Iranian Journal of Medical Physics
Volume:18 Issue: 1, Jan Feb 2021

The present study investigatedthe risks of ionizing radiation on sperm counts in chronic doses and compared the findings with previous results in similar and different conditions to minimize oxidant stress on sperm parameters rather than using black seed oil.

Twenty rats were used in experimental designs 1 and allocated unordered to four groups. Each group included five. The ranges of 2-3 months and 170 -200 g, respectively .The healthy rats were obtained from the University of Mosul ,Iraq .Experimental design 2, was conducted on  50 rats .The rats were exposed to three different doses for 30 days similar to those of experimental design 1. Oral black seed oil was administrated a dose of 20 mg/kg  in group 2 .

In experimental design 1, there was a significant decrease in sperm count, live sperm percentage and normal sperm percentages respectively. However a significant increase was observed in dead sperm and abnormal sperm percentages in experimental design 1.The administration of black seed oil  in excremental design 2 improved all the parameters with reducing abnormal and dead sperm counts rather than increasing normal and live sperm counts at all doses .

The use of black seed reduce the oxidative stress caused by low dose gamma radiation .Therefore , this substance can be used as a therapeutic option for the treatment  of several type of cancer especially those under the treatment of low dose gamma radiation through enhancement of  protection for a long time.

Electromagnetic waves that are of higher energy than visible light transmit information between mobile phones and antennas BTS (Base Transceivers Station). The increasing use of mobile phones due to the proliferation of antennas is a matter of concern. The present study aimed to investigate the correlation between distance from the BTS antennas and the quality of sleep and life of nearby residents.

For the assessment of the quality of sleep, the Pittsburgh Sleep Quality standard questionnaire (PSQI) was used. On the other hand, the 12-item Short -Form Health Survey (SF-12) was used to assess the quality of life. This questionnaire contains two parameters: Mental Health Composite Scores (MCS) and Physical Health Composite Scores (PCS).

The analysis of the data obtained from 810 people indicated that the most sleep disturbance and the minimum average MCS score (p <0.05) were detected in the residents who were living within 50-100 meters from the antenna. Moreover, it was found that the average PCS score was lower among those residing within 100-200 meters from the antenna, as compared to other residents.

The present study demonstrates that exposure to electromagnetic waves can affect sleep quality, as well as the mental and physical life qualities of the residents depending on the distance from BTS. Antennas implant must be set in patterns that have the lowest intensity in terms of beam convergences for all residents.

The long-term use of fluoroscopy in cardiac interventional procedures increases the patient dose and causes severe skin reactions, which lead to growing concern. The aim of the present study was to evaluate the risk and the effect of X-ray irradiation on apoptosis in the peripheral blood lymphocytes of patients treated with ablation in electrophysiological studies. A total of 30 patients who underwent ablation therapy participated in this study. The absorbed dose in the given area was measured by a thermos luminescent dosimeter (TLD). The duration of dose delivery, absorbed dose by the apparatus, and dose area product (DAP) factor were measured for each patient. The skin changes were observed within the 1st day to 5th week after the operation. Blood sampling was conducted (before and 24 h after the treatment), and then, flow cytometry was performed to investigate the apoptotic changes in the blood lymphocytes. The statistical analysis showed that there was a significant difference in the apoptosis of patient blood lymphocytes before irradiation and following that (p <0.05). There was a correlation between the amount of DAP and TLD dose (p <0.001). Furthermore, a correlation was observed between the total apoptosis and fluoroscopic time. The patient radiation dose in the ablation test was not in the threshold level required to create skin erythema. The results of the present study revealed that the use of long-time fluoroscopy in electrophysiological studies may cause a significant increase of apoptosis in the peripheral blood lymphocyte of patients treated using this procedure.

To compare the dosimetric outcomes of 6 and 10 MV flattening filter free beam (FFFB) energies in gynaecological malignancies RapidArc (RA) planning.

The RA plans were generated for a cohort of 20 patients using 6 and 10 MV FFFBs. The plans aimed to deliver a dose of 50.4Gy in 28 fractions to planning target volume (PTV); moreover, planning objectives were kept as low as reasonably achievable for organs at risk (OARs). Dosimetric analysis was performed in terms of PTV coverage, conformity index (CI), homogeneity index (HI), dose to OAR’s, integral dose to normal tissue (NTID), and total number of monitor units (MU’s).

