The predictors of lymphopenia and its effects on survival in locally advanced esophageal squamous cell carcinoma.

To investigate the impact of the effective radiation dose to immune cells (EDIC) and gross tumor volume (GTV) on lymphopenia and survival in patients with locally advanced esophageal squamous cell carcinoma (LAESCC). Between January 2013 and December 2020, 272 LAESCC patients were treated with definitive radiotherapy in two institutions. Based on radiation doses to the lungs, heart, and body region scanned, EDIC was calculated as an equal uniform dose to the total blood considering blood flow and fraction effect. The radiotherapy plan was used to calculate the GTVs. Lymphopenia was graded based on the lowest lymphocyte count during RT. The overall survival (OS), progress-free survival (PFS), and local recurrence-free survival (LRFS) were analyzed statistically. The lowest lymphocyte count was significantly correlated with EDIC (r= -0.389, p < .001) and GTV (r= -0.211, p < .001). Lymphopenia, EDIC, and GTV are risk factors for patients with ESCC. In a Kaplan-Meier analysis with EDIC and GTV as stratification factors, lymphopenia was not associated with OS in the EDIC>12.9 Gy group (p = .294)and EDIC ≤ 12.9 Gy group, and it was also not associated with OS in GTV>68.8 cm3 group (p = .242) and GTV ≤ 68.8 cm3 group(p = .165). GTV and EDIC had an impact on the relationship between lymphopenia and OS in patients with LAESCC undergoing definitive RT. Poorer OS, PFS, and LRFS are correlated with lymphopenia, higher EDIC, and larger GTV.

Assessment of cancer risk and radiological effects from 210Po and 210Pb with consumption of wild medicinal herbal plants.

BACKGROUND: Plants' raw materials can accumulate chemical elements, including radioisotopes, to some extent and reflect the region they grow in. Due to their high environmental content and toxicity, natural radionuclides - polonium 210Po and lead 210Pb are the most dangerous radioisotopes for human health. METHODS: 70 raw medicinal herbal materials from 54 popular wild-growing medicinal plant species, most of them included in the European Pharmacopoeia, were collected across three regions. In 210 samples, the activity concentrations of 210Po and 210Pb were determined, and their radiotoxicity and cancer risk were calculated. RESULTS: The results of 210Po and 210Pb activities measured in herbal raw material were from 0.12 mBq g-1 dry weight in the fruits of the common chestnut (Aesculus hippocastanum) to 19.7 mBq g-1 dw in herb of ground elder (Aegopodium podagraria) for 210Po, while for 210Pb ranged from 0.16 mBq g-1 dw to 34.3 mBq g-1 dw in the same plants. There were statistically significant differences between 210Po and 210Pb content in leaves, herbs, flowers, and fruit. The studies indicated that the estimated annual effective radiation dose from Polish medicinal herbs consumption was low, ranging 0.03-105 µSv from 210Po and 0.02-98.2 µSv from 210Pb, while the risk of cancer morbidity and mortality ranged from 10-5 to 10-9. CONCLUSIONS: Consumption of the tested medicinal herbs is safe from the radiological point of view and, based on the predictions related to the calculated risk of cancer, should not increase the probability of its occurrence.

Sensitivity of genotypically diverse rice varieties to radiation and the related changes to antioxidant enzyme activities.

