Colon Cancer Treatments Radiotherapy

Radiation therapy is a localized treatment that uses high-energy x-rays to shrink tumors and kill cancer cells.

Although radiotherapy is not as common in colorectal cancer (CRC) as in other types of malignancies, it is often used to treat patients whose malignancy has not spread beyond the rectum. Use of radiotherapy for colon cancer remains controversial among medical professionals because of the possible risk of permanent damage to the small bowel and nearby organs.

Radiation therapy may be used to shrink a rectal tumor before surgery, so that the malignant tissue is easier to remove. Alternatively, it is often used after surgery to destroy any remaining cancerous cells and to minimize the risk of recurrence. Radiotherapy is also effective for relieving the distressing symptoms and side effects of the disease, such as localized pain and fatigue.

Types of Radiation Therapy

Several different types of radiation are used to treat cancer of the rectum. Variations include x-rays and electron, proton, or neutron beams. A variety of methods are available for administering the therapy.

For instance, narrow x-ray beams may be delivered from a machine directly on to the diseased area. This method, called external radiation, is the most common form of radiotherapy used for rectal cancer.

In another technique, internal radiation (sometimes called brachytherapy), small implants of radioactive material are inserted directly into or near the malignant tumor. This technique can be used for rectal cancer, but not in the colon. This method is sometimes referred to as interstitial radiotherapy, and the radioactive implants are commonly called “seeds”.

Radioimmunotherapy is a similar technique that involves injecting radioisotopes into a vein. The radioisotopes are attached to a “carrier” that targets the tumor but not the healthy surrounding tissue. However, the use of radioimmunotherapy to treat CRC malignancies is still at the clinical trial stage. Further studies are required.

Endocavitary radiation therapy emits short wavelength radiation using a small wand inserted in the rectum. This technique is currently not widely available because it requires expensive, specialized equipment.

All these techniques are used for treating cancer of the rectum. Sometimes patients are given a combination of external and internal radiation therapies.

Palliative Care

Palliative radiotherapy is sometimes used to treat incurable CRC. Although radiotherapy at this advanced stage is unlikely to offer a cure, it is nevertheless able to slow down the cancer development and relieve symptoms and side effects of the disease, such as fatigue and rectal pain.

Palliative care is usually administered in the hospital radiotherapy department, in five short daily sessions per week and can significantly reduce the symptoms and unpleasant side effects associated with terminal colorectal cancer.