Duration of 18F-FDG avidity in lymph nodes after pandemic H1N1v and seasonal influenza vaccination

Abstract

Influenza vaccination may lead to FDG-avid draining lymph nodes beyond 1 month.

Systemic Immune Response to Vaccination on FDG-PET/CT

“…The highest uptake typically occurred within the first 2 weeks after vaccination [1,3], but persisted beyond 1 month in some cases [2]. Additionally, lymph node size was normal [1][2][3][4], in contrast to our case. These reports advocate caution when considering changes to the treatment plan prior to confirmation of the suspected false-positive uptake.…”

“…Several previous reports demonstrated the occurrence of false-positive ipsilateral FDGavid axillary lymph nodes following vaccination [1][2][3][4]. The highest uptake typically occurred within the first 2 weeks after vaccination [1,3], but persisted beyond 1 month in some cases [2]. Additionally, lymph node size was normal [1][2][3][4], in contrast to our case.…”

“…Compared to the initial scan (left), new enlarged and FDG-avid left axillary lymph nodes (a) were seen on the examination 2-3 days following the influenza vaccination (middle), which resolved 12 days later (right). Several previous reports demonstrated the occurrence of false-positive ipsilateral FDGavid axillary lymph nodes following vaccination [1][2][3][4]. The highest uptake typically occurred within the first 2 weeks after vaccination [1,3], but persisted beyond 1 month in some cases [2].…”

Nano‐particle vaccination combined with TLR‐7 and ‐9 ligands triggers memory and effector CD8+T‐cell responses in melanoma patients

“…It has rather been described as an epiphenomenon in relation to the last vaccination campaigns against influenza A/H1N1 pandemic as seen in patients undergoing oncologic PET/CT [40][41][42] or in sporadic immunization cases [43,44]. Increased glucose metabolism in lymph nodes was not observable >14 days after immunization in the study by Burger et al [42] or >30-50 days by Thomassen et al [41], possibly due to the shorter stimulation time of these vaccines as opposed to the vaccine formulations used in the present study. Interestingly, Iyengar et al [45] found an association between PET-measured lymph node signals and viremia in HIV-infected patients that was attributed to CD4 lymphocyte activation in relation to HIV replication.…”

Latissimus dorsi free flap reconstruction of major abdominal defect in treatment of giant Marjolin’s ulcer: a short report focused on preoperative imaging

“…Ipsilateral lymph nodes metastases could not be ruled out due to the FDG uptake and the appearance on CT which showed marginally enlarged nodes with an eradicated fatty hilus. On the contrary the contralateral lymph nodes were less FDG-accumulating and had a preserved fatty hilus on CT, as observed in inflammatory lymph nodes (10). A drawback is, of course, that PET/CT may not be able to detect micrometastases (11).…”