Evaluation the Safety and Security Procedures used In X-ray Clinics in Al-Harthiya-Baghdad

Radiation is a form of energy, its emitted either in the form of particles such as α-particles and β-particles (beta particles including the electron and the positron) or waves such as sunlight, X-rays and γ-rays. Radiation found everywhere around us and it comes from many different sources naturally or man-made sources. In this study a questionnaire was distributed to people working in the field of X-rays that used for a medical imaging (X-ray and CT-scan) to evaluate the extent of awareness and knowledge in estimate the damage of ionizing radiation as a result of wrong use. The questionnaire was distributed to medical clinics in Al-Harithiya in Baghdad, which it’s considered as one of the important areas in Iraq to attract and treat patients. It’s found that most of the commitment of radiography clinics by safety and security procedures. Most of the radiology clinics abide by most of the Iraqi Ministry of Health laws. However, some clinics did not implement some of the security and safety conditions

CTNI-29. SAFETY AND FEASIBILITY OF RHENIUM-186 NANOLIPOSOME (186RNL) IN RECURRENT GLIOMA: THE RESPECT™ PHASE 1 TRIAL

BACKGROUND Liposomal rhenium-186 (186RNL) is a potent source of beta particles with short path length, variable dose rate, high radiation density and gamma emission. Preclinically, 186RNL delivered via convection enhanced delivery (CED) achieves very high doses of targeted radiation with a wide therapeutic index. We report the results of ReSPECT, the first in man, dose escalation phase 1 trial of 186RNL in recurrent glioma. METHODS Following computer assisted treatment planning and placement of intracranial catheter(s), we performed a single administration of 186RNL by CED. We obtained whole body planar and SPECT/CT imaging on days 1-8 following treatment for dosimetry and distribution and followed patients for safety, progression and survival. RESULTS Twenty-one patients across 7 cohorts received 1.0-22.3mCi in a volume of 0.6-8.80mL. Mean tumor volume was 8.3mL (0.9-22.8mL). Patients had a mean of 1.7 recurrences, 5 received prior bevacizumab. Overall, 19/21 patients and all after cohort 4 had grade 4 glioma (glioblastoma). We used a CED rate of 5-20µl/min per catheter, with 1-4 catheters used per patient. Mean absorbed radiation dose to the tumor was 255Gy (8.9-740Gy) while exposure outside the brain was negligible. The mean percentage tumor in the treated volume (Tu/Tv) was 60.3% (19.8%-100%). Thus far, we have observed no dose limiting toxicities, one grade 3 treatment related adverse event (AEs), and the majority of AEs were mild in intensity. The incidence and severity of AEs did not correlate with increasing dose. Mean Tu/Tv in patients not receiving prior bevacizumab was 75% vs. 48% in those that had. Thus far, overall survival (OS) in 16 bevacizumab naïve patients is 49 weeks with 7 (44%) patients still alive and a positive correlation of OS to Tu/Tv. CONCLUSIONS 186RNL achieves high absorbed doses without significant toxicity with favorable overall survival.

Assessment of the radiation situation in the territory of the Saumalkol village, located near the mothballed uranium mine of the North Kazakhstan region

For the first time after the mothballing of the uranium mine, comprehensive studies were carried out to assess the radiation situation in the territory of the Saumalkol settlement in the North Kazakhstan region. On the territory of the Saumalkol settlement, pedestrian and automobile gamma surveys were carried out, the rates of the ambient equivalent dose of gamma radiation, the flux density of alpha and beta particles and the equivalent equilibrium volumetric activity of daughter products of 222Rn and 220Rn isotopes in residential premises were measured. Samples of soil, water and bottom sediments were taken for laboratory radio spectrometric and radiochemical analyzes. At all measurement points, geographic coordinates were determined using a satellite navigation device. On the territory of the abandoned mine and in some areas of the Saumalkol settlement, anomalous areas with a high value of gamma radiation power from 0.35 to 1.08 μSv/h were revealed. In the residential premises of the Saumalkol village, the equivalent equilibrium volumetric activity of daughter products of radon isotopes is up to 8 times higher than the norm (200 Bq/m3 ).

Attenuation of beta radiation in granular matrices: implications for trapped-charge dating

Mineral grains within sediment or rock absorb a radiation dose from the decay of radionuclides in the host matrix. For the beta dose component, the estimated dose rate must be adjusted for the attenuation of beta particles within the mineral grains. Standard calculations, originally designed for thermoluminescence dating of pottery, assume that the grain is embedded in a homogenous medium. However, most current applications of trapped-charge dating concern sand- or silt-sized dosimeters embedded in granular sediment. In such cases, the radionuclide sources are not homogeneous, but are localized in discrete grains or held on grain surfaces. We show here that the mean dose rate to dosimeter grains in a granular matrix is dependent on the grain-size distributions of the source grains, and of the bulk sediment, as well as on the grain size of the dosimeters. We further argue that U and Th sources are likely to be held primarily on grain surfaces, which causes the dose rate to dosimeter grains to be significantly higher than for sources distributed uniformly throughout grains. For a typical well-sorted medium sand, the beta dose rates derived from surface U and Th sources are higher by 9 % and 14 %, respectively, compared to a homogenous distribution of sources. We account for these effects using an expanded model of beta attenuation, and validate the model against Monte Carlo radiation transport simulations within a geometry of packed spheres.

