International Journal of Radiation Research
Volume:19 Issue: 4, Oct 2021

Hypoxia, a common phenomenon in solid tumors can promote dysfunctional vascular growth and epithelial-to-mesenchymal transition, leading to cell mobility and metastasis. The decreased sensitivity of hypoxic tumor cells to ionizing radiation is one of the main factors affecting the effect of conventional radiotherapy. It is well known that conventional radiotherapy mainly reduces the effect of hypoxic radiation resistance by reoxygenation between fractions. With the improvement of radiation treatment planning and delivery, more and more cancer patients have been treated with hypofractionated radiotherapy (HFRT), which have achieved a much higher effect than conventional radiotherapy. Given that HFRT is delivered within one or a few fractions, does tumor hypoxia affect its efficacy? Is there any way to further improve the effect of HFRT? In this review, we focus on the interaction between HFRT and hypoxia, and how to optimize the regimen of HFRT to decrease the effect of hypoxia and improve the efficacy is discussed in detail.

Non-small-cell lung carcinoma (NSCLC) as the most common type of lung cancer has the most leading mortality rate among other cancers. Diabetes mellitus is one of the most common comorbidities of this disease. Metformin is a conventional anti-diabetic drug that is evaluated in various studies as an anti-cancer agent. This study was an updated systematic review and meta-analysis evaluating the effect of metformin on NSCLC.

A systematic search was conducted through PubMed/Medline, EMBASE, and Cochrane library databases and all retrospective studies with the title the effect of metformin on the non-small cell lung cancer were collected. Statistical analyses were carried out using either random-effects or fixed-effects models according to the heterogeneity examined by I2 statistics and assessing Hazard Ratio of overall survival (OS) using Revman version 5 software.

Fourteen studies involving 3164 patients were included in the current meta-analysis. The pooled hazard ratio (HR) of comparison of overall survival (OS) between metformin user diabetic patients and diabetic patients without a history of using metformin was 0.87 (95 % CI 0.74–1.02; P = 0.08). Sub-group analysis showed that when studies were divided by region the HR of OS for Asia was 0.77 (95 % CI 0.65–0.90; P = 0.001), 1.11 (95 % CI 0.72–1.71; P = 0.64) for USA, and 0.86 (95 % CI 0.57–1.30; P = 0.47) for Europe.

The use of metformin beside radiotherapy in patients with type 2 diabetes may be associated with a good prognosis. While this impact was just significantly seen in Asian studies.

Liangxue Guyuan decoction (LGD) has been used to alleviate symptoms of radiation enteritis (RE) in the clinic. This study aimed to investigate the effects and anti-apoptosis and proliferative mechanisms of LGD in rats with RE.

A total of 115 male Sprague Dawley rats were used. The control group consisted of 15 rats, and the remaining 100 rats were irradiated with 60Co γ rays at a dose of 11 Gy and randomly divided into four groups of 25 each: the model group, the dexamethasone (DXM) group, the low-dose LGD (LGDl) group, and the high-dose LGD (LGDh) group. The treatment was administered intragastrically for 7 days, and the number of rats that died was recorded daily. On days 3 and 7 after irradiation, five rats were randomly chosen and sacrificed from each group, and ileum samples were taken for pathological observation, immunofluorescence staining, western blotting, and PCR experiments.

Compared with the model group, the mean survival time, villus length (V), and the ratio of V to crypt depth C (V/C), the number of Ki67-positive cells was increased, and the number of TUNEL-positive cells was reduced in the LGDh group. In addition, LGDh showed some effects on upregulating p-PI3K, p-AKT, and Bcl-2 and downregulating caspase-3 and Bax. The effect of LGD was better than that of DXM.

LGDh prolonged the survival time of irradiated rats, inhibited intestinal epithelial cell apoptosis, and promoted intestinal repair. This mechanism may be related to the regulation of the PI3K/AKT pathway.

To evaluate the predictive value at the hepatobiliary phase (HBP) magnetic resonance imaging (MRI) after gadobenate dimeglumine (Gd-BOPTA) injection for histologic grades of hepatocellular carcinoma (HCC).

HCC patients who underwent Gd-BOPTA-enhanced MRI were analyzed and divided into four histologic grades of differentiation based on Edmonson-Steiner grade. Besides, HCC tumor differentiations grade I, II and III, IVwere defined as well-differentiated (WD), moderately-differentiated (MD), poorly-differentiated (PD), respectively. The clinical, pathological and imaging features of patients were assessed. Receiver operating characteristic (ROC) curve was to evaluate the significance between WD/MD HCC and PD HCC using the apparent diffusion coefficient (ADC), relative intensity ratio (RIR) of T1WI and T2WI (T1RIR, T2RIR), contrast-enhancement ratio in arterial phase (CERA) and contrast-noise-ratio (CNR) in HBP (CNRhbp).

A total of 102 HCC patients were analyzed (grade I,  n=19; grade II, n=30; grade III, n=30; grade IV, n=23). There was no statistical difference regarding to the pathological and clinical features among four grades. There were significant differences in CERA, CNRhbp, T1RIR, T2RIR and ADC values among the four HCC grades (all P<0.05). Based on ROC curve, comparison of the five quantitative MRI parameters indicated ADC (sensitivity 84.8%, specificity 82.6%, AUC 0.862) and CNRhbp value (sensitivity 78.5%, specificity 91.3%, AUC 0.916) could significantly distinguish the HCC histological grade.

The ADC and/or CNRhbp value in HBP-MRI after GD-BOPTA injection might be as the significant quantitative parameters to distinguish HCC histological grade.

The present study aims to investigate and characterize radiation dosimetric phantom that is made from Rhizophora spp. particleboards using SPC/NaOH/IA-PAE adhesive.

Modification of soy protein concentrate (SPC) bonded Rhizophora spp. particleboard phantoms were carried out using sodium hydroxide (NaOH) with different amount of bio-based cross-linking agent (IA-PAE) with three different categories of particle size. The radiation attenuation parameters were evaluated with photons energies between 16.59 and 25.26 keV derived from X-ray fluorescence. SPC-based plug phantoms were scanned together with the CT density phantom 062M at 80, 120, and 135 kVp, and 250 mAs.