PURPOSE: Radiation mutagenesis, which typically involves gamma rays, is important for generating new rice germplasm resources. Determining the appropriate radiation dose range is critical for the success of radiation mutagenesis. Clarifying the sensitivity and tolerance of genotypically diverse rice varieties to gamma irradiation as well as the radiation-induced changes to reactive oxygen species (ROS) generation and antioxidant enzyme activities is crucial for increasing the utility of radiation mutagenesis in rice breeding programs. MATERIALS AND METHODS: The seeds of the following four rice varieties with different genotypes were used as test materials: indica Zhe 1613, glutinous indica Zhe 1708, japonica Zhejing 100, and glutinous japonica Zhenuo 65. Additionally,60Co was used as the source of gamma rays. The rice seeds were irradiated with 14 doses (0, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, and 750 Gy). Non-irradiated seeds were used as the control. The seedling survival rate for each variety was recorded at 3, 7, 14, and 28 days after sowing. Moreover, the median lethal dose (LD50) and critical dose (LD40) were calculated according to the seedling survival rates at 28 days after sowing. The seedling superoxide anion (O2•-), hydrogen peroxide (H2O2), and malondialdehyde (MDA) contents and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) activities were analyzed at 7 days after sowing. RESULTS: As the radiation dose increased, the seedling survival rate decreased. The seedling survival rate also decreased significantly as the number of days after sowing increased. Among the rice genotypes, the rank-order of the radiation tolerance was as follows: indica Zhe 1613 > glutinous indica Zhe 1708 > japonica Zhejing 100 > glutinous japonica Zhenuo 65. The LD50 values were 426.7 Gy for Zhe 1613, 329.2 Gy for Zhe 1708, 318.3 Gy for Zhejing 100, and 316.6 Gy for Zhenuo 65. Increases in the radiation dose resulted in significant increases in the seedling O2•- and H2O2 contents, but only up to a certain point. Further increases in the radiation dose caused the seedling O2•- and H2O2 contents to decrease. The H2O2 content for each variety peaked when the radiation dose was very close to the LD50. We propose that the radiation dose associated with the highest H2O2 content (±50 Gy) should be used as the recommended dose for the gamma irradiation of rice. The radiation dose that resulted in peak seedling O2•- contents in the analyzed rice varieties was very close to the LD40. In all rice varieties, the MDA content increased as the radiation dose increased. The SOD, CAT, POD, and APX activities increased as the radiation dose increased within a certain range (less than 600 Gy for Zhe 1613 and 400 Gy for the other varieties), but there were slight differences among the rice varieties. CONCLUSIONS: Genotypically diverse rice varieties vary regarding their sensitivity to gamma irradiation. Our findings suggest that ROS generation and antioxidant enzyme activities are important factors associated with the radiation mutagenesis of rice. The close relationship between the activities of key antioxidant enzymes, such as SOD, POD, APX, and CAT, and the LD50 and LD40 may be exploited to enhance radiation mutagenesis through the use of plant growth regulators.

On 210Po and 210Pb in algae diet supplements - The assessed radiation hazard of aquatic superfoods.

Algae are believed to give health benefits. However, the studies showed they contain toxic elements, including radionuclides, and may affect human health. The study presents the values of activity concentrations of 210Po and 210Pb in the algae supplements available worldwide for adults. The activity concentrations (Bq/kg dw) ranged from 0.07 to 14.5 (210Po) and from 0.06 to 8.48 (210Pb). Also, the effective radiation doses and the cancer risk from 210Po and 210Pb decay ingested with analyzed algal supplements have been assessed. The highest values of annual effective doses have been estimated for 210Po in the recommended portion of Spirulina (Arthrospira platensis) from China (59.7 µSv/year) and Diatomaceous earth from the USA (50.4 µSv/year). The cancer morbidity and mortality risk ranged from 10-4 to 10-8. The study indicated the activity concentrations of 210Po and 210Pb were low, and algae supplements for human consumption could be considered safe food.

Effective radiation dose of skeletal surveys performed for suspected physical abuse.

BACKGROUND: A skeletal survey is an important diagnostic tool for patients presenting with suspected physical abuse. A relatively recent change in guidelines for skeletal surveys by the Royal College of Radiologists (RCR) in 2017 has led to more initial and follow-up images for these patients, which would be expected to have led to an increase in effective radiation dose. OBJECTIVE: To estimate the effective dose following the change in guidelines and to ascertain the difference between doses before and after the change in guidelines. MATERIALS AND METHODS: Data were collected retrospectively on children younger than 3 years old referred for skeletal surveys for suspected physical abuse at a tertiary paediatric centre. A Monte Carlo radiation patient dose simulation software, PCXMC v 2.0.1, was used to estimate the effective dose, expressed in millisieverts (mSv). RESULTS: Sixty-eight children underwent skeletal surveys for suspected physical abuse. The total estimated effective dose for skeletal surveys with the previous RCR guidelines was found to be 0.19 mSv. For initial skeletal surveys with the current RCR guidelines, the estimated effective radiation dose was 0.19 mSv. Eighteen children had both initial and follow-up skeletal surveys as indicated by the current RCR guidelines, with an estimated effective total radiation dose of 0.26 mSv. CONCLUSION: Skeletal surveys deliver a relatively low estimated effective radiation dose equivalent to 1 month of United Kingdom background radiation, with no significant change in dose following the change in guidelines. Therefore, the benefits of having a skeletal survey outweigh the main radiation risk. However, accurate data regarding the radiation dose are important for clinicians consenting parents/guardians for imaging in suspected physical abuse.

