February 25, 2021 -- Researchers are warning that the COVID-19 vaccine can manifest on imaging in ways that appear to be disease, according to two studies published February 24 in the American Journal of Roentgenology and Radiology.
As more people get vaccinated for COVID-19, radiologists must be familiar with how the vaccine may affect imaging results, wrote Dr. Shabnam Mortazavi of the University of California, Los Angeles. Mortazavi conducted a study that included data from 23 women who underwent breast imaging after being vaccinated.
"Practice recommendations are needed to prevent excessive follow-up imaging and potential biopsy of COVID-19 associate axillary adenopathy," she noted.
Current recommendations from the Society of Breast Imaging (SBI) for managing unilateral axillary adenopathy on screening exams after COVID-19 vaccination suggest that clinicians categorize these findings as BI-RADS 0 for further follow-up of the ipsilateral breast; after diagnostic workup, conduct a follow-up exam four to 12 weeks after the second vaccine dose; and if adenopathy remains, perform a biopsy. But it isn't clear whether this protocol is really necessary, according to Mortazavi.
Mortazavi and colleagues evaluated data from 23 women who presented with axillary adenopathy on mammography, breast ultrasound, or breast MRI after being vaccinated for COVID-19 between December 2020 and February 2021. Of these, 13% underwent breast imaging because they were symptomatic, while 43% were undergoing screening and 43% were having imaging for other reasons.
The team found that most of the adenopathy on breast imaging occurred with the Pfizer vaccine (52%), among asymptomatic women presenting for either screening or diagnostic purposes (86%), and on ultrasound (52%).
|Features of axillary adenopathy in women with COVID-19 vaccination|
|Type of vaccine|
|Time between first dose of vaccine and imaging|
|Two to six days||35%|
|Seven to 13 days||35%|
|14 to 20 days||25%|
|Reason for breast imaging|
|Mammography and ultrasound||17%|
"This study highlights axillary adenopathy ipsilateral to the vaccinated arm with Pfizer-BioNTech or Moderna COVID-19 vaccine as a potential reactive process with which radiologists must be familiar," Mortazavi concluded. "Incorporating a patient's COVID-19 vaccination history, including vaccination date and laterality, is critical to optimize assessment and management of imaging-detected axillary adenopathy in women with otherwise normal breast imaging."
Vaccine or metastasis?
In a related study in Radiology, a group led by Dr. Can özütemiz of the University of Minnesota in Minneapolis presented results from five patients whose imaging showed axillary lymphadenopathy after receiving the Pfizer-BioNTech COVID-19 vaccine and which initially prompted concerns of cancer metastasis. The five patients included the following:
"Our findings are important, particularly for cancer patients," özütemiz and colleagues wrote. "Radiologists, oncologists, and internists should be aware of this secondary effect of vaccination to obviate unnecessary changes in management, unnecessary patient emotional stress, or biopsy."
Finally, in a special report -- also published February 24 in Radiology -- Dr. Anton Becker, PhD, of Memorial Sloan Kettering Cancer Center in New York City and colleagues offered the following guidelines for considering COVID-19 vaccine effects on imaging.
"Clear and effective communication between patients, radiologists, referring physician teams and the general public should be considered of the highest priority when managing adenopathy in the setting of COVID-19 vaccination," Becker and colleagues concluded.