This week's artwork was donated by a pediatric cancer patient who received treatment at The Children's Hospital of Philadelphia . Doctors have traditionally used x-rays as a tool for painlessly visualizing the inside of the human body. The radiation used to treat cancer is given in doses many times higher than those delivered by x-rays. This application of high-energy radiation has had a profound positive effect on cancer survival. Normal cells divide and replace themselves in an orderly process, keeping the body healthy and repairing structures as needed.
Cancer occurs when cells lose the ability to control their own growth.
Radiation therapy works by damaging the cancer cells' DNA, the genetic information that is vital for reproduction. Once the DNA has been damaged, the cancer cells are not able to divide and grow, causing the tumor to shrink. Cells that are growing and multiplying rapidly are especially sensitive to the effects of radiation. Radiation therapy treatments are designed to destroy the cancer cells while limiting the amount of normal tissue exposed and injured by the rays. Special shields may be used to protect parts of the body that do not require treatment.