gated SPECT scan.

In this work, we confirmed our previously published value for the inhibiting resonance frequency (4.5 Hz) of electromagnetic radiation for solid tumor implanted in mice. The inhibiting electromagne...

A study of solid tumor growth retardation by employing extremely low frequency (ELF) electric fields has been carried out. ELF electric fields were generated in tumor tissue in mice by the interference of two high frequency sinusoidal waves with the beat frequency centered at the tumor core. The results indicated a pronounced decrease in tumor growth rate in animals exposed to a 5-Hz interferential frequency for 1 hr daily. The 1 hr/day treatment produced a greater retardation effect than the 1 hr/week treatment. This indicates that treatment duration at the applied field frequency appears to play an important role in tumor growth delay. The dielectric properties of the tumor cells showed higher permittivity and conductivity values than homologous normal tissue. The permittivity of tumor cells treated daily with 5 Hz reaches nearly the same value as control tissue. Moreover, histological studies show that tumor tissues treated daily with the same frequency undergo partial regression and shrinkage of the a...

During radiotherapy, ionizing irradiation interacts with biological systems to produce free radicals, which attack various cellular components. The hematopoietic system is easily recognized to be radiosensitive and its damage may be severe. Melanin nanoparticles (MNPs) act as free radical scavengers prepared by polymerization of dopamine. In this study, a total of 110 male BALB/C mice were divided into five equal groups. Each group contained 22 mice. Mice of group A did not receive MNPs or irradiation (control group), group B was injected intraperitoneally (i.p.) with 50 mg/kg MNPs. Mice of group C and D were exposed to a dose of 7 Gy ɣ-irradiation and injected with the same dose of MNPs as in group B either 30 min pre- or post-irradiation, and group E was exposed to a dose of 7 Gy ɣ-irradiation only. The impact of MNPs on peripheral blood, spleen, and DNA damage induced by irradiation was evaluated by blood count, histopathology of the spleen, and comet assay for the DNA in the bone marrow at 1, 4, 8, and 12 days post-irradiation. Results of group E compared with control group (A) showed a significant depression in complete blood count. Additionally, histopathological observation showed the absence of megakaryocytes with delayed time post-irradiation, deposition of eosinophilic protein of their spleen appeared, as well as a remarkable decrease in spleen size was observed. Moreover, ɣ-irradiation-induced DNA damage as can be inferred from a significant increase by about 5–10 folds in all comet parameters (% of DNA, tail length, tail moment, and olive moment) in the DNA of the bone marrow. In contrast, pre-post treatment with MNPs protected hematopoietic tissues against radiation damage, and therefore, enhanced the survival of mice with 40 % in groups (C&D) compared with 10 % to group (E) till 30 days post-irradiation. In conclusion, these results demonstrated that synthetic MNPs provide significant radioprotection to the hematopoietic tissues.

In this work the retardation of Ehrlich tumor growth implanted in mice was studied by employing 4.5 Hz magnetic field. Eighty female Balb/c mice were used, twenty as normal group; the other sixty mice were inoculated with Ehrlich tumor, then they were divided equally into three groups namely A, B and C. Group A (control group) animals were not exposed to the magnetic field. The tumors in the thigh of the animals of group B were exposed to 4.5 Hz, 2 Gauss square wave magnetic field by using a small solenoid connected to a power square wave generator. Group C animals were whole body exposed inside a large solenoid to 4.5 Hz, 2 Gauss square wave magnetic field. Both groups B and C were exposed for a period of 2 weeks at a rate 2 hours per day. Tumor volume, survival period, histological examination and dielectric relaxation of the tumor were measured to investigate the activity of the tumor of the exposed and the unexposed animals. The results indicated that exposing the tumor tissue to 4.5 Hz square wave magnetic field for 2 weeks at a rate 2 hours/day inhibited tumor growth and increased the survival period of the animals. However, group B showed more improvements than did group C. This was attributed to some distortions in the square waveform in the large solenoid (group C). By comparing data from current and previous work, it was concluded that the use of magnetic waves showed better results over previously published work using amplitude modulated electromagnetic waves with the same frequency.