hormonal and metabolic disorders
Gigantism and Acromegaly
Treatment of Gigantism and Acromegaly
Surgery Radiation therapy Medication Stopping or reducing the overproduction of growth hormone is not easy. Doctors may need to use a combination of surgery, radiation therapy, and medication. Surgery to remove the pituitary tumor by an experienced surgeon is currently regarded as the best first treatment for most people with gigantism and acromegaly caused by a tumor. It results in an immediate reduction in tumor size and growth hormone production, most often without causing deficiency of other pituitary hormones. Unfortunately, tumors are often large by the time they are found, and surgery alone does not usually cure the disorder. Long-term treatment with medication is often needed after surgery. Radiation therapy is sometimes used as a follow-up treatment, particularly if a substantial amount of the tumor remains after surgery and acromegaly symptoms persist despite other treatments. Medications can also be used to treat elevated growth hormone levels. Medications that act on the tumor to suppress growth hormone secretion and medications that block growth hormone from interacting with its receptor are available. Both types of medication reduce symptoms related to excessive growth hormone secretion. The choice of medication is individualized to the person being treated, but most people receive treatment with a class of medications called somatostatin receptor ligands, which reduce growth hormone secretion, thereby reducing IGF-1 production. In many cases, these medications also shrink the tumor. These medications includeoctreotide,lanreotide, andpasireotide. Each is usually given once a month. Pegvisomant, a growth hormone receptor blocker, is also used to treat acromegaly. It may be useful for people who do not respond to somatostatin-type medications. It lowers IGF-1 production by interfering with the action of the growth hormone coming from the tumor. It is given as a daily injection under the skin and is effective in most people when the dose is increased to adequate levels. Occasionally,cabergolineis used to treat acromegaly, especially in milder cases when the serum IGF-1 level is not very elevated above normal. This medication is not as effective as somatostatin receptor ligands, but because it is taken by mouth rather than injection, it may be preferred by some people. All of these medications are effective in controlling acromegaly in many people as long as they continue to be taken; however, they do not provide a cure. Radiation Therapy for Cancer involves the delivery of single or multiple smaller doses of radiation to the tumor, which is less traumatic than surgery. However, it may take several years for radiation to have its full effect on reducing growth hormone secretion. Later on, radiation therapy often results in deficiencies of other pituitary hormones because normal tissue is often also affected. Stereotactic radiation therapy, in which the radiation comes from several different directions (so it does not always go through the same normal tissue), has been developed for use with multiple types of radiation used including linear accelerators, proton beam, and gamma knife. 