International Journal of Radiation Research
Volume:9 Issue: 4, Oct 2011

To retrospectively describe imaging characteristics of liver metastases on fused FDG-PET/ MRI data sets and to compare the diagnostic accuracy of MRI and fused FDG-PET/MRI data sets for the detection of liver metastases in patients undergoing systemic anticancer treatment. 43 oncological patients (mean age: 56+/- 11 years) were investigated by FDG-PET/CT and liver MRI. FDG-PET data from PET/CT scans were fused with MRI. 556 lesions were evaluated. 5 different evaluation algorithms were used for FDG-PET/ MRI evaluation. The sensitivity, specifity, PPV, NPV and accuracy of MRI and FDG-PET/MRI data for the detection of liver metastases were calculated. A mean follow-up of 647 days served as reference standard. McNemar’s test was used to test for statistically significant differences between MRI and FDG-PET/MRI (p<0.5). The sensitivity, specificity, PPV, NPV and accuracy of MRI for the detection of liver metastases were 86%, 81%, 97%, 47%, and 85% and 50%, 100%, 100%, 22%, and 56%, for FDGPET/ MRI. FDG-PET/MRI was significantly less accurate than MRI alone (p<.001). In opposite to patients before systemic anticancer therapy the fusion of FDG-PET data with liver MRI cannot be recommended for the detection of liver metastases in patients undergoing systemic oncological therapy. Iran. J. Radiat. Res., 2012; 9(4): 209-219

The aim of this study was to analyze the effects of thoron and thermal treatment for aging-related diseases in humans. All subjects inhaled thoron with a high concentration (about 4900 Bq/m3) for 2 weeks. Blood pressures were measured and blood samples were collected after each treatment 1, 2 and 3 weeks after the first treatment. The α-atrial natriuretic peptide level of the rheumatoid arthritis group was increased and the blood pressure was significantly decreased. Superoxide dismutase activity of rheumatoid arthritis group was significantly increased by treatment. In addition, thoron and thermal treatment significantly enhanced the concanavalin A-induced mitogen response and increased the level of CD4-positive cells; it decreased the level of CD8-positive cells. The results suggest that thoron and thermal treatment activates antioxidative function. Furthermore, these findings suggest that thoron and thermal treatment prevents diabetic ketoacidosis and contributes to the prevention of aging-related diseases. Thoron and thermal therapy may be part of the mechanism for the alleviation of diabetes mellitus and rheumatoid arthritis.

Radon and its daughter product are a major source of natural radiation exposure, the measurement of radon concentration in dwellings is assuming ever increasing importance. It is known from recent surveys in many countries that radon and its progeny contributes significantly to total inhalation dose and is well established that radon when inhaled in large quantity causes lung disorder. In view of this the authors have measured 222Rn and 220Rn levels in dwellings of different volumes at Bangalore Metropolitan, India. Integrated and long duration measurements of radon were carried out using twin cup dosimeters with Solid State Nuclear Track Detector technique. Results showed that concentrations of 222Rn, 220Rn, their progenies and dose rates in dwellings decreased with increase in room volume. The annual effective inhalation dose due to 222Rn, 220Rn and their progenies from the study ranged between 0.2–4.4 with an arithmetic mean of 1.7 ± 1.1 mSv y-1. The dwellers of lower volumes are posed to high dose rates.

Quantification of radiation-induced apoptosis in peripheral blood lymphocytes (PBLs) has been proposed as a possible screening test for cancer-prone individuals and also for the prediction of normal tissue responses after radiotherapy. The neutral version of the comet assay (single-cell gel electrophoresis) was used 24, 48, 72 hours after irradiation with 8 Gy gamma rays to assess interindividual differences in gamma rays-induced apoptosis in peripheral blood leucocytes between a panel of 30 normal individuals, and 30 breast cancer patients who hadn’t received radiotherapy or chemotherapy previously. Slides were stained with ethidium bromide and comets were assessed using visual and computer analysis. In all incubation times, the baseline and radiation induced apoptosis values were higher in breast cancer patients compared to normal individuals which were significantly different (p<0.01). Although, both baseline and radiation induced values were higher in young breast cancer patients, the age did not seem to have a significant effect on apoptosis values both in cancer cases and controls. The increased rate of apoptosis observed in the leukocytes of breast cancer cases might be associated with their deficient DNA repair mechanisms. This finding might indicate that the radiation induced apoptosis could have some predictive potential. However, large interindividual variation has been a drawback. More studies are required to investigate the causes of interindividual variation and how it might be minimized.

