International Journal of Radiation Research
Volume:19 Issue: 2, Apr 2021

Technical advances have allowed the delivery of a higher dose to the tumor volumes, while reducing the dose to nearby organs at risk. Laboratory and clinical evidence suggest that hypofractionation might raise the therapeutic effect. We report our outcomes of moderately hypofractionated schedules with volumetric modulated arc radiotherapy (VMAT) on biochemical failure (BCF) free survival and toxicities in patients with localized prostate cancer.

Between 2013 and 2017, 58 patients were treated using the VMAT technique with daily image guided radiotherapy (IGRT). 3 (5.2%), 32 (55.2%), and 23 (39.7%) of patients had low, intermediate, or high risk disease, respectively. A prescription dose of 70 Gy in 2.5 Gy daily for 28 fractions was used. BCF-free survival was evaluated using 2005 Phoenix criteria and estimated using the Kaplan–Meier method. Radiotherapy-related toxicity was scored according to the Common Terminology Criteria for Adverse Events 4.0 criteria.

The median follow-up was 37.3 months (range 18.8-82.1). Overall 4 year BCF-free survival were 94.0%. For low-intermediate and high risk patients, the 4 year BCF-free survival were 100% and 83.3%, respectively (p=0.027). Pretreatment prostate-specific antigen (p=0.016) and Gleason score (p=0.007) were significant predictors of BCF-fee survival. The incidence of late grade 2 gastrointestinal and genitourinary toxicity was 8.6% and 13.8%, respectively. No grade 3 or greater toxicities were observed.

Outcoms after moderately hypofractionated VMAT-IGRT were encouraging. Moderate hypofractionation was effective and safe for the treatment of localized prostate cancer.

The aim of this study was to compare the dosimetric values of TomoHelical (TH) plans using modulation factors 3 and 5 in patients with breast cancer.

Two different radiotherapy treatment plans, including modulation factors 3 and 5, were generated retrospectively for 12 consecutive intact breast cancer patients. Twelve different plans in terms of the modulation factor were generated. Other optimization parameters (i.e., pitch and field width) were the same for all plans.

No differences were found between the conformity index (CI) and homogeneity index (HI) values of both plans (p>0.05). The values of D mean, V5, and V20 of the ipsilateral lung in the TomoHelical plan with modulation factor 5 (TH5) were significantly lower than with modulation factor 3 (TH3) for all 12 patients (4.9 Gy, 20.14%, 3.23%. Vs, 10.95 Gy, 58.9%, 18.7%; p=0.01, p=0.00, p=0.002, respectively). Also, the values of Dmean and V5 of the heart in TH5 were significantly lower than in TH3 (6.45 Gy, 34.33%, vs. 7.12 Gy, 64.22%; p=0.004, p=0.00, respectively).

Both the TH5 and TH3 plans provided adequate coverage of the intact breast. TH5 delivered a decreased dose to the ipsilateral organs at risk (OARs), especially in the lung and heart volume, which is the main cause of long-term toxicity. The novelty of this work is the obvious reduction in same-sided lung volume irradiation by increasing the modulation factor.

Current dose algorithms, such as the collapsed cone convolution algorithm and anisotropic analytical algorithm, are widely used in commercial treatment planning systems. Nevertheless, it is difficult to calculate the dose distribution of heterogeneities for small fields by using these algorithms, because of the electronic disequilibrium. However, contemporary treatment uses small beamlets more and more frequently, such as stereotactic body radiation therapy and intensity-modulated radiation therapy. In this study, a new inhomogeneity method in lung medium for small fields was presented.

Inhomogeneous lung phantoms for different small fields were established, and different locations and thicknesses of lung media in inhomogeneous phantoms were also considered. The Monte Carlo code EGSnrc was used to calculate the density factor and the percentage depth-dose (PDD) distribution of lung phantoms. The PDDs were also calculated with the new algorithm, and then differences in the PDDs were determined.

The comparison shows that there is a good agreement between the new algorithm and the Monte Carlo code in different energy. The discrepancies of the three field sizes were less than 3%. With an increase in field size, the discrepancies were less than 1%. Even with changes in the location and thickness of the lung media in inhomogeneous phantoms, the discrepancies were always less than 1%.

The comparative results revealed the effectiveness of the new algorithm in calculating depth-dose distribution, under different conditions, and that it can meet the requirements for calculating percentage depth dose distribution.

To audit image quality (IQ) of computed radiography (CR), indirect digital radiography (IDR) and direct digital radiography (DDR) systems used in nine centers affiliated to Shiraz University of Medical Sciences, Shiraz, Iran.

