Acromegaly: Medical, Surgical and Radiological Treatments
Acromegaly is a rare endocrinal condition of increased level of growth hormone, the hormone responsible for the growth and regeneration of your body tissues and bones. In most cases, Acromegaly is caused by a non-cancerous benign tumor secreting growth hormone either in the pituitary gland or in other body organs such as the pancreas and lungs.
There are three main treatment options for Acromegaly: surgical, medical and radiation. Your doctor will choose the best option(s) for you according to your age and your tumor site and size. The aim of treatment is to restore your normal levels of growth hormone and IGF-1. This may make your swelling and enlargement of your body soft tissue to regress. But, your bone enlargement is irreversible; however, further growth of your bone will be prevented.
Cases of Acromegaly caused by extra-pituitary tumors are treated by special treatment plans according to the tumor site, and whether it is benign or cancerous.
Your doctor will discuss with you the best option(s) that suite(s) you best.
Medical treatment of Acromegaly is usually recommended when it is difficult to reach the pituitary tumor to surgically excise it, or you are at great risk of surgery complications. In other cases, surgery alone can’t restore your normal level of growth hormone. Therefore, your doctor may recommend taking the drugs that lower your growth hormone level after surgery. These medications include:
1. Somato-Statin Analogues (SSAs):
They are synthetic forms of your brain hormone Somato-Statin, a hormone that inhibits the production of growth hormone by the pituitary gland. They work as growth-hormone release-inhibiting hormones. They include Octreotide (Sandostatin, Sandostatin LAR) and Lanreotide (Somatuline Depot). They can restore your normal level of growth hormone and may even make the tumor shrink.
Before taking Octreotide, you should inject yourself under the skin with a short acting preparation of Octreotide to check if it causes any adverse effects and it is effective. If there are no side effects and it is tolerated, you can begin to receive long acting form of Octreotide which is injected intra-muscular in your buttocks (gluteal muscle) once every month. Lanreotide is also injected sub-cutaneous once every month.
Side effects of SSAs may include muscle cramps, diarrhea, and pain in the site of injection and gall-bladder problems.
2. Growth Hormone Receptors Antagonists (GHRAs):
They interfere with the action of growth hormone on body tissues by blocking its tissue receptors leading to decreased formation of IGF-1. But, the level of growth hormone remains high. They include Pegvisomant (Somavert), and are injected sub-cutaneous daily.
They may be associated with some side effects such as fatigue, headache, nausea and diarrhea.
3. Dopamine Agonists:
Dopamine agonists may reduce the tumor size and decrease the production of growth hormone. They include Cabergoline (Dostinex) and Bromocriptine (Parlodel) which can be administered as pills instead of injections. However, they are effective only in few cases. Sometimes, they are used in combination with SSAs.
Side effects of dopamine analogues include headache, nausea and intestinal cramps.
Surgical removal of pituitary tumors is one of the effective treatments available for Acromegaly. In this procedure, your surgeon will reach your pituitary gland to remove the tumor through a small incision made in the back wall of your nose where the sphenoid sinus presents. Therefore, it is named trans-sphenoidal surgery.
Trans-sphenoidal surgery is very complex and needs a highly-experienced surgeon to be performed. It is believed that the more experienced is your surgeon, the more successful outcomes. You should choose your surgeon carefully depending on the number of successful procedures performed.
Surgical removal of tumor can rapidly and significantly restore your normal level of growth hormone. In addition, it relieves the pressure applied on the surrounding tissue and structures, and hence makes your headache improve.
If your tumor has greatly enlarged or extended into the nearby blood vessels or other structures, your surgeon, despite of his/her experience, can’t remove it completely. And, your growth hormone level may remain high. So, you will have to continue other treatments such as radiation or medications.
Radiation treatment is usually recommended if there are tumor cells remaining after a surgery and the medications are unable to reduce your high growth hormone level. Radiation therapy can stop the growth of these tumor cells very rapidly; however, your growth hormone level may take some time to be reduced. And, your symptoms of Acromegaly may take up to many years till they begin to improve.
During radiation therapy, your doctor may recommend to continue to take medications to control your growth hormone level until the results appear.
There are two ways of radiation therapy:
1. Conventional Radiation Therapy:
This type of radiation uses the classic radiation to destroy the tumor. It is usually given in a certain day every week for at least 4 to 6 weeks.
The result of this type of radiation may take up to 10 years for the results to appear, and your growth hormone level decreases.
2. Stereotactic Radio-surgery:
Stereotactic Radio-surgery includes stereotactic delivery of high dose of precisely-focused and intense radiation beams from many directions to the tumor cells without damaging or affecting the surrounding normal tissues and structures by a Gamma-knife, which is a linear accelerator or a proton beam. Therefore, it is also called Gamma-knife surgery.
The tumor may be destroyed in a single session or multiple sessions, and your growth hormone may return back to its normal level within only 3 to 5 years.
Not every patient with Acromegaly is a candidate of these treatments. Some patients have their pituitary tumors near the optic chiasma, the point in your brain where the two optic nerves cross with each other. Gamma-knife surgery is contra-indicated in those patients. These treatments are also very advanced, and may not be available in many medical centers.
In general, after you have completed your treatment of Acromegaly, you should be checked-up regularly, and may be for the rest of your life, by your doctor to evaluate your symptoms’ improvement and monitor your growth hormone level.
Cancerous colon polyps are sometimes a complication of Acromegaly; your doctor may recommend you to have periodic colonoscopy, just for assurance.