June 30, 2008 - The Center for Radiation Therapy of Beverly Hills is the first medical center in California to commence treating cancer patients with a new technique utilizing RapidArc radiotherapy technology, aiming to deliver an advanced image-guided, intensity-modulated radiation therapy (IMRT) treatment two to eight times faster than is possible with conventional IMRT or helical tomotherapy.
Prior to each treatment, special imaging technology is used to pinpoint the targeted tumor and line it up so that the radiation is delivered precisely and accurately. Once the patient is properly positioned, the actual treatments are typically delivered in less than two minutes with just a single 360-degree rotation of the treatment machine around the patient.
Studies comparing fixed-beam and helical IMRT with RapidArc show that RapidArc can reduce the amount of non-therapeutic radiation reaching healthy tissues during treatment. For example, in the case of head and neck cancer treatments, RapidArc plans are better at protecting critical structures like the spinal cord, brain stem, eyes, optic nerve and chiasm, parotid (salivary) glands and brain. Due to RapidArc's efficient use of the primary beam, secondary stray radiation caused by scatter and leakage are reduced by over 50 percent on average compared with fixed field IMRT.
RapidArc technology utilizes a proprietary algorithm that creates a finely-shaped IMRT dose distribution that closely matches the size and shape of the tumor. It works by varying three parameters simultaneously: 1) the speed with which the treatment machine rotates around the patient, 2) the dimensions of the beam-shaping aperture, which change continually during the treatment based on the patient's unique anatomy, and 3) the rate at which the dose is delivered.
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