Radiation therapy works by directing high-energy beams at cancer cells. These beams damage the DNA of the cells, preventing them from dividing and multiplying. Thus, it effectively halts tumor growth.
Radiation therapy, when used in conjunction with surgery, can be used before, during, and after surgery. For tumor cells that are beyond the reach of surgery, radiation can neutralize them.
Since sarcomas can spread along muscles and between them usually without associated symptoms, radiation targets a perimeter of tissue that surrounds the tumor. Microscopically, sarcoma cells are discrete, but they can trickle out deceptively and remain after surgery.
Beyond targeting visible tumors, radiation therapy can also be beneficial in eliminating microscopic cancer cells that may linger in the area surrounding the tumor - also known as the tumor bed. These microscopic cells can be difficult to remove completely with surgery alone, and radiation therapy can help address this concern.
However, further away from the tumor site, the likelihood of sarcoma cells is lower. Radiation oncologists typically irradiate tissue 5 to 10 centimeters (approximately two inches) beyond the tumor site.