Focally Increased MIBG Activity in the Muscle: Real Lesion or LOVENOX Injection Artifact?

[18F]MFBG PET/CT outperforming [123I]MIBG SPECT/CT in the evaluation of neuroblastoma

PURPOSE

Iodine 123 labeled meta-iodobenzylguanidine ([123I]MIBG) scan with SPECT/CT imaging is one of the most commonly used imaging modalities in the evaluation of neuroblastoma. [18F]-meta-fluorobenzylguanidine ([18F]MFBG) is a novel positron emission tomography (PET) tracer which was reported to have a similar biodistribution to [123I]MIBG. However, the experience of using [18F]MFBG PET/CT in the evaluation of patients with neuroblastoma is limited. This preliminary investigation aims to assess the efficacy of [18F]MFBG PET/CT in the evaluation of neuroblastomas in comparison to [123I]MIBG scans with SPECT/CT.

MATERIALS AND METHODS

In this prospective, single-center study, 40 participants (mean age 6.0 ± 3.7 years) with history of neuroblastoma were enrolled. All children underwent both [123I]MIBG SPECT/CT and [18F]MFBG PET/CT studies. The number of lesions and the Curie scores revealed by each imaging method were recorded.

RESULTS

Six patients had negative findings on both [123I]MIBG and [18F]MFBG studies. Four of the 34 patients (11.8%) were negative on [123I]MIBG but positive on [18F]MFBG, while 30 patients were positive on both [123I]MIBG and [18F]MFBG studies. In these 34 patients, [18F]MFBG PET/CT identified 784 lesions while [123I]MIBG SPECT/CT detected 532 lesions (p < 0.001). The Curie scores obtained from [18F]MFBG PET/CT (11.32 ± 8.18, range 1-27) were statistically higher (p < 0.001) than those from [123I]MIBG SPECT/CT (7.74 ± 7.52, range 0-26). 30 of 34 patients (88.2%) with active disease on imaging had higher Curie scores based on the [18F]MFBG study than on the [123I]MIBG imaging.

CONCLUSION

[18F]MFBG PET/CT shows higher lesion detection rate than [123I]MIBG SPECT/CT in the evaluation of pediatric patients with neuroblastoma.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov : NCT05069220 (Registered: 25 September 2021, retrospectively registered); Institute Review Board of Peking Union Medical College Hospital: ZS-2514.

Current Status and Future Perspective on Molecular Imaging and Treatment of Neuroblastoma

Neuroblastoma is the most common extracranial solid tumor in children and arises from anywhere along the sympathetic nervous system. It is a highly heterogeneous disease with a wide range of prognosis, from spontaneous regression or maturing to highly aggressive. About half of pediatric neuroblastoma patients develop the metastatic disease at diagnosis, which carries a poor prognosis. Nuclear medicine plays a pivotal role in the diagnosis, staging, response assessment, and long-term follow-up of neuroblastoma. And it has also played a prominent role in the treatment of neuroblastoma. Because the structure of metaiodobenzylguanidine (MIBG) is similar to that of norepinephrine, 90% of neuroblastomas are MIBG-avid. 123I-MIBG whole-body scintigraphy is the standard nuclear imaging technique for neuroblastoma, usually in combination with SPECT/CT. However, approximately 10% of neuroblastomas are MIBG nonavid. PET imaging has many technical advantages over SPECT imaging, such as higher spatial and temporal resolution, higher sensitivity, superior quantitative capability, and whole-body tomographic imaging. In recent years, various tracers have been used for imaging neuroblastoma with PET. The importance of patient-specific targeted radionuclide therapy for neuroblastoma therapy has also increased. 131I-MIBG therapy is part of the front-line treatment for children with high-risk neuroblastoma. And peptide receptor radionuclide therapy with radionuclide-labeled somatostatin analogues has been successfully used in the therapy of neuroblastoma. Moreover, radioimmunoimaging has important applications in the diagnosis of neuroblastoma, and radioimmunotherapy may provide a novel treatment modality against neuroblastoma. This review discusses the use of current and novel radiopharmaceuticals in nuclear medicine imaging and therapy of neuroblastoma.

MIBG Uptake in a Gastric Gastrointestinal Stromal Tumor

ABSTRACT

MIBG scintigraphy is the imaging choice in the evaluation of pheochromocytoma and neuroblastoma. 131 I-MIBG uptake by gastrointestinal stromal tumors was rare. Here we report a case in which an increased 131 I-MIBG activity in an endoluminal gastric gastrointestinal stromal tumor was noted.

Elevated 123I-MIBG Activity in Intramuscular Hemangioma

ABSTRACT

A 3-year-old boy with high-risk neuroblastoma underwent 123I-MIBG scan to evaluate the disease status after surgery and chemotherapy. 123I-MIBG SPECT/CT demonstrated liver metastasis. In addition, mildly increased uptake in the inferior left erector spinae was noted. Contrast-enhanced CT suggested intramuscular hemangioma. The 123I-MIBG accumulation in the intramuscular hemangioma persisted during the follow-up scan, whereas the abnormal activity in the liver was resolved.

Roles of PET/Computed Tomography in the Evaluation of Neuroblastoma

Neuroblastoma is one of the most common pediatric malignant tumors. Functional imaging plays an important role in the diagnosis, staging, and therapy response monitoring of neuroblastoma. Although metaiodobenzylguanidine scan with single-photon emission computed tomography/computed tomography remains the mainstay in functional imaging of the neuroblastomas, PET/CT has begun to show increased utility in this clinical setting.

SPECT/CT MIBG Imaging Is Crucial in the Follow-up of the Patients With High-Risk Neuroblastoma

BACKGROUND

Planar whole-body imaging with I-radiolabeled metaiodobenzylguanidine (I-MIBG) is routinely used in the follow-up evaluation of neuroblastoma. In recent years, SPECT with integrated low-dose CT (SPECT/CT) has become more accessible. We investigated how much SPECT/CT can have additional diagnostic value over planar imaging in detection of residual and recurrent neuroblastoma.

METHODS

A total of 170 planar I-MIBG imaging scans with SPECT/CT follow-up scans performed in 147 patients with known high-risk neuroblastoma were retrospectively analyzed. Regions of increased I-MIBG uptake on planar images and the findings on SPECT/CT were compared.

RESULTS

In 61% of the studies, the whole-body planar images and SPECT/CT images yielded the same result. In 39% of the time, however, SPECT/CT images provided additional information.

CONCLUSIONS

In the follow-up of patients with high-risk neuroblastoma, SPECT/CT can significantly improve planar imaging interpretation and impact patient management.

Prominent Pulmonary Metastases Without Concurrent Osseous Involvement in Patients With High-Risk Neuroblastoma

Metastases from high-risk neuroblastomas generally are to the bone or bone marrow. Multiple lung metastases are rare, especially when there was no concurrent osseous metastasis. We report 2 cases of high-risk neuroblastomas having prominent lung metastases without concurrent osseous lesion observed.

Acrometastasis of Neuroblastoma to the Great Toe Revealed by MIBG Scan

A 3-year-old boy with history of neuroblastoma underwent I-MIBG scan. The whole-body images showed relatively normal tracer distribution except for mild activity in the right foot, which was located in the first metatarsal on SPECT/CT images. The subsequent MRI scan of the right foot showed infiltration of the metatarsal of the right first toe. The findings were consistent with solitary acrometastasis of neuroblastoma to the great toe.