Sixteen imaging units (four CR, five IDR and seven DDR) employing 26 image receptors were assessed. After ensuring the accuracy of X-ray generator performance, IQ was evaluated using a contrast-detail phantom. Spatial resolution, low contrast detectability (LCD) and dynamic range (as subjective indicators) and contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) (as objective quantities) were evaluated. Further, the IQ evaluators of different image receptor types were compared. 

One CR unit failed the X-ray generator performance tests and was excluded from the rest of the study. All 25 remaining image receptors passed the LCD, CNR and SNR criteria. Contrast dynamic range failed in 19 receptors, 17 of them being within a ‘borderline’ failure range. Spatial resolution failed in 18 detectors; 12 of them were borderline failures. The IDR units performed better than the CR and DDR detectors in terms of LCD (p=0.012) and SNR (p=0.007). 

All of the evaluated receptors passed the majority the IQ tests (both physical indicators and one out of the three subjective ones), while contrast dynamic range and spatial resolution of the majority of the failed detectors were borderline failures. Significant differences were observed in IQ among the three image receptors types. The results suggest the need for an improved maintenance, quality assurance and audit program.

The purpose of this study was to investigate the dosimetric characteristics of a new type of two-dimensional diode detector array used for quality assurance of stereotactic radiosurgery (SRS).

The devices used in this study were the SRS MapCHECK detector and the StereoPHAN. The detector has 1013 diode detectors over an area of 77 x 77 mm2. The reproducibility, dose linearity, dose rate dependencies, output factors (OPFs) and angular dependencies were investigated as dosimetric characteristics. The OPFs were measured and compared between AP and PA direction ranging from 0.5 x 0.5 to 7 x 7 cm2. The angular dependencies were measured using 19 gantry angles.

The dose reproducibility and linearities showed sufficient performance of 6 MV and 10 MV. At 40 MU/min, there was a 1.3% difference from the ionization chamber measurements. For the flattening filter-free beam, there was no dose rate dependency from the 400 MU/minute to 2400 MU/minute, and the variation was within 0.5%. For small irradiation fields of 1 cm or less, the measured value of the SMC differed in AP and PA directions by up to 4.5%. The maximum gantry angle dependency of the detector was 5.3%. A maximum difference of -3.1% occurred between the measurements and TPS calculations.

Results indicate that the new 2D diode detector is stable and useful for QA and end-to-end testing of SRS due to its excellent dose characteristics, high resolution and ease of handling when combined with the StereoPHAN.

This study aimed to select the optimum computerized (CT) slice thickness by analyzing its effect on the volumes and dosimetric parameters in treatment planning of low grade Glioma.

Fused brain CT and magnetic resonance imaging (MRI) images of 17 patients were used for treatment planning for three-dimensional conformal radiation therapy (3D-CRT) and Intensity-modulated radiation therapy (IMRT) using CT dataset with the thickness of 1.5 mm, 3, 5, and 10 mm slice. Volume of target and organs at risk (OARs), dosimetric parameters and contouring times using the reconstructed images were compared with the original dataset.

Using larger than 3 mm slice thicknesses resulted in significant increase up to 76% in target volumes as well as the volumes of OARs (p-value<0.05). The variation in normalization point coordinates was also significant using larger than 3 mm slice thicknesses. The contouring time of tumor and OARs using the original data set was up to 35% more compared to the 3 mm dataset. Dosimetric parameters were comparable for 1.5 and 3 mm datasets, however, significant difference of up to 200% was observed for 5 and 10 mm datasets (P<0.05).

CT slices larger than 3mm resulted in significant inaccuracies in volumes and dose coverage of target and OARs. Although using the slice thickness larger than 1.5 mm reduced contouring time significantly, this slice thickness is only recommended when the oncologist is not concerned about the dose received by the small critical organs especially those adjacent to the tumor.

Single photon emission computed tomography (SPECT)-alone imaging using the Tc-99m radiopharmaceutical labeled with methylene diphosphonate or similar analogs is usually employed to diagnose metastatic bone and is typically followed by complementary magnetic resonance (MR) imaging for support in clinical decision-making. In this study, two attenuation map generation approaches from MR and SPECT non-attenuation corrected (SPECT-nonAC) images were evaluated in the context of quantitative SPECT imaging.

