Managed Care - February 2009 - (Page 46) TOMORROW’S MEDICINE Expanded Availability of Isotope Boon to Neuroblastoma Diagnosis Until GE found a better way to produce and deliver I123, most nuclear medicine labs had to make do with an isotype that produced an inferior image Thomas Morrow, MD his edition of Tomorrow’s Medicine highlights neuroblastomas and pheochromocytomas — two different tumors that affect widely differing age groups but share several characteristics. T Neuroblastoma Most people do not associate newborns with cancer, but one cancer in particular can occur at birth — the neuroblastoma. In fact this tumor is occasionally discovered on prenatal ultrasounds. This highly malignant cancer has its origin either in the adrenal gland, in nerve cells in the abdomen, or in the ganglia of the nervous system. About 650 children will be diagnosed with neuroblastoma this year and the incidence is about one in 100,000 children — making it the second most common pediatric cancer after leukemia and other lymphoproliferative diseases. About 50 percent of cases are diagnosed in children less than 2 years old. By the time of diagnosis, 70 percent of patients have metastatic disease. It is one of the few cancers that secrete hormones, mainly epinephrine and norepinephrine (NE). There are no data to support routine screening for neuroblastoma. Parents who find a lump in the abdomen of their child typically are the first to notice a neuroblastoma. Occasionally it can occur behind the eye and cause a proptosis or bulging of the eye. High blood pressure, diarrhea, rapid pulse, abnormal sweating, or uncontrollable eye movements can accompany it. If the tumor Thomas Morrow, MD, is the immediate past president of the National Association of Managed Care Physicians. He has 24 years of managed care experience at the payer or health plan level. originates in the paraspinal ganglia, paralysis can occur as the tumor compresses the spinal cord. Treatment consists of surgical removal with follow-up chemotherapy and radiation therapy used to attempt to destroy cells not removed by surgery. First described in 1886, the pheochromocytoma is a predominantly benign tumor originating in the medulla of the adrenal glands that, like the neuroblastoma, also secretes excessive amounts of catecholamines. It is diagnosed in approximately 1,000 people each year in the United States and occurs mainly in young or middle-aged adults. In about a quarter of cases it is familial. It might be suspected when symptoms of a hyperactive sympathetic nervous system are present, such as rapid pulse, sporadic resistant elevation of blood pressure, palpitations, sweating, anxiety, headache, and elevated blood glucose. About 10 percent of pheochromocytomas are malignant. Surgical resection of the tumor is the common treatment. Analyzing urine and blood samples for the byproducts of the secreted hormones helps with the differential diagnosis for both of these tumors. Tests that determine the levels of catecholamines or their metabolites — dopamine, homovanillic acid (HVA) and vanilly mandelic acid (VMA) — are usually undertaken. Nuclear imaging A variety of imaging studies are used to diagnose and localize both neuroblastoma and pheochromocytoma, including ultrasound, computed tomography (CT) scans, magnetic resonance imaging (MRI) tests and nuclear imaging using radioactive labeled agents. 46 MANAGED CARE / FEBRUARY 2009
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.