The physical and mechanical properties were found to be improved, while the dimensional stability was decreased through the addition of 15 wt% IA-PAE with decreasing particle size. The lowest HVL and MFP, and the highest μm with their corresponding values of Zeƒƒ  (p-values of 0.054, 0.055, 0.060, and 0.075), and the relatively low X2 values are the characteristics of samples labeled as A15, B15, C10, and C15. Sample C15 gave the closest values of CT number, ED, and DDPs to water for all tested tube voltages.

The results point to the possibility of employing C15 as a promising TEPM.

Conventional radiation dosimetry methods in computed tomography (CT) are not able to measure the dose distribution along the patient’s longitudinal axis. To calculate the dose index on a CT scan, the dose distribution from the center of the radiation field must be calculated. In this study, the most appropriate integral interval for calculating the CT dose index in the axial mode was determined using the Monte Carlo (MC) method based on X-ray photon energy and slice thickness.

The computed tomography dose index (CTDI) phantom was simulated in the EGSnrc/BEAMnrcMC system and was irradiated with several X-ray energies and several slice thicknesses and dose profiles in phantom were investigated. The area under the dose profile and the scatter to primary radiation dose ratio (SPR) were calculated.

The range of scattered beams from the center of the radiation field reaches 450 mm in 140 kV and a 40 mm slice thickness. The SPR value for all levels of X-ray photon energy (between 80 and 140 kV) significantly decreases as slice thickness increases. CT scan imaging technical factors greater than 310 mm from the center of the slice thickness have no effect on the behavior of the scattered radiation.

The primary beams are more affected by the energy of the photons, and the scatter beams are more strongly affected by the slice thickness. For 64-slice scanners, the polymethyl methacrylate (PMMA) phantom length should be between 700 mm and 900 mm to yield accurate CTDI estimations.

To investigate the difference between CT-guided three‑dimensional brachytherapy using insertion needles and Fletcher applicator brachytherapy.

Ninety-three patients with cervical squamous cell carcinoma were included. Insertion needle or Fletcher applicators were used depending on tumor conditions. The target volume, target and organs at risk (OAR) dose, and treatment-related complications, in patients receiving the different brachytherapy techniques were compared.

The mean volume of the high-risk clinical target volume (HR-CTV) and intermediate-risk clinical target volume (IR-CTV) in the Fletcher applicator group were smaller compared with the insertion needle group (P<0.05). The mean values of D90 per fraction of the HR-CTV and IR-CTV in the Fletcher applicator group were 101 cGy and 60 cGy lower, respectively, compared with the insertion needle group (P<0.05). The mean bladder and rectum D0.1cm3 per fraction, the mean sigmoid and small intestine D2cm3 per fraction were statistically different between two groups( all P<0.05), the remaining dosimetric parameters were no significant differences (P>0.05). Following dose normalization, with the exception of the mean normalized sigmoid D0.1cm3 per fraction for the received by the OAR in the Fletcher applicator group and the insertion needle group were significantly different (P<0.05). There was no serious complication in the brachytherapy of two types applicators.

Brachytherapy using insertion needles enables the treatment of larger target volumes with higher target doses when compared with conventional Fletcher applicator brachytherapy. In addition, the doses received by the OAR are lower, indicating that it is a safe and effective technique that warrants wide adoption.

The whole neck is often included in the radiation therapy (RT) field of head and neck cancer (HNC), and carotid vessels of the neck may be affected by radiation in a manner that increases the risk of ischemic stroke (IS). In the present study, we analyzed the relationship between RT for HNC and subsequent IS using a database managed by the Health Insurance Review & Assessment Service.

A public insurance system was used to identify a nationwide cohort of patients diagnosed with HNC that underwent RT. The incidence of IS after RT was determined up to the end of December 2018, and associated risks were analyzed. In addition, patients that underwent frequent elective neck irradiation as determined by disease classification or less frequent elective neck irradiation were allocated to groups A and B, respectively.

12,079 HNC patients that received RT between 2010 and 2014 were identified. 472 (3.9%) of the subjects experienced IS and incidence rates were > 5% for hypopharyngeal cancer and supraglottic cancer. The incidence of IS was 5.4% in patients > 60 years and 2.2% in patients < 60 years (relative risk (RR) 2.59). In addition, the incidence of IS was greater in group A than in group B (RR 1.29), and in men than in women (RR 1.33).

When performing extensive RT involving the whole neck in older men, close follow-up and prophylactic medication should be considered to prevent IS.

The free flattening filter (FFF) beam can affect the characteristics of the linac output such as the maximum dose depth, surface dose, dose in the fall-off area, and doses outside the field because the beam hardening effect does not occur in the FFF linac head. Therefore, the present study aimed to investigate the influence of the FFF beam on the dose distribution in an inhomogeneous phantom using the EGSnrc/DOSXYZnrc Monte Carlo package.

In the present study, an Elekta Infinity 10 MV photon beam equipped with a multileaf collimator Agility linear accelerator was used. Two types of virtual inhomogeneous phantoms were built for percent depth doses (PDDs) and dose profiles measurement. The first phantom comprised four layers: water (4 cm thickness), bone (2 cm thickness), lung tissue (5 cm thickness), and water (19 cm thickness). The second phantom had a half-lung tissue slab and a half-bone slab (10 cm thickness) on the left side of the water.

The PDD curves in the inhomogeneous phantom considerably decreased in the lung area for small exposure fields because the charged particle equilibrium was not achieved. The dose in the lung was higher than the dose in the water when the charged particle equilibrium was reached. Meanwhile, the dose in the bone is always lower than the dose in the water.

The dose distribution of flattening filter (FF) and FFF beams in the inhomogeneous phantom was the same in the small field of exposure. However, differences in dose distribution are increasingly apparent for larger field sizes.

Comparing three whole pelvic radiotherapy (WPRT) procedures as well as two local radiotherapy (LRT) procedures with each other for the treatment of prostate cancer patients using dosimetric parameters and radiobiological models: tumor control probability (TCP), normal tissue complication probability (NTCP), and equivalent uniform dose (EUD).

