Dr. Swarupa Mitra Consultant, radiation Oncology. Rajiv Gandhi Cancer hospital and research Institute. Rohini. New DelhiRead more
Radiation therapy or radiotherapy, also called radiation oncology, is the use of ionizing radiation as part of cancer treatment to destroy malignant cells.
Most common cancers can be treated with radiotherapy in some way. The precise treatment intent may be curative, or palliative, adjuvant, or neoadjuvant depending on the tumour type, location, and stage, as well as the general health of the patient.
The radiation fields may include the gross tumor, the draining lymph nodes if they are clinically or radiologically involved with tumour, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumour to allow for uncertainties in daily set-up and internal tumor motion caused by respiration or rectal or bladder filling.
To spare normal tissues, radiation beams are shaped and aimed from several angles of exposure to intersect at the tumour, providing a much larger absorbed dose there than in the surrounding, healthy tissues