Nucl Med Mol Imaging.  2011 Jun;45(2):125-131.

Role of 18F-FDG PET/CT, 123I-MIBG SPECT, and CT in Restaging Patients Affected by Malignant Pheochromocytoma

• Cantalamessa A
• Caobelli F
• Paghera B
• Caobelli A
• Vavassori

Abstract

PURPOSE
Pheochromocytoma (PH) is a rare catecholaminesecreting tumor that arises from chromaffin tissue within the adrenal medulla and extra-adrenal sites; commonly it is sporadic, and malignant PH accounts for about 10% of all cases. Several imaging modalities have been used for the diagnosis and staging of this tumor: functional imaging using radio-labelled metaiodobenzylguanidine and, more recently, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT), which offers substantial sensitivity and specificity to correctly detect metastatic PH and helps to identify patients suitable for treatment with radiopharmaceuticals. The aim of our study was to compare CT, 18F-FDG PET/CT, and 123I-metaiodobenzylguanidine single photon emission tomography (123I-MIBG SPECT) as feasible methods to restage patients diagnosed histologically with PH.
METHODS
We retrospectively evaluated 38 patients (27 females and 11 males; mean age: 44+/-15 years) with malignant PH documented histologically after surgical intervention. These patients underwent CT, 18F-FDG PET/CT, and 123I-MIBG SPECT.
RESULTS
18F-FDG PET/CT showed positive results for neoplastic tissue in 33/38 patients (86.8%) and negative in 5/38 (13.2%), in concordance with CT alone. 123I-MIBG SPECT was positive in 30/38 patients (78,9%) and negative in 8/38 (21.1%). No differences in lesion numbers were found between 18F-FDG PET/CT and CT, whereas a difference could be demonstrated between 18F-FDG PET/CT and 123I-MIBG SPECT.
CONCLUSION
18F-FDG PET/CT could more accurately restage patients with PH than CT and 123I-MIBG SPECT, also in the absence of a staging study.

Keyword

PET; Pheochromocytoma; Paraganglioma; MIBG; SPECT

MeSH Terms

3-Iodobenzylguanidine
Adrenal Medulla
Female
Fluorodeoxyglucose F18
Humans
Hydrogen-Ion Concentration
Paraganglioma
Pheochromocytoma
Positron-Emission Tomography
Radiopharmaceuticals
Retrospective Studies
Sensitivity and Specificity
Tomography, Emission-Computed, Single-Photon
3-Iodobenzylguanidine
Fluorodeoxyglucose F18
Radiopharmaceuticals