Two groups of prostate cancer patients underwent WPRT (n=16) and LRT (n=16) procedures. In the WPRT group, the patients treated with two intensity modulated radiation therapy (IMRT+IMRT) procedures at two consecutive phases. Then, two other techniques including a three dimensional (3D) conformal radiation therapy (3DCRT) phase followed by an IMRT phase (3DCRT+IMRT) and also two consecutive 3DCRT procedures (3DCRT+3DCRT) were carried out on the patients' data. In the LRT group, the patients treated with just an IMRT technique. Then a 3DCRT technique was also performed on the patients' data. All the WPRT and LRT procedures compared with each other based on the dosimetric parameters and radiobiological models.

The mean of dosimetric parameters did not exceed the specified dose constraints for the bladder and femoral heads in the 3DCRT+ IMRT, and for the bladder in the 3DCRT technique. In the WPRT and LRT procedures, the TCP values for the prostate did not reveal any significant differences (P>0.05). The NTCP results in accordance with the dosimetric results for the organs at risk (OARs) showed a significant decrease in the IMRT+IMRT (WPRT) and the IMRT (LRT) techniques (P<0.05). However, the EUD results were dependent on the type of the procedure and OARs.

For selecting the appropriate treatment technique for each prostate cancer patient, a compromise between the dosimetric and radiobiological evaluation of the WPRT and LRT procedures should be considered.

The purpose of this study is to compare SOURCE 8 and 20 in the EGSnrc-based DOSXYZnrc Monte Carlo code for Jaws-only intensity-modulated radiation therapy (JO-IMRT) dose distribution, and demonstrate the advantage of SOURCE 20 to SOURCE 8 to treat head-and-neck cancer.

The clinical photon beams of the HPD Siemens Primus linear accelerator simulated using the BEAMnrc code and then verified by measurement. The phase-space files generated by the BEAMnrc code were used as an input for the DOSXYZnrc to calculate the JO-IMRT dose distributions of patients (in form of CT images) using the SOURCES 8 and 20. The isodose distribution on slices, DVH and gamma index (3%/3 mm, 2%/2 mm, and 1%/1 mm) were compared with Monte Carlo and treatment planning system (TPS) results. Furthermore, the efficient computation of dose distributions such as time running, working load and uncertainty error calculation also considered for evaluation.

JO-IMRT dose distributions calculated by SOURCE 8 and 20 compared with the Prowess Panther TPS. The time running, working load based on SOURCE 20 were significantly less than SOURCE 8. Futhermore, the uncertainty calculation based on SOURCE 20 was also significantly less than SOURCE 8.

The JO-IMRT dose distributions calculated by SOURCE 20 are more efficient than SOURCE 8.

Spleen is the largest lymphatic organ that is seriously affected during irradiation. Radiation exposure reduces both of spleen size and weight; that in turn decreases the numbers of immune cells. Melatonin is an effective free radicals scavenger. Therefore, this study aimed to evaluate the effects of melatonin on both blood and spleen of whole body γ-irradiated male Sprague dawley rats.

Animals were intraperitoneally injected with 100 mg/kg melatonin prior to radiation exposure by 30 minutes. Experimental groups were group I: control rats, group II: irradiated rats, group III: melatonin administrated unirradiated rats and group IV: melatonin administrated irradiated rats. Blood and spleen samples were collected 24 hours post irradiation for biochemical, immunological and blastogenesis measurements. Apoptosis, pro- and anti-apoptotic proteins of spleen cells were measured by flow cytometry techniques.

Melatonin significantly upregulated the activities of superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT); and reduced malondialdehyde (MDA). It down regulated the expression of pro-apoptotic proteins (p53, Bax, caspase-3 and caspase-8) and up regulated the expression of anti-apoptotic protein Bcl-2 in spleen cells; that in turn reduced the radiation-induced apoptosis. Levels of pro-inflammatory cytokines (TNF-α, IFN-γ and IL-1β) were significantly reduced in group IV. Blastogenesis assay showed that melatonin protects PBMC and spleen B lymphocytes and stabilized their proliferation.

Melatonin administration prior to whole body γ-radiation successfully protected rat's spleen from the consequences of radiation exposure. This was due to its free radicle scavenger nature, its reduction of lipid peroxidation and its anti-apoptotic effects.

Synuclein γ (SNCG), a member of the brain protein synuclein family, is highly expressed in pervasive human breast carcinoma and was associated with poor outcomes in radiotherapy treatment. So, the present study was conducted to assess the C243G and A377T polymorphisms of this gene in relationship with the success of radiotherapy.

In this retrospective study, 114 patients who had undergone a radical modified mastectomy and referred for radiation therapy were studied. Genomic DNA was extracted from peripheral blood cells. Genotyping was done for C243G and A377T polymorphisms. Differences in allele or genotype frequencies were evaluated.

The median overall Survival (OS) Rate of all patients was 44 months (IQR: 5.09). Genotyping the patients, there were 25 (%) GG, 34 (%) CG, and 55 (%) CC patients for exon 3 polymorphism (C243G). Comparison of three genotypes effect on OS was not significant (X2(2) =2.25, P=0.323). Hazard Ratio of CC vs. GG was 1.042 (95%CI:0.5360- 2.027), which was not statistically significant. There were 60 (%) AA, 37 (%) AT, and 17 (%) TT patients for exon 4 polymorphism (A377T). Comparison of three genotypes effect on OS was not significant (X2(2) =0.441, P=0.802). Comparing only patients with AA and TT genotypes, Hazard Ratio of AA vs. TT was 1.26 (95%CI:0.5123-3.118), which was not statistically significant.

There is a possibility of the role of GG and TT genotypes as a genetic risk factor in breast cancer which should be evaluated in a study with higher sample size.

The radiobiological effect of high dose rate FFF beams on the DU-145 cells was investigated with SBRT plans which have >10 Gy.

To compare the radiobiological effect on DU-145 cell line four experiments designed: (1) the constant dose rate of 6 MV and 6 MV FFF with increased dose per pulse (2) the effect of dose per pulse while increasing instantaneous dose rate for 6 MV and 6 MV FFF, (3) the effect of increased average dose rate for 6 MV FFF and (4) the effect of protracted treatment time and modulation of 6 MV FFF beams. The survival fraction was counted with WST.

