Whole-Body MRI and Whole Body 123I-MIBG scintigraphy: comparison in Lines and High Risk Neuroblastoma. A pilot study.

Abstract Purpose: To assess agreement between 123I-metaiodobenzylguanidine (MIBG) and Whole Body Magnetic Resonance Imaging with diffusion-weighted whole-body imaging with background body signal suppression (WB MRI-DWIBS) in High and Low, Intermediate risk neuroblastoma, a retrospective review was performed on MIBG and DWIBS paired scans acquired at diagnosis, response-to-therapy steps, after-surgery, off therapy.Methods: 80 paired MIBG and DWIBS scans were acquired for 31 patients between June 2009 and June 2019 within 30 days, without intercurrent therapy. SIOPEN Semi-quantitative scoring systems for NB with 12 body sections was applied at whole body MIBG and WB MRI-DWIBS acquired to evaluate the disease extent. We evaluated specificity, sensitivity, overall accuracy, positive predictive value (PPV) and negative predictive value (NPV) of WB MRI-DWIBS respect MIBG scintigraphy considered as gold standard, and vice versa.Results: DWIBS and MIBG images were concordant in 890 out of the 960 analyzed segments, with high agreement between the two techniques (kendal =0.85 P<0.0001 and Chi 536.5975 p<0.0001). Considering MIBG as gold standard, WB MRI-DWIBS overall accuracy was 93%, sensitivity 78%, specificity 95%, PPV 77% and NPV 96%. Otherwise, MIBG overall accuracy was 93%; sensitivity 77%; specificity 97%; VPP 78%; VPN 95%, considering DWIBS as gold standard. MIBG and WB MRI-DWIBS SIOPEN scoring resulted superimposable (Rho Spearman = 0,88, p < 0,0001).Conclusions: DWIBS and MIBG images showed very high concordance. WB MRI may represent an alternative in weak-avid MIBG tumors and for follow up assessment. An integrated imaging model is proposed for HR, Low and Intermediate Risk protocols.