The approaches chosen for control of Outbreaks of infectious diseases in Aquatic farming industry include improvement of environmental conditions, stocking of specific pathogen free (SPF) brood stockings, and application of vaccines and immunostimulants. Despite numerous studies on the effects of Ergosan on immune system of aquatic animals, there is no data available on antioxidant activities of Ergosan. The aim of the present study was to investigate and evaluate the radical scavenging activities of Ergosan extract by DPPH (1, 1- diphenyl-2-picrylhydrazyl) free radical scavenging assay, and the possible effects of gamma irradiation on its assumed radical scavenging activities. Ergosan was irradiated with gamma rays (10, 20, 30, 40 and 50 kGy), and their structural changes and antioxidant activities were investigated by UV absorbanceand DPPH (1,1- diphenyl-2-picrylhydrazyl) assays, respectively. The gamma irradiation decreased the average pH of irradiated Ergosan, and UV spectra of irradiated product showed increase in the number of carboxyl groups and double bonds. Our results showed that 30 kGy irradiated Ergosan suspension had significant higher level of antioxidant activity in comparison with non-irradiated Ergosan (P<0.05). Also, the reducing power values of 30 and 50 kGy irradiated Ergosan were higher than that of nonirradiated (P<0.05) and the other doses of irradiation couldn’t make any significant difference in reducing power of Ergosan. Results indicate that the 30 kGy irradiated Ergosan might be an appropriate candidate for the use in aquatic animal diets as a natural antioxidant agent besides its immunostimulant role.

Attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. So, its exact measurement or calculation is very important. The aim of this study was to evaluate the μ in different points in the water phantom analytically as a formula, in addition to derive and parameterize it with dosimetry measurements data results. To find the attenuation coefficients at each point along the central axis of the beam in the phantom for every size of the fields, the first mathematical approach was performed for derivation of μs from percentage depth dose (PDD) formula. Then by dosimetry for different fields in different depths of water phantom, one can parameterize the obtained formula for μ in any field and depth. By comparing the mathematical and dosimetry results, the parameters of the μ-expression were derived in terms of the dimension of square field in different depths. From this formula one can find the μ for any field in different depths for two energies of the Varian 2100CD linear accelerator, 6, 18MV with the statistical coefficient of determination of R2>0.98. The measurement of the μ in each field size and depth has some technical problems, but one can easily measure the μ for every point of central axis of the beams in any field size. Iran.

Recently, different investigators have studied the possibility of radiation therapy in restenosis prevention and have shown promising results. In this study a unique radioactive source for intra vascular brachytherapy (IVBT) was investigated. The two-dimensional dose distribution in water for a 32P IVBT stent has been calculated. The pure beta emitter source 32P has been coated on Palmaz- Schatz stent. The dosimetric parameters required by the AAPM TG-60 formalism are discussed and calculated. The dose distribution of the activated stent was determined by Version 4C of the (MCNP) Monte Carlo radiation transport code in water and it was verified by TG-60 experimental results. Dosimetric parameters such as anisotropy function, F(r, θ), and the radial dose function, gL(r), around the Palmaz-Schatz stent at distances from 0.18 to 0.9 cm have been calculated. The Palmaz- Schatz stent with 3.5 mm external diameter and 14 mm length is coated with a thin layer of 32P. The Monte Carlo calculated dose rate at the reference point is found to be 17.85 Gy. The results were compared with previously published paper for an actual same source. The difference between these two data sets is in acceptable range. There were almost little differences (less than 0.05%) in values among them. The dosimetry parameters such as, geometry function, G(r,θ), anisotropy function, F(r,θ) and radial dose function, g(r), were determined according to TG-60 protocols and listed in tabular format. High dose variants were visible near the 32P stent surface, but these values decreased with depth in vessel layers rapidly. There are an acceptable agreement between the calculated data in this study and other published data for the same source. However, the observed differences between the calculated and measured values could be explained by the measurement uncertainty and the geometry modeling during the simulations.

Saffron, the dried stigmas of crocus sativus, is the world's most expensive spice which has been used as food additive and flavoring agent. The aim of the present study has been to investigate the combination effects of gamma irradiation and silver nano particles packing on the chemical properties of saffron during storage time. A combination of hurdles can ensure stability and microbial safety of foods. To investigate the combination effects, saffron samples were packed by Poly Ethylene films which were possed up to 300 ppm nano silver particles as antimicrobial agents and then irradiated in cobalt – 60 irradiator (gamma cell Model: PX30, dose rate 0.55 Gy/sec) to 0, 1, 2, 3 and 4 kGy at room temperature. UVspectrophotometer was used to quantify the most important components crocin, picrocrocin and safranal which were respectively responsible for color, taste and odor. Statistical analysis showed that irradiation and silver nano particles films packing could increase the flavor and aroma of saffron, and the best optimum dose of irradiation was 2 kGy. Also, sensory evaluation showed no significant difference between them (P<0.05). Hurdle technology has been more effective than irradiation or nano-silver particles packing methods. Therefore combined method can be used for microbial decontamination of saffron with no significant differences on chemical characteristics and sensory attributes.

The present nuclear leakage crisis from Japan is a topic to be discussed in present public health. In radiology, the leaked radioactive elements are considered hazard. Here, the author briefly reviews and discusses on two important radio-hazard elements in post nuclear power plant crisis, radioactive iodine and radioactive cesium. Based on previous similar nuclear crisis in Russia, it is evidenced that the increased incidence of some cancers in post-crisis period is due to exposure to these two important radioactive elements. Iran.