Gamma Knife radiosurgery is a technique that uses intracranial stereotactic radiosurgery. It may be helpful in treating primary brain tumors, such as pituitary adenoma.  

What is Gamma Knife radiosurgery for pituitary adenoma?

Pituitary adenomas are benign tumors that arise from the pituitary , which is the gland located at the base of the skull that controls all hormonal secretions of the body, thus regulating the thyroid, adrenal glands, gonads, growth, eyesight, thirst, and the secretion of milk in the puerperium. The symptoms may be related to hormonal disorders or compression of the optic chiasm, with narrowing and blurring of vision.

How is Gamma Knife radiosurgery for pituitary adenoma performed?

The patient is lightly sedated and then given a local anesthesia, where the stereotactic frame is placed to subject the patient to imaging tests (brain MRI with gadolinium, brain CT scans). The images will allow the specialist to plan for the most proper form of treatment. Once decided upon, the patient will lay with a stereotactic frame fixed onto the Gamma Knife bed. The treatment can last from one to six hours, depending on the needs of the patient and the target area for radiation.

What are the advantages to undergoing Gamma Knife radiosurgery for pituitary adenoma?

Gamma Knife radiosurgery is a minimally invasive procedure , done in a single session and free of pain and surgical incisions. The procedure is almost always done on an outpatient basis and the patient is usually discharged the very same day.  

Is Gamma Knife radiosurgery for pituitary adenoma painful and / or dangerous?

The procedure is not painful, though the patient may feel pain during positioning of the four small metal pins to stabilize the helmet. During the actual treatment, the patient will undergo subtle movements of the head, though they will not experience any pain or noises. The risks associated with this procedure may be pituitary deficits with the need to undergo replacement therapy, such as deregulation affecting thirst and worsening visual disturbances. 

Which patients can undergo this procedure? 

The primary treatment of pituitary adenoma is surgery, except for in special cases. Often, adenomas are not completely removable due to the proximity with important structures (carotid arteries, cranial nerves) in which case patients with a residual tumor are candidates for treatment with Gamma Knife.


The results of the procedure are not immediate . The patient will be informed of any additional examinations that need to be carried out during discharge.  The radiation effect can take effect after weeks and / or months. Sometimes, Gamma Knife treatment may not be enough; the tumor may continue to grow and cause symptoms, both immediately after treatment  and last for a longer period of time. Further treatment may be necessary, such as Gamma Knife combined with surgery or fractional radiotherapy.

What steps should be taken to help prepare for this procedure?

A few days before undergoing the procedure, the patient will travel to Humanitas for pre-admission and will be subjected to a blood test, an electrocardiogram (ECG), an eye examination and a medical examination for a complete compilation of medical records. It is important that the patient announce any allergies to medications or contrast agents, or claustrophobia. On the day of the procedure, the patient should be accompanied by a family member or an acquaintance and should have been fasting from midnight the night before. On the night before the procedure, the patient should cleanse themselves with a product-based disinfectant shampoo, such as chlorhexidine. It is best to avoid wearing any jewelry: brooches, hairpins, makeup, hair products, and artificial nails; but rather wear comfortable clothing and footwear, preferably with buttons or zippers.