Pediatric effective dose assessment for routine computed tomography examinations in Tehran, Iran.

Background: The purpose of this study is to evaluate the effective dose (ED) for computed tomography (CT) examination in different age groups and medical exposure in pediatric imaging centers in Tehran, Iran. Methods: Imaging data were collected from 532 pediatric patients from four age groups subjected to three prevalent procedures. National Cancer Institute CT (NCICT) software was used to calculate the ED value. Results: The mean ED values were 1.60, 4.16, and 10.56 mSv for patients' procedures of head, chest, and abdomen-pelvis, respectively. This study showed a significant difference of ED value among five pediatric medical imaging centers (P < 0.05). In head, chest, and abdomen-pelvis exams, a reduction in ED was evident with decreasing patients' age. Conclusion: As there were significant differences among ED values in five pediatric medical imaging centers, optimizing this value is necessary to decrease this variation. For head CT in infants and also abdomen-pelvis, further reduction in radiation exposure is required.

Cumulative diagnostic imaging radiation exposure in premature neonates.

BACKGROUND: To date, there has been limited work evaluating the total cumulative effective radiation dose received by infants in the neonatal intensive care unit. Most previous publications report that the total radiation dose received falls within the safe limits but does not include all types of ionizing radiation studies typically performed on this vulnerable patient population. We aimed to provide an estimate of the cumulative effective ionizing radiation dose (cED) in microSieverts (µSv) received by premature infants ≤32 weeks from diagnostic studies performed throughout their NICU stay, and predictors of exposures. METHODS: Retrospective chart review from 2004-2011. Data included demographics, gestational age (GA), birth weight (BW), length of stay (LOS), clinical diagnosis, and radiological studies. RESULTS: 1045 charts were reviewed. Median GA = 30.0 weeks (SD 2.7, range 22.0-32.6). Median BW = 1340.0 grams (SD 445.4, range 420-2470). Median number of radiographic studies = 9 (SD 28.5, range 0-210). Median cED = 162µSv (range 0-9248). The cED was positively associated with LOS (p < 0.001) and inversely correlated with GA (p < 0.001) and BW (p < 0.001). Infants with intestinal perforation had the highest median cED 1661µSv compared to 162µSv for others (p < 0.001). CONCLUSION: Our results provide an estimate of the cumulative effective radiation dose received by premature infants in a level 4 neonatal intensive care unit from all radiological studies involving ionizing radiation and identifies risk factors and predictors of such exposure. Radiation exposure in NICU is highest among the most premature and among infants who suffer from intestinal perforation.

Intraoperative Computed Tomography-Based Navigation with Augmented Reality for Lateral Approaches to the Spine.

Background. Lateral approaches to the spine have gained increased popularity due to enabling minimally invasive access to the spine, less blood loss, decreased operative time, and less postoperative pain. The objective of the study was to analyze the use of intraoperative computed tomography with navigation and the implementation of augmented reality in facilitating a lateral approach to the spine. Methods. We prospectively analyzed all patients who underwent surgery with a lateral approach to the spine from September 2016 to January 2021 using intraoperative CT applying a 32-slice movable CT scanner, which was used for automatic navigation registration. Sixteen patients, with a median age of 64.3 years, were operated on using a lateral approach to the thoracic and lumbar spine and using intraoperative CT with navigation. Indications included a herniated disc (six patients), tumors (seven), instability following the fracture of the thoracic or lumbar vertebra (two), and spondylodiscitis (one). Results. Automatic registration, applying intraoperative CT, resulted in high accuracy (target registration error: 0.84 ± 0.10 mm). The effective radiation dose of the registration CT scans was 6.16 ± 3.91 mSv. In seven patients, a control iCT scan was performed for resection and implant control, with an ED of 4.51 ± 2.48 mSv. Augmented reality (AR) was used to support surgery in 11 cases, by visualizing the tumor outline, pedicle screws, herniated discs, and surrounding structures. Of the 16 patients, corpectomy was performed in six patients with the implantation of an expandable cage, and one patient underwent discectomy using the XLIF technique. One patient experienced perioperative complications. One patient died in the early postoperative course due to severe cardiorespiratory failure. Ten patients had improved and five had unchanged neurological status at the 3-month follow up. Conclusions. Intraoperative computed tomography with navigation facilitates the application of lateral approaches to the spine for a variety of indications, including fusion procedures, tumor resection, and herniated disc surgery.

