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Stress is a ubiquitous challenge in modern societies. Symptoms range from mood swings and cognitive impairment to autonomic symptoms. This study explores the link between work-related stress and the neurobiological element of brain processing, testing the hypothesis that patients with occupational stress have altered cerebral glucose consumption compared to healthy controls. The participants' present conditions were evaluated using an adapted WHO SCAN interview. Neural activity at rest was assessed by positron emission tomography (PET) with the glucose analogue [18F]fluorodeoxyglucose. Participants were genotyped for the Val158Met polymorphism of the COMT gene, believed to influence stress resilience. This study included 11 women with work-related stress and 11 demographically comparable healthy controls aged 28-62 years, with an average of 46.2 years. The PET scans indicated clusters of decreased glucose consumption primarily located in the white matter of frontal lobe sub-gyral areas in stress patients. COMT Val158Met polymorphism detection indicated no immediate relation of the homozygous alleles and stress resilience; however, healthy controls mainly had the heterozygous allele. In conclusion, the results support that work-related stress does affect the brain in the form of altered glucose metabolism, suggesting neurobiological effects could be related to white matter abnormalities rather than gray matter deterioration. Genotyping indicates a more complex picture than just that of the one type being more resilient to stress. Further studies recruiting a larger number of participants are needed to confirm our preliminary findings.

The evidence on atherosclerosis imaging with 18 F-sodium-fluoride (NaF) positron emission tomography (PET) is hotly debated because of the different patient characteristics, methodology, vascular beds, etc. in reported studies. This review is a continuation of a previous review on this topic, which covered the period 2010-2018. The purpose was to examine whether some of the most important questions that the previous review had left open had been elucidated by the most recent literature. Using principles of a systematic review, we ended analyzing 25 articles dealing with the carotids, coronary arteries, aorta, femoral, intracranial, renal, and penile arteries. The knowledge thus far can be summarized as follows: by targeting active arterial microcalcification, NaF uptake is considered a marker of early stage atherosclerosis, is age-dependent, and consistently associated with cardiovascular risk. Longitudinal studies on NaF uptake, conducted in the abdominal aorta only, showed unchanged uptake in postmenopausal women for nearly four years and varying uptake in prostate cancer patients over 1.5 years, despite constant or increasing calcium volume detected by computed tomography (CT). Thus, uncertainty remains about the transition from active arterial wall calcification marked by increased NaF uptake to less active or consolidated calcification detected by CT. The question of whether early-phase atherosclerosis and calcification can be modified remains also unanswered due to lack of intervention studies.

This study aimed to compare the prognostic value of quantitative measures of [ 18 F]-fluorodeoxyglucose positron emission tomography with integrated computed tomography (FDG-PET/CT) for the response monitoring of patients with metastatic breast cancer (MBC). In this prospective study, 22 patients with biopsy-verified MBC diagnosed between 2011 and 2014 at Odense University Hospital (Denmark) were followed up until 2019. A dual-time-point FDG-PET/CT scan protocol (1 and 3 h) was applied at baseline, when MBC was diagnosed. Baseline characteristics and quantitative measures of maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), corrected SUVmean (cSUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and corrected TLG (cTLG) were collected. Survival time was analyzed using the Kaplan-Meier method and was regressed on MTV, TLG, and cTLG while adjusting for clinicopathological characteristics. Among the 22 patients included (median age: 59.5 years), 21 patients (95%) died within the follow-up period. Median survival time was 29.13 months (95% Confidence interval: 20.4-40 months). Multivariable Cox proportional hazards regression analyses of survival time showed no influence from the SUVmean, cSUVmean, or SUVmax, while increased values of MTV, TLG, and cTLG were significantly associated with slightly higher risk, with hazard ratios ranging between 1.0003 and 1.004 ( p = 0.007 to p = 0.026). Changes from 1 to 3 h were insignificant for all PET measures in the regression model. In conclusion, MTV and TLG are potential prognostic markers for overall survival in MBC patients.

This study measures the total graft of 18 F-sodium fluoride (NaF) uptake in non-instrumented posterolateral lumbar fusion (niPLF) patients one month after surgery and correlates it with the difference in the clinical findings between the baseline and one year after surgery. The walking distance (WLK-D), visual analog scale of back pain (VAS-B), VAS score of leg pain (VAS-L), tandem test (TAN), Oswestry Disability Index questionnaire (ODI), and European Quality of Life-5 Dimensions questionnaire (EQ-5D) were assessed before surgery and one year after. The graft NaF uptake was analyzed quantitatively with a fixed threshold algorithm resulting in the total graft uptake (SUVtotal) and partial volume corrected SUVtotal (cSUVtotal). Only 4 out of 18 patients experienced fusion; they had an insignificantly lower median total graft uptakes, i.e., 1178 SUVtotal vs. 1224 SUVtotal ( p = 0.73) and 1282 cSUVtotal vs. 1231 cSUVtotal ( p = 0.35), respectively. Similarly, fused patients experienced insignificantly larger pain decreases, i.e., median VAS-B 4.3 vs. 3.8 ( p = 0.92) and VAS-L -6.4 vs. -4.4 ( p = 0.2). We found an insignificant trend for a lower NaF uptake and less pain in fused patients. The NaF uptake did not correlate with the chronological change in the clinical parameters.

The Guidelines for Reporting Reliability and Agreement Studies (GRRAS) were proposed in 2011 to support transparent and accurate reporting. These studies may be conducted with the primary aim of estimating reliability and/or agreement itself, but are more often than not part of larger diagnostic accuracy studies, clinical trials, or epidemiological studies. As such, the study design may be compromised in terms of practicability issues, preventing the collection of sufficient results. We presented an example from a consultancy with a difficult mission and discussed five questions that concern the very nature of such a study (agreement vs. reliability; intra- vs. interrater), the rater population, explanatory factors in a multivariable model, and the statistical analysis strategy. Discussion of such basic methodological and statistical questions must take place before an investigation is started in order to ensure adequate data collection, to predict possible complications in the study, to plan sufficient statistical analyses, and to request timely assistance from an experienced statistician. GRRAS and its accompanying checklist of 15 items proved to be most helpful. Hopefully, our commentary will help improve the planning of agreement and reliability studies, which, in turn, will then be more focused, more appropriate, and more easily reported using GRRAS.