CT of Pheochromocytoma and Paraganglioma: Risk of Adverse Events with IV Administration of Nonionic Contrast Material

OBJECTIVE: When pheochromocytoma or paraganglioma is suspected, many institutions perform only unenhanced CT because of a perceived risk of inducing a hypertensive crisis with i.v. administration of contrast material. The purpose of this study was to review our experience with the use of nonionic i.v. contrast material for CT of patients with pheochromocytoma or paraganglioma. The specific goal was to determine whether adverse events occurred. MATERIALS AND METHODS: A retrospective review of radiology records identified 25 patients (17 women, eight men; mean age, 43 years; age range, 27-70 years) with 40 pathologically proven pheochromocytomas or paragangliomas who received nonionic i.v. contrast material for CT. There were 16 adrenal pheochromocytomas, 12 abdominal paragangliomas, five neck paragangliomas, and seven metastatic lesions. Medical records were reviewed to determine whether the tumors were sporadic or associated with a syndrome, incidentally detected, or biochemically active; and whether patients were taking alpha-blocking medication at the time of CT. Adverse events were documented. RESULTS: Nineteen patients had 23 sporadic tumors, and six patients had 17 tumors associated with a syndrome. In 12 (48%) of the 25 patients the diagnosis was clinically unsuspected at the time of CT. Elevated levels of urinary catecholamines or their metabolites were found in 19 (90%) of the 21 patients for whom this test was performed. No patients were taking alpha-blocking medication at the time of CT. No adverse events occurred in association with i.v. administration of nonionic contrast material. CONCLUSION: I.v. administration of nonionic contrast material for CT is a safe practice for patients with pheochromocytoma and related tumors even without alpha-blocking medication.