FF and FFF for 6 MV with same dose rate and treatment time has no effect on cell survival. Significant differences was observed on survival which were irradiated with 6 MV 600 MU/min and 6 MV FFF 1400 MU/min (p=0.024). There was no difference between 6 MV FFF 600 MU/min and 6 MV FFF 1400 MU/min for 10 Gy. The significant survival difference obtained for 20 Gy. The survival percentages for both 10 Gy and 20 Gy with Cyberknife were obtained higher than FFF.

Our in-vitro study presented here show that higher dose rate and reduced treatment time might become a crucial factor for SBRT especially which has >10 Gy fraction dose.

To explore the efficiency of transvaginal ultrasonography in determining muscular infiltration of phase I endometrial cancer prognosis for radiotherapy.

A total of 96 phase I endometrial cancer patients who were admitted between March 2018 and March 2020 were enrolled and transvaginal ultrasonography was applied for the diagnosis of muscular infiltration. Demographic variables and radiotherapy outcomes were recorded. We hypnotized that only patients with unfavorable profile of sonography receive pelvic radiotherapy.

Patients with muscular infiltration > 1/2 had much thicker endometrium than those with muscular infiltration ≤ 1/2. the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of transvaginal ultrasonography in diagnosis of muscular infiltration of phase I endometrial cancer versus surgery results were 84.9%, 88.9%, 87.5%, 80.0% and 91.8%, while the consistency and Kappa value between the transvaginal ultrasonography and pathological test was 72.2% and 0.580. Positive Likelihood ratio of muscular infiltration more than 1/2 was 2.10 (CI95%: 1.22 to 3.61), meaning that approximately 10 patients of 17 patients with muscular infiltration more than ½ would experience radiotherapy later. Negative Likelihood ratio was 0.63 (CI95%: 0.44 to 0.91), meaning that approximately 10 patients of 15 patients with muscular infiltration less or equal than ½ would not experience radiotherapy later.

Muscular infiltration of endometrial cancer in transvaginal ultrasonography could be a reliable, simple, convenient and low-cost method predicting the need for the external beam pelvic radiotherapy as an unfavorable progression in endometrial cancer.

This study aimed to determine entrance surface dose (ESD), calculate effective dose (ED), organ dose, and local dose  levels in three general hospitals of Khorramabad in common diagnostic radiographic examinations, including Chest and Skull.

Exposure parameters and data of 110 patients were collected during 6 months. In this study, three radiological devices including Shimadzu R-20, Mehran Teb DMT II and Varian Rad-8, were evaluated. Four radiographic views, including Chest posterior-anterior and lateral projections (PA/LAT), and Skull PA/LAT were also assessed. The index used for comparison and measurement of radiation dose was ESD measured using thermo luminescent dosimeter (TLD). In this study, a pc program for X-ray Monte Carlo (PCXMC) software was used to calculate the organs’ dose and effective dose.

The results obtained show that there is a significant relationship between mAs and kVp changes with ED and ESD values. ESD range in Chest PA, Chest LAT, Skull PA, and Skull LAT examinations were 0.1075-0.8844, 0.2059-2.2997, 0.0729-1.44, and 0.03478-1.15 mGy, respectively. In this study, the mean ESD estimated was lower than the diagnostic reference levels (DRLs) recommended by the National Radiological Protection Board (NRPB), the Commission of Europian Communities (CEC), and International Atomic Energy Agency (IAEA), but the ED calculated was relatively higher than other studies.

A combination of experimental and simulation methods usually makes the accuracy of the dose estimates more reliable. The mean ESD estimated in this study is lower than the DRL published by NRPB, CEC, and IAEA. Also the published ED is almost more than other studies. The results of this study are used to optimize the dose level of patients.

To investigate the clinical efficacy of apatinib in combination with oxaliplatin + 5-fluorouracil + leucovorin in clinical chemotherapy for the advanced gastric cancer.

Between June 2016 and December 2018, we enrolled a total of 92 patients with advanced gastric cancer who were receiving 4500 cGy of radiation through the 5 weeks after resection of adenocarcinoma, and divided them into two groups as per the treatment strategies, with 46 patients in each group. Patients in the control group underwent the regular chemotherapy (oxaliplatin + 5-fluorouracil + leucovorin), while those in the observation group would additionally receive the medication of apatinib. We compared the efficacy, changes in the levels of high-sensitivity C-reactive protein (hs-CRP) and Tumor necrosis factor (TNF-α) in serum, prognosis and adverse reactions between two groups, or before and after treatment.

In the observation group, the total effectiveness rate was higher than that in the control group. Also, after treatment, significant decreases were found in levels of high-sensitivity C-reactive protein and TNF-α in serum of patients in the observation group, more evident than those in the control group. Moreover, progression-free survival and total survival durations of patients were significantly longer than those in the control group, while the incidence rate of adverse reaction was reduced sharply (all P < 0.05).

our study showed that apatinib combination with oxaliplatin + 5-fluorouracil + leucovorin seems to have promising efficacy, and is worthy of being studied as a new regimen of gastric cancer treatment.

This study aimed to assess and compare the radioprotective and cytotoxic effects of various concentrations of cerium oxide nanoparticles (CONPs) in aqueous solution combined with sodium dodecyl sulphate (SDS) against high energy X-ray beams in Vero cells.

The scanner electron microscopy (SEM) method was used to analyze the properties of CONPs. The cells were incubated with different concentrations of CONPs in aqueous solution combined with SDS. The non-toxic CONPs concentrations in Vero normal cells were determined using MTT assay. The cell’s uptake was measured by an UV/VIS absorption spectrophotometry. The cells were irradiated with different doses of 18 MV photon (1, 2, and 3 Gy), and their viabilities at various concentrations were measured to evaluate the radiation protection effects of CONPs.

