CXCR4 PET/MRI for follow-up of gastric mucosa–associated lymphoid tissue lymphoma after first-line Helicobacter pylori eradication

Marius E Mayerhoefer,Markus Raderer,Wolfgang Lamm,Michael Weber,Barbara Kiesewetter,Johannes Rohrbeck,Ingrid Simonitsch-Klupp,Marcus Hacker,Asha Leisser,Lukas Nics,Stefan Schmitl,Hans-Juergen Wester,Alexander Haug

doi:10.1182/blood.2021013239

Abstract

AbstractPosttreatment evaluation of gastric mucosa-associated lymphoid tissue (MALT) lymphoma currently relies on esophagogastroduodenoscopy with histological assessment of biopsies. Overexpression of the G protein–coupled C-X-C chemokine receptor type 4 (CXCR4) has been previously observed in MALT lymphoma. The aim of this prospective study was to evaluate positron emission tomography (PET) with the novel CXCR4 tracer [68Ga]Pentixafor as a potential alternative to follow up biopsies for assessment of residual disease (noncomplete remission [CR]) after first-line Helicobacter pylori eradication. Forty-six post–H pylori eradication [68Ga]Pentixafor–PET/magnetic resonance imaging (MRI) examinations of 26 gastric MALT lymphoma patients, and 20 [68Ga]Pentixafor–PET/MRI examinations of 20 control group patients without lymphoma, were analyzed. In the MALT lymphoma group, time-matched gastric biopsies were used as reference standard and showed CR in 6 cases. Pooled examination-based accuracy, sensitivity, specificity, and positive and negative predictive values of [68Ga]Pentixafor–PET for detection of residual gastric MALT lymphoma at follow-up were 97.0%, 95.0%, 100.0%, 100.0%, and 92.9%, respectively. Maximum and mean PET standardized uptake values showed moderate correlation with immunohistochemistry-based CXCR4+ cell counts, with correlation coefficients of r = 0.51 and r = 0.52 (P = .008 and P = .006). In summary, CXCR4 imaging with [68Ga]Pentixafor–PET may represent a promising test for assessment of residual gastric MALT lymphomas after H pylori eradication.

Highlights

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) accounts for 7-8% of newly diagnosed lymphomas; the stomach is its most common organ of origin (30-50% of all cases).[1]
Post-treatment evaluation of gastric mucosa-associated lymphoid tissue (MALT) lymphoma currently relies on esophagogastroduodenoscopy with histological assessment of biopsies
Since gastric MALT lymphoma is closely associated with Helicobacter pylori (HP) infection, antibiotic H. pylori (HP) eradication is the first-line treatment; refractory cases receive second-line radiation or systemic chemo- or immunotherapy.[1, 2]

Summary

Introduction

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) accounts for 7-8% of newly diagnosed lymphomas; the stomach is its most common organ of origin (30-50% of all cases).[1]. In gastric MALT lymphoma after H. pylori eradication, [68Ga]Pentixafor-PET shows high accuracy for detection of residual disease.

Results

Conclusion