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Low‐dose computed tomography (LDCT) screening is increasingly used for early lung cancer detection targeted to high‐risk populations. Quantifying overdiagnosis, its potential harms, and economic consequences is important. We assessed the magnitude, harms, and economic impact of lung cancer overdiagnosis from LDCT screening in high‐risk populations. We synthesized evidence from eight randomized trials involving 84,660 participants. LDCT may increase overdiagnosis compared to no screening (relative risk [RR] 1.05; 222 additional cases per 100 000 people screened; low certainty). Compared to chest x‐ray (CXR), LDCT likely slightly increases overdiagnosis (RR 1.01; 63 additional cases per 100 000 people screened; moderate certainty). The proportion of overdiagnosed cancers is 0.07 (7000 more lung cancers overdiagnosed per 100 000 lung cancers detected; low certainty) when compared to no screening, and 0.01 compared to CXR (1000 more lung cancers overdiagnosed per 100 000 lung cancers detected; moderate certainty). In terms of cost, LDCT resulted in an additional societal burden of €2,026,422.00 per 100 000 individuals screened compared to no screening. The magnitude of overdiagnosis in LDCT screening is likely low compared to CXR.

Dosimetry during peptide receptor radionuclide therapy (PRRT) has mainly focused on normal organs and less on the tumors. The absorbed dose in one target tumor per patient and several response related factors were assessed in 23 pancreatic neuroendocrine neoplasms (P-NENs) and 25 small-intestinal NEN (SI-NENs) during PRRT with Lu-DOTATATE. The total administered activity per patient was (mean ± standard error of mean (SEM) 31.8 ± 1.9 GBq for P-NENs and 36 ± 1.94 GBq for SI-NENs. The absorbed tumor dose was 143.5 ± 2 Gy in P-NENs, 168.2 ± 2 Gy in SI-NENs. For both NEN types, a dose-response relationship was found between the absorbed dose and tumor shrinkage, which was more pronounced in P-NENs. A significant drop in the absorbed dose per cycle was shown during the course of PRRT. Tumor vascularization was higher in P-NENs than in SI-NENs at baseline but equal post-PRRT. The time to progression (RECIST 1.1) was similar for patients with P-NEN (mean ± SEM 30 ± 1 months) and SI-NEN (33 ± 1 months). In conclusion, a dose response relationship was established for both P-NENs and SI-NENs and a significant drop in the absorbed dose per cycle was shown during the course of PRRT, which warrants further investigation to understand the factors impacting PRRT to improve personalized treatment protocol design.

Abstract Context: Porcine sequence corticotropin (PSC) stimulation test (PSCST) is a reliable, cost-effective alternative to the short Synacthen test. Long-acting PSC is widely available as a 300 IU multidose vial (60 IU per 1 ml). Aims: To compare the efficacy of lower doses of PSC that can be given directly from the multidose vial without reconstitution, with standard dose in assessing the hypothalamic pituitary adrenal (HPA) axis in healthy individuals. Settings and Design: Prospective study comparing different doses of PSC. Methods and Material: In 13 healthy volunteers, serum Cortisol was estimated at 30 and 60 minutes after intramuscular administration of 24IU/250 μg standard dose (0.4 ml) and lower doses of PSC (18 IU/0.3 ml/;12 IU/0.2 ml; and 6 IU/0.1 ml), with a gap of 4 weeks between each dose. Statistical Analysis Used: Mean ± SD was used to express quantitative variables. ANOVA and paired T-test were used for statistical analysis. Results: The mean ± SD of peak Cortisol levels after PSCST with all doses of PSC were >18 ug/dl. The means of peak Cortisol responses to different doses of PSC among subjects were comparable. In a subject, there was no significant dose effect and interaction (dose x time) effect indicating that the different doses were comparable (both at 30 and 60 minutes) (p = 0.735). Conclusions: All tested lower doses of PSC obtained from the multidose vial without reconstitution, including the lowest dose (6 IU/62.5 μg) tested, were comparable in efficacy to the standard dose (24IU/250 μg) in assessing the adequacy of HPA axis in healthy individuals.