The CONPs concentrations lower than 600 μg/ml were referred as non-toxic effects regarding MTT results. The 600 μg/ml was regarded as the highest radioprotection effect among the non-toxic concentrations (P-value˂0.05). The average percentage of cell viability improvement was estimated as 17, 23.61, and 27.21% for 1, 2, and 3 Gy doses, respectively, compared to the control group (with no CONPs). Pearson’s correlation coefficients between the CONPs concentration and cell viability were obtained as 0.96, 0.99, and 0.99 for 1, 2, and 3 Gy doses, respectively; showing that the increased concentration leads to an increase in higher radioprotection.

The 600 μg/ml of CONPs aqueous solution combined with SDS, as a stable non-toxic concentration, has the highest radiation protection effect when exposed to high-energy photon beams. So, this concentration can be considered as an appropriate candidate of radioprotection for further research.

There is no clear guideline regarding the optimum intensity modulated radiation therapy (IMRT) technique for patients with breast cancer (BC) requiring radiotherapy (RT) treatment of the regional node area but not of the internal mammary node (IMN). We evaluated the IMRT technique with a focus on secondary cancers of stomach and thyroid.

Eight patients with left BC treated with RT after breast conserving surgery at a single institution in 2017 were enrolled. Three-dimensional conformal radiation therapy (3D-CRT) consisting of two opposed half tangential breast fields and IMRT plans was performed. Normal organ dosimetric parameters were compared. Excess absolute risks, excess relative risks, and lifetime attributable risks (LAR) were calculated.

Stomach V30 values were 10.27 and 1.31 for tangential 3D-CRT and IMRT, respectively, and corresponding V40 values were 7.46 and 0.2, whereas V5 values were 21.15 and 49.62, respectively. Thyroid values were similar; V30 26.53 and 7.93, V40 22.37 and 2.63, and V5 40.93 and 88.86, respectively. LAR values of stomach were 1.76 (per 100 persons) and 2.31 and for thyroid were 5.3 and 9.5, respectively. LAR values of contralateral breasts were 0.35 and 0.99, of ipsilateral lungs were 1.68 and 2.39, and of contralateral lungs were 0.58 and 1.73. All values were​significantly different (p<0.05).

LAR values of stomach and thyroid were higher for IMRT than 3D-CRT in left BC patients requiring regional node treatment without including IMN. Consensus on the priority ​​among disease control rate, secondary cancer risk, and toxicity is required.

This study aimed at estimating the mean glandular dose (MGD) and cancer risks during mammography examinations.

The patients underwent three projections per breast: using craniocaudal (CC), mediolateral oblique (MLO) and mediolateral (ML) projections in a calibrated digital mammography unit at Najran University Hospital, Najran, Saudi Arabia. A total of 510 mammograms were performed, using the three views per breast. The MGD values were estimated indirectly from the entrance surface air Kerma (ESAK) and half-value layer (HVL) based on the conversion factors reported in the literature. The breast cancer risks were estimated based on the data available in the International Commission on Radiological Protection (ICRP) publication 103.

Mean breast thickness of 4.4, 5.3 and 5.0 cm and MGD of 1.01±0.3, 1.09±0.2 and 1.09±0.2 mGy were noted for CC, MLO, and ML views, respectively. A significant correlation has been observed between breast thickness and MGD as well as applied exposure factors. Moreover, the results indicated that the cancer risk per projection was estimated to be 178 x106, which can be significant during repeated exposure to these examinations.

The comparison with the published data of the countries reported in this study revealed that the mean MGD is comparable or less compared to previous studies. However, young patients required a precise justification. The results are useful for national and professional organisations. Moreover, the results of MGD in Najran could be a helpful guide to the local authorities.

Development of digital radiography revolutionized the field of medical imaging and increased the diagnostic accuracy. Despite its advantages, such as wide dynamic range and post-processing capacity, patient dosage has increased. The present study aimed to evaluate the entrance surface doses (ESDs) of primary beams to organs and the scatter dose received by pelvis in digital and analog systems with an emphasis on the radiation field size.

A whole body phantom PBU-50, and TLD GR-200 chips, were used to measure ESDs. Radiation techniques used in analog and digital systems were implemented, using a Pars Pad radiography unit. Exposure factors in digital radiography were applied for both standard and clinically used radiation field sizes. Radiography was performed in the extremities, skull, chest, abdomen, pelvis, and lumbar spine. In each view, three dosimeters were placed on the phantom body to measure primary dose. Three others were also placed on pubic symphysis to measure scattered dose.

In digital and analog techniques, the difference in primary doses was significant for limbs, unlike large organs (P=0.00). However, scattered dose to the pelvis was not significantly different (P=0.7417). Comparison of standard digital and clinically used field sizes showed significant differences in the scattered dose received by pelvis (P=0.014), while the primary dose differences were not significant (P=0.468).

Inadequate radiation protection, especially the use of an improper radiation field size and misuse of digital system capabilities, can result in increased patient dosage.

Percutaneous biliary drainage (PTBD) is a palliative treatment for malignant biliary obstruction. The present study adopted different methods of fixing the drainage tube, aiming to evaluate the efficacy and complications for patients.

Total 68 patients with malignant biliary obstruction, enrolled from 2015 May to 2018 March, were randomly divided into two groups to perform PTBD. 34 patients in group A were fixed the drainage tube by using the traditional way and 34 patients in group B by using an ameliorated approach. The clinical success rate, level of direct/indirect bilirubin, complications and quality of life of patients were recorded.

PTBD was successfully performed on all 68 patients. The direct and indirect bilirubin levels of all patients were significantly decreased at 1-week and 1-month post-surgery (P<0.001). Compared with group A, the level of direct bilirubin in group B decreased more significantly at 1-month after the operation (P<0.05). The quality of life of patients was improved in the two groups at 1-month after the operation (P<0.001). In addition, the rate of early postoperative complications was 38.24% in group B, which was not significantly different from the rate in group A (41.18%) (P>0.05). However, the complication rate of late postoperative in group B (6/34) was significantly less than complication rate in group A (16/34) (P<0.05).

PTBD is an effective method of treating malignant biliary stricture. The ameliorated fixing method for the drainage tube in PTBD effectively decreases the incidence of late complications, further improving patient quality of life.

