Treatment focuses on lowering your production of GH, as well as reducing the negative effects of the tumor on the pituitary gland and surrounding tissues. You may need more than one type of treatment.
Doctors can remove most pituitary tumors using a method called transsphenoidal surgery. In this procedure, your surgeon works through your nose to extract the pituitary tumor.
Removing the tumor can normalize GH production and eliminate the pressure on the tissues surrounding your pituitary gland to relieve associated signs and symptoms. In some cases, your surgeon may not be able to remove the entire tumor. This may result in persistently elevated GH levels after surgery, requiring further medical or radiation treatments.
Drugs used to lower the production or block the action of GH include:
- Drugs that reduce excess growth hormone secretion (somatostatin analogues). The drugs octreotide (Sandostatin) and lanreotide (Somatuline Depot) are synthetic versions of the brain hormone somatostatin. They can interfere with the excessive secretion of GH by the pituitary gland, causing rapid declines in GH levels. These drugs are given by injection into the muscles of your buttocks (gluteal muscles) once a month by a health care professional.
- Drugs to lower hormone levels (dopamine agonists). The oral medications cabergoline and bromocriptine (Parlodel) lower levels of GH and IGF-I in some people. The tumor may decrease in size in some people taking a dopamine agonist. Some people may develop compulsive behaviors, such as gambling, while taking these medications.
- Drug to block the action of GH (growth hormone antagonist). The medication pegvisomant (Somavert) blocks the effect of GH on body tissues. Pegvisomant may be particularly helpful for people who haven't had good success with other forms of treatment. Given as a daily injection, this medication can normalize IGF-I levels and relieve symptoms in most people with acromegaly, but it doesn't lower GH levels or reduce the tumor size.
Your doctor may recommend radiation treatment when tumor cells remain after surgery. Radiation therapy destroys any lingering tumor cells and slowly reduces GH levels. It may take years for this treatment to noticeably improve acromegaly symptoms.
Types of radiation therapy include:
- Conventional radiation therapy. This type of radiation therapy is usually given every weekday over a period of four to six weeks. You may not realize the full effect of conventional radiation therapy for 10 or more years after treatment.
- Proton beam therapy. Proton beam therapy delivers a targeted, high dose of radiation to the tumor, sparing radiation exposure to normal tissues. Proton beam therapy is provided in fractions over time, but treatment times are generally less than conventional radiation.
- Stereotactic radiosurgery. Stereotactic radiosurgery delivers a high dose of radiation to tumor cells in a single dose while limiting the amount of radiation to normal surrounding tissues. This type of radiation may bring GH levels back to normal within five years.
Even after initial treatment, acromegaly requires periodic monitoring by your doctor to make sure that your pituitary gland is functioning properly, which will help you avoid complications. This follow-up care may last for the rest of your life.