18F-MFBG PET/CT Is an Effective Alternative of 68Ga-DOTATATE PET/CT in the Evaluation of Metastatic Pheochromocytoma and Paraganglioma

Abstract

PurposeThe current guidelines state that the functional imaging choice in the evaluation of metastatic pheochromocytoma and paraganglioma (PPGL) is 68Ga-DOTATATE PET/CT. 18F–meta-fluorobenzylguanidine (18F-MFBG) is a new PET tracer and an analog of meta-iodobenzylguanidine (MIBG). This study aimed to compare 18F-MFBG and 68Ga-DOTATATE PET/CT in patients with metastatic PPGL.Patients and MethodsTwenty-eight patients with known metastatic PPGL were prospectively recruited for this study. All patients underwent both 18F-MFBG and 68Ga-DOTATATE PET/CT studies within 1 week. Lesion numbers detected were compared between these 2 studies.Results18F-MFBG PET/CT was positive for detecting metastases in all patients, whereas positive results of 68Ga-DOTATATE PET/CT were in 27 (96.4%) patients. A total of 686 foci of metastatic lesions were detected by both 18F-MFBG and 68Ga-DOTATATE imaging. In addition, 33 foci of abnormal activity were only detected by 18F-MFBG, whereas 16 foci were only shown on 68Ga-DOTATATE PET/CT.ConclusionsOur data suggest that 18F-MFBG PET/CT is an effective imaging method in the evaluation of metastatic PPGL and could be alternative of 68Ga-DOTATATE PET/CT in this clinical setting.

Comparison of 18F-FDOPA and 18F-MFBG PET/CT Images of Metastatic Pheochromocytoma

“…5 Therefore, 18 F-MFBG PET imaging can be used to evaluate pheochromocytoma and assess the suitability and efficacy of 131 I-MIBG radiotherapy for malignant pheochromocytoma. 6,7 In this case, 18 F-MFBG PET/CT showed slightly more pheochromocytoma lesions than 18 F-FDOPA PET/CT, whereas 18 F-FDOPA was more concentrated than 18 F-MFBG in larger metastases in the intracranial and left lung, resulting in more obvious development. These differences might be related to individual genotypes, diversity in the expression number of related transporters within the lesions, or different degrees of pathological differentiation of the lesions.…”

“…1,10 Therefore, compared with broad-spectrum tumor function imaging agents, FDOPA and MFBG are considered to have higher specificity in diagnosing pheochromocytoma. 6,11 Our case indicates that MFBG, like FDOPA, can be used to accurately target pheochromocytoma metastases.…”

“…18 F-MFBG is a norepinephrine guanethidine analog taken up by tumor cells expressing norepinephrine transport (NET), highly expressed in pheochromocytoma foci 5 . Therefore, 18 F-MFBG PET imaging can be used to evaluate pheochromocytoma and assess the suitability and efficacy of 131 I-MIBG radiotherapy for malignant pheochromocytoma 6,7 . In this case, 18 F-MFBG PET/CT showed slightly more pheochromocytoma lesions than 18 F-FDOPA PET/CT, whereas 18 F-FDOPA was more concentrated than 18 F-MFBG in larger metastases in the intracranial and left lung, resulting in more obvious development.…”

Biomarker identification of immune-related genes in pheochromocytoma and paraganglioma

“…For malignant PPGL or unresectable PPGL, chemotherapy, isotope therapy, and molecular targeted drugs are the main treatment methods. Cyclophosphamide, vincristine, and dacarbazine (CVD), and etoposide and cisplatin (EP) are commonly used chemotherapy regiments that are controlled or effective in about half of PPGL patients (44,45). PPGL has been studied at the molecular level, and the understanding of molecular signaling, metabolism, and resistance mechanisms suggests that treatment regimens can be optimized for each molecular subtype to improve selectivity and effectiveness (46,47).…”

Something old has become new: PET imaging of neural-crest tumors with [18F]-meta-fluorobenzylguanidine

“…Furthermore, the diagnostic performance of [ 18 F]-mFBG with respect to the already mentioned tracers commonly employed for NCT imaging, other than [ 123 I]-mIBG, has still to be addressed [15]. In this regard, Wang et al carried out a prospective comparative study including 28 patients with metastatic PGLs submitted to both [ 18 F]-mFBG and [ 68 Ga]-DOTATATE PET/CT within 1 week [16]. The authors compared the diagnostic performance of the 2 PET-imaging modalities (i.e., number of detected lesions): an overall number of 686 metastatic lesions were identified by both [ 18 F]-mFBG and [ 68 Ga]-DOTATATE, being 33 lesions positive only on [ 18 F]-mFBG and 16 being detected exclusively by [ 68 Ga]-DOTATATE PET/CT.…”