The current study was designed to compare the genes expression levels of MHC-П, IL-8 and IgM in the head kidney and liver (central organs), as well as gill tissue (mucosal surface) of juvenile rainbow trout. 

 Juvenile rainbow trout were immunized with gamma-irradiated and formalin inactive trophonts with/without alginate nanoparticles against Ichthyophthirius multifiliis. On day 20 after bath-immunization, fish in all the treatments, except negative control, were exposed to live trophonts. On the 30th day, fish tissues were analyzed by real-time PCR. 

 The IL-8 expression up-regulated in the kidney, hepatic and gill of immunized fish with irradiated and formalin inactive trophonts plus alginate nanoparticles and non-immunized fish challenged with live trophonts (P<0.05). The MHC-II showed up-regulation in gill and kidney of immunized fish and non-immunized fish challenged with live trophonts while hepatic MHC-П was up-regulated in immunized fish with formalin inactive trophonts plus alginate nanoparticles (P<0.05). A significant increase in the IgM expression was detected in gills of immunized fish with irradiated trophonts with/without alginate nanoparticles and formalin inactive trophonts plus alginate nanoparticles (P<0.05). The renal IgM showed up-regulation in all of treatments (P<0.05). A significant increase in the hepatic IgM expression was in immunized fish via irradiated trophonts with/without alginate nanoparticles (P<0.05). 

 These findings indicated that the higher expression of IgM, MHC-II and IL-8 at the gill, kidney and liver could prove the potential of the entire treatments to enhance both mucosal and systemic immune responses in immunized fish with gamma irradiated trophonts against I. multifiliis.

Panoramic radiography is one of the common dental imaging procedures using ionizing radiation. It is necessary to control the level of exposure and use the optimized levels. So, the current work aimed to estimate the surface absorbed doses of critical organ regions, namely thyroid and parotid glands. Moreover, dose area product (DAP) values were measured and a local DRL was then established for panoramic radiography.

The data from 201 patients including 141 adults and 60 children (5-10 years) were used for this cross-sectional study. Seven panoramic radiography systems were selected from 6 radiology clinics in Yazd province. For each patient, 12 thermoluminescence dosimeters (TLD GR-200) were used to obtain the surface absorbed dose in both the thyroid and parotid gland regions. The DRL values were calculated using DAP values in terms of the ICRP recommendation.

The mean and standard deviation (SD) of thyroid and parotid glands’ surface absorbed doses were equal to 60.6±3.7 and 290±12.4 µGy in the adult group, respectively. In the children group, these values were 40.7±2 and 189.3±11.5 µGy, respectively. Moreover, the local DRL values were obtained as 99.7 and 73.4 mGy.cm2 for the adults and children groups, respectively.

The higher surface absorbed dose values in the adult group can be related to the use of higher radiation parameters. The local DRL proposed for the adult and pediatric groups in the current study was relatively lower than those established by other reports, which seemed acceptable for panoramic radiography in Yazd, Iran.

To approach the mammographic X-ray investigations in a metrological manner, any potential improvement needs to be considered. In this study, the influence of skin thickness variation on the mammographic X-ray spectra was investigated. Additionally, some attenuation parameters such as linear and mass attenuation coefficients, mean free path, and half-value layer thickness were assessed for exposure of the skin to the mammographic X-rays.

A theoretical experiment was performed using MCNP6.2 by simulation of two collimators, a detection area, a skin sample, and a point monoenergetic X-ray source. Carrying out this experiment, the above-mentioned parameters were estimated. As a validation process, the mass attenuation coefficients obtained by MCNP were compared with the results of XCOM.

The good agreement between the results of MCNP and XCOM reveals that the geometrical setup was modeled correctly by MCNP. It also implies the reliability of the Monte Carlo technique for attenuation calculations of low-energy X-rays through the skin. Upon increasing the breast skin thickness, its transmission factor against mammographic X-rays decreases linearly, and it increases by increasing the photon energy. The older the patient, the more transmission factor of the breast skin against the low energy X-ray.

Increasing the X-ray energy leads to less sensitivity of the transmission factor to the skin thickness. Thus, to have the best possible quality of X-ray mammography images, the patient’s age may also be considered as well as the other factors, when selecting the proper energies and for fine-tuning the used X-ray generators.

Approximation of radiation risks in computed tomography (CT) requires knowledge of specific organ doses. A Rando phantom and thermoluminescent dosimeters (TLDs) provide a proxy for in-vivo measurements. In this study, measured chest CT doses were used to calculate dose length product (DLP), a dosimetric needed for estimation of effective dose (E).

Ninety-five calibrated TLDs embedded at peripheral and central positions of Rando phantom chest slice measured chest CT dose during imaging using Phillips Brilliance 64-slice CT scanner. Three measurements were conducted each with new TLDs. Irradiated TLDs were read with a Harshaw TLD reader (Model 3500). One-way ANOVA test verified statistical significance of TLD measurements. TLD doses were used to calculate chest CT dose given as dose length product (DLP), a product of chest slice CT dose measured by volumetric CT dose index (CTDIv) multiplied by scan length. Consequently, E was calculated as the product of DLP and k, an adult chest conversion factor published by International Commission on Radiological Protection Publication 103.

  Differences in mean TLDs measurements were statistically significant (p=0.032). The mean chest slice peripheral and center doses were 3.61 ± 0.6 and 4.60 ± 0.31 mGy respectively. Adult chest CT dose was 178.8 ± 15 mGy. E was estimated as 2.5 ± 0.21 mSv. It is than the range (5.6 – 9.3 mSv) found in literature.

E relates radiation exposure to stochastic effects. The estimated value (E = 2.5±0.21 mSv), reveals that chest CT protocol used was optimized.

The aim of this study was to investigate the antioxidant effect of L-carnitine (LC) against gamma-irradiation-induced oxidative damage in tongue of albino rats after total body irradiation with a single dose of 6 Gy.