Radiation-induced late brain injury consisting of vascular abnormalities, demyelination, white matter necrosis, and cognitive impairment has been described in patients subjected to cranial radiotherapy for brain tumors. Accumulating evidence suggests that various degrees of cognitive deficit can develop after much lower doses of ionizing radiation, as well. The pathophysiological mechanisms underlying these alterations are not elucidated so far. A permanent deficit in neurogenesis, chronic microvascular alterations, and blood-brain barrier dysfunctionality are considered among the main causative factors. Chronic neuroinflammation and altered immune reactions in the brain, which are inherent complications of brain irradiation, have also been directly implicated in the development of cognitive decline after radiation. This review aims to give a comprehensive overview on radiation-induced immune alterations and inflammatory reactions in the brain and summarizes how these processes can influence cognitive performance. The available data on the risk of low-dose radiation exposure in the development of cognitive impairment and the underlying mechanisms are also discussed.

This position statement represents a consensus of an expert committee composed by the Italian Academy of General Dentistry (Accademia Italiana Odontoiatria Generale COI-AIOG) and Italian Academy of Legal and Forensic Dentistry (Accademia Italiana di Odontoiatria Legale e Forense OL-F) on the appropriate use of cone beam computed tomography (C.B.C.T.) in dentistry. This paper analyzes the use of C.B.C.T. in light of the rapid evolution of volumetric technologies, with the new low- and ultra-low-dose exposure programs. These upgrades are determining an improvement in the precision and safety of this methodology; therefore, the need of a guideline revision of the use of C.B.C.T. for treatment planning is mandatory. It appears necessary to develop a new model of use, which, in compliance with the principle of justification and as low as reasonably achievable (ALARA) and as low as diagnostically acceptable (ALADA), can allow a functional “Dedicated C.B.C.T.” exam optimized for the individuality of the patient.

Background With the clinical release of a photon counting detector-based computed tomography (CT) system, the potential benefits of this new technology need to be evaluated clinically. Literature concerning this new generation of detector is sparse, especially in the field of pediatric radiology. Therefore, this study outlines our initial experience with ultra-low dose chest CT imaging on the new photon counting CT system. Materials and methods A pediatric phantom (1-year old, CIRS ATOM phantom, model 704 [CIRS-computerized imaging reference system, Norfolk, VA]) was scanned at different dose levels and different image quality levels to define a protocol for clinical examinations. Next, 20 consecutive pediatric non-contrast ultra-low dose chest CT examinations were evaluated for radiation dose and diagnostic image quality using a 4-point Likert-scale—1 = excellent, 4 = bad image quality—by two radiologists in a consensus reading. This retrospective analysis was approved by the local research ethics committee. Results Chest CT examinations performed at ultra-low radiation dose (effective dose 0.19 ± 0.07 mSv; size-specific dose estimate 0.45 ± 0.14 mGy) in pediatric patients ages (2.6 ± 1.8 years) show good to excellent image quality for lung structures (1.4 ± 0.4) and moderate image quality for soft tissue structures (2.8 ± 0.2). Conclusion Pediatric ultra-low dose chest CT examinations are feasible with the new generation photon counting detector-based CT system. The benefits of this technology must be evaluated for pediatric patients from the outset.

Background Topical minoxidil is the recommended first‐line pharmacologic treatment for male and female pattern hair loss. However, low‐dose oral minoxidil has been used off‐label with good clinical efficacy and safety. Aim To compare the effectiveness and safety of topical minoxidil as a first‐choice treatment of androgenetic alopecia versus 1 mg daily oral minoxidil. Method Sixty‐five AGA patients were randomly allocated to receive either 5% topical solution or 1 mg/day oral minoxidil for 6 months. Treatment efficacy was evaluated by measuring hair diameter, photographic assessment, and patient self‐assessment questionnaires. The safety of treatment was checked through history taking and physical examination. Results Both topical and oral minoxidil groups showed significant improvement in hair diameter after 6 months of treatment (p < 0.001). However, there was no significant difference between the two groups. The photographic assessment demonstrated a significant improvement in hair density in the topical minoxidil group in all marked points located at 12 cm (p = 0.025), 16 cm (p = 0.034), and 24 cm (p = 0.014) distance from the glabella but not in the oral minoxidil group. Nevertheless, the difference between the two groups was not significant. In each group, over 60% of patients expressed satisfaction with their treatments, and no significant difference was detected between the two groups. Conclusion Although topical minoxidil has a better overall therapeutic effect than 1 mg oral minoxidil, the difference between the two groups was not significant. Therefore, 1 mg oral minoxidil may be as effective and safe as standard topical minoxidil in female and male pattern hair loss.

