South Sacramento Cancer Center

Linear Accelerator

The South Sacramento Cancer Center is equipped with a state of the art fully digital Varian 21iX linear accelerator with Multileaf collimation and portal imaging. The center has full Intensity-modulated radiation therapy (IMRT) capability. IMRT is an advanced mode of high-precision radiotherapy that utilizes computer-controlled x-ray accelerators to deliver precise radiation doses to a malignant tumor or specific areas within the tumor. The radiation dose is designed to conform to the three-dimensional (3-D) shape of the tumor by modulating—or controlling—the intensity of the radiation beam to focus a higher radiation dose to the tumor while minimizing radiation exposure of surrounding normal tissues. Treatment is carefully planned using 3-D CT images of the patient in conjunction with computerized dose calculations to determine the dose intensity pattern that will best conform to the tumor shape. Typically, combinations of several intensity-modulated fields coming from different beam directions produce a custom tailored radiation dose that maximizes tumor dose while also protecting adjacent normal tissues.

Because the ratio of normal tissue dose to tumor dose is reduced to a minimum with the IMRT approach, higher and more effective radiation doses can safely be delivered to tumors with fewer side effects as compared with conventional radiotherapy techniques. IMRT also has the potential to reduce treatment toxicity, even when doses are not increased.

The center provides treatment for all forms of external beam, including but not limited to cancers of the prostate, breast, cervix, vocal cords, tonsil, mouth, thyroid, rectum / anus, and skin. Other, less sensitive, tumors can also be treated for palliation, to decrease the size of the tumor, reduce pain, control bleeding, and thus to prolong lives or improve quality of life for patients with tumors considered incurable.

The center will also be moving towards the delivery of High Dose Rate Brachy Therapy. HDR brachytherapy involves placing a protected source of high energy radiation directly within the tumor and using radioactive plaques, needles, tubes, wires, or small "seeds" made of radionuclides. These radioactive materials are placed over the surface of the tumor or implanted within the tumor, or placed within a body cavity surrounded by the tumor. The high energy of the source used in HDR brachytherapy means that doctors can deliver equivalent doses of radiation in just a few minutes by inserting and then removing the radioactive beads. Thus, HDR brachytherapy is usually performed as a short series of outpatient procedures. HDR brachytherapy is generally delivered to gynecological cancer patients, and in clinical trials of Mammosite brachytherapy to breast cancer patients. In addition, patients with head and neck cancer, gynecological cancer, pulmonary cancer, and other local regional tumors can be considered for HDR brachytherapy on an individual basis.