According to the results, volumes of PTV receiving prescription dose and CI values were 95.03±0.10% and 95.02±0.18%, as well as 1.018±0.028 and 1.024±0.027, respectively. Moreover, HI values were estimated at 1.063±0.008 and 1.068±0.010. Additionally, the corresponding values of mean NTID and MUs were 280.3±42.5 and 267.9±39.1 (liter-Gy), as well as 610.3±30.3 and 630.6±39.7 for FFFB using 6 and 10 MV, respectively. The 6 and 10 MV FFFBs were statistically similar in terms of mean dose to bladder, rectum and both femoral heads, while comparison yielded significant difference (p <0.05) in terms of HI, CI, MUs and NTID.

The FFFB of 6MV was found superior, compared to 10MV, for RA planning in case of gynaecological malignancies. Moreover, it offers better HI and CI values, as well as fewer numbers of MUs (3.33%). In addition, it delivers more NTID (4.42%) for similar target coverage and OAR’s sparing.

“Muscular synergy” is one of the methods for determining the relationship between the central nervous system and muscles which are involved in performing a specific movement. To perform each movement, certain patterns are followed through the central nervous system that control the number of synergies, and these patterns are modified and optimized during the skill. Thepresent study aimed to classify basketball athletes based on muscular synergy analysis. For the purpose of the study, the electromyography (EMG) signals of six dominant hand muscles were recorded during performing three basketball skills. Subsequently, synergy was identified using the non-negative matrix factorization method. In the next stage, the cosine similarity feature was calculated separately; furthermore, the time and frequency of the main signal were analyzed, and the neural network was evaluated using MATLAB software. The result of the classification was obtained by applying the dimensioned reduced matrix of all the existing features with a reliability of 73.68%. In addition, the results demonstrated that the cosine similarities between the muscles of each person could lead to the training of the neural network and classification of individuals at different levels of skill. The present study suggested a new idea regarding synergistic features for classifying athletes based on EMG signal. However, the use of time and frequency features only facilitated differentiation between a maximum of two groups.

For decades, hyperthermia had been widely used for tumor ablation by increasing the temperature of cancerous tissues. For clinical treatment, a capacitance system was developed around the world. In this study, a capacitance system of radiofrequency (RF) hyperthermia was simulated to achieve the temperature distribution map of the entire breast equivalent phantom. Therefore, the efficiency of this method in the treatment of breast cancer was investigated in the current study.

In this study, an RF system with a frequency of 13.56 MHz was simulated by Comsol Multiphysics software (Version 5.3). The geometry of the breast cancerous tissue was modeled by the consideration of three different tissues, including the fat, gland, and tumor tissues. The two electrodes of the system were modeled as two disks with a radius of 15 cm. The calculations of the RF wave and bioheat equation were accomplished by numerical simulation and finite element method.

The temperature plots were obtained in 5 min. The temperature distribution map was entirely achieved and the results were compared with experimental findings to check the accuracy of the RF device and precision of the thermometer.

The obtained results showed that the temperature of the whole tumor region increased uniformly (3-4˚C). Moreover, the temperature of the whole healthy tissues (i.e., the gland and fat tissues) did not increase (1.9-2.1˚C). Consequently, in the capacitive hyperthermia system, the tumor reached extreme heat; however, the healthy tissues were completely protected from damages.

TrueBeam STx® latest generation linear accelerators (linacs) were installed at Sheikh Khalifa International University Hospital Casablanca, Morocco, this study aimed to present and analyse the dosimetric characteristics obtained during the commissioning.

Dosimetric parameters, including percentage depth dose, profiles, output factor, multileaf collimator (MLC) transmission, and dosimetric leaf gaps (DLG) factors were systematically measured for commissioning. Moreover, six photons beams (i.e., X6MV, X6FFFMV, X10MV, X10FFFMV, X15MV, and X18MV) were examined in this study, and a comparison was made between flattening filter (FF) and flattening filter free (FFF) beams.

