Radiation therapy (also called radiotherapy) is not commonly used to treat chronic lymphocytic leukemia (CLL), but it can be used to relieve pain caused by a swollen lymph node, spleen or other enlarged masses that result from CLL.
The therapy destroys cancer cells using high-energy rays, such as X-rays. As a result, the enlarged organs reduce in size. Although the radiotherapy is directed at cancer cells, it can also damage healthy cells near the cancer cells. Radiation therapy is generally a painless treatment.