Radiation Therapy

Radiation therapy uses high-energy radiation to shrink tumors and kill cancer cells. Physicians have been treating patients with radiation therapy safely and effectively for more than 100 years. Estimates are that nearly two-thirds of patients with cancer are treated with radiation during their illness and also to prevent relapse.

Methods Of Radiation Therapy

External Radiation

External Radiation

External beam radiation therapy uses a high-energy x-ray machine — called a linear accelerator (linac) — to direct radiation to the tumor. It is a cancer treatment modality that uses doses of radiation to destroy cancerous cells and shrink tumors. The procedures include 3D conformal radiation therapy, IMRT, IGRT, rapidArc (VMAT) and Stereotactic Body Radiation Theraphy (SBRT). The procedure lasts a few minutes, and is typically repeated five times a week for 4-6 weeks.

Steps on
External Radiation

  1. Initial Consultation
  2. Informed Consent Process
  3. Immobilization devices and CT simulation
  4. Marking
  5. Technical Planning Process
  6. Set-Up
  7. Daily Treatment
  8. On Treatment Examination
  9. End-of-Treatment visit
  10. Follow-up care
External Radiation


Internal radiation is also called as brachytherapy. It is a procedure where the radioactive “seeds” are carefully placed inside the cancerous tissue and positioned in a manner that will kill most cancer cells and has now been in use for over a century. This procedure allows doctors to deliver higher doses of radiation to more-specific areas of the body, compared with the conventional form of radiation therapy (external beam radiation) that projects radiation from a machine outside the body. Brachytherapy is an outpatient procedure. Brachytherapy may cause fewer side effects than does external beam radiation, and the overall treatment time is usually shorter.