According to the results, the FF and FFF beams symmetry and flatness were in the tolerance intervals. The unflattness values were estimated at 1.1% and 1.2% for X6FFFMV and X10FFFMV, respectively. Furthermore, tissue phantom ratio(20/10)(TPR) values of the FF beams were X6MV, 0.664; X10MV, 0.738; X15MV, 0.761; and X18MV, 0.778, and the TPR (20/10) values of the FFF beams included 0.632 and 0.703 for 6FFFMV and 10FFFMV, respectively. The results also revealed that the output factor values increased with field size, the surface dose decreased with increasing energy, and the FFF obtained lower mean energy. The MLC transmissions factors were 0.0121, 0.0103, 0.0136, 0.0122, 0.0133,  and 0.0121 for X6, X6FFF, X10, X10FFF, X15, and X18, respectively; additionally, the DLG factors were obtained at 0.32, 0.26, 0.41, 0.37, 0.42, and 0.38 mm for X6, X6FFF, X10, X10FFF, X15, and X18, respectively.

Photon beams reference dosimetric characteristics were successfully matched with the international recommendations and vendor technical specifications.

It is well known that neutrons are more effective treatments than photons to treat hypoxic tumors due to the interaction with the nucleus and the production of heavy particles. This study aimed to evaluate the suitability of Boron neutron capture therapy (BNCT) for the treatment of lung cancer. To this end, neutron dose distributions were calculated in lung tumor volume and peripheral organs at risk (OARs).

Dose distribution to treat lung cancer was calculated by MCNPX code.  An elliptical tumor with a volume of 27cm3 was centered in the left lung of the ORNL phantom and was irradiated with neutron spectrums of Massachusetts Institute of Technology (MIT) and CNEA-MEC. The tumor was loaded with different concentrations of Boron 0, 10, 30, and 60 ppm to evaluate the delivered dose to OARs.

Neutron absorbed dose rates in the tumor were 2.2×10-3, 2.6×10-3, 3.4×10-3, and 4.7×10-3 Gy/s for boron concentrations of 0, 10, 30, and 60 ppm, respectively for MIT. Moreover, similar results for CNEA-MEC were 1.2×10-3, 1.6×10-3, 2.5×10-3, and 3.7×10-3 Gy/s. The heart absorbed the maximum neutron dose rate of 1.7×10-4 and 1.6×10-4 Gy/s in MIT and CNEA, respectively. For all energy bins of spectrums, the neutrons flux is decreased as it penetrates the lung.

An increase in boron concentrations in tumors increases the absorbed doses while deteriorates dose uniformity. The results show that the MIT source is well suited to treat deep lung tumors while maintaining the OARs’ dose within the threshold dose.

Photoelectric effect and X-ray scattering determine the attenuation coefficient of materials in diagnostic radiology. This manuscript presents an iterative gradient search method to separate the contributions to attenuation from these two independent sources. This issue assumes importance due to two reasons, including 1) Electron density determination of scanned materials and 2) correct dose calculation in diagnostic radiology. A special water-filled phantom which was custom-built for simultaneous scanning of 12 samples was used in the current study. Attenuation coefficient equations were iteratively solved to calculate the contributions from x-ray scattering and photoelectric effects. Data converged after five iterations (within 1%). Error in the attenuation coefficient was measured at ±3%. As evidenced by the obtained results, this method can be used to determine the Compton and photoelectric contributions with sufficient accuracy. Moreover, the inversion of Dual- Energy computed tomography (DECT) data for finding electron density and effective atomic number of materials also presents satisfactory results.

Humans are continuously exposed to ionizing radiation. In order to evaluate health hazards, the measurements of background radiation in most countries have special importance. The measurements were carried out by an Ion Chamber Survey Meter (X5C plus), during daylight in 2016. The collected and reported data were based on two ways. Firstly, the measurements of gamma background radiation were performed directly in indoor and outdoor places of five areas, including north, south, west, center, and east, in 11 cities of South Khorasan province, Iran. Secondly, the related data of other studies were used for several provinces of Iran. According to the obtained results, the maximum and minimum of annual effective gamma dose were 0.72 and 0.34 nSvh-1 in Asadabad and Tabas, Iran, respectively. The maximum and minimum of annual effective gamma dose were 0.84 and 0.27 nSvh-1 in Hamedan, as well as Chaharmahal and Bakhtiari, Iran, respectively. The average values of the annual effective dose and estimated excess lifetime cancer risk (ELCR) were 0.60 nSv and 2.11×10-3, respectively, which were higher than the amounts of the world average. The calculated ELCRs for all Iran provinces were higher in comparison to the world average value of 0.25×10-3.