The 2class-MR attenuation map was generated via segmenting an MR image into air and soft tissue. Likewise, SPECT-nonAC was segmented into background air and soft tissue to generate a 2class-SPECT attenuation map. The reference attenuation map was generated through manual bone segmentation from an MR image to develop a 3class-bone attenuation map. Standard uptake value (SUV) bias was calculated using the different attenuation maps on 50 vertebrae from normal patients and 16 vertebrae from metastatic patients.

The 2class-MR approach resulted in -16% and -8% SUV bias in normal and metastatic groups, respectively, while 2class-SPECT led to 33% and 26% SUV underestimation for the normal and metastatic patient groups, respectively.

The 2class-SPECT approach led to a significant underestimation of SUV due to the uncertainty of body contour delineation. However, the 2class-MR approach resulted in less than -9% SUV bias in metastatic patients, demonstrating its potential to support quantitative SPECT imaging.

River Niger is the principal river of Western African and is Africa’s third longest river. The dredged project covers 572 km of the lower Niger, extending from Baro in Niger State to Warri Bifurcation in Delta State. 

The current study estimated the activity concentrations of naturally occurring radionuclides and heavy metals concentrations in the sediment samples from Lower Niger River using gamma-ray and Atomic Absorption spectrometric techniques.

The weighted activity concentrations of radionuclides 40K (231± 21 Bq kg-1), 232Th (10±1 Bq kg-1), 226Ra (75±17 Bq kg-1), were obtained in the sediment samples. The radium equivalent, absorbed dose rate, hazardous indices and excessive-life time cancer risk were compared with the international recommended limits.

The measured heavy metal concentrations, contamination factor, pollution load index and quantification of contamination indicated that sediment samples from the River were moderately contaminated.

The purpose of this study was to evaluate the impact of moderate exercise training as an effective strategy to attenuate the harmful effects of electromagnetic radiation emitted from a cell phone on Wistar Ratchr('39')s semen quality.

Twenty four male Wistar rats (10 weeks old) were randomly assigned to groups: control group, exercise group, radiation group, and radiation plus exercise group. The animals in radiation and radiation plus exercise groups were exposed to radiofrequency electromagnetic radiation of a cell phone 3 hours/day for 28 days. The animals in exercise and radiation plus exercise groups performed moderate exercise training six days a week for 28 days. At the same time, the control and exercise groups exposed to a mobile phone in switch off. Basic parameters of testes weight, sperm count, motility, progressivity, morphology, and viability assessed.

Exposure to the cell phone for 28 days significantly reduced sperm count, progressivity, and normal morphology. Exercise alone caused a significant increase in sperm progressivity only. Radiation plus exercise caused a significant increase in sperm progressivity and morphology compared with the radiation group.

Moderate exercise training may attenuate the harmful effects of exposure to cell phone radiation and enhance sperm quality and the fertility status of men.

Cesium-137 is one of those man-made radioactive nuclides that results from human activities including open air nuclear weapons testing, nuclear accidents, operation of nuclear reactors and has a relative long half-life, higher water solubility, high fission yield, relatively high volatility and a close physic-chemical similarity to potassium that makes it a dangerous radioactive element in the human environment and is a hazardous byproduct of nuclear fission. Cesium-137 being a γ-emitter is also a potential carcinogen.

A total of 100 soil samples were collected from various sites in Islamabad and its suburbs for the assessment of the presence of Cesium-137 in the environment. Spectroscopy of the collected samples for determination of aforementioned radionuclide was performed using a computer based High Purity Germanium (HPGe) detector.

The highest value of Cesium-137 was found to be 57.0±4.2 Bq/kg in samples collected from Nilore, a suburb of Islamabad.

The presence of Cesium-137 in all samples is clear evidence that the studied area is contaminated either due to past fallout or ongoing nuclear activities in this area. Cesium-137 was found in higher concentration for this area than the reported values in literature for the rest of country, but not to an alarming level. However, local concerned authorities must pay attention to avoid the development of possible future health hazards to the residents of this area.

Radiation therapy (RT) is one of the common and successful treatments for brain malignancies and benign disorders. In spite of its irrefutable merits, it is associated with a number of complications caused by radiation damage to the important Organs at Risks (OARs), which is strongly correlated with the radiation dose during RT. This study aimed to determine the range of radiation dose to Hippocampus and certain OARs in the brain.

Thirty-two patients with primary brain cancer, undergoing RT, were selected retrospectively. The selected OARs were contoured using the RT Treatment Planning Software through assessing the images from the computed tomography and magnetic resonance imaging (MRI). Dose parameters, namely maximum dose (Dmax) and median dose (Dmedian), to OARs (optic nerves, chiasm, retinas, lenses, orbits, lachrymal glands, brainstem, hippocampi, etc.) were assessed.