48 adult rats were randomly divided into 3 groups of 16 animals each. Group I was irradiated with a single dose of 6 Gy. Group II received a daily i.p. injection of LC (250 mg/kg, i.p.) for 5 consecutive days and 1 h after the last dose, rats were irradiated with a single dose (6 Gy). Group III received a daily i.p. injection of LC (250 mg/kg, i.p.) and Vitamin E 40 mg/kg intramuscular daily  for 5 consecutive days and 1 h after the last dose, rats were irradiated with a single dose (6 Gy). At day 7 and day 14 after treatment exposure, 8 rats from each group were sacrificed.

Administration of LC resulted in attenuation of the histological changes noticed in irradiated rats. The number of p53 positive nuclei significantly decreased in rats receiving LC alone or in combination with VE.

LC and VE has shown positive effect in minimizing the epithelial atrophy of tongue mucosa after radiotherapy, which was emphasized by decreasing apoptotic activity in these tissues.

The central nervous system is sensitive to radiation exposure as environmental pollution. This project aimed to evaluate the influence of jammer exposure radiation on spatial learning and memory.

50 adult male Sprague-Dawley rats were divided into five groups. The experimental groups were exposed to jammer radiation for 2h/day once or 2h/day for two weeks. Sham groups were similar to the experimental groups which were exposed to switch-off. The distance from the jammer router to the animals’ cages was 30 cm. In the second phase, using Morris Water Maze, the effect of jammer exposure radiation on spatial learning and memory was studied.

Data showed that radiation exposure once a day for 2h caused a significant increase in the learning procedure in the experimental group1, but we observed an increase in the parameters of distance and escape latency in finding the platform for two weeks' exposure in the experimental group 2.

Results indicated that probably the motivation of escape and use of the different cues led to learning in the animals, while disrupting mobile performance through jammer router from animal environment caused a better brain performance in the spatial learning and memory in short term jammer radiation-treated animals group. However, with the same test conditions, in long term jammer the radiation-treated animals’ motivation reduced, which affected the responses and performance and reduced the learning. Moreover, environmental conflicts such as radiofrequency waves lead to behavioral alternations.

To explore the efficacy of inducing chemotherapy in combination with the synchronized chemotherapy and radiotherapy on the local advanced cervical cancer.

In this prospective cohort study, 212 patients with moderate or advanced cervical cancer who underwent their chemoradiotherapy were assessed. These patients were divided into the Group A, B and Group C. At 3 months, 1, 3, and 5 years after radiotherapy, efficacy and adverse effects evaluation were conducted. Data were analyzed using SPSS software.

Among Group A, B, and C, comparison over their short-term efficacy showed that the differences had no statistical significance (P > 0.05). The overall survival of patients in the Group A, B, and C was 90.12%, 85.29%, and 91.75% in the 1st year, 85.19%, 79.41%, and 88.66% in the 3rd year, and 82.72%, 73.53% and 84.54% in the 5th year; differences among these OS showed no statistical significance (P > 0.05). While the dose modification factor (DMF) rate in Group C was higher than those in Group A and B (P < 0.05), showing its radioprotective effect. The incidence of the blood responses at Grade 3 or 4 in Group A was significantly lower than those in Group B and C (P < 0.05).

Our results showed a radioprotective effect of inducing chemotherapy in combination with the synchronized chemotherapy and radiotherapy, while the possibility of risk of blood responses was relatively high. So further studies assessing blood reactions are recommended in the long term.

The importance of dose in prostate radiotherapy is well known, and the dosimetric effects of radiotherapy in node-positive or node-negative patients with prostate cancer have become an important issue.

Helical tomotherapy (TH) plans of 19 pelvic node-positive [THpn(+) plan] or node-negative [THpn(-) plan] patients with prostate cancer were retrospectively created in our clinic. In these plans, the beam angle was set to cover the planning target volume (PTV) of prostate cancer and minimize the dose to the organs at risk, including the bladder, rectum, femoral head, and bowel.

There were no differences in the conformity index, Dmax, Dmean, and homogeneity index of PTV between the THpn (+) and THpn (-) plans (p>0.05). However, V95 in the THpn (+) plan was lower than that in the THpn (-) plan (p=0.017). Moreover, Dmax, V75, V70, V65, V60, V50, V40, V30, and V20 for the rectum were not significantly different between the two plans (p>0.05), whereas Dmean was significantly different (p=0.025). Dmax, V70, V65, and V60 for the bladder were not significantly different between the two plans (p>0.05), whereas V55, V50, V40, and V30 were significantly different (p<0.05). Finally, Dmax and V50 for the femoral head and bowel were significantly different between the two plans (p<0.05).

The THpn (+)] and [THpn(-) plans achieved acceptable target dose coverage in prostate radiotherapy.

Medical workers are exposed to long-term low levels of ionizing radiation, which makes them vulnerable to DNA damage. There are potential occupational health hazards from radiation exposure in a large occupational segment of the population. Matherials and

During this study, 69 blood samples were taken from 45 medical workers (including diagnostic radiologists, radiographers, and cathlab nurses) and 24 nonmedical workers as controls from three hospitals across Indonesia, and were analyzed for the presence of DNA damage. Detection of γ-H2AX expression as a biomarker of DNA DSB damage and the micronucleus assay were carried out by immunofluorescence microscopy and Giemsa staining, respectively.

The mean γ-H2AX foci index in workers was 0.02(0.00-0.24) and in control was 0.02(0.00-0.12), micronucleus frequency of workers (5-30 per 1000 cells) and control (12-29 per 1000 cells). The annual occupational dose of workers was recorded as (0.01-1.12 mSv). There was no statistical difference in the mean number of γ-H2AX foci and the micronuclei frequency between workers and controls, but there was a small tendency toward correlation between γ-H2AX foci and micronuclei frequency and the annual occupational dose of workers.

γ-H2AX foci have the potential to be used as a biomarker to detect radiation-induced DNA DSB damage in workers caused by occupational dose exposure.

Nerium oleander L. plant comprises a large number of components that are beneficial to human health The DNA polymorphism is a useful molecular genetics marker assessment to describe and recognize new germplasm for employing in the crop breeding programs. This study aims at determining the best time durations used to expose Nerium oleander cell suspensions cultures to UV-A rays, for studying differences in the DNA to create new cell lines.

In this study, ISSR was used for the identification of markers associated with the seven treatments exposed to UV-A rays of N. oleander cell suspensions cultures using 10 primers.

