Salivary Gland Scan

Definition

A salivary gland scan is a nuclear medicine test that examines the uptake and secretion in the salivary glands of a radioactively labeled marker substance. The pattern of uptake and secretion shows if these glands are functioning normally.

Purpose

A salivary gland scan is done to help diagnose the cause of dry mouth. It is a test that is done when Sjogren's syndrome, salivary duct obstruction, asymmetric hypertrophy, or growths such as Warthin's tumors are suspected.

Precautions

Salivary gland scans are a safe and effective way to diagnose problems associated with dry mouth. The level of radioactivity in the marker substance is low and poses no threat to health. The only people who should not undergo this test are pregnant women.

Other recent nuclear medicine tests may affect the results of this scan. It may be necessary to wait until earlier radiopharmaceuticals have been cleared from the body before undergoing this scan.

Description

A salivary gland scan, also called a parotid gland scan, is a noninvasive test. The patient is positioned under a gamma scintillation camera that detects radiation. The patient then is injected with a low-level radioactive marker, usually technetium-99m or technetium pertechnetate.

Immediately after the injection, imaging begins. For accurate results, the patient must stay still during imaging. After several images, the patient is given lemon drop candies to suck on, which stimulate the salivary glands. Another set of images is made for comparison purposes. The entire process takes about ten minutes for the injection and 30-45 minutes for the scan.

Preparation

No special preparations are needed for this test. It is not necessary to fast or to restrict medications before testing. Any blood that needs to be drawn for other tests should be taken before the radiopharmaceutical is injected.

Aftercare

Patients can return to normal activities immediately.

Risks

A salivary gland scan is a safe test. The only risk is to the fetus of a pregnant woman. Women who are pregnant should discuss the risks and benefits of this procedure with their doctor.

Normal results

Normally functioning salivary glands take up the radiopharmaceutical then secrete it when stimulated by the lemon drops.

Abnormal results

Abnormally functioning salivary glands fail to exhibit a normal uptake and secretion pattern. This test does not differentiate between benign and malignant lesions.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Disorders of the Oral Region: Neoplasms." Section 9, Chapter 105 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

PERIODICALS

Baur, D. A., T. F. Heston, and J. I. Helman. "Nuclear Medicine in Oral and Maxillofacial Diagnosis: A Review for the Practicing Dental Professional." Journal of Contemporary Dental Practice 5 (February 15, 2004): 94-104.

Chae, S. W., J. H. Sohn, H. S. Shin, et al."Unilateral, Multicentric Warthin's Tumor Mimicking a Tumor Metastatic to a Lymph Node. A Case Report." Acta Cytologica 48 (March-April 2004): 229-233.

ORGANIZATIONS

Society of Nuclear Medicine (SNM). 1850 Samuel Morse Drive, Reston, VA 20190-5316. (703) 708-9000. Fax: (703) 708-9015. 〈http://www.snm.org〉.

OTHER

"Salivary Gland Scan." HealthGate Page. 〈http://www3.healthgate.com〉.

KEY TERMS

Hypertrophy— Overgrowth of tissue not due to a tumor.

Parotid gland— The salivary gland that lies below and in front of each ear.

Radiopharmaceutical— A radioactive pharmaceutical or chemical (usually radioactive iodine or cobalt) used for diagnostic or therapeutic purposes.

Sjögren's syndrome— A disease often associated with rheumatoid arthritis, that causes dry mouth, lesions on the skin, and enlargement of the parotid glands. It is often seen in menopausal women.

Technetium— A synthetic element used in nuclear medicine; it is obtained from the fission of uranium.

Warthin's tumor— A benign tumor of the parotid gland.