Comparison of 18F-MFBG PET/CT and MRI in the evaluation of Neuroblastoma

Introduction: The norepinephrine transporter-targeting PET tracer, ¹⁸F-labeled norepinephrine analog ¹⁸F-MFBG, exhibits potential in evaluation of neuroblastoma. MRI is currently used as a routine imaging modality in the detection of lesions of neuroblastoma. This study aims to compare the accuracy ¹⁸F-MFBG PET/CT in comparing to MRI in detecting neuroblastoma lesions.

Methods: This retrospective analysis included thirty-nine patients (20 females, average age 4.9 years) who underwent sixty-five regional MRI and whole-body MFBG PET/CT scans (average interval of 15.3 days). The findings in regional MRI were compared to the corresponding region in the MFBG PET/CT.

Results: Among the 65 paired comparison between the MRI images and MFBG PET/CT, 52 were in bone/bone marrow (32 head, 2 maxillofacial, 5 limb, 13 spine) while 13 in the soft tissue. 18F-MFBG PET/CT identified 25 positive and 41 negative images. Based on the clinical follow-up and histological findings, ¹⁸F-MFBG PET/CT achieved a 100% in both sensitivity and specificity. In comparison, MRI showed 37 negative results and 29 positive results. The sensitivity, specificity, and accuracy of MRI were 80% (20/25), 78.0% (32/41), and 80% (52/65), respectively. In bone/bone marrow evaluations, MRI demonstrated a sensitivity of 70.6% (12/17), specificity of 80% (28/35), and accuracy of 76.9% (40/52). Out of the 13 soft tissue images, 4 showed negative results on both MRI and PET, 8 were positive on both, and 1 case presented a false positive MRI in a high-risk neuroblastoma, which was confirmed during a follow-up of 2-year 4 month. Lesion-by-lesion comparison revealed 23 soft tissue lesions, with MRI having a sensitivity of 82.4% (14/17), specificity of 66.7% (4/6), and an accuracy of 78.3% (18/23).

Conclusions: In our patient population, ¹⁸F-MFBG PET/CT demonstrates higher sensitivity and higher specificity than MRI imaging in the evaluation of patients with neuroblastoma. The results confirm that MFBG PET/CT can be a better diagnostic tool in the management of the patients with neuroblastoma.