The mean age of the patients was 37.8±14.3 years (from 5 to 60 years), and 19 patients (59%) were male. Glioblastoma multiforme and astrocytoma were the most common tumors. The maximum dose received by the brainstem, lenses, and eye ranged between 32-62 Gy, 0.75-40 Gy, 1.5-65 Gy, respectively. The maximum dose received by the hippocampi was 62.7 Gy.

Important OARs can tolerate the received doses which were lower than the threshold level of serious complications. However, the maximum dose received by the hippocampi was higher than the recommended tolerated radiation dose; therefore, it is recommended to conduct more studies in this regard.

Researches on attenuated Toxoplasma gondii vaccine have shown its protective effect against challenged infection in addition to its therapeutic rather than preventative activity against some autoimmune and malignant diseases. Rise in oxidative stress is one of the most common signs of toxoplasmosis; hence this study aims to determine local oxidative stress on hepatocytes as well as associated immune variations in mice vaccinated with gamma radiation-attenuated Toxoplasma gondii.

Thirty female Swiss albino mice are divided into: normal control; mice infected with T. gondii cysts (infected control) and mice vaccinated with the same infective dose attenuated with 0.4 KGy of gamma radiation (vaccinated group).

Hepatic superoxide dismutase (SOD), Malondialdehyde (MDA) and inducible nitric oxidase (INOs) levels were significantly increased with a significant decrease in reduced glutathione (GSH) in liver tissues of infected control mice. Besides, serum levels of interlekin-10 (IL-10) and tumor necrosis factor-α (TNF-α) were significantly elevated. Moreover, histopathological examinations revealed distinct alterations with decreased nuclear expression of DNA in hepatocytes. Conversely, vaccinated group exhibited an improvement in oxidative stress and elevation in nuclear expression of DNA in hepatocytes collimated with an amelioration of the histopathological alterations. Furthermore, reduced serum IL-10 and TNF-α level were detected.

It is concluded that attenuation of Toxoplasma gondii with gamma radiation exerted protective effect in liver tissues against oxidative stress and DNA damages of hepatocytes with an improvement of host´s immune response.

A new coronavirus appeared in late December 2019 in Wuhan, China. He was named Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). This virus is responsible for Covid-19, the name given to the disease associated with it. It spreads worldwide, infecting more than a million people and killing more than 70 miles. The rapid and accurate diagnosis of suspected Covid-19 cases plays a crucial role in medical treatment and timely quarantine.

In order to counter the Covid-19 pandemic, we have developed a method for the automatic detection of Covid-19, from 2D computed tomography (CT) chest images. It is a supervised software system based on the ANN (Artificial Neural Network) algorithm. Pulmonary CT images were collected from multiple international datasets, with a total of 395 images: 70% were used for training and 30% were used for testing. For each patient, the lungs were segmented using simple thresholding. Then, the segmented lungs were fed into a neural network to predict the probability of SARS-CoV-2 infectious.

The internal validation achieved a total accuracy of 97.5% with a specificity of 96.6 % and a 100 % sensitivity.

These results demonstrate the proof-of-principle for using artificial intelligence to extract radiological features for timely and accurate Covid-19 diagnosis.

Based on the principle of oxime formation, 18F labeling of polypeptides can be achieved via a reaction between an aldehyde group-containing 18F-prosthetic group and an aminooxy-modified polypeptide. The focus of this study was to investigate the one-step synthesis of 2-[18F] fluoro-2-deoxyglucose (18F-FDG)- arginine-arginine-leucine (RRL) from open-ring 18F-FDG and the aminooxy-modified RRL peptide cyclo(RRLfK)-ONH2 and to study the biological distribution of 18F-FDG-RRL in a nude mouse model of human neuroglioma.

The aminooxy-modified RRL peptide cyclo(RRLfK)-ONH2 was used as the precursor to react with 18F-FDG at 100 ℃ and different pH values for 30 minutes to synthesize 18F-FDG-RRL. The labeling yield, radiochemical purity, and in-vitro stability of the product were measured, and the biological distribution of 18F-FDG-RRL in tumor-bearing nude mice was analyzed at 30 minutes, 60 minutes and 120 minutes.

