Stereotactic radiosurgery is a non-invasive procedure that applies focused therapeutic radiation to brain tumors, cancers in various parts of the body, blood vessel malformations, and even some nervous conditions. Unlike its conventional counterpart, SRS is considered unconventional surgery as it does not require incisions. With 3D imaging, high doses of radiation are delivered to small areas to damage the DNA of affected cells, making tumors shrivel. Typically, SRS of the brain and spine are completed in a single session.
Scientific name: Stereotactic Radiosurgery
SRS applied to body tumors: Stereotactic Body Radiotherapy (SBRT)
Brain, nervous system, blood vessels, lungs and other body parts.
How is it Performed?
Stereotactic radiosurgery takes place in four phases:
- Head frame placement
- Tumor location imaging
- Computerized dose planning
- Radiation delivery
The surgery is broadly divided into three types:
Gamma Knife Radiosurgery
In the first phase, medication is administered to the patient and contrast (if required) for imaging. The head frame is attached to the patient's skull to restrict movement and guide the Gamma knife beams to the affected portion.
An MRI or CT scan is taken to study the tumor's exact location in relation to the head frame. This helps minimize damage to the surrounding cells as well. This process can be done a day before to improve the efficiency of the treatment.
The patient can relax for an hour or two in the next phase. The specialized team identifies the tumor(s) to be treated and develops a treatment plan using special computer software.
After this, the treatment team steps into the control area to begin the patient's treatment. The patient will be able to converse with the physician the entire time and be seen by the treatment team.
The machine is quiet, and the patient does not feel anything during this time. Based on the machine model and the treatment plan, the procedure may be continuous or broken into smaller parts, concluding in less than an hour or up to four hours.
Linear Accelerator Radiosurgery (LINAC)
The four phases of this surgery are the same, but LINAC technology is more common. The head frame is optional as well.
While the Gamma Knife remains unmoving, the gantry of the LINAC machine rotates around the patient to deliver the planned radiation beams from different angles.
Cyber Knife (Robotic Arm with LINAC)
The four phases of this surgery are the same. The treatment is done with or without frame or mask. The LINAC machine situated on Robotic Arm moves around patient to deliver therapy.
A CT scan or MRI is often ordered before the procedure as per the patient treatment plan. Structuring the treatment plan and studying the scans to understand the location and size of the tumor are all part of the pre-planning process.
Devices or implants such as pacemakers, stents, implanted pumps, artificial heart valves, and any medication being taken by the patient must be brought to the physician's attention.
Before the surgery, the patient needs to keep the following points in mind:
- Food must not be consumed after midnight, the day before the surgery.
- Patients should remove their makeup and jewelry and avoid hair products such as hair spray and mousse.
- Patients must remove their sunglasses, contact lenses, and dentures before treatment.
Once the procedure is complete, the head frame (if used) will be removed. The patient may experience minor bleeding or tenderness at the pin sites. There is no cause for worry unless the pain becomes unbearable. If the patient experiences any headache, nausea, or vomiting, medications are administered.
The patient is then moved to the recovery area, where they will be kept under observation until the treatment team is convinced that the patient is well and can be discharged. Since the procedure is an outpatient surgery, if the patient shows no side effects, they can often leave the same day.
Side effects of stereotactic radiosurgery are usually temporary. These may include -
- Scalp and hair problems
- Red, peeling, or blistering skin
- Gastrointestinal indicators such as vomiting, diarrhea, and nausea
- Neurological symptoms such as headaches, seizures, numbness or tingling, and even weakness
- Difficulty swallowing
Rarely do side effects such as brain or neurological problems occur. Radiation may slightly increase the risk of cancer as well.
Once the patient is home, they can resume their normal activities in no time. During follow-up sessions, the neurology and neurosurgery team will monitor the patient's progress from their MRI and CT scans. Therapy typically only requires a single treatment. However, if some lesions persist, they may need more than one treatment session and will likely finish within five.
Some conventional radiation therapies can need up to ten sessions, depending on the nature of the diagnosis and treatment plan. Cancer patients should regularly visit their radiation oncologists to test for recurring or new cancers. Often, patients see a steady decline in tumor size over 18-24 months.