Ehsan Saraee, MD

The spread of malignant cells from the place where it was origined to another part of the body is called metastasis. In metastasis, malignant (cancerous) cells break away from the primary tumor, travel through the blood or lymphatic system, and form a new tumor in other organs or tissues of the body. Metastatic tumor is of the same histologic type as the primary tumor. For example, if breast cancer spreads to the lung, the cancer cells that develop in the lung are the same type of breast cancer cells, not the original lung cancer cells. When these cancer cells have limited spread to the brain, there are generally two treatment methods available to physicians. In one of these methods, the patient's entire brain will be irradiated and the malignant cells will be treated wherever they are located in the brain. Among the most important side effects of this treatment method, we can mention memory disorder and patient dysfunction. In patients whose number and volume of brain metastatic lesions are limited, radiosurgery technique using Gamma Knife can be used for their treatment. Among the most important advantages of treating patients with this method, we can point out the very low side effects of the treatment, the possibility of repeating the treatment in new lesions, and the very low dose of radiation for healthy brain tissue. Compared to the stereotactic treatment using the Cyberknife device, the Gamma Knife Icon device has much higher accuracy and much fewer side effects. Also, after using the Gamma Knife device, the radiation dose to healthy brain tissue is much lower than other methods.

It is one of the most common brain lesions that make up many patients in neurosurgery and radiotherapy departments. One of the most important symptoms of this disease in the early stages is hearing loss. This hearing loss has different degrees in different patients, from very little hearing loss to complete deafness. Vestibular schwannoma or acoustic neuroma is a disease resulting from involvement of the auditory nerve after exiting the brain stem. Simply put, this nerve transmits messages related to hearing and balance to the brain, that's why the involvement of this nerve will cause hearing loss and balance disorder. This lesion does not grow fast by itself, but its proximity to sensitive areas of the brain requires more attention to this lesion. One of the most important organs that is next to this lesion and may be involved in the advanced stages of this disease is the brain stem. Pressure on the brain stem will disrupt several brain mechanisms. The next complication observed in this lesion is paralysis of the facial nerve, which causes many complications for patients (dry eyes, masking of the face). In general, there are three ways to deal with this disease: The first method - Follow-up: One of the treatment methods is to follow up patients whose lesion has a very low growth rate and the size of the lesion is very small. The second method - Gamma Knife Radiosurgery: one of the most accurate treatment methods in all parts of the world is treatment with stereotactic techniques with Gamma Knife device. In this treatment method, the tumor is targeted by gamma rays from dozens of different angles, a high dose of gamma rays is irradiated on it, and its growth is stopped in a high percentage of patients. The success rate of this treatment method in 10 years of follow-up is 95%, which is equivalent to surgery, with the difference that it will have much less complications than surgery. Among the most important complications of surgery, facial nerve paralysis (in 20% of cases) and severe hearing loss (in 30% of cases) can be mentioned. But in the treatment with Gamma Knife, these side effects are 1 to 2% of facial nerve damage (returning to normal in 50% of cases) and about 10 to 20% complete hearing loss. The third method - lesion surgery: in this treatment method, all parts of the lesion are removed, but there is a high probability of complications of facial nerve paralysis or balance disorder in these patients. It should be noted that the decision to use each of the mentioned methods will be made according to the characteristics of the lesion.

Meningioma is a type of tumor that develops in the meninges, which are the protective membranes of the brain and spinal cord. These tumors are usually slow-growing and usually non-cancerous, although in rare cases they can be malignant. The exact cause of meningioma is unknown, but it is more commonly diagnosed in older people, especially women. Common symptoms of brain meningioma include headache, seizures, changes in vision or hearing, weakness or numbness in limbs, and cognitive problems. Meningioma treatment options depend on various factors, including tumor size, location, and overall health of the patient. Surgical removal is often the primary treatment, but conventional radiotherapy, Gamma Knife, or targeted drug therapy may also be used to slowen tumor growth. Regular follow-up to monitor tumor progression and ensure early detection of any possible recurrence is of utmost importance in these patients. With proper medical care and support, many patients with cerebral meningioma can lead normal lives.

The pituitary gland is one of the most important secretory glands in the body that controls hormones in your body that have various functions such as stress response, metabolism, growth and sexual function. Pituitary gland tumors can cause a variety of problems. Radiosurgery of the pituitary gland can be used to shrink tumors in this area and reduce hormone regulation disorders.

AVMs are abnormal formations of arteries and veins in your brain. In an AVM, blood flows directly from the arteries into the veins, bypassing smaller blood vessels (capillaries). Over time, AVMs may disrupt normal blood flow and lead to brain hemorrhage or stroke. Stereotactic radiosurgery causes damaged blood vessels to close over time. Of course, it is necessary to mention that in order to observe the treatment response to radiosurgery in AVM patients, a longer period of time is needed compared to angioembolization treatments (injection of blocking substance into the lesion).

Trigeminal Neuralgia is a chronic pain disorder in branches of the trigeminal nerve, which transmits sensory information between the brain and the forehead, cheek, and lower jaw regions. This nerve disorder causes severe pain in the face, which is similar to the application of electric shocks in these areas at time intervals but continuously. Stereotactic radiosurgery treatment for trigeminal neuralgia targets the nerve root to disrupt these pain signals. It should be noted that the selection of patients for Gamma Knife treatment is highly dependent on their response to previous treatments. Somehow, this treatment method is not usually used in the first line of treatment for trigeminal neuralgia patients.