Value of Coronary Calcium Scoring in Symptomatic and Asymptomatic Coronary Artery Disease Patients.

AIM AND OBJECTIVE: The study aimed to estimate the relationship between Coronary Calcium Scoring (CCS) and the presence of different degrees of obstructive coronary artery disease (CAD) to avoid unnecessary examinations and hence unnecessary radiation exposure and contrast injection. BACKGROUND: Coronary Calcium Scoring (CCS) is a test that uses x-ray equipment to produce pictures of the coronary arteries to determine the degree of its narrowing by the build-up of calcified plaques. Despite the lack of definitive data linking ionizing radiation with cancer, the American Heart Association supports widely that practitioners of Computed tomography Coronary Angiography (CTCA) should keep "patient radiation doses as low as reasonably achievable but consistent with obtaining the desired medical information". METHODS: Data obtained from 275 CTCA examinations were reviewed. Radiation effective doses were estimated for both CCS and CTCA, and measures to keep them as low as possible were presented. CCS and Framingham risk estimates were compared to obtain the final results of CTCA to detect sensitivity and specificity of each one in detecting obstructive lesions. RESULTS: CCS is a strong discriminator for obstructive CAD with high sensitivity and specificity and correlates well with the degree of obstruction even more than Framingham risk estimate, which has high sensitivity and low specificity. CONCLUSION: CCS helps to reduce the effective radiation dose if properly evaluated to skip unnecessary CTCA if obstructive lesions are unlikely, and this as a test does not use contrast material, thus harmful effect on the kidney will be avoided as most of the coronary atherosclerotic patients have renal problems.

The new ultralow dose CT protocol for the diagnosis of fractures of the ankle: A prospective comparative study with conventional CT.

PURPOSE: Computerized tomography (CT) imaging is increasingly being used to evaluate patients with ankle trauma. However, conventional CT (C CT) has a significantly higher radiation dose (RD) than plain radiography. This study aimed to evaluate the diagnostic accuracy and reliability of ultra-low-dose CT (ULDCT) protocol for ankle fractures. METHODS: Ninety-eight consecutive patients who had ankle CT for suspected ankle fracture were included in our prospective study. C CT and ULDCT protocols were simultaneously performed on these 98 patients. Two observers independently evaluated ULDCT and C CT images. The effective RD of the ULDCT and C CT groups was calculated. RESULTS: The interobserver agreement was 1 (perfect). ULDCT and C CT group images showed no significant difference in image quality. The effective RD of the ULDCT was significantly lower than the C CT (p < 0.001). CONCLUSIONS: By evaluating the results of this study, ULDCT proved to be a reliable diagnostic imaging method for fractures of the ankle. The satisfactory diagnostic image quality of the ULDCT protocol provides promising results. LEVEL OF EVIDENCE: Level II/lesser quality RCT or prospective comparative study.

Effective Doses of Ionizing Radiation during Therapeutic Peat Mud Treatment from a Deposit in the Knyszyn Forest (Northeastern Poland).

Radioactivity measurements of 61 therapeutic peat mud samples from the Podsokoldy deposits, near Suprasl, were performed using gamma spectrometry. The authors identified the presence of 13 isotopes with the arithmetic mean of activity (in Bq kg-1): 137Cs-7, 40K-24, 208Tl-1, 212Bi-3, 212Pb-2, 228Ac-2, 210Pb-33, 214Bi-11, 214Pb-11, 226Ra-53, 234Th-47. The effective dose obtained during treatment with 15 peat mud baths (lasting 30 min) was 0.078 µSv. Use of peat mud compresses in the same number and period of exposure to the entire body surface caused absorption of a dose of 0.153 µSv. The authors discuss the probability of tissue radiation from isotopes present in the peat mud. In light of radiobiological knowledge, the therapeutic effect of ionizing radiation during peat mud therapy appears to be very unlikely.

Bolete mushroom Boletus bainiugan from Yunnan as a reflection of the geographical distribution of 210Po, 210Pb and uranium (234U, 235U, 238U) radionuclides, their intake rates and effective exposure doses.

