A New Approach for a Safe and Reproducible Seeds Positioning for Diffusing Alpha-Emitters Radiation Therapy of Squamous Cell Skin Cancer: A Feasibility Study

The purpose of this study is to discuss how to use an external radio-opaque template in the Diffusing Alpha-emitters Radiation Therapy (DaRT) technique’s pre-planning and treatment stages. This device would help to determine the proper number of sources for tumour coverage, accounting for subcutaneous invasion and augmenting DaRT safety. The procedure will be carried out in a first phase on a phantom and then applied to a clinical case. A typical DaRT procedure workflow comprises steps like tumour measurements and delineation, source number assessment, and therapy administration. As a first step, an adhesive fiberglass mesh (spaced by 2 mm) tape was applied on the skin of the patient and employed as frame of reference. A physician contoured the lesion and marked the entrance points for the needles with a radio opaque ink marker. According to the radio opaque marks and metabolic uptake the clinical target volume was defined, and with a commercial brachytherapy treatment planning system (TPS) it was possible to simulate and adjust the spatial seeds distribution. After the implant procedure a CT was again performed to check the agreement between simulations and seeds positions. With the procedure described above it was possible to simulate a DaRT procedure on a phantom in order to train physicians and subsequently apply the novel approach on patients, outlining the major issues involved in the technique. The present work innovates and supports DaRT technique for the treatment of cutaneous cancers, improving its efficacy and safety.

Assessment of Radon, Radium, and Uranium Concentrations in Decorative Materials (Used to walls) Samples in Iraqi Markets

In present study, natural alpha emitters (222Rn, 226Ra, and 238U) were tested in decorative materials used as walls collected from different Iraqi local markets by CR-39 detectors that it was purchased from TASTRAK Analysis System. Annual effective dose and radon exhalation rate were calculated. The results obtained showed that the range and average value of 222Rn concentrations in air container were 7.94 – 738.10 Bq/m3 and 252.38±37.63 Bq/m3, while 222Rn concentrations in in sample were 45.73– 4252.99 Bq/m3 and 1454.25±216.84 Bq/m3. The ranged of 226Ra and 238U concentrations were 0.010- 1.000 Bq/kg, with an average value 0.278±0.04 Bq/kg and 0.01- 1.24 ppm, with an average value 0.344±0.05 ppm, respectively. The results obtained showed that the range and average value of annual effective dose in mSv/y were 0.2 –18.62 and 6.29±0.95. Also, it is found that the mass exhalation rate as well as surface exhalation rate were 8.38±1.33 mBq/kg.day and 240.77±36.56 mBq/m2.day, respectively. The data of 222Rn concentration (in air container), and annual effective dose in some samples of the present study were higher than the global limit range (200-300 Bq/m3), and (3-10 mSv/y) according to ICRP. While, all results of 226Ra, and 238U concentrations as well as the mass with surface exhalation rate were within the permissible limits that suggested by UNSEAR, and ICRP. Then, it can be concluded that the most samples of decorative materials which used as walls according to radiation scope no causes health risk.

Alpha Emitter Concentration in Blood of Iraqi Museum Workers

The aim of this study is to evaluate the risk of alpha emitter’s concentrations and measure it in human blood. The current study was done in the central laboratory and archaeologist employees of the Iraqi museum; likewise, the study also involved employees in State board of antiquities and heritage and Abd al-karim qasim museum that are located in Baghdad, Iraq. CR-39 Detector was used to measure alpha emitters track density. 60 participants Blood samples were collected in total (30 people in workers and 30 people in controls that were collected from general population). The maximum obtained values of alpha track density were (213.16±7.58 tracks/ mm2) and minimum obtained values (32.61±3.70 tracks/ mm2) in workers group with average of (81.36±3.78 No. of tracks/mm2) and the maximum obtained values of alpha track density were (219.37±6.75 tracks/ mm2) and minimum obtained values (3.02±0.37 tracks/ mm2) in control group with average of (28.45± 2.10 tracks/mm2). The result showed higher alpha emitter concentration in workers compared to the control group. Based on these results, high alpha concentrations to museum workers and archaeologists may have increased risk to DNA damage and cancer compared to non-occupational workers.

Natural Radionuclide (Gamma and Alpha Emitters) in Grain Samples Collected from Kerbala Governorate, Iraq

The aim of this research is to detect nature radioactivity for gamma emitters (specific activity 238U, 232Th, and 40K) using NaI(Tl) detectors and alpha emitters (concentrations of 222Rn, 226Ra, and 238U) using CR-39 detectors in selected samples of grain that are collected from Kerbala governorate. Also, annual effective dose and some radiological parameters due to gamma and alpha emitters to assess the health risk were calculated. Results have been shown that the average value of specific activities for 238U, 232Th and 40K were 6.61±0.91 Bq/kg, 3.07±0.22 Bq/kg and 227.59±32.34 Bq/kg respectively, while the average value of alpha emitters concentrations for 222Rn, 226Ra, and 238U were 3.99±1.13 Bq/m3, 4.69±1.28 mBq/kg and 0.072±0.019 Bq/kg respectively. The results of average total of annual effective dose associated with the exposure due to gamma and alpha emitted from ingestion grain samples in the present study were 0.139±0.013 mSv/y and 0.172±0.047 µSv/y, respectively. The results of natural Radionuclide and radiological parameter hazard based on gamma and alpha emitters from grain samples were discovered to be within the world acceptable levels. Finally, natural radioactivity from the grain samples that collected from Kerbala governorate were safety for the human consumption.

