RT Journal Article SR Electronic T1 Chromogranin A Assay and 131I-MIBG Scintigraphy for Diagnosis and Follow-Up of Pheochromocytoma JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 993 OP 997 VO 42 IS 7 A1 d’Herbomez, Michèle A1 Gouze, Valérie A1 Huglo, Damien A1 Nocaudie, Marie A1 Pattou, François A1 Proye, Charles A1 Wémeau, Jean-Louis A1 Marchandise, Xavier YR 2001 UL http://jnm.snmjournals.org/content/42/7/993.abstract AB We assessed the performance of a new serum chromogranin A (CgA) assay in combination with the results of 131I-metaiodobenzylguanidine (MIBG) scintigraphy for diagnosis and follow-up in 89 patients with clinical findings suggestive of pheochromocytoma. Methods: The study population consisted of 41 patients with proven pheochromocytoma and 48 patients with refuted pheochromocytoma. Eighty-seven scintigraphy examinations were performed, 52 in patients with proven pheochromocytoma (39 before surgery and 13 after surgery) and 35 in patients with refuted pheochromocytoma. Results: The sensitivity of the CgA level was 90.2%, and the specificity was 99.0% and 92.3% in the control and refuted pheochromocytoma groups, respectively. A significant relationship was seen between serum levels of CgA and tumor mass (r = 0.70; P < 10−5). The postoperative CgA level was an early and accurate predictor of curative surgery or relapse. The concordance between CgA levels and scintigraphic data was 90.8%. Conclusion: Serum CgA level is an effective marker of pheochromocytoma. Increased levels strongly correlate with tumor mass; therefore, small tumors may go undetected. The concordance between CgA level and the results of 131I-MIBG scintigraphy is high. A CgA level in the reference range is highly predictive of normal scintigraphy findings.