First know about radiotherapy
The goal of radiation therapy is to destroy or stop the growth of brain tumors. Most importantly, radiotherapy is the main stay of treatment of brain tumors after surgery. The radiation may be used after a biopsy, or following a partial or complete removal of brain tumor. However, when a tumor is removed, some microscopic tumor cells may remain.
What is Stereotactic Radiation (SRt)?
Delivered by several other devices like Cyberknife, Gamma Knife, Novalis, Primatom, X-Knife, Clinac IX, Synergy, TomoTherpy or Triology, it is a specialized type of external beam radiotherapy that targets very precisely at the tumor. This technique is suitable only for small and well defined tumors. The advantage of this radiotherapy is that it delivers the right amount of radiation to the cancer in a shorter amount of time than traditional treatments. Detailed imaging, computerized three dimensional treatment planning and precise treatment to deliver the radiation dose with extreme accuracy (i.e. stereotactically) is used for the treatment. A customized holder mask may be used to keep the body perfectly still during the treatment, or the treatment machine may have the ability to adjust the patient motion such as during breathing.
Few similarities between these treatments:
- Use multiple radiation beamlets
- Target small, well defined area with precision
- Use immobilization devices that limit, monitor or adjust for any movement during treatment
- Give high doses of radiation safely and accurately over just a few fractions
Differences between these treatments:
- Different capabilities: Some stereotactic systems can treat only tumors in the head, others in the head and neck and other elsewhere in the body.
- Different schedules: Some stereotactic treatments may be best given in single session, others may be given over several days
- Different ways to achieve accuracy: Different systems use different ways to keep patients in the correct position. Some use customized holders that keep the patient immobile, and others have the machine track any movement of the patient.
Who are the Right Candidates?
All patients do not get benefitted by this treatment. The right candidates for this treatment are those having small and few tumors or:
- Secondary brain tumours
- Reirradiation of gliomas
- Small low grade brain tumours
It is also used for a number of benign (non cancerous) brain tumours such as:
- Vestibular schwannomas
- Meningiomas growing in the base of the skull
- Pituitary adenomas
What are the Side effects of Radiotherapy?
Stereotactic radiotherapy treatment has fewer side effects than the usual type of radiotherapy, mainly because the area being treated is smaller and less healthy brain tissue is exposed to radiation. There are less chances to have hair loss, feel sick, or have any reddening of skin.