The labeling yield of 18F-FDG-RRL was (25.5±5.0) % at a pH of 2.0, and its radiochemical purity was greater than 95%. 18F-FDG-RRL was mainly excreted through the kidneys, with rapid blood clearance. One hour after injection, the uptake of 18F-FDG-RRL in tumors was (1.83±0.12) injected dose per gram of tissue (%ID/g), with a tumor/muscle ratio of 7.03±0.04, a tumor/blood ratio of 4.36±0.21 and a tumor/brain ratio of 7.53±1.37.

The synthesis of 18F-FDG-RRL can be achieved through oximation. This method is straightforward and easy to promote. 18F-FDG-RRL has rapid blood clearance and high uptake by tumors.

With the rapid development of medical imaging equipment and applications of radioactive substances in the diagnosis and treatment of diseases, the exposure of staff and patients to radiation doses becomes increasingly an alarming issue.

This study aimed at estimating the effective dose during radiologic and nuclear medicine examinations of patients, based on their administered dose activity. In parallel, the staff doses were also assessed using thermoluminescent dosimeters (TLDs). The staff members, specifically dealing with 99mTc, were also investigated for their eye lens dose exposure and radiogenic risk.

The mean of occupational annual dose for the whole body, Hp(10),  during the examinations of standard radiography, computed tomography (CT), interventional cardiology, and nuclear medicine were estimated to be 0.33, 0.31, 0.81, and 11.6 mSv, respectively. The annual exposure of eye lens dose, Hp(3), from 99mTc medicine examinations ranged from 4.9 to 11.8 mSv.

In this study, the Hp(3) for medical staff, at the nuclear medicine department, was evaluated by measuring the Hp(10). The doses reported in this study were interestingly found to be less than the annual dose limits recommended by the concerned international organizations.

The aim of this study was to compare the treatment plans of three techniques namely three-dimensional conformal radiotherapy (3DCRT), Electronic tissue compensator (ECOMP) based planning and Volumetric Modulated Arc Therapy (VMAT).

The planning goal was set to cover 95% of the planning target volume with 95% prescription dose for the dose plan of 40 Gy in 16 fractions. Treatment techniques with improved dose homogeneity, optimum skin dose, lung dose (V20Gy) and contralateral breast dose were used as the criteria to select the optimized treatment plan. The treatment planning time and the number of monitor units (MU) required to execute the plan were also taken into consideration. 

 PTV coverage (V95%) for the patient of ca-right breast and the ca-left breast was superior in VMAT plans. Ipsilateral lung (V5Gy %) showed significant dose reduction in ECOMP plans compared to 3DCRT and VMAT plans. Similarly, for the heart and contralateral lung, the mean doses were least in ECOMP plans. Dose homogeneity Index (HI) and Dose conformity Index (CI) was better in ECOMP plans compared to 3DCRT, but VMAT plans were superior to both the other techniques. The skin surface dose was less in VMAT plan. 

 VMAT has high CI as well as HI but at the cost of higher OAR doses (lung and heart) and large treatment planning time. For a busy center, ECOMP can be a good choice of treatment technique which can optimize the OAR doses and treatment planning time but for dose homogeneity and conformity, VMAT is superior to others.

Interventional cardiology (IC) procedures such as percutaneous coronary intervention (PCI) could generate a high radiation dose to both patients and medical staff. In this study, a comprehensive analysis was performed on patient dose during PCI procedures and evaluating the effect beam angulation on dose-area product  (DAP) rate in cardiac catheterization laboratory.

We studied 30 PCI procedures in angiography department during four months. A calibrated DAP meter was used to record patients’ dosimetric characteristics. Effective dose (ED) was calculated using DAP values along with DAP to ED conversion factor. Local diagnostic reference levels (DRLs) of the DAP, fluoroscopy time, and number of CINE frames were calculated as third quartile values of these parameters.

The mean ± SD of DAP value per procedure was 31.4 ± 17.1 Gy.cm², while corresponding values for fluoroscopy and CINE-acquisition (CINE) were 17.1 ±‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌ 11.2 Gy.cm² and 14.4 ± 8.2 Gy.cm², respectively. The estimated mean value of effective dose per procedure was 5.7 ± 3.1 mSv. The projection 40º LAO/ 30º caudal had the highest DAP rate value during CINE across various projections. Local DRLs were proposed as follows: 39.6 Gy.cm², 6.9 min, and 679 frames.

The mean values of DAP in this study were lower than in previous published literature. Further, deep tube angulation led to increase DAP rates. It is recommended to use minimum tube angulation for avoiding unnecessary radiation exposure.

Inclusion of air-filled cavities in the head and neck treatment fields due to electronic disequilibrium may lead to uncertainties in predicting dose distribution by treatment planning systems (TPS). In this study the Full Scatter Convolution Algorithm (FSC) used in TiGRT treatment planning systems was evaluated using a novel 3D film dosimetry method.