Upper limits on the escape fraction of ionizing radiation from galaxies at 2 ≲ z < 6

In this work, we investigate upper limits on the global escape fraction of ionizing photons ($f_{\rm esc/global}^{\rm abs}$) from a sample of galaxies probed for Lyman-continuum (LyC) emission characterized as non-LyC and LyC leakers. We present a sample of 9 clean non-contaminated (by low redshift interlopers, CCD problems and internal reflections of the instrument) galaxies which do not show significant (&gt; 3σ) LyC flux between 880Å &lt;λrest &lt; 910Å. The 9 galaxy stacked spectrum reveals no significant LyC flux with an upper limit of $f_{\rm esc}^{\rm abs} \le 0.06$. In the next step of our analysis, we join all estimates of $f_{\rm esc}^{\rm abs}$ upper limits derived from different samples of 2 ≲ z &lt; 6 galaxies from the literature reported in last ∼20 years and include the sample presented in this work. We find the $f_{\rm esc}^{\rm abs}$ upper limit ≤ 0.084 for the galaxies recognized as non-LyC leakers. After including all known detections from literature $f_{\rm esc/global}^{\rm abs}$ upper limit ≤ 0.088 for all galaxies examined for LyC flux. Furthermore, $f_{\rm esc}^{\rm abs}$ upper limits for different groups of galaxies indicate that the strongest LyC emitters could be galaxies classified as Lyman alpha emitters. We also discuss the possible existence of a correlation among the observed flux density ratio $(F_{\nu }^{LyC}/F_{\nu }^{UV})_{\rm obs}$ and Lyman alpha equivalent width EW(Lyα), where we confirm the existence of moderately significant correlation among galaxies classified as non-LyC leakers.

Nanoradiopharmaceuticals Based on Alpha Emitters: Recent Developments for Medical Applications

The application of nanotechnology in nuclear medicine offers attractive therapeutic opportunities for the treatment of various diseases, including cancer. Indeed, nanoparticles-conjugated targeted alpha-particle therapy (TAT) would be ideal for localized cell killing due to high linear energy transfer and short ranges of alpha emitters. New approaches in radiolabeling are necessary because chemical radiolabeling techniques are rendered sub-optimal due to the presence of recoil energy generated by alpha decay, which causes chemical bonds to break. This review attempts to cover, in a concise fashion, various aspects of physics, radiobiology, and production of alpha emitters, as well as highlight the main problems they present, with possible new approaches to mitigate those problems. Special emphasis is placed on the strategies proposed for managing recoil energy. We will also provide an account of the recent studies in vitro and in vivo preclinical investigations of α-particle therapy delivered by various nanosystems from different materials, including inorganic nanoparticles, liposomes, and polymersomes, and some carbon-based systems are also summarized.

222Rn,226Ra and 238U concentration in water samples for some marshes in Dhi-Qar governorate, Iraq

Radon (222Rn), radium (226Ra) and uranium (238U) concentration in the samples of marshes' water have been measured. The samples were collected from various places at the marshes, in Dhi-Qar governorate. The method that used in the present study is the can technique by Solid State Nuclear Track Detectors (SSNTDs) with CR-39 detectors. Also, it was determined the average internal effective dose risk (AED), with lifetime cancer risk due to ingestion of 222Rn and 226Ra in drinking water. The average values of 222Rn, 226Ra and uranium 238U concentration in water samples were found to be 288.02 ± 31.21 Bq/m3, 0.45 ± 0.04 Bq/L, and 0.60 ± 0.06 ppm respectively. The average values of AED (in mSv/y unit) caused by ingestion of 222Rn and 226Ra in the samples of the study were found to be 0.019 ± 0.002 and, 0.093 ± 0.01, respectively. The average values of total AED and lifetime cancer risk values were calculated to be 0.11 ± 0.01 mSv/y and (4.34 ± 0.47) × 10−4, respectively. The average concentration values of 222Rn and 226Ra were found to be within the global average limitations (0.4 Bq/L), and (1 Bq/L) that are recommended by World Health Organization (WHO) 1993 and 2011, while the average of 238U concentrations were higher than that of global average limitation (0.566 ppm) that was recommended by Environmental Protection Agency (EPA). When some results of AED due to 222Rn and 226Ra concentrations, in the samples under study, were compared with the worldwide median value, that is recommended by WHO (2011); it was found that the lifetime cancer risk in all samples of the present study were higher than the safety limit for the healthy drinking water. Therefore, consuming the water of Marshes in the Dhi-Qar governorate- Iraq, for cooking and drinking (which is contaminated with alpha emitters like; 222Rn, 226Ra, and 238U) may lead to a considerable variation in the internal effective dose. HIGHLIGHT In this manuscript, I have been affording in a truly innovative way the issue to put the basis towards the realization for the first time of a baseline for assessment of the exposure of Iraq's people to lifetime cancer risk and annual effective dose assessment due to alpha emitters concentrations in water of Marshes in Dhi-Qar Governorate, Iraq. The results show that the cancer risk in samples is higher than the world.

Natural Alpha Emitters in Some Types of Medical of Parenteral Solutions (Domestic and Imported) Samples in Iraqi Hospitals

In this research, alpha emitters (222Rn, 226Ra and 238U) were measured by solid state nuclear track detector (LR-115 type 2 detector) in some types of medical of parenteral solutions samples that commonly used in Iraqi hospitals. The results show that the average values of the concentrations for 222Rn (in air space and inside sample), 226Ra, and 238U in samples of the present study were 52.62±9.01 Bq/m3, 0.26±0.04 Bq/L, 0.246±0.04 Bq/L, and 0.232±0.039 ppm, respectively. The average value of alpha emitters was within the acceptable world limitations. Therefore, it may conclude that there is no danger in medical parenteral solutions samples of the present study on human health.