Radiation Therapy is a form of therapy where ionizing radiation is used to treat or control cancer cells and it is normally delivered by a linear accelerator. It is a type of cancer treatment where beams of high energy are used to kill cancer cells. It most often uses X-rays which is produced in Linear accelerator. The high energy beams damages cells by destroying its genetic material that controls cell growth and cell division. Usually, the treatment is given in 3 to 6 weeks depending upon the tumor and stage.
Stereotactic Radiotherapy is a technique of targeting tumors very precisely with the help of special positioning /immobilization devices with high dose of radiation in comparison to the normal conventional radiation therapy treatment. Usually, it is finished with one to five radiations fractions over a period of one week.
Radiosurgery is limited to the head and neck area only as this anatomical region can have strict immobilization, permitting the most precise and accurate treatment dose delivery. Radio surgery administers a very high dose of radiation and is not used to treat other areas of the body because there is no way to immobilize those parts of body. In contrast stereotactic radiotherapy, which administers a lower dose of radiation per treatment session and total treatment period stretches for days to weeks. This is with the help of removable masks and frames which achieves immobilization to a lesser degree.
SRS is mostly used for brain tumors for both cancerous and non-cancerous disease as well as tumors of other sites like lung, liver, prostate, pancreas etc. it is also useful for small size recurrences in bones and head and neck areas. Early results suggest that SRS/SBRT is as effective as, or more effective than standard radiation therapy – especially for early-stage lung cancer, gastrointestinal tumors such as pancreatic tumors, and liver tumors. Although the effects of SRS/SBRT on tumor tissue can be seen a few weeks after the procedure, it may take up to two years to see the effects of SRS on an AVM like benign tumors.
Common Brain Tumors
- Metastatic brain tumors
- Vestibular schwannoma
- Pituitary gland tumor
- Metastatic spine and bone tumors
Dr. Kanhu Charan Patro,
Chief Radiation Oncologist,
Mahatma Gandhi Cancer Hospital and Research Institute, Visakhapatnam