123Iodine-metaiodobenzylguanidine scintigraphy versus whole-body magnetic resonance imaging with diffusion-weighted imaging in children with high-risk neuroblastoma - pilot study

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

BACKGROUND

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.

PROCEDURE

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.

RESULTS

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%.

CONCLUSION

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.

1.5 vs 3 Tesla Magnetic Resonance Imaging: A Review of Favorite Clinical Applications for Both Field Strengths-Part 2

ABSTRACT

The second part of this review deals with experiences in neuroradiological and pediatric examinations using modern magnetic resonance imaging systems with 1.5 T and 3 T, with special attention paid to experiences in pediatric cardiac imaging. In addition, whole-body examinations, which are widely used for diagnostic purposes in systemic diseases, are compared with respect to the image quality obtained in different body parts at both field strengths. A systematic overview of the technical differences at 1.5 T and 3 T has been presented in part 1 of this review, as well as several organ-based magnetic resonance imaging applications including musculoskeletal imaging, abdominal imaging, and prostate diagnostics.

[Radiological imaging of neuroblastoma]

BACKGROUND

Neuroblastomas are tumors of the sympathetic nervous system that arise from the sympathetic trunk and adrenal glands. Tissue compositions, molecular genetics, and overall prognosis are heterogeneous. With an incidence of 1:6000, neuroblastomas account for 5.5% of childhood tumors. They usually occur in children up to preschool age with the mean age of 14 months. Adults are very rarely affected. Imaging, especially magnetic resonance imaging (MRI), plays an essential role in diagnosis, risk stratification, and therapy control.

MATERIALS AND METHODS

Based on a selective literature search in the PubMed database, the national and international societies' guidelines and study protocols, the imaging standards and the latest developments are presented.

CONCLUSION

Imaging plays a key role in neuroblastomas due to the heterogeneous prognosis and the resulting very different therapy. A high degree of standardization in implementation and interpretation is important in every phase of the disease process. Sonography, MRI with diffusion weighting, and ¹²³I‑mIBG-SPECT are essential modalities. The extent of the diffusion restriction for assessing the degree of maturity and assessing the therapeutic response is becoming increasingly important in clinical routine. Up to now, PET imaging has mostly been complementary. Newly developed PET tracers promise comprehensive diagnostics and may also play a major role in theranostics.