9 pieces of EBT2 films were embedded in a rectangular inhomogeneous head and neck phantom. Three approximately small field sizes including sandwiched EBT films which embedded between phantom slabs were exposed with 6 MV X-ray photons. A homemade computer code was developed in MATLAB for the creation of a 3D dose map of irradiated films and calculation of enclosed volumes which were surrounded by isodose lines in films. Then the calculated dose volumes were compared with the same quantities derived from Dose Volume Histogram (DVH) which is available in TPS outputs.

Our results showed significant differences between the results of the film dosimetry and DVH values. The maximum difference of calculated and measured values was observed in volumes surrounded by 95% isodose curves and 3x3cm2 field size (P=0.035) and the minimum difference was observed in volumes surrounded by 95% isodose curves and 5x5cm2 field size (P=0.047).

The results of this study demonstrated overestimated results in volumetric dose calculation of the FSC dose calculation algorithm in the presence of inhomogeneities and the 3x3cm2 field size. Also, these results confirmed that the utilization of an accurate and comprehensive method such as 3D film dosimetry can be useful for TPS verification.

Radiation pneumonitis (RP) is a common complication of thoracic radiation which affects patients’ ability to breathe, limits the deliverable intensity of radiotherapy and impairs clinical outcomes, indicating the need for timely diagnosis and management. The purpose of this study was to determine the predictive capability of two peripheral inflammatory cells for RP.

A murine RP model was established using SD rats that received a single dose of 20 Gy thoracic radiation. At 2 and 4 weeks post-radiation, mice were processed to harvest lungs for hematoxylin-eosin (HE) staining and collect blood for flow cytometry analysis.

By 2 weeks post-radiation, histopathological changes had occurred in the lungs indicating the onset of RP. Peripheral CD45+HIS48+ granulocytes were significantly increased by the radiation treatment at both the early and later time points (P<0.05). However, we did not observe a statistically significant increase of CD45+CD11b/c+HIS48- monocytes/macrophages.

Our study highlights the possibility that increased levels of peripheral CD45+HIS48+ granulocytes could serve as a predictive indicator of RP. Early detection provides the opportunity for early intervention and therefore, a reduction in the rate and extent of RP.

Radiation not only kills tumor cells, but also damages other sites. The mechanisms of damage caused by the bystander effect of irradiation in animal models are unclear and the time node is single. In this study, we aimed to investigate the inflammatory response of thymus tissue injury in non-irradiated areas at different times after irradiating rat skin.

Rats were irradiated with an X-ray dose of 38 Gy, and at 15 d after irradiation, when the skin wound was most severe, the pro-inflammatory drug high mobility group box1 (HMGB1) and the anti-inflammatory drug glycyrrhizic acid (GA) were injected intraperitoneally into rats. After irradiation, skin tissues were collected for histology, and thymus tissues were collected for gene and protein testing.

Animal model of skin damage was successfully established. The expression of macrophage (F4/80) increased after irradiation, and F4/80 produced cytokines. Through the flow which was activated by inflammatory factors in the blood, DNA damage and the expression of inflammatory-related cytokines in non-irradiated area of the thymus peaked at 15 d after irradiation. Moreover, HMGB1 treatment increased the expression at 1 d after intraperitoneal injection, and GA solution decreased the expression of inflammatory-related cytokines.

When radiation damages the skin, it can cause damage to other organs through the circulation, and an anti-inflammatory GA solution reduced inflammatory responses, which are required to modify radiation-induced systemic effects with anti-inflammatory drugs or agents that affect pathways that cause bystander instability.

In diagnostic radiography, selection of kVp and mAs to produce acceptable image quality with a minimum dose has been a challenge even for experience radiographers. The aim of this study was to determine optimal exposure factors for lumbar spine AP examinations in computed radiograph using dose-image quality analysis.

A female anthropomorphic phantom was used for dose-image quality analysis to determine the optimal exposure factors (mAs and kVp) for lumbar spine AP. Indirect method was used to estimate the entrance skin dose (ESD) to the anthropomorphic phantom. kVp values of 70, 80, 90 and100 were selected while mAs values of 16, 18, 20,22,25, 28,32, 36, 40, 45 and 50 were also selected for the acquisition of all the images. Three (3) senior radiographers evaluated the image quality using image quality criteria set up by European Commission.

