Italian researchers conducted a retrospective observational study and concluded that positron emission tomography combined with computed tomography (PET/CT) is a highly accurate tool for diagnosing fever of unknown origin, aiding in making informed clinical decisions. These findings were published in The Journal of Nuclear Medicine.
Fever of unknown origin is characterized by a persistent elevation of body temperature as the sole observed symptom, where standard examination methods, such as blood and urine tests, X-rays, or ultrasound, fail to establish an exact diagnosis. The causes of this condition are extremely diverse and can include oncological diseases, systemic inflammatory processes, or various infections, making diagnosis a complex task because there is no single protocol for these cases.
The PET/CT method is based on the difference in increased metabolism in foci of inflammation and tumors. A nutrient substance, most often glucose, is administered and labeled with a radioactive atom. Upon decay, this isotope emits positrons, which accumulate predominantly in pathological areas. The tomograph records this positron radiation and integrates the obtained information with CT data to accurately determine the source location. Although this method is often used in oncology, in this study it was applied to diagnose fever of unknown origin.
Domenico Albano from the University of Brescia and his team analyzed data from 929 patients aged 18 to 88 years (mean age—60.4 years, including 548 men). All these patients underwent PET/CT using 18F-fluorodeoxyglucose across 12 Italian medical centers. The final diagnosis for each patient was established after a comprehensive analysis of laboratory and imaging data, as well as histological or pathological autopsy reports, and after observation for at least six months. Diagnoses were classified into four groups: infections, non-infectious inflammatory diseases, oncological diseases, and cases where the cause remained unknown.
According to the results, infections accounted for the final diagnosis in 36% of cases, non-infectious inflammatory diseases in 30%, oncological diseases in 11%, and 23% of diagnoses could not be established. Among the identified infections, pneumonia, spondylodiscitis, endocarditis, abscess, and vascular shunt inflammation were most common, along with bone and joint infections. In the group of non-infectious inflammations, large vessel vasculitis and spondyloarthropathies predominated, while among oncological diseases, lymphoma and lung cancer were recorded. False negative results were also noted: for infections, this included endocarditis and urinary tract infections; for non-infectious inflammations—vasculitis, encephalitis, and pericarditis; for oncological diseases—leukemia, gastrointestinal cancer, and apudoma.
The analysis showed that PET/CT results were truly positive in 56% of cases, truly negative in 19%, false positive in 3%, and false negative in 22%. The sensitivity of the method reached 72%, and specificity was 85%. Positive predictive value was 94%, and negative predictive value was 47%. The overall diagnostic value of the method was estimated at 75%. Prognostic factors for a positive result included elevated C-reactive protein levels, erythrocyte sedimentation rate, neutrophil-to-lymphocyte ratio, presence of fever during the procedure, and a short period of antibiotic use. In conclusion, PET/CT directly influenced patient management in 73% of cases, and in the remaining cases, it helped select either additional non-invasive tests or a watchful waiting strategy; only in 16 truly positive cases did the method not change the treatment tactics.
A bill allowing women to purchase pepper spray for personal self-defense purposes in Brazil was approved by the National Congress last month. The proposal received the endorsement of the Brazilian President, Lula da Silva, who sanctioned the measure, introducing some changes to the version published in the Official Gazette of the Union.
To purchase the aerosol, the woman must present an official photo ID, proof of fixed residence, and a Criminal Record Certificate, which must attest to the absence of conviction for a willful crime. The legislation restricts the purchase to sprays with a maximum capacity of 50 milliliters for women, while larger containers are reserved exclusively for public security agents and members of the armed forces.
Retail establishments authorized to sell the device are required to archive purchase and sale records for a period of five years, and must also maintain data on both the buyer and the person who will possess the aerosol. Furthermore, selling companies must provide basic guidance on the correct use of pepper spray. The law establishes that these devices are for individual and non-transferable use, and prohibits them from containing lethal or permanently toxic substances.
The use of pepper spray will be considered legal in situations of self-defense, aiming to ward off an aggressor when facing an unjust aggression that is occurring or about to occur. Lula validated the law but vetoed specific sections, such as the requirement for explicit authorization from legal guardians for adolescents between 16 and 18 years old, thus maintaining the possibility of automatic purchase for adult women. The Brazilian President also vetoed the application of penalties, such as fines, against women who used the spray outside legal guidelines, arguing that this section 'contradicts the public interest.'
The approval of this project occurs in a scenario where Brazil has registered an increase in femicides for the fourth consecutive year. According to the 20th Brazilian Yearbook of Public Security 2026, in 2025, 1,571 victims of femicide were recorded, totaling four daily deaths in the country. The report from the Brazilian Forum of Public Security points out that, besides fatal cases, there were 4,189 attempted femicides in the previous year, representing a 5.9% growth compared to 2025. The non-governmental organization emphasizes that for every completed femicide, there were almost three attempts.
Additionally, the Violence Atlas 2026, produced by the Institute of Applied Economic Research and the Brazilian Forum of Public Security, indicates that sexual violence in Brazil is often underreported, potentially reaching around 822,000 incidents of violation annually.
Thousands of patients are in danger, and hundreds already have cancelled procedures due to specialists' objections to the order regarding medical actions outside regular working hours.