Animal experimental studies indicate that acute or chronic low-dose ionizing radiation (LDIR) (≤100 mSv) or low-dose-rate ionizing radiation (LDRIR) (<6 mSv/h) exposures may be harmful. It induces genetic and epigenetic changes and is associated with a range of physiological disturbances that includes altered immune system, abnormal brain development with resultant cognitive impairment, cataractogenesis, abnormal embryonic development, circulatory diseases, weight gain, premature menopause in female animals, tumorigenesis and shortened lifespan. Paternal or prenatal LDIR/LDRIR exposure is associated with reduced fertility and number of live fetuses, and transgenerational genomic aberrations. On the other hand, in some experimental studies, LDIR/LDRIR exposure has also been reported to bring about beneficial effects such as reduction in tumorigenesis, prolonged lifespan and enhanced fertility. The differences in reported effects of LDIR/LDRIR exposure are dependent on animal genetic background (susceptibility), age (prenatal or postnatal days), sex, nature of radiation exposure (i.e. acute, fractionated or chronic radiation exposure), type of radiation, combination of radiation with other toxic agents (such as smoking, pesticides or other chemical toxins) or animal experimental designs. In this review paper, we aimed to update radiation researchers and radiologists on the current progress achieved in understanding the LDIR/LDRIR-induced bionegative and biopositive effects reported in the various animal models. The roles played by a variety of molecules that are implicated in LDIR/LDRIR-induced health effects will be elaborated. The review will help in future investigations of LDIR/LDRIR-induced health effects by providing clues for designing improved animal research models in order to clarify the current controversial/contradictory findings from existing studies.

•Cardiac vagal activity increases after acute, low-dose hypoxic gas inhalation.•Executive function and task-related neural activation improve after low-dose hypoxia.•Cardiac vagal activity mediates hypoxia's beneficial effects on executive function.•Hormetic low-dose hypoxia broadens neurocognitive means to boost executive function. Today, diverse psychophysiological stresses, such as severe time constraints and busy lifestyles, contribute to cardiac parasympathetic dysfunction, potentially leading to mental health issues and declines in critical executive functions. It is essential to develop accessible methods of enhancing cardiac vagal activity (CVA) to mitigate these adverse effects. We previously demonstrated that inhaling low-dose hypoxic gas (FIO₂: 13.5 %) for 10 min acts as a hormetic stressor, inducing a supercompensation effect in CVA post-hypoxia. Since CVA is a key mediator of brain-heart communication in that it influences executive functions by interacting with the left dorsolateral prefrontal cortex (L-DLPFC), increasing CVA may enhance cognitive ability. We hypothesized that acute low-dose hypoxia leads to enhanced executive function via CVA modulation. Twenty-six individuals participated in both normobaric hypoxia (NH; FIO₂: 13.5 %) and normoxia (NN; ambient air) conditions. CVA, measured through heart rate variability, was analyzed three times: pre-hypoxia/normoxia, hypoxia/normoxia, and post-hypoxia/normoxia. Executive function was assessed using the Stroop task before and after exposure, and prefrontal cortex activity during the task was monitored using multichannel functional near-infrared spectroscopy. A supercompensation of CVA occurred concomitantly with a reduction in heart rate following hypoxic gas inhalation. Stroop performance improved with increased task-related activation of the L-DLPFC in the NH condition. Causal mediation analysis revealed that the post-hypoxia enhancement of CVA mediated improvements in Stroop performance and increased L-DLPFC activation. These findings strongly support our hypothesis that the enhancement of CVA following hormetic hypoxic stress contributes to improved executive function, broadening the scope of neurocognitive approaches for effectively enhancing executive function. [Display omitted]

Early identification of epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations is crucial for selecting a therapeutic strategy for patients with non-small-cell lung cancer (NSCLC). We proposed a machine learning-based model for feature selection and prediction of EGFR and KRAS mutations in patients with NSCLC by including the least number of the most semantic radiomics features. We included a cohort of 161 patients from 211 patients with NSCLC from The Cancer Imaging Archive (TCIA) and analyzed 161 low-dose computed tomography (LDCT) images for detecting EGFR and KRAS mutations. A total of 851 radiomics features, which were classified into 9 categories, were obtained through manual segmentation and radiomics feature extraction from LDCT. We evaluated our models using a validation set consisting of 18 patients derived from the same TCIA dataset. The results showed that the genetic algorithm plus XGBoost classifier exhibited the most favorable performance, with an accuracy of 0.836 and 0.86 for detecting EGFR and KRAS mutations, respectively. We demonstrated that a noninvasive machine learning-based model including the least number of the most semantic radiomics signatures could robustly predict EGFR and KRAS mutations in patients with NSCLC.