Treatment involves lowering your production of GH, as well as reducing
the negative effects of the tumor on the pituitary and surrounding
tissues. Often, you'll need more than one type of treatment:
Surgery
Surgery is commonly the first treatment option. Most pituitary tumors
can be removed by a method called transsphenoidal surgery. While
under general anesthesia, the surgeon works through your nose to extract
the pituitary tumor. With smaller tumors, the procedure successfully
eliminates the entire tumor and normalizes GH production in up to 90
percent of people. With larger tumors, there is a lower likelihood of
removing the entire tumor, and many people may have elevated GH levels
after surgery, requiring further medical or radiation treatments.
Removing the tumor, even partially, can eliminate the pressure on the
tissues surrounding your pituitary to relieve associated symptoms.
Medications
Drugs used to lower the production or block the action of GH include:
-
Octreotide (Sandostatin).
This drug can interfere with the excessive secretion of GH by the
pituitary, and thus can produce rapid declines in GH levels. When
starting on octreotide, you initially inject yourself with a
short-acting preparation under your skin (subcutaneously) three
times a day to determine if you have any side effects from the
medication and if it's effective. Then, you may be able to take a
long-acting form that requires an injection into the muscles of your
buttocks (gluteal muscles) by your doctor and administered once a
month. Side effects of octreotide may include diarrhea, bloating,
cramping and nausea.
-
Cabergoline (Dostinex)
or bromocriptine (Parlodel).
These medications, called dopamine agonists, are taken as pills, and
in some people, they can lower levels of GH and IGF-I by reducing
the size of pituitary tumors.
-
Pegvisomant (Somavert).
This medication, a growth hormone antagonist, received Food and Drug
Administration approval in April 2003. It acts to block the effect
of GH on body tissues. You administer this medication yourself daily
by injection.
Radiation
Your doctor may recommend radiation treatment when tumor cells remain
after surgery. Radiation therapy destroys any lingering tumor cells, and
reduces GH levels. It is given in one of two ways:
-
Conventional
"fractionated" radiation therapy.
This type of radiation therapy is usually given daily over a period
of 4 to 6 weeks.
-
Stereotactic
radiosurgery.
Also known as gamma knife radiation therapy, stereotactic
radiosurgery can deliver a high dose of radiation to the tumor cells
in a single dose while limiting the amount of radiation to the
normal surrounding tissues.
The type of radiation therapy recommended depends on the size and
location of the remaining tumor cells.
Even after initial treatment, acromegaly requires periodic monitoring by
your doctor to make sure that your pituitary is functioning properly.
This follow-up care may last for the rest of your life.