PET/MRI for staging patients with Hodgkin lymphoma: equivalent results with PET/CT in a prospective trial

M Picardi,M.G Rascato,N Pugliese,I Cappuccio,E Vigliar,R Della Pepa,M Salvatore,M Franzese,R Castaldo,C Cerchione,C Giordano,M Mascolo,C Cavaliere,E Nicolai,A Soricelli,G Troncone,F Pane,G Campagna

doi:10.1007/s00277-021-04537-5

Abstract

To compare FDG-PET/unenhanced MRI and FDG-PET/diagnostic CT in detecting infiltration in patients with newly diagnosed Hodgkin lymphoma (HL). The endpoint was equivalence between PET/MRI and PET/CT in correctly defining the revised Ann Arbor staging system. Seventy consecutive patients with classical-HL were prospectively investigated for nodal and extra-nodal involvement during pretreatment staging with same-day PET/CT and PET/MRI. Findings indicative of malignancy with the imaging procedures were regarded as lymphoma infiltration; in case of discrepancy, positive-biopsy and/or response to treatment were evidenced as lymphoma. Sixty of the 70 (86%) patients were evaluable having completed the staging program. Disease staging based on either PET/MRI or PET/CT was correct for 54 of the 60 patients (90% vs. 90%), with difference between proportions of 0.0 (95% CI, −9 to 9%; P=0.034 for the equivalence test). As compared with reference standard, invasion of lymph nodes was identified with PET/MRI in 100% and with PET/CT in 100%, of the spleen with PET/MRI in 66% and PET/CT in 55%, of the lung with PET/MRI in 60% and PET/CT in 100%, of the liver with PET/MRI in 67% and PET/CT in 100%, and of the bone with PET/MRI in 100% and PET/CT in 50%. The only statistically significant difference between PET/MRI and PET/CT was observed in bony infiltration detection rates. For PET/CT, iodinate contrast medium infusions’ average was 86 mL, and exposure to ionizing radiation was estimated to be 4-fold higher than PET/MRI. PET/MRI is a promising safe new alternative in the care of patients with HL.

Highlights

Hodgkin lymphoma (HL) requires accurate staging to plana proper therapy (1)
Between 2 January 2017 and 31 July 2019, a total of 70 consecutive patients with newly diagnosed and untreated classical HL were scheduled to undergo on the same-day FDGPET/diagnostic computed tomography (CT) first, followed by FDG-positron emission tomography (PET)/unenhanced magnetic resonance imaging (MRI) for pretreatment staging
The complete staging work-up consisted in routine assessments [clinical and laboratory evaluations together with bone marrow biopsy, gray-scale ultrasonography, and contrastenhanced ultrasonography], and FDG-PET/diagnostic CT scans and experimental investigation with PET/ MRI

Summary

Introduction

Hodgkin lymphoma (HL) requires accurate staging to plana proper therapy (1). The Lugano Classification recommends a full diagnostic CT, by using intravenous (i.v.) injected iodinate contrast medium and current at full dose (the so-called FDG-PET/diagnostic CT), as part of hybrid imaging for improving nodal measurements and extra-nodal disease detection especially in clinical trials (1–4). Concerns have been raised over the safety profile of such diagnostic tool, especially when new generation PET/CT scanners are not employed (5–7). Because of the increased survival of patients with HL, the current strategy is to maximize cure rates while minimizing toxicity (1). In line with this paradigm, it is desirable to avoid side effects induced by iodinate contrast medium and

Methods

Results

Conclusion