Imaging work-up for screening of paraganglioma and pheochromocytoma in SDHx mutation carriers: a multicenter prospective study from the PGL.EVA Investigators.

CONTEXT

Recommendations have not been established concerning imaging to screen SDHx mutation carriers for paraganglioma and pheochromocytoma.

OBJECTIVE

Our objective was to compare the performance of gadolinium-enhanced magnetic resonance angiography, contrast-enhanced computed tomography, and [(123)I]metaiodo-benzylguanidine and somatostatin receptor scintigraphies for detecting head and neck and thoracic-abdominal-pelvic paragangliomas in SDHx mutation carriers.

DESIGN AND SETTING

We conducted a prospective, multicenter study from June 2005 to December 2009 at 23 French medical centers.

PATIENTS

A total of 238 index cases or relatives carrying mutations in SDHD, SDHB, or SDHC genes were included.

INTERVENTION

Images obtained by each technique were analyzed blind, without knowledge of results from other tests, first in each local center and then centrally.

MAIN OUTCOME MEASURES

We evaluated sensitivity, specificity, and likelihood ratios for individual and combinations of tests, the gold standard being the consensus of an expert committee.

RESULTS

Two hundred two tumors were diagnosed in 96 subjects. At local assessment, the sensitivity of anatomical imaging for detecting all tumors was higher (85.7%) than that of both scintigraphic techniques (42.7% for [(123)I]metaiodo-benzylguanidine and 69.5% for somatostatin receptor scintigraphy), except for thoracic localizations where somatostatin receptor scintigraphy was more sensitive (61.5 vs. 46.2% for anatomical imaging and 30.8% for [(123)I]metaiodo-benzylguanidine scintigraphy). The best diagnostic performance during local assessment was obtained by combining anatomical imaging tests and somatostatin receptor scintigraphy (sensitivity 91.7%). Central assessment significantly increased the sensitivity (98.6%) of tests in combination.

CONCLUSIONS

In routine practice, the imaging work-up for screening SDHx mutation carriers should include thoraco-abdomino-pelvic computed tomography, head and neck magnetic angiography, and somatostatin receptor scintigraphy. Expert centralized image assessment is recommended.