High energy rays are used in radiation therapy to stop cancer cells from growing and dividing.
Radiation therapy is used to treat cancer because cancer cells grow and divide more rapidly than normal cells around them.
Radiation therapy for breast cancer:
Radiation therapy is used to destroy breast cancer cells which are remaining after the surgery in the chest wall, breast, or axilla area.
Sometimes, the therapy is used before surgery to shrink the tumor size. If your breast cancer is in early stage, breast conserving therapy (BCT) is used.
Breast lump (lumpectomy) and surrounding margin of normal breast tissue are surgically removed with breast conserving therapy. Radiation therapy is given for at least six to seven weeks after BCT.
Radiation treatment begins one month after surgery because the breast tissue need time to heal. Radiation therapy is also recommended for women after mastectomy to destroy remaining cancer cells.
Radiation therapy for prostate cancer:
Radiation therapy is used as an initial treatment for prostate cancer.
External beam radiation therapy: The tumor cells are located with the help of CT scans and MRIs and x-rays are targeted on those areas. Prostate tumors are located exactly with 3D conformal radiotherapy so that the highest radiation dose can reach the cancer cells within the gland.
Intensity modulated radiation therapy: This therapy allows the oncologist to change or modulate the dosage and radiation beam intensity to better target the radiation delivered to the prostate. At the same time, low doses are delivered to the tumor cells which are immediately adjacent to the rectal tissue and bladder.
Brachytherapy: In brachytherapy, tiny little metal pellets that contain radioactive iodine or palladium are inserted into the prostate via needles which enter through the skin behind the testicles. To ensure that the seeds are placed in correct locations, careful and precise maps are used.
In several months period, the radiation is given by the seeds to the immediate surrounding area to kill the prostate cancer cells.
Radiation therapy for skin cancer:
External beam radiation therapy focuses radiation on the skin tumor from outside the body. Radiation is used as the primary treatment if the tumor is large or located in such an area of the skin that makes surgery difficult.
This therapy treats small melanoma skin cancers and can delay the more advanced cancer growths. After the surgery, if there are any small deposits of remaining cancer cells, radiation can be used. Therefore, it reduces the coming back of cancer risk after surgery. For Merkel cell carcinoma, radiation therapy is used in combination with other therapies.
If non-melanoma skin cancer has spread to lymph nodes or other organs, radiation therapy helps to treat it.