Figure 5. A 65-year-old prostate cancer patient underwent [¹⁸F]Choline PET/CT due to biochemical relapse of disease, two years after radical prostatectomy. PSA at the time of the scan was 0.4 ng/mL. Patient also underwent COVID-19 vaccine injection in the left arm 6 days before the exam.

Note: PET imaging (a) was negative for disease relapse but showed a single area of focal [¹⁸F]Choline uptake in the left axilla, corresponding to a 1 cm wide, ovoid lymph node, displayed in axial PET/CT view (b), with fatty hilum detectable in the axial, co-registered low dose CT (c). This lymph node was considered as reactive, following vaccine administration; SUVmax was 2.3.