Functional characterization of nonmetastatic paraganglioma and pheochromocytoma by 18F‐FDOPA PET: focus on missed lesions. (6th May 2013)

• Record Type: Journal Article
• Authors: Gabriel, Sophie; Blanchet, Elise M.; Sebag, Frédéric; Chen, Clara C.; Fakhry, Nicolas; Deveze, Arnaud; Barlier, Anne; Morange, Isabelle; Pacak, Karel; Taïeb, David
• Is Part Of: Clinical endocrinology. Volume 79:Number 2(2013:Aug.)
• Page Start: 170
• Page End: 177
• Publication Date: 2013-05-06
• Subjects: Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.12126
• Languages: English
• ISSNs: 0300-0664

Abstract

<abstract abstract-type="main" id="cen12126-abs-0001"> <title>Summary</title> <sec id="cen12126-sec-0001" sec-type="section"> <title>Aims and methods</title> <p>To evaluate the clinical value of <sup>18</sup>F‐fluorodihydroxyphenylalanine (<sup>18</sup>F‐FDOPA) PET in relation to tumour localization and the patient's genetic status in a large series of pheochromocytoma/paraganglioma (PHEO/PGL) patients and to discuss in detail false‐negative results.</p> <p>A retrospective study of PGL patients who were investigated with <sup>18</sup>F‐FDOPA PET or PET/CT imaging in two academic endocrine tumour centres was conducted (La Timone University Hospital, Marseilles, France and National Institutes of Health (NIH), Bethesda, MD, USA).</p> </sec> <sec id="cen12126-sec-0002" sec-type="section"> <title>Results</title> <p>One hundred sixteen patients (39·7% harbouring germline mutations in known disease susceptibility genes) were evaluated for a total of 195 PHEO/PGL foci. <sup>18</sup>F‐FDOPA PET correctly detected 179 lesions (91·8%) in 107 patients (92·2%).</p> <p>Lesion‐based sensitivities for parasympathetic PGLs (head, neck, or anterior/middle thoracic ones), PHEOs, and extra‐adrenal sympathetic (abdominal or posterior thoracic) PGLs were 98·2% [96·5% for Timone and 100% for NIH], 93·9% [93·8 and 93·9%] and 70·3% [47·1 and 90%] respectively (<italic>P </italic><<italic> </italic>0·001).</p> <p>Sympathetic (adrenal and extra‐adrenal) SDHx‐related PGLs were at a higher risk for negative <sup>18</sup>F‐FDOPA PET than non‐SDHx‐related PGLs (14/24 <italic>vs</italic> 0/62, respectively, <italic>P</italic> < 0·001). In contrast, the risk of negative <sup>18</sup>F‐FDOPA PET was lower for parasympathetic PGLs regardless of the genetic background (1/90 in SDHx <italic>vs</italic> 1/19 in non‐SDHx tumours, <italic>P</italic> = 0·32).</p> <p> <sup>18</sup>F‐FDOPA PET failed to detect two head and neck PGLs (HNPGL), likely due to their small size, whereas most missed sympathetic PGL were larger and may have exhibited a specific <sup>18</sup>F‐FDOPA‐negative imaging phenotype. <sup>18</sup>F‐FDG PET detected all the missed sympathetic lesions.</p> </sec> <sec id="cen12126-sec-0003" sec-type="section"> <title>Conclusions</title> <p> <sup>18</sup>F‐FDOPA PET appears to be a very sensitive functional imaging tool for HNPGL regardless of the genetic status of the tumours. Patients with false‐negative tumours on <sup>18</sup>F‐FDOPA PET should be tested for SDHx mutations.</p> </sec> </abstract>