Image-Guided Radiation Therapy for Treating Cancer

We recently installed a Clinac iX medical linear accelerator from Varian Medical Systems, for treating cancer with Dynamic Targeting image-guided radiotherapy (IGRT). This new robotic and automated technology combines a state-of-the-art treatment machine with sophisticated digital imaging, and tracking and monitoring tools, enabling doctors to deliver the most accurate treatments possible, even when treating tumors that move as the patient breathes. This technology is equivalent to what is available at leading medical centers, including M.D. Anderson Cancer Center in Houston and the Memorial Sloan-Kettering Cancer Center in New York. We are proud to bring this advanced and sophisticated technology to the Greater Austin area.

This highly advanced system incorporates a high-quality imaging device that enables clinicians to position patients very precisely and to deliver the radiation dose directly to a targeted area with submillimeter accuracy, guided by three-dimensional images of the patient’s anatomy. The system’s versatility makes it appropriate for treating a wide range of abnormalities, from small metastases to large tumors, even in cases where the tumor is close to critical structures like the spinal cord or the optic nerve. A “respiratory gating” tool compensates for normal respiratory motion during treatment. Together, these tools deliver extremely precise treatments with better outcomes and fewer side-effects.

The Clinac iX with its On-Board Imager device is visually compelling. Housed in a specially designed vault visible through closed circuit television, the machine stands approximately nine feet tall and rotates 360 degrees around the patient to deliver radiation from several angles. The On-Board Imager is attached to the machine on a pair of robotic arms that extend out on either side of the patient to generate anatomical images that will guide the treatment. Sophisticated image-matching software shows patient anatomy on computer monitors outside the treatment room.

SmartBean IMRT involves varying (or modulating) the intensity of the radiation (in this case, X-rays), being used as therapy for cancer. It is a new form of radiation therapy that uses computer generated images to plan and then deliver more tightly focused radiation beams to cancerous tumors than is possible with conventional radiotherapy. With this capability, clinicians can deliver a precise radiation dose that conforms to the shape of the tumor, while significantly reducing the amount of radiation to surrounding healthy tissues. Consequently, the technique can increase the rate of tumor control while greatly reducing adverse side effects.