This pioneering study aimed to determine the activity concentrations of 210Po, 210Pb and uranium (234U, 235U, 238U) radionuclides in fruit bodies of wild bolete Boletus bainiugan Dentinger and to estimate its edible safety, which may give scientific evidence for the consumption of this species. The analyses were performed using alpha spectrometer after digestion, exchange resins separation and deposition. Measurement data were analysed and interpolation maps reflecting 210Po, 210Pb and uranium (234U, 235U, 238U) geographical distribution in Yunnan province (China) were presented. In addition, from the perspective of food safety, the possible related effective radiation dose to mushrooms consumers were estimated. The results indicated that 210Po, 210Pb and uranium (234U, 235U, 238U) radionuclides contents in B. bainiugan were significantly different with respect to geographical distribution, and their possible intake in a part of the region was considerably higher. A very interesting observation was done according to the values of 235U/238U activity ratio indicating the occurrence of uranium faction from the global fallout of nuclear weapon tests.

Distribution of 239,240Pu in marine products from the seas around the Korean Peninsula after the Fukushima nuclear power plant accident.

In March 2011, an earthquake caused the shutdown of the active reactors at the Fukushima Daiichi Nuclear Power Plant (NPP), with the succeeding tsunami resulting in the release of radioactively contaminated water into the adjacent Japanese coastal waters. Marine biota selected from various trophic levels were collected in Korean coastal waters throughout 2014 and 2015 and their plutonium levels were measured to evaluate the radioactive contamination levels in the marine organisms that constitute the primary seafood diet in the Republic of Korea (ROK). The results showed that the activity concentrations of 239,240Pu in plankton, macroalgae, mollusks, crustaceans, and cephalopods ranged from 13 to 58, 0.64 to 0.80, 0.94 to 5.40, 0.06 to 0.50, and 0.26 mBq kg-1 of wet weight (w.w.), respectively. The activity concentrations of 239,240Pu measured in the muscles of fish varied from 0.09 to 0.30 mBq kg-1 (w.w.), relatively low values compared to those in other groups regardless of fish species, size, and sampling area. The concentration characteristics of 239,240Pu in the various organs in the respective marine products revealed that the internal organs showed higher concentrations than the muscle or skin (or exoskeleton). The highest concentration of 239,240Pu was measured in the viscera of an abalone, which had an activity concentration of 6.31 mBq kg-1 (w.w.). The concentration factors (CFs) in the >300-µm fraction of plankton and in anchovy, shrimp, and mackerel ranged 67-84% of the International Atomic Energy Agency (IAEA)-recommended values, although the CF in macroalgae was much lower at approximately 5% of IAEA values, suggesting a wide range of 239,240Pu CF in macroalgae. The mean transfer factor (TF) between macroalgae (0.6-0.8 mBq kg-1) and abalone (5.4 mBq kg-1) was estimated to be 7.5, implying that effective Pu transfer occurred between the two species. These figures equate to annual effective doses of 239,240Pu to Koreans through consumption of macroalgae, shellfish, and fish of 1.8 × 10-6, 1.4 × 10-6, and 7.1 × 10-7 mSv yr-1, respectively, and a total dose of 3.9 × 10-6 mSv yr-1, values that are negligible compared to the annual effective dose limit of 1 mSv yr-1.

Uranium (234U, 238U) and thorium (230Th, 232Th) in mushrooms of genus Leccinum and Leccinellum and the potential effective ionizing radiation dose assessment for human.

Evaluated has been bioconcentration potential by fungi and risk to human consumers from exposure to natural long-lived radioactive uranium (234U, 238U) and thorium (230Th, 232Th) sequestered in stems, caps and the whole fruiting bodies by mushrooms of the genus Leccinum and Leccinellum. Edible species in the study were collected from boreal forests in the northern regions of Poland and investigated: red-capped scaber (Leccinum aurantiacum), orange oak bolete (Leccinum aurantiacum var. quercinum), foxy bolete (Leccinum vulpinum), slate bolete (Leccinum aurantiacum var. duriusculum) and hazel bolete (Leccinellum pseudoscabrum). The study showed the species accumulated uranium (234U, 238U) and thorium (230Th, 232Th) form soil to some degree but the calculated values of the bioconcentration factor were below 1. The evaluation showed that Leccinum and Leccinellum mushrooms can contribute to annual effective radiation dose maximally at about 0.9 µSv. Hence, consumption of these mushrooms might increase the annual effective ionizing radiation dose received by a human, while the exposure is considered low from the toxicological point of view even if eaten at elevated amounts.

