The Effects of CoronaVac (Sinovac) and BNT162b2 (BioNTech/ Pfizer) Vaccination on Oncologic ¹⁸F-FDG PET/CT Studies

Abstract

Objectives: BioNTech (Pfizer) and CoronaVac (Sinovac) vaccines are two of the most administered coronavirus disease-2019 (COVID-19) vaccines worldwide. Vaccination against severe acute respiratory syndrome-coronavirus-2 has caused a diagnostic challenge in oncological 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) studies. The aim of our study was to evaluate the 18 F-FDG PET/CT findings of the two most commonly administered vaccines worldwide. Methods: Patients over 18 years old who underwent 18 F-FDG PET/CT for oncological purposes in our institution between January 13, 2021 and January 31, 2022, who received a single or second dose of the BioNTech or CoronaVac vaccines in the last two months, were included in the study. Descriptive analyses were presented as mean, standard deviation, frequency and ratio. Additionally, chi-square test was used to analyze categorical variables. Results: Ipsilateral deltoid muscle hypermetabolism was observed in 6.9% (n=15) and 14.3% (n=22) patients who received CoronaVac and BioNTech vaccines, respectively. Ipsilateral axillary lymph node hypermetabolism was observed in 11% (n=24) and 41.6% (n=64) patients who received CoronaVac and BioNTech vaccines, respectively. Synchronous deltoid muscle and axillary lymph node hypermetabolism was observed in 4.14% (n=9) and 12.33% (n=19) patients who received CoronaVac and BioNTech vaccines, respectively. Significant differences were detected between CoronaVac and BioNTech vaccines in terms of ipsilateral deltoid muscle hypermetabolism, ipsilateral axillary lymph node hypermetabolism and synchronous deltoid muscle and axillary lymph node hypermetabolism (p<0.05). Conclusion: COVID-19 vaccination may result in ipsilateral axillary lymph node hypermetabolism, ipsilateral deltoid muscle hypermetabolism, or synchronous deltoid muscle and axillary lymph node hypermetabolism with different frequencies depending on the type of vaccination. Although synchronous deltoid muscle and axillary lymph node hypermetabolism can reduce misinterpretation of 18 F-FDG PET/CT, to avoid misinterpretation, it is important to question the vaccination history during ongoing COVID-19 vaccination process.

Reactive axillary lymph nodes after COVID-19 mRNA vaccination: comparison of mRNA vs. attenuated whole-virus vaccines

“…Accounting for differences in adopted methodologies, significant variations in the incidence of RAL were observed across studies in the literature. Analyzing studies spanning from the onset of the pandemic in late 2019 through late 2023, wide variations in RAL incidence on FDG PET/CT were noted based on the standardized uptake value maximum for different vaccine types and doses, overall aligning with our current study findings [15][16][17][18][19][20][21][22][23]. Retrospective studies on Pfizer-BioNTech vaccinated patients reported incidences ranging from 25% [19] to 43% [16], while studies on Moderna vaccinated patients showed incidences between 42% [20] and 72% [18].…”

“…Retrospective studies on Pfizer–BioNTech vaccinated patients reported incidences ranging from 25% [19] to 43% [16], while studies on Moderna vaccinated patients showed incidences between 42% [20] and 72% [18]. CoronaVac vaccines reported incidences between 11% [21] and 16% [22]. To the best of our knowledge, our study is the first to report on RAL incidence on FDG PET/CT following J&J vaccine.…”