Procedure-related uptake on CXCR4 PET/CT: a frequent pitfall independent of time and anatomical site

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Abstract Introduction As a pan-tumor tracer, chemokine receptor 4 (CXCR4)-directed [ 68 Ga]Ga-PentixaFor is frequently utilized in patients with hematological malignancies. We aimed to evaluate the impact of recent surgical and interventional procedures on uptake. Methods Patients undergoing [ 68 Ga]Ga-PentixaFor PET/CT after prior surgical or interventional procedures were analyzed. Uptake at the procedural site was assessed visually and quantitatively (by applying maximum standardized uptake values [SUV max ], target-to-background ratios [TBR]). Quantitative parameters were compared across anatomical region groups (bone, organ, (sub-)cutaneous, muscle). We stratified patients demonstrating uptake in procedural sites into an early (0–30 days) and late group (≥ 31 days between intervention and [ 68 Ga]Ga-PentixaFor PET). In patients with available [ 18 F]FDG PET/CT, quantitative correlation analyses between both radiotracers were also performed. Results Among 425 [ 68 Ga]Ga-PentixaFor PET/CT examinations, 87 prior invasive procedures (20.5%) were identified. In 53 patients allocated to the early group, 29 subjects demonstrated uptake (54.7%), while in the late group, 22 out of 34 subjects revealed tracer accumulation at procedural sites (64.7%). Across the predefined temporal intervals, uptake rates varied numerically but did not differ significantly overall ( p = 0.071). [ 68 Ga]Ga-PentixaFor SUV max (ρ = -0.03, p = 0.807) and TBR (ρ = 0.02, p = 0.876) showed no significant association between time since procedure. On a compartment level, SUV max ( p = 0.482) and TBR ( p = 0.696) revealed no significant differences across investigated anatomical regions. In cases with available [ 18 F]FDG PET (21/51 [41.2%]), quantitative uptake in procedural sites correlated significantly between both radiotracers (SUV max : ρ = 0.55, p = 0.016; TBR: ρ = 0.68, p = 0.001), indicating that different inflammatory signatures at procedural sites may be captured by both radiotracers. Conclusions Post-procedural CXCR4 uptake occurs frequently, with no statistically significant overall association with time since intervention or involved anatomical compartment.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.