Colorectal Cancer Program

Radiation Oncology

The clinical experts in St. Joseph Hospital’s Radiation Oncology department work with your physicians and other healthcare providers in a multidisciplinary approach to provide comprehensive treatment.

Radiation therapy uses high-energy X-rays to kill cancer cells. Side effects vary depending on the area of the body treated, and can be minimized using technological advances available at St. Joseph Hospital. These innovations include 3-dimensional CT-guided treatment planning, intensity-modulated radiation therapy (IMRT), and image-guided radiation therapy (IGRT)---all of which help reduce radiation dose to normal cells and ensure tumor cells are targeted. Most people receive radiation treatments once a day, five days a week. Treatment lasts for 2-10 weeks, depending on the type of cancer and goals of treatment.

In colorectal cancer, radiation is usually combined with chemotherapy, and may be recommended before surgery, after surgery, or to reduce symptoms if surgery is not possible:

  • Radiation before surgery (neoadjuvant therapy) – May be used to shrink the tumor and make a smaller surgery possible. This is often done in rectal cancer to preserve the anal sphincter and decrease the possibility of a permanent colostomy after surgery.
  • Radiation after surgery (adjuvant) – May be used to kill microscopic tumor cells that are left after surgery and reduce the risk of cancer recurrence.
  • Radiation to reduce symptoms (palliative) – May be recommended to treat pain, bleeding or bowel obstruction due to tumor.