The result indicated that the image quality score increased as ESD (mGy) increased. However, there was no significant change in image quality score between ESD of 1.941 and 4.882 mGy. 70 kVp and 22 mAs were accepted as optimal exposure factors for standard body size lumbar spine AP examinations in diagnostic radiography of computed radiography (CR).

Optimization of exposure factors (kVp and mAs) is necessary in radiographic examinations to ensure safe use of radiation in medicine. It ensures effective patient dose management because radiograph with high quality can be obtained for effective diagnostic information.

This study aims to compare retrospectively generated gated internal target volumes (ITVs) and to evaluate whether gated ITVs can reduce planned target volumes (PTVs) compared with standard ITV expansions.

In this study, we retrospectively generated respiratory-gated ITVs and PTVs for our cohort of patients who underwent four-dimensional computed tomography for thoracic radiotherapy in our department between August 2018 and February 2019. We calculated the standard ITVs and two gated ITVs to analyze the volumetric reduction. Further, we considered a PTV reduction of >10% to be significant, and we analyzed the role of the localization and the size of the gross tumor volumes.

We included 38 patients with a median age of 70 years (mean = 68, SD ± 13,4, range =43–89), of whom 18 (47%) were females and 20 (52%) were males. The two gated PTVs (PTV 30%–70% and PTV 80%–20%) were significantly smaller than the standard PTVs (p-value < 0,001 for both PTVs). Considering the volume of the gross target volume (GTV), we found a significant correlation between GTV30cc and ITV30%–70% (chi-square analysis, p:0,006) and between GTV5cc and ITV80%–20% (p:0,003). We also found a correlation between the localization of the target lesion (mediastinal/central/peripheral lesion) for both the gated ITVs (p: 0,030 for ITV 30%–70% and p:0,018 for ITV 80%–20%).

Gated ITV plans could be useful for the sparing of normal tissues. Our results show that this approach could be useful for small lesions and for certain localizations (island tumors).

The solar radiation consists of a vast spectrum of wavelengths such as visible light and ultraviolet radiation (UVR). The amount of UVR that reaches the Earthchr('39')s surface is very important due to its role in vitamin D synthesis and causing skin cancers. The hourly and daily mean values of solar UV type A, B, and visible light radiation were measured for the first time during the year.

The hourly and daily mean values of UVR and visible light intensity of solar radiation at Tabriz were measured and analyzed between the 2017 and 2018 years. The intensity of solar UVA and UVB radiation was measured by Hand-held Lux-UV meter device from sunrise to sunset for one hour.

The results showed that the highest values of UVA and UVB radiation, reaching the Earth were between 12 and 13 o’clock. The maximum and minimum values of UVR were recorded during the months of May and January, respectively. The maximum amounts of UVA and UVB during the whole year were 52.48 and 2.82 W/m2, respectively. Also, the lowest intensity of UVA and UVB radiation during the whole year was 22.19 and 0.79 W/m2, respectively.

Comparison of maximum and minimum UV amounts of type A and B in May was about 2.36 and 3.56 times more than in January. The measurements showed that the intensity of UVA was significantly higher than UVB amounts.

To evaluate and compare the dosimetric advantages of lateral opposing fields (LOF) and intensity-modulated radiation therapy (IMRT) in moderate-to-severe active thyroid-associated ophthalmopathy (TAO) retro-orbital irradiation.

Fifty-eight TAO patients who underwent radiotherapy from 2012 to 2018 were chosen. LOF and IMRT plans were separately developed for each patient. The independent samples t-test was used to compare the differences among conformity index (CI), homogeneity index (HI), dose received by the maximal 95% of the target (D95), and organs-at-risk (OAR) doses between the two groups. Pearson’s correlation analysis was used to analyze the relationship between exophthalmos and OAR dose.

CI and HI in the IMRT group were better than those in the LOF group, but crystal, eyeball, and optic nerve dose were higher than those in the LOF group (P<0.05). There was no significant difference in D95 (P=0.261). In the LOF group, exophthalmos was negatively correlated with crystal and eyeball dose (P= 0.000).  However，there was no correlation between these indicators in the IMRT group (P>0.05). In the LOF group, the median observation time was 26 months; the CT value of post-ball adipose tissue, exophthalmos, and clinical activity score was lower than those before treatment (P=0.000), and eyesight was better than that before treatment (P=0.000); 10% (2/20) had dry eyes and 5% (1/20) had decreased vision.

LOF is safer than IMRT and can make full use of the high exophthalmos of TAO patients to reduce OAR dose.

