Rapid Full Body MRI Screening is an Efficient and Effective Method for Identifying Occult Tumors in Unaffected Patients with Succinate dehydrogenase subunit B Gene Mutations

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 37-82-Pheochromocytoma & Paraganglioma
Clinical
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-58
Lauren Fishbein*1, Shana Merrill2, Dana Butler3, Bridget Pomponio3, Debbie L. Cohen2, Lori Loevner2, Mark Rosen2 and Katherine L Nathanson4
1Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 2Perelman School of Medicine at the University of Pennsylvania, 3University of Pennsylvania, 4Abramson Cancer Center and the Perelman School of Medicine University of Pennsylvania, Philadelphia, PA
Ten known pheochromocytoma and paraganglioma (PCC/PGL) susceptibility genes have been identified. Carriers of a Succinate dehydrogenase subunit B (SDHB) gene mutation are at increased risk of developing primary and metastatic PCC/PGL and other tumors such as renal cell carcinoma, gastrointestinal stromal tumors and papillary thyroid cancer. Given these risks, for unaffected SDHB mutation carriers, we recommend screening with at least biennial MRI from the skull base to the pelvis and annual biochemical testing including plasma catecholamines and metanephrines. MRI was chosen over nuclear medicine scans because it has greater sensitivity for the detection of non-functional tumors, and there is no radiation exposure in patients who need lifelong scanning due the carriage of a mutated tumor suppressor gene. Recently, we have implemented a rapid full body MRI protocol with the advantage of offering shorter scan time compared to traditional MRI (60-90 minutes verses several hours). We performed a retrospective chart review from July 2010 through December 2012 and found 13 unaffected SDHB mutation carriers underwent 16 MRI exams, including 13 with rapid full body protocol. Rapid full body MRI of the neck, chest, abdomen, and pelvis was performed axially at 1.5T using continuous table movement (Siemens©) imaging, included T2 (with and without fat saturation), diffusion, and T1 chemical shift before and after gadolinium. In one symptomatic patient, conventional MRI revealed a 4 cm abdominal PGL. Two additional occult lesions were discovered on rapid full body MRI of asymptomatic patients, including a 2 cm bronchial carcinoid, and a 1.8 cm mildly MIBG avid retrocural mass. No false positive results were obtained. No severe adverse events were noted. One mild contrast reaction to gadolinium in a patient with an asthma history spontaneously resolved without treatment. In summary, MRI, and rapid full body MRI, is an efficient and effective method for screening unaffected SDHB mutations carriers who are at increased risk for PCC/PGL and other tumor types. Rapid full body protocols have been examined for staging in other cancers, but this is the first report, to our knowledge, of using rapid full body MRI for screening SDH mutation carriers. In addition, the rapid full body MRI protocol offers the advantage of being performed in a shorter time period compared to conventional whole body MRI making it more convenient for patients without compromising results.

Nothing to Disclose: LF, SM, DB, BP, DLC, LL, MR, KLN

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