The level of 210Pb extraction efficiency in Polish herbal teas and the possible effective dose to consumers.

The article presents the results of a study on the level of 210Pb efficiency extraction in Polish herbal teas as a possible additional source of this radioactive isotope in the human diet. The twelve most popular herbal teas available in Poland and their infusions in filtered and tap water were analyzed as well as 210Pb activity concentrations and effective doses (radiation) were calculated. The highest activity concentration of 210Pb in dried plants was determined in cistus - 35.5 Bq kg-1 dry wt, while the lowest was in milk thistle - 3.25 Bq kg-1 dry wt what gives respectively for cistus 46.1 ± 0.7 and 6.50 ± 0.29 mBq for milk thistle per one tea bag. The extraction efficiencies in the filtered water oscillated from 5.1 ± 0.5 for milk thistle to 27.3 ± 0.8% for cistus, while for the tap water they ranged from 7.3 ± 0.6% for lime to 33.3 ± 2.2% for white mulberry. Based on the study, it was found that the analyzed herbal tea consumption would give a small portion of the annual effective dose of 210Pb received in Poland - the annual effective radiation dose of 210Pb taken with herbal tea infusions (one glass daily) was calculated from 0.08 ± 0.01 to 3.17 ± 0.08 µSv.

Reliable navigation registration in cranial and spine surgery based on intraoperative computed tomography.

OBJECTIVE: Low registration errors are an important prerequisite for reliable navigation, independent of its use in cranial or spinal surgery. Regardless of whether navigation is used for trajectory alignment in biopsy or implant procedures, or for sophisticated augmented reality applications, all depend on a correct registration of patient space and image space. In contrast to fiducial, landmark, or surface matching-based registration, the application of intraoperative imaging allows user-independent automatic patient registration, which is less error prone. The authors' aim in this paper was to give an overview of their experience using intraoperative CT (iCT) scanning for automatic registration with a focus on registration accuracy and radiation exposure. METHODS: A total of 645 patients underwent iCT scanning with a 32-slice movable CT scanner in combination with navigation for trajectory alignment in biopsy and implantation procedures (n = 222) and for augmented reality (n = 437) in cranial and spine procedures (347 craniotomies and 42 transsphenoidal, 56 frameless stereotactic, 59 frame-based stereotactic, and 141 spinal procedures). The target registration error was measured using skin fiducials that were not part of the registration procedure. The effective dose was calculated by multiplying the dose length product with conversion factors. RESULTS: Among all 1281 iCT scans obtained, 1172 were used for automatic patient registration (645 initial registration scans and 527 repeat iCT scans). The overall mean target registration error was 0.86 ± 0.38 mm (± SD) (craniotomy, 0.88 ± 0.39 mm; transsphenoidal, 0.92 ± 0.39 mm; frameless, 0.74 ± 0.39 mm; frame-based, 0.84 ± 0.34 mm; and spinal, 0.80 ± 0.28 mm). Compared with standard diagnostic scans, a distinct reduction of the effective dose could be achieved using low-dose protocols for the initial registration scan with mean effective doses of 0.06 ± 0.04 mSv for cranial, 0.50 ± 0.09 mSv for cervical, 4.12 ± 2.13 mSv for thoracic, and 3.37 ± 0.93 mSv for lumbar scans without impeding registration accuracy. CONCLUSIONS: Reliable automatic patient registration can be achieved using iCT scanning. Low-dose protocols ensured a low radiation exposure for the patient. Low-dose scanning had no negative effect on navigation accuracy.

Investigation of the cumulative number of chromosome aberrations induced by three consecutive CT examinations in eight patients.

