What is radiation oncology?

Radiation oncology is a medical specialty focused on the treatment of cancer using radiation therapy to control or kill malignant cancer cells. Radiation therapy can stop tumors from growing by damaging the DNA in cancer cells, preventing them from dividing. As the cancer cells die off, some tumors can actually shrink and even be eliminated with radiation therapy. Radiation is often used in conjunction with surgery and chemotherapy to treat many types of cancer.

At Sonora Regional Cancer Center, we utilize Intensity Modulated Radiation Therapy (IMRT) which targets cancer cells while limiting radiation to important normal tissues. The machine used to deliver the radiation, called a linear accelerator, uses a very narrow X-ray beam (smaller than the point of a pencil) to send strong doses of radiation to the tumor while avoiding surrounding, healthy tissues. The very small beams or beamlets can be aimed at a tumor from many angles with exact precision. The intensity of each beamlet can be controlled and the radiation dose can be made to bend around important normal tissues.

Patients undergoing radiation therapy usually require daily treatments over the course of several weeks. For each treatment, the patient is carefully positioned so that the beamlets can be aimed precisely at the tumor. Depending on the location of the tumor, some patients may require a mask or other bracing to hold them still and in the exact same position for each treatment.

Radiation therapy is provided by a team of highly trained professionals including a radiation oncologist, a physician who examines the patient, assesses the size and position of the tumor, and plans and oversees the course of treatment; a medical physicist, who makes sure that the linear accelerator is calibrated and that the machine will deliver the precise dose; a dosimetrist, who calculates the intensities and angles of the beamlets to deliver the exact dose prescribed by the physician; a radiation therapist, who operates the machine during treatment; and a radiation therapy nurse who monitors the patient during treatment and provides patient education and support.