Comparison between whole‐body magnetic resonance imaging and whole‐body metaiodobenzylguanidine scintigraphy in the evaluation of primary tumor and metastases in neuroblastoma

Whole-body metaiodobenzylguanidine (131 I-MIBG) scintigraphy is the gold standard method to detect neuroblastoma; however, it depends on radioactive material and is expensive. In contrast, whole-body magnetic resonance imaging (WB-MRI) is affordable in developing countries and has been shown to be effective in the evaluation of solid tumors. This study aimed to compare the sensitivity and specificity of WB-MRI with MIBG in the detection of primary tumors and neuroblastoma metastases.This retrospective study enrolled patients with neuroblastoma between 2013 and 2020. All patients underwent WB-MRI and MIBG at intervals of up to 15 days. The results were marked in a table that discriminated anatomical regions for each patient. Two experts evaluated, independently and in anonymity, the WB-MRI images, and two others evaluated MIBG. The results were compared in terms of sensitivity and specificity, for each patient, considering MIBG as the gold standard. This study was approved by the UNIFESP Ethics Committee.Thirty patients with neuroblastoma were enrolled in this study. The age ranged from 1 to 15 years, with a mean of 5.7 years. The interval between exams (WB-MRI and MIBG) ranged from 1 to 13 days, with an average of 6.67 days. Compared to MIBG, WB-MRI presented a sensitivity and specificity greater than or equal to 90% for the detection of primary neuroblastoma in bones and lymph nodes. When we consider the patient without individualizing the anatomical regions, WB-MRI presented sensitivity of 90% and specificity of 73.33%.In conclusion, WB-MRI is a sensitive and specific method to detect neuroblastoma in bone and lymph nodes and highly sensible to primary tumor diagnosis, suggesting that this test is a viable alternative in places where MIBG is difficult to access. Studies with a larger number of cases are necessary for definitive conclusions.