Challenging Axillary Lymph-Nodes on F-18-FDG, F-18-Choline and Ga-68-DOTATOC PET/CT in Cancer Patients throughout Covid-19 Vaccination Era (preprint)

Objectives: unexpected detection of axillary lymphadenopathy (AxL) in cancer patients (Pts) represents a real concern during COVID-19 vaccination era. Benign reactions may take place after vaccine inoculation, confounding image interpretation in patients undergoing F-18-FDG, F-18-Choline and Ga-68-DOTATOC PET/CT. It may simulate loco-regional metastases/disease. To assess PET/CT findings after COVID-19 vaccination in cancer patients and the consequent impact on their management. Methods: we evaluated 333 patients undergoing PET/CT (257 F-18-FDG, 54 F-18-Choline and 23 Ga-68 DOTATOC) scans after first vaccination with mRNA vaccine (Pfizer-BioNTech). Uptake index (SUVmax) of suspected AxL was defined significant when the ratio >1.5 as compared to the contralateral inoculation site. Besides, co-registered CT (Co-CT) features of target lymph-nodes were evaluated. Nodes with aggregate positivity were further investigated. Results: overall, the prevalence of apparently positive lymph-nodes on PET scans was 17.1% during vaccination era. 107 Pts had undergone PET/CT before COVID-19 pandemic and only 3 shown reactive lymph-nodes with a prevalence of 2.8% (p<0.001 as compared to vaccination era). 84.2% exhibited benign characteristics on Co-CT images and only 9 Pts needed additional appraisal. Conclusions: the correct interpretation of images is crucial to avoid unnecessary management changes and to rule out invasive procedures in cancer Pts undergoing diagnostics. An accurate anamnestic interview and the precise assessment of nodes’ Co-CT characteristics when performing PET/CT may help to address the diagnostic hypothesis.

Evidence of exposure to SARS-CoV-2 in cats and dogs from households in Italy (preprint)

SARS-CoV-2 originated in animals and is now easily transmitted between people. Sporadic detection of natural cases in animals alongside successful experimental infections of pets, such as cats, ferrets and dogs, raises questions about the susceptibility of animals under natural conditions of pet ownership. Here we report a large-scale study to assess SARS-CoV-2 infection in 817 companion animals living in northern Italy, sampled at a time of frequent human infection. No animals tested PCR positive. However, 3.4% of dogs and 3.9% of cats had measurable SARS-CoV-2 neutralizing antibody titers, with dogs from COVID-19 positive households being significantly more likely to test positive than those from COVID-19 negative households. Understanding risk factors associated with this and their potential to infect other species requires urgent investigation. One Sentence SummarySARS-CoV-2 antibodies in pets from Italy.