Treating Cancer Patients With RapidArc Radiotherapy Technology
Verity Radiation Therapy is the second medical center in the United States to commence treating cancer patients with RapidArc radiotherapy technology from Varian Medical Systems. RapidArc is an advanced form of image-guided, intensity-modulated radiation therapy (IMRT) that can be delivered two to eight times faster than is possible with conventional IMRT or helical tomotherapy.
"We delivered our first RapidArc treatment yesterday, to a patient with prostate cancer who was about two weeks into an eight and a half week course of traditional IMRT treatments," said Dr. Ed Gilbert, radiation oncologist. "Before, his treatments were taking about 10 minutes each day to complete. Yesterday, using the RapidArc approach, we completed the entire process in about 6 minutes. That included positioning the patient, taking images, adjusting his position, and delivering the treatment. Actual treatment delivery was completed in less than 90 seconds, compared to five and a half minutes with the conventional approach."
RapidArc treatments, created with Varian's Eclipse treatment planning system and proprietary RapidArc software, are faster because they use a Varian linear accelerator to deliver a complete volumetric IMRT treatment with a single rotation of the treatment machine around the patient. Conventional IMRT required the machine to make intermittent stops and starts during a treatment, as the machine was moved to deliver the beam from several different beam angles. Varian treatment planning analyses have shown that RapidArc plan dose distributions are comparable to those possible with conventional IMRT planning, and RapidArc plans are delivered with the same precision.
"IMRT was already a tremendous gain in curving around normal structures, such as the rectum in prostate cancer treatment, thereby allowing for higher doses given to the prostate," Dr. Gilbert pointed out. "The ability to deliver these treatments so much faster is a real win for us and for our patients. Faster treatments are not only more comfortable for the patient, but they have the potential to spare more healthy tissue during the course of treatment since there is less likelihood that the patient will move during the treatment, or that some normal physiological process, such as gas moving through the digestive system, will displace the tumor."
"In addition to shortening the patient's treatment time, with RapidArc we are able to reduce the amount of radiation generated by the machine," added Randi Aaronson, PhD, medical physicist. "While the dose to the target does not change, the dose to the rest of the body from scatter and leakage radiation is reduced compared to conventional IMRT."
"With the addition of RapidArc, the Varian linear accelerator at The Texas Clinic can now be used for an even broader spectrum of advanced clinical capabilities, which already include fixed-beam IMRT, stereotactic treatments, and electron treatments for tumors near the body's surface," added Matt McNeeley, director of marketing and business development. "It is part of our ongoing commitment to offering our patients the most appropriate form of treatment available, based on each patient's unique clinical situation."