%0 Journal Article %A Johannes Duell %A Franziska Krummenast %A Andreas Schirbel %A Philipp Klassen %A Samuel Samnick %A Hilka Rauert-Wunderlich %A Leo Rasche %A Andreas K. Buck %A Hans-Jürgen Wester %A Andreas Rosenwald %A Herrmann Einsele %A Max S. Topp %A Constantin Lapa %A Malte Kircher %T Improved Primary Staging of Marginal-Zone Lymphoma by Addition of CXCR4-Directed PET/CT %D 2021 %R 10.2967/jnumed.120.257279 %J Journal of Nuclear Medicine %P 1415-1421 %V 62 %N 10 %X PET/CT with 18F-FDG is an integral component in the primary staging of most lymphomas. However, its utility is limited in marginal-zone lymphoma (MZL) because of inconsistent 18F-FDG avidity. One diagnostic alternative could be the targeting of C-X-C motif chemokine receptor 4 (CXCR4), shown to be expressed by MZL cells. This study investigated the value of adding CXCR4-directed 68Ga-pentixafor PET/CT to conventional staging. Methods: Twenty-two newly diagnosed MZL patients were staged conventionally and with CXCR4 PET/CT. Lesions identified exclusively by CXCR4 PET/CT were biopsied as the standard of reference and compared with imaging results. The impact of CXCR4-directed imaging on staging results and treatment protocol was assessed. Results: CXCR4 PET/CT correctly identified all patients with viable MZL and was superior to conventional staging (P < 0.001). CXCR4-directed imaging results were validated by confirmation of MZL in 16 of 18 PET-guided biopsy samples. Inclusion of CXCR4 PET/CT in primary staging significantly impacted staging results in almost half of patients and treatment protocols in a third (upstaging, n = 7; downstaging, n = 3; treatment change, n = 8; P < 0.03). Conclusion: CXCR4 PET/CT is a suitable tool in primary staging of MZL and holds the potential to improve existing diagnostic algorithms. %U https://jnm.snmjournals.org/content/jnumed/62/10/1415.full.pdf