Oncology and Cancer Care at St. Luke's Health

Diagnosis of Neuroendocrine Tumors

Most neuroendocrine tumors are diagnosed by biomarker testing. Imaging and endoscopic modalities can localize the original site of the tumors and their metastasis. A wide range of diagnostic tools are available at the Baylor St. Luke’s Medical Center Neuroendocrine Tumor Program to support our effort to make an accurate diagnosis.


  • Computed Tomography (CT-scan): Triple phase helical CT-scan images are recommended for localization and staging of neuroendocrine tumors. Neuroendocrine tumors are generally vascular tumors that enhance intensely with intravenous contrast injection during the arterial phase imaging with washout during the delayed portal venous phase. This is also available at our Kirby Glen location.
  • Magnetic Resonance Imaging (MRI): Is preferred over CT for patients with a history of allergy to iodine contrast. In addition to a closed MRI, St. Luke's is taking imaging to new heights, offering Houston's first site for a new panoramic, wide-open, high-field MRI. This is also available at our Kirby Glen location. We provide:
    • Exceptional image quality
    • More space, more comfort
    • Unlimited joint positioning
    • Imaging for any patient, large or claustrophobicescan??): Provides a useful tool to detect metastatic disease in unsuspected sites. This technique utilizes a radio-labeled contrast agent (Indium 111-labeled somatostatin analog) administered intravenously prior to scintigraphy with a special large field gamma camera. The overall sensitivity is about 80 percent to 90 percent.
  • 131- IodineMetaiodobenzylguanidine (MIBG) Scintigraphy: Useful for identifying pheochromocytoma.
  • Positron Emission Tomography (PET-scan) using 18-flurodeoxyglucose (FDG) Imaging: Useful in detecting high grade neuroendocrine tumors as a result of their high proliferative activity.

Biochemical Assessment

  • Plasma Chromogranin A: Most useful tumor marker for neuroendocrine tumor. The blood level is elevated in more than 90 percent of patients with neuroendocrine tumors. The level is correlated with tumor burden and may have prognostic significance. It can be used to monitor disease progression, as suggested by the National Comprehensive Cancer Network (NCCN) guidelines. The levels are independent of hormone secretion.
  • Serum Serotonin and Urinary 5-Hydroxyindoleacetic Acid (5-HIAA): Useful tool to detect neuroendocrine tumors with liver metastasis in patients with carcinoid syndrome.
  • Other biomarkers such as Intact Parathyroid Hormone (PTH), PTH-related Protein, Calcitonin Level, Substance-P, Vasointestinal Polypeptide (VIP), Serum Insulin Level, and Serum Proinsulin Level are available at St. Luke's Medical Center to diagnose functional neuroendocrine tumors.
  • Pancreatic Polypeptide and Neuron Specific Enolase: Useful markers for follow-up in patients with known diagnosis of neuroendocrine tumors.

Endoscopic Techniques

  • Flexible Endoscopy: Useful in detecting neuroendocrine tumors in the upper and lower GI tract. Endoscopy is a way of looking inside the body using a flexible tube that has a small camera on the end of it. This instrument is called an endoscope. An endoscope is passed through a natural body opening or small cut.
  • Endoscopic Ultrasound: A gastrointestinal endoscope may be inserted through the mouth or anus. An ultrasound probe can be added to a gastrointestinal endoscope. Depending on the area of interest, this device can also be passed through the mouth or anus. When used in combination with fine needle-aspiration, it can distinguish between neuroendocrine tumors and adenocarcinoma. In addition, it may help in staging by detecting any lymph node involvement.

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