Are superior cervical sympathetic ganglia avid on whole body 68Ga-PSMA-11 PET/magnetic resonance?: a comprehensive morphologic and molecular assessment in patients with prostate cancer

Abstract

Objectives Recent reports warn against erroneous mistaking of celiac and stellate sympathetic ganglia for metastatic lymph nodes on multimodal prostate-specific membrane antigen (PSMA)-ligand PET imaging. The aim was to check the intensity of 68Ga-PSMA-11 uptake and magnetic resonance (MR) features of superior cervical ganglia (SCG) on PET/MR imaging. Methods In 89 patients 106 SCG were reliably identified on 68Ga-PSMA-11 PET/MR. For each SCG, qualitative assessment (visual subjective avidity, diffusion restriction, shape, and the presence of central hypointensity) and quantitative measurements [dimensions, maximal standardized uptake value (SUVmax), mean apparent diffusion coefficient (ADC)] were performed. Results Mean SUVmax in SCG amounted to 1.88 ± 0.63 (range: 0.87–4.42), with considerable metabolic activity (SUVmax ≥ 2) in 37.7% of SCG; mean thickness was 3.18 ± 1.08 mm. In subjective visual evaluation, SCG avidity was classified as mistakable or potentially mistakable with underlying malignancy in 32.1% of cases. Mean ADC values amounted 1749.83 ± 428.83 × 10−6 mm2/s. In visual assessment, 74.5% of ganglia showed moderate to high diffusion restriction. An oval or longitudinal shape on transverse MR plane was presented by 59.4% of SCG. The central hypointensity was detected on MR T2-weighted images only in 10.4% of SCG. Conclusion SCG, similar to other sympathetic ganglia, show 68Ga-PSMA-11 uptake. SCG avidity may be of significance, especially in view of frequently occurring SCG oval or longitudinal shape, and moderate to high diffusion restriction in visual assessment, potentially suggesting malignancy on transverse MR plane. Diagnostic imaging specialists and clinicians should be aware of the above.

Intra-Individual Comparison of Physiologic [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 Uptake in Ganglia in Patients with Prostate Cancer: A Retrospective, Monocentric Analysis

“…Of the 22-23 pairs of ganglia that comprise the sympathetic chain, the stellate ganglia (which emerged from the combination of C7 and T1 ganglia during evolution), the coeliac ganglia (at the level of T11/12), and the sacral ganglia have been predominantly shown to exhibit a substantial PSMA uptake. Despite multiplex, clinical, and imaging correlation methods, it has occasionally led to pitfalls and misdiagnoses in regular clinical care [9,12,13].…”

Potential Pitfall in the Interpretation of Ganglioneuronal Uptake of 18F-PSMA-1007 PET/CT Scans Performed With a High Spatial Resolution Digital PET Scanner

“…Note the presence of multiple, sometimes asymmetric, well-defined, tiny nodular foci involving the bilateral superior thoracic inlet, paravertebral regions, and lumbar and presacral regions corresponding to the expected locations of sympathetic ganglia. Physiologic PSMA uptake within the sympathetic ganglia has been extensively described with 68 Ga-labeled PSMA tracers ( 68 Ga-PSMA-HBED 1–7 ). Regarding 18 F-labeled PSMA ligands, PSMA ganglia uptake has also been identified on 18 F-DCFPyL, 8–10 being the most prevalent pitfall with 18 F-PSMA-1007 11,12 .…”