Bismuth Polyurethane composite is a novel shield for breast protection while saving image quality in chest CT. Bismuth different concentrations used for constructing polymer composites breast shields in this study.

Bismuth with particle size <150 micrometer used in bismuth polyurethane composite (BPC) with a ratio of 10%, 15% and 1.1, 2.2 mm thicknesses. The BPC was examined on the female chest phantom (skin and fourth layers), 120 kV and 80 mA selected as an exposure factors in chest CT. The dose reduction was recorded by TLD and the image quality was evaluated quantitatively and quantitatively.

Using BPC shields 10% and 15% (2.2 mm) induced to breast dose reduction to 69.1% and 77.5% for skin layer and 44.7% and 52.8% for fourth layer, respectively.  The image noise Increasing in BPC for breast and mediastinum areas were 9.43% (P=0.347) and 15.44% (P=0.386), respectively.

Application of Bismuth with different weight ratios in polyurethane composite was useful shield for radiation dose reduction of the breast in chest CT.

Radioprotective effects of melatonin and famotidine were reported in previous studies. In this study, modulating effects of these agents alone or in combination were tested on high dose radiation induced cell lethality in MRC5 and Hela cells.

DPPH (2,2-Diphenyl1-picrylhydrazyl) was used to measure antioxidant property of famotidine and melatonin at different concentrations. Famotidine at a concentration of 80 µg/ml and melatonin at a concentration of 80 µg/ml was added to culture flasks containing MRC5 and Hela cells two hr prior to gamma-irradiation. Treated and untreated cells were irradiated with doses of 4 and 8 Gy gammarays. MTT assay was used to measure cell viability 48 and 72 hours after irradiation. Data were analyzed using nonparametric one way analysis of variance (ANOVA).

DPPH assay showed high antioxidant potential for melatonin. Presence of melatonin led to significant elevation of cell viability of both MRC5 and Hela cell lines after 4 and 8 Gy gamma-irradiation at both sampling times (p<0.01). However, for Hela cells exposed to 4 Gy, melatonin led to reduced cell viability (p<0.05). Famotidine, did not improve radiation induced cell lethality for both MRC5 and Hela cells exposed to 4 and 8 Gy.

Except for 4 Gy irradiated Hela cells, presence of melatonin led to a significant radioprotection against radiation induced cell lethality of cells, Famotidine failed to improve cell viability in both cell lines. The mechanism of radioprotection of melatonin might be attributed to its radical scavenging potential.

Intramuscular hemangioma is a rare type of hemangioma. Ossification of an intramuscular hemangioma is even rarer. This study reports the case of a young man admitted to our hospital with complaints of pain and swelling in the right buttock. We were unable to confirm the type of tumor on evaluation of X-ray, ultrasound, magnetic resonance imaging, and needle biopsy examination. The mass was excised and histopathology confirmed the diagnosis of an ossified intramuscular hemangioma with immature ossification. This case report demonstrates that the diagnosis of an immature ossified intramuscular hemangioma should be considered as differential diagnosis in patients presenting with a soft tissue tumor.

A solitary fibrous tumor of the urinary bladder is an extremely rare type of mesenchymal tumor. We present a case of an 85-year-old woman with a large (14.5×10.7×10.1 cm) protruding intravesical mass detected by computed tomography (CT) and magnetic resonance imaging (MRI), which was proven to be a solitary fibrous tumor through histopathological examination. The clinicopathologic and radiological features are here discussed, along with a review of the published literature on this topic. Solitary fibrous tumors of the urinary bladder are more common in men (76%), with a peak incidence in people 40–60 years old. Most such tumors show heterogeneous intensity with a complete capsule. A decrease in the T2WI signal with an increase in collagen tissue content and gradual enhancement on CT/MRI images are their main features. Most such tumors are positive for CD34 under immunohistochemistry (100% in 24 available cases). The majority of tumors (88%) studied have been non-malignant and most patients (95.5%) showed favorable prognosis after a long-term follow-up.

We report a case of a metastatic breast cancer woman undergoing therapy with fulvestrant and palbociclib that was successfully treated with thoracic stereotactic ablative radiation therapy (SABR) for a hilar lymph node metastasis.

The patient began the radiation treatment in the week off of the palbociclib and reported no acute toxicity. The CT scan showed acute pneumonia 60 days after RT although the patient reported no symptomatology. In addition, the subsequent PET/TC scan performed six months after RT exhibited a complete response of the irradiated lesion.

The use of SABR in patients undergoing cyclin inhibitors appears to be potentially effective although the association must be further studied to investigate the toxicities.