In our previous study, we found that chromosomes were damaged by the radiation exposure from a single computed tomography (CT) examination, based on an increased number of dicentric chromosomes (Dics) formed in peripheral blood lymphocytes after a CT examination. We then investigated whether a cumulative increase in the frequency of Dics and chromosome translocations (Trs) formation could be observed during three consecutive CT examinations performed over the course of 3-4 years, using lymphocytes in peripheral bloods of eight patients (five males and three females; age range 27-77 years; mean age, 64 years). The effective radiation dose per CT examination estimated from the computational dosimetry system was 22.0-73.5 mSv, and the average dose per case was 40.5 mSv. The frequency of Dics formation significantly increased after a CT examination and tended to decrease before the next examination. Unlike Dics analysis, we found no significant increase in the frequency of Trs formation before and after the CT examination, and we observed no tendency for the frequency to decrease before the next CT examination. The frequency of Trs formation was higher than that of Dics formation regardless of CT examination. Furthermore, neither analysis of Dics nor Trs showed a cumulative increase in the frequency of formation following three consecutive CT examinations.

Isotopes of 210Po and 210Pb in Hazel bolete (Leccinellum pseudoscabrum) - bioconcentration, distribution and related dose assessment.

The hazel bolete Leccinellum pseudoscabrum (Kallenb.) Miksík 2017 specimens and beneath soil layer (0-10 cm) have been examined on the occasion of 210Po and 210Pb activity concentrations, the nuclide bioaccumulation potential by species and distribution in fruit bodies. Mushrooms and forest soils came from six geographically distant locations in the northern and central parts of Poland. The threat to humans from 210Po and 210Pb contained in mushrooms has been also assessed. The absolute values of the 210Po radioactivity, respectively, in caps and stems of fruit bodies were in the range 0.74 ± 0.06-8.59 ± 0.36 Bq kg-1 dry biomass and from 0.81 ± 0.06-8.23 ± 0.37 Bq kg-1 dry biomass, while the values of the 210Pb radioactivity in caps and stems were in the range 0.61 ± 0.04-6.33 ± 0.22 Bq kg-1 dry biomass and 0.83 ± 0.04-4.59 ± 0.24 Bq kg-1 dry biomass, respectively. A potential related effective dose assessment showed that mushrooms L. pseudoscabrum can contribute at 0.89-10.3 µSv kg-1 db from 210Po decay and 0.42-4.37 µSv kg-1 db from 210Pb decay.

On uranium 234U and 238U radionuclides in calcium and magnesium supplements and the potential effective radiation dose assessment to the consumers.

In this survey the concentrations of the radioactive nuclides uranium 234U and 238U were determined in the most popular calcium and magnesium supplements for adults in Poland. It was also investigated whether the supplements contain uranium isotopes and could be a potential source in the human diet and have an influence on the value of effective radiation doses to the consumers. The analyzed calcium and magnesium pharmaceuticals contained organic or inorganic compounds, several of natural origin as mussel's shells, fish extracts, or sedimentary rocks. As results showed, 234U and 238U concentrations in natural origin calcium and magnesium supplements were significantly higher than in other, synthetic ones. The highest 234U and 238U activity concentrations were determined in tablets from mussel's shells. The radiochemical hazard was assessed and the highest annual radiation dose was found in 234U and 238U present in supplements produced from shells or dolomite rock.

Low-Dose Radiation Advances in Coronary Computed Tomography Angiography in the Diagnosis of Coronary Artery Disease.

BACKGROUND: Coronary computed tomography angiography (CCTA) is now widely used in the diagnosis of coronary artery disease since it is a rapid, minimally invasive test with a diagnostic accuracy comparable to coronary angiography. However, to meet demands for increasing spatial and temporal resolution, higher x-ray radiation doses are required to circumvent the resulting increase in image noise. Exposure to high doses of ionizing radiation with CT imaging is a major health concern due to the potential risk of radiation-associated malignancy. Given its increasing use, a number of dose saving algorithms have been implemented to CCTA to minimize radiation exposure to "as low as reasonably achievable (ALARA)" without compromising diagnostic image quality. OBJECTIVE: The purpose of this review is to outline the most recent advances and current status of dose saving techniques in CCTA. METHOD: PubMed, Medline, EMBASE and Scholar databases were searched to identify feasibility studies, clinical trials, and technology guidelines on the technical advances in CT scanner hardware and reconstruction software. RESULTS: Sub-millisievert (mSv) radiation doses have been reported for CCTA due to a combination of strategies such as prospective electrocardiogram-gating, high-pitch helical acquisition, tube current modulation, tube voltage reduction, heart rate reduction, and the most recent novel adaptive iterative reconstruction algorithms. CONCLUSION: Advances in radiation dose reduction without loss of image quality justify the use of CCTA as a non-invasive alternative to coronary catheterization in the diagnosis of coronary artery disease.