In the ISSR marker assay, all the primers amplified gave bands, but three primers (UBC810, UBC819 and UBC814) generated low polymorphism, two of them (UBC810 and UBC819) had given low polymorphism percentages (43%) and (19%) respectively and the third primer UBC814 had given a medium polymorphism percentage (57%). The highest value of similarity was 0.950, while the lowest similarity indexed was 0.012. The present study revealed that the Inter-simple sequence repeats   (ISSR) would be a useful assay to identify the genetic variations of the Nerium oleander genome under UV rays stress.

This study revealed that the use of ultraviolet rays induces changes in the DNA of N. oleander cell suspensions cultures that produce new genotypes for use in cell lines programs.

This research focuses on the study of 40K, 238U, and 232Th in a specific area at Kufa Cement Factory Sites in Najaf Governorate, Iraq using the γ-ray spectrometry scintillation detector NaI(Tl).

Samples of soil were collected from locations around the Kufa cement factory in Najaf city of Iraq that are about 10 km2  away from the center of Najaf city. They were analyzed to set the concentrations of natural radioactivity samples of 40K,238U and 232Th.

The specific activity values of 40k, 238U and 232Th varied from (378.54±11.39 to 2404.27±26.13)Bq/kg, (15.51±5.88 to 106.08±7.35) Bq/kg and (1.80±3.41 to78.19±3.05) Bq/kg continually.

Results demonstrate that the convergences of radiation and doses due to radionuclides in the overviewed area are higher than the safety field of the worldwide average (UNSCAR 2000). Almost all of the radiological parameters are inconsequential to cause any dangerous health problems to people living in the area.

Local Dose Reference Level (LDRL) values as the standard radiation dose of all radiography examinations are used in medical imaging to reveal the patient dose level or administered activity for a specified imaging procedure.

The incident air kerma (Ki) was measured for five radiographic examinations (Skull AP/Lat, Chest AP/Lat, Lumbar AP/Lat, Thoracic AP/Lat and Pelvic AP) throughout the province of Kohgiluyeh and Boyer-ahmad (as a deprived area). The founding DRLs results were sort; the third quartile was selected as the average DRL and compared with the other DRLs provinces of Iran as well as the standard data of developed countries.

The radiographic LDRL were found to be 0.72, 1.62, 3.06, 2.96, 7.21, 9.99, 7.1, 8.42 and 5.56 mGy for Chest PA, Chest Lat, Skull AP, Skull Lat, Lumbar AP, Lumbar Lat, Thoracic AP, Thoracic Lat and Pelvic AP, respectively.

The founding revealed that if the applied radiation protocols are as same as developed countries the DRL values in some projections such as the lumbar vertebrae could be close to international references.

Pretreatment with lithium in thyroid cancer patients before radioiodine therapy (RIT) has been suggested to improve the results of therapy in terms of higher radiation to thyroid tissue and limiting extra-thyroid irradiation.

The beta and gamma radiation to the thyroid gland and lungs in 8 female New Zealand rabbits weighing 2.7 to 3.6 kg were simulated employing GATE Monte Carlo code. The study design was before-after and crossover; rabbits were orally treated with 165 to 288 µCi 131I with or without pretreatment with 60 mg per day lithium. SPECT/CT imaging was done 20 to 24 hours after RIT providing the distribution and attenuation maps for simulation. The S-values were calculated and compared between the rabbits prepared with and without lithium before RIT by analysis of covariance.

For beta radiation, the thyroid to lung S-value ratios (TLR) was 10.5 ± 1.6 with lithium pretreatment and 15.9 ± 12.5 without it. For gamma rays, TLR was 4.8 ± 1.8 vs. 6.7 ± 3.1 in rabbits with and without lithium pretreatment. The values of TLR were higher without lithium pretreatment but statistically insignificant.

Lithium demonstrated no improvement in radioiodine uptake in thyroid tissue. Pretreatment of differentiated thyroid cancer patients with lithium before RIT, which is backed by old literature, should be reconsidered.

This study sought to assess the organ absorbed dose using ImPACT software and evaluate the effect of small and large fields of view (FOVs) for three cone-beam computed tomography (CBCT) devices on the organ absorbed dose.

The weighted computed tomography dose index (CTDIw) is measured using a pencil ionization chamber which was incorporated in a polymethyl methacrylate (PMMA) phantom for three CBCT devices with small and large FOVs. The calculated CTDIw was entered into the ImPACT software. Then the organ absorbed dose of the thyroid gland, salivary glands, oral mucosa, skin, brain, and red bone marrow and the whole-body effective dose were calculated by the software.

Irrespective of the type of CBCT device, the organ absorbed dose was obtained higher value in use of a larger FOV (P<0.01). The mean organ absorbed dose in use of large and small FOVs was 0.13 and 0.08 for New Tom GiANO, 0.49 and 0.13 for Vista Vox S and 0.69 and 0.38 for XMIND Trium, respectively. Salivary glands had the highest organ absorbed dose among all of the organs within the field. Larger FOVs yielded higher whole-body effective and organ absorbed doses compared with smaller FOVs.  

The results showed that using the ImPACT software to estimate the organ absorbed dose can serve as a suitable alternative to other costly and time-consuming methods available for this dose assessment in CBCT.

Anaplastic large T-cell lymphoma (BI-ALCL) is a rare primitive lymphoma found particularly in women with textured breast implant prostheses, which has been arousing interest in recent years due to its potentially high social impact. The difficult diagnosis together with the increasingly high number of prosthetic implants worldwide has led to a hypothesize of an underestimation of its real impact in prosthesis-bearing women. The clinical onset usually occurs with a cold seroma and disease confined to the prosthetic capsule while the more advanced stages may involve 1 or more lymph nodes or, rarely, distant metastases. Early diagnosis is essential as the disease has a favorable prognosis in over 90% of cases when detected in the early stages while it often has a poor prognosis in the advanced ones: despite this, the radiological signs of early disease are still non-specific. This report describes a case of BI-ALCL confined to the capsule which was studied using all diagnostic techniques in order to highlight its early radiological signs.