64Cu-DOTATATE-PET/CT in Neuroborreliosis Shows Increased Tracer Uptake in Dorsal Root and Paravertebral Ganglia.

Background: Macrophages play a key role in clearing Borrelia burgdorferi infection and express somatostatin receptor subtype 2 (SSTR2), a potential imaging target. This study investigates immune activation in neuroborreliosis (NB) and assesses the diagnostic value of 64Cu-DOTATATE positron emission tomography/computed tomography (PET/CT) alongside magnetic resonance imaging (MRI). Methods: Prospective cohort study (2024-2025) enrolling patients with suspected NB from four Danish hospitals. NB was defined by the following ≥2 criteria: neurological symptoms, cerebrospinal fluid (CSF) pleocytosis, and intrathecal B. burgdorferi-specific antibodies; patients not meeting these criteria served as controls. Results: The study included 20 participants: 15 NB patients (75%) and 5 controls (25%). PET/CT was performed after a median of 9.5 days of antibiotic treatment. Symmetric 64Cu-DOTATATE uptake in dorsal root and paravertebral ganglia was observed in 10 of 15 patients, with cervical involvement in 8 and lumbosacral in 9. All of them had symptoms that corresponded to the anatomical distribution of the uptake. No controls had lumbosacral involvement (p = 0.04). One control with erythema migrans and systemic symptoms showed cervical ganglia uptake. MRI showed cranial or spinal nerve enhancement in five patients. Only one patient had focal PET uptake matching MRI findings and clinical facial palsy. Conclusions: Symmetric 64Cu-DOTATATE ganglionic uptake in NB patients may reflect immune activation or altered ganglionic physiology. One patient had focal 64Cu-DOTATATE uptake corresponding with palsy and MRI and 64Cu-DOTATATE PET/CT did not contribute additional diagnostic value beyond standard clinical evaluation.