Role of rapid sequence whole-body MRI screening in SDH-associated hereditary paraganglioma families.

Patients with germline mutations in one of the SDH genes are at substantially increased risk of developing paragangliomas, pheochromocytomas (pheos), and other tumors (all combined referred to as SDH-related tumors). However, limited data exist on screening in SDH mutation carriers and no studies have evaluated whole-body MRI as a screening tool in asymptomatic patients. This was a single-center observational study. We evaluated the results of screening in 37 SDH carriers who underwent 45 whole-body MRIs and 47 biochemical tests. Screening included annual biochemical testing (catecholamines, metanephrines and chromogranin A) and biennial or annual rapid sequence whole-body MRI from the base of the skull to the pelvis beginning at age 10 years old. Six tumors (paragangliomas of the organ of Zuckerkandl, the aortocaval/vas deferens, of the carotid body times three, and a renal cell carcinoma) were diagnosed in five patients. In total, 13.5 % of all patients screened were diagnosed with SDH-related tumors. Whole-body MRI missed one tumor, while biochemical testing was normal in five patients with SDH-related tumors. The sensitivity of whole-body MRI was 87.5 % and the specificity was 94.7 %, while the sensitivity of biochemical testing was 37.5 % and the specificity was 94.9 %. Whole-body MRI had a higher sensitivity for SDH-related tumors than biochemical testing in patients undergoing screening due to their SDHB or SDHC mutation status. Whole-body MRI reduces radiation exposure compared to computed tomography scan and time compared to dedicated MRI of the head/neck, thorax, and abdomen/pelvis.