Brain Tumors
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Brain tumours act very differently to cancers, they originate from one cell at a time and travel to other brain cells. They can arise either from the brain itself (primary brain tumors: astrocytoma, glioblastoma, oligodendroglioma, ependymoma), or its coverings (meningiomas, pituitary tumors, pineal tumors), or the nerves at the base of the brain (acoustic neuromas, schwannomas), or even from outside the brain (metastatic brain tumors). Tumours from outside of the brain occur when cancer cells get lodged in the brain when travelling through the bloodstream.
Important Points Regarding Primary Brain Tumours
However even today the treatment of brain tumours is extremely difficult because of the Blood: Brain barrier. This barrier is semi- permeable, meaning that it allows some material to cross (glucose), but prevents others from crossing (“foreign substances”).
To conclude the only therapies that could possibly cure primary brain tumours must:
Important Points Regarding Primary Brain Tumours
- Brain tumors are different!
- Brain tumors are not cancers.
- They do not travel beyond the brain but grow only in the brain itself.
- They don't metastasize (spread or grow to other parts of the body). Treatment to the brain should be limited due to its high risk.
- The whole brain is involved meaning even though the tumours seem to grow locally, tumour cells are always found beyond the tumour margins as they can travel around the brain, even to the opposite side of the brain.
- Benign tumours may be malignant by location - easy tumours in tough places.
- True tumour margins do not exist. Total removal by local therapy (surgery, radiation, heat, cold, etc.) is not possible.
- The brain is immunologically isolated.
- Many helpful treatments can not enter the brain via the bloodstream.
- Primary brain tumours are polyclonal meaning they are actually many tumours in one, in some cases over thousands.
- There is a different sensitivity/ resistance to anti-tumour treatments for each clone.
- Each clone has its own cell cycle time, doubling time, etc.
However even today the treatment of brain tumours is extremely difficult because of the Blood: Brain barrier. This barrier is semi- permeable, meaning that it allows some material to cross (glucose), but prevents others from crossing (“foreign substances”).
To conclude the only therapies that could possibly cure primary brain tumours must:
- Treat the whole brain
- Cross the Blood: Brain barrier
- Get to each and every tumour cell
- Kill all cell types within the tumour
- Spare the remaining normal brain.
Improvement in Neurosurgery
![Facilites](/uploads/1/0/3/6/10360216/4619983.jpg?413)
Over the past 40 years Brain surgery has become a true miracle due to these significant factors:
Simplicity is also many surgeons preference, this means avoiding the use of technology when possible in neurosurgery unless it simplifies the work. However certain technology allows the surgeon to minimize everything, making it possible to do all of the following, in a more complete and accurate manner:
When the brain is injured, it will most certainly swell. This swelling will cause parts of the brain to compress as it is encased within the skull. This compression decreases the blood flow and oxygen to the different parts of the brain which as a result will cause more swelling.
The main goal of a neurosurgeon is to break or diminish this cycle which can be achieved by removing any hematomas (blood clots) that are pressing on the brain. Following this the damaged blood vessels are surgically repaired to stop any further bleeding which as a result gives the brain more room, increases the blood flow and helps diminish the cycle of swelling and compression. In some severe case in which the brain is damaged beyond recovery, this portion of the brain can be completely removed to increase the chances of recovery for the healthy parts of the brain.
In neurosurgery devices such as the Intracranial Pressure monitor are used to measure the pressure within the brain, and the neurosurgeon is responsible for the insertion of this device. It allows the medical team to increase the pressure and also gives them the ability to intervene when dangerous levels are reached. A shunt or ventricular drain can be used to drain off excess fluids or surgical intervention may be called for.
- Improved technology - Anatomic visualization (CAT scan, spiral CAT scanning, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and digital angiography). These three dimensional recon-structions all use improved computers. The surgeon can predict and avoid problems prior to surgery.
- Better lighting is of great importance as there are countless possibilities of errors occurring during an operation. With current lighting technology, neurosurgery has been made easy, thus an increase in the success rate compared with neurosurgery in the mid 20th century.
- The operating microscope is a binocular microscope (adapted to the use of both eyes) used in surgery to view extremely small and inaccessible parts of the body clearly. This enables surgeons to see everything with outstanding clarity in three dimensions. Recognition of the vital structures is also of great importance, no matter how small they may be. The result showing a dramatic reduction in operative error.
- Coagulation instrumentation is an essential equipment that not just neurosurgeons but many other surgeons use in operation. It is a complex process by which blood forms clots. Bleeding has never really been a problem for brain surgeons. The need for blood transfusions has been almost eliminated, except for certain vascular lesions (e.g. brain aneurysms and certain rare tumours). The surgeon can stop bleeding reliably and relatively easily with such instruments whilst assuring no damage to the surrounding brain.
- Intraoperative guidance systems guide the surgeons in mid-operation. Stereotactic guidance systems (involving surface markers or "frames," computers, etc.), three dimensional computer-assisted guidance systems (infrared lights, lasers, mechanical arms, radio telemetry) and computer guided mechanical arms are all available to today’s neurosurgeons.
Simplicity is also many surgeons preference, this means avoiding the use of technology when possible in neurosurgery unless it simplifies the work. However certain technology allows the surgeon to minimize everything, making it possible to do all of the following, in a more complete and accurate manner:
- Shorten the operation time. In the past surgical operations used to take 12 hours, now routinely take 1-2 hours and with better results!
- Sparing the normal brain. The risk of brain surgery has been greatly reduced and patients seldom wake up with neurologic problems. With today’s advanced technology “exploratory” surgeons no longer exist.
- Perform a better job. In the past removal of primary brain tumours and vascular lesions with preservation of surrounding eloquent brain (parts of the brain that control speech, motor functions, and senses, localization of which is important in treating brain tumours) was only a dream, now a reality, with 90-99% removals being successful.
- Improve the patient’s outcome. Risks are now dramatically reduced, and it is not uncommon for patients to leave the hospital two days after their surgery. Furthermore brain surgery no longer has to be traumatic; it is the most successful tool in the treatment of brain disease.
When the brain is injured, it will most certainly swell. This swelling will cause parts of the brain to compress as it is encased within the skull. This compression decreases the blood flow and oxygen to the different parts of the brain which as a result will cause more swelling.
The main goal of a neurosurgeon is to break or diminish this cycle which can be achieved by removing any hematomas (blood clots) that are pressing on the brain. Following this the damaged blood vessels are surgically repaired to stop any further bleeding which as a result gives the brain more room, increases the blood flow and helps diminish the cycle of swelling and compression. In some severe case in which the brain is damaged beyond recovery, this portion of the brain can be completely removed to increase the chances of recovery for the healthy parts of the brain.
In neurosurgery devices such as the Intracranial Pressure monitor are used to measure the pressure within the brain, and the neurosurgeon is responsible for the insertion of this device. It allows the medical team to increase the pressure and also gives them the ability to intervene when dangerous levels are reached. A shunt or ventricular drain can be used to drain off excess fluids or surgical intervention may be called for.
Watch this video about the removal of a brain tumor with high tech equipment at the UCLA medical center.
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Milad Rouf
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