How radiation therapy is used in treating acromegaly?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

Radiation therapy is usually reserved for people who have some tumor remaining after surgery and who do not respond to medications. Because radiation leads to a slow lowering of growth hormone (GH) and insulin-like growth factor 1 (IGF-I) levels, these patients often also receive medication to lower hormone levels. The full effect of this therapy may not occur for many years.

The two types of radiation delivery are conventional and stereotactic. Conventional radiation delivery targets the tumor with external beams but can damage the surrounding tissue. The treatment delivers small doses of radiation multiple times over four to six weeks, giving the normal tissue time to heal between treatments.

Stereotactic delivery allows precise targeting of a high-dose beam of radiation at the tumor from varying angles. A patient must wear a rigid head frame to keep the head still. The types of stereotactic radiation delivery currently available are proton beam, linear accelerator (LINAC), and Gamma Knife. With stereotactic delivery, the tumor must be at least 5 mm from the optic chiasm to prevent radiation damage. This treatment can sometimes be done in a single session, reducing the risk of damage to the surrounding tissue.

All forms of radiation therapy cause a gradual decline in production of other pituitary hormones over time, resulting in the need for hormone replacement in most patients. Radiation can also impair a patient's fertility. Vision loss and a brain injury are rare complications. Rarely, secondary tumors can develop many years later in areas that were in the path of the radiation beam.

This answer is based on source  information from the National Institute of Diabetes and Digestive and Kidney Diseases.

Continue Learning about Acromegaly

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.