Estimation of 90Sr content in wood of scots pine based on measurement surface flux density of beta-particles from stem bark

This paper presents an approach for indirect measuring of 90Sr activity concentration in stem wood of Scots pine`s live trees within the Chernobyl exclusion zone based on values of beta-particles surface flux density from stem bark at a thee height of 1.3 m above the forest floor that obtained by use STORA-TU RKS-01 radiometer-dosimeter under field condition. The similar express-methods often consider in scientific publications so as they allow to obtain probable levels of radiation contamination without taking samples for laboratory measurements. That in turn can be used to optimize sampling or for example in the case of the need to preserve the intact initial state of the biota during long-term in situ or/and in vivo observations. The empirical data for validation of the method have received on 13 experimental sites of artificial (plantation) even-aged stands which consist only of one woody species: Scots pine. The correlation analysis discovered statistical significant relation at p-value=0.05 between arithmetic averages of beta-particles surface flux density from stem bark of pine trees at the forest sites and 90Sr activity concentration in stem wood elements (sap wood, heartwood and all stem wood), and functional dependencies among these parameters are described by a simple linear equation with only one slope parameters (R2 = 0.90–0.96) whose predicted values for sap wood, heartwood, and all stem wood are (± standard deviation) 23.1±8.5, 42.3±10.3, and 26.8±6.8 Bq·cm2·min·(kg·pcs)-1, respectively. Moreover, the influence of biometric indicators of individual trees (diameter, height, age) on this pattern was not detected. However, the average diameter (DBH) of stands has the strongest influence among forest inventory indicators on the value of the 90Sr activity concentration ratio between sap wood and heartwood (r = 0.93), that is, the radial distribution of the studied radionuclide in stem wood of pine trees. The results of these studies should be confirmed by a larger collection of observations for Scots pine given the small sample size for her in this paper. Also, scientists are necessary to include empirical data for other major forest-forming woody species within the research region due to the importance of using express-methods of radioactive contamination levels estimation for the planning and optimization of forest management.

Radiometer for measuring gamma-radiation, beta-particles and neutrons based on DRG-05M dosimeter

As a result of the modernization of the DRG-05M dosimeter, a convenient device was obtained, which allows estimating the level of gamma- and X-ray radiation, beta-particles, and neutrons without changing the detector heads. Two devices were manufactured and a third one was prepared for metrological certification.

The Effect of Iodine-131 Beta-particles in Combination With A-966492 and Topotecan on Radio-sensitization of Glioblastoma

The authors have requested that this preprint be withdrawn due to erroneous posting.

Computational evaluation of a novel beta radiation probe design using integrated circuits

Researchers at Texas A&M University (TAMU) have designed the radiation integrated circuit (RIC) for deployment as a new radiation detection system. Most integrated circuits are susceptible to radiation-induced failures, and decades of research have gone into solving this problem. Research at TAMU has led to a novel integrated circuit design that utilizes both radiation-hardened areas (RHAs) and radiation-sensitive areas (RSAs) to take advantage of these failures. The RSAs are susceptible to charged particle interactions, allowing the RIC to detect alpha and beta particles. However, beta particles are more penetrating compared to alpha particles, resulting in a lower interaction probability for beta particles incident on a bare RIC. In any material, the higher the beta energy, the deeper the beta particle can penetrate; therefore, the use of a wedge-shaped attenuator for beta particle detection not only increases interaction probability, but also provides the capability to perform maximum beta energy discrimination in the field. The objective of this research was to optimize the design of the RIC. Monte Carlo N-particle radiation transport code (MCNP) simulations assessed the beta particle detection and maximum energy discrimination performance of plate glass, borosilicate (Pyrex®) glass, acrylic (Lucite®), and natural rubber attenuators. In this proof-of-concept analysis, natural rubber was observed to be the optimal attenuating material for the beta probe with respect to maximum energy discrimination capability and weight, but all materials considered proved to be good candidates. The results of this study are promising and indicate the potential to achieve maximum beta particle energy discrimination of 50 keV using a wedged, natural rubber attenuator on the RIC.

The Effect of Iodine-131 Beta-particles in Combination With A-966492 and Topotecan on Radio-sensitization of Glioblastoma

Glioblastoma tumors are resistant to radiotherapy, and the need for drugs to induce radio-sensitization in tumor cells has always been a challenge. Besides, radiotherapy using targeted radionuclide is effective even for resistant tumors. Poly (ADP-ribose) polymerase (PARP) and topoisomerase I enzymes have critical roles in the repairmen of DNA damage in cells. Thus, the inhibition of the activity of these enzymes can prevent the process of DNA repair and lead to the accumulation of damaged DNA in cells, resulting in the induction of cell death in tumors. In the current study, we investigated the effect of beta-particles of iodine-131 in combination with Topotecan (TPT), as the inhibitor of topoisomerase I, and A-966492, as the inhibitor of the PARP enzyme to increase radio-sensitivity of glioblastoma cells.The U87MG cell line (a human glioblastoma cell line) were cultured in Poly-Hema-coated flasks to reach 300μm-diameter spheroids. Then, the cells were treated with non-toxic concentrations of A-966492 and TPT. The viability of the cells treated with iodine131 in combination with A-966492 and TPT was determined by the clonogenic assay. The expression level of the gamma-H2AX protein, as a biomarker of DNA double-strand breaks, was measured by the immunofluorescence staining method to examine the impact of A-966492 (1μM), TPT, and radiation on the induction cell death.The combination of A-966492 and TPT with radiation resulted in the enhanced cell death, and sensitizer enhancement ratios at 50% survival (SER50) were 1.25 and 1.45, respectively. Radio- and chemo-sensitization were promoted when iodine-131 was combined with A-966492 and TPT, with the SER50 of 1.68. Also, the expression of γ-H2AX was significantly increased in cells treated with A-966492 and TPT combined with radiation.The results demonstrated that iodine-131, in combination with A-966492 and TPT, had marked effects on radio-sensitizing and can be used as a targeted radionuclide for targeting radiotherapy in combination with PARP and topoisomerase I inhibitors to improve radiotherapy in clinics.