RapidArc ™ Radiotherapy
Alta Bates Summit Comprehensive Cancer Center is the first in Northern California to offer RapidArc ™ Radiotherapy
Overview
RapidArc™ radiotherapy technology is a new approach to image-guided, intensity-modulated radiation therapy (IG-IMRT) that delivers precise treatments in shorter times than conventional IMRT.
RapidArc represents a major medical advance and is more comfortable for patients because they spend less time in their daily treatments. A fast, precise RapidArc treatment takes 80% less time. Patients can be in and out of treatment quickly and return to their daily routine.
RapidArc rotates 360 degrees around the patient, enabling the very small beams with varying intensity to be aimed at the tumor from multiple angles. Unlike helical IMRT treatments or other forms of radiation therapy, with RapidArc the radiation treatment being delivered to the patient can be modulated continuously throughout treatment. This means that higher doses of radiation are delivered to hit the tumor harder, and less radiation is delivered to surrounding healthy tissue.
RapidArc treatments are delivered using a Clinac® linear accelerator outfitted with imaging capabilities. The RapidArc imaging capabilities let the clinician see the location of the tumor in three dimensions before treatment. If the cancer has moved due to physical changes, treatment can be adjusted so the patient receives a precise treatment.
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How it Works
RapidArc™ radiotherapy technology delivers treatments using Clinac® linear accelerator, outfitted with an On-Board Imager® kV imaging system and Cone Beam CT (CBCT) for using images to guide patient placement and treatment delivery. The linear accelerator rotates around the patient to deliver radiation treatments from nearly any angle. During a RapidArc treatment, radiation is shaped and reshaped as it is delivered continuously from virtually every angle in a 360-degree revolution around the patient.
RapidArc Planning
Like other forms of radiation therapy, RapidArc treatments are planned using sophisticated computer programs that analyze diagnostic image data and calculate the best way of delivering the radiation dose to minimize impact on healthy tissues for each patient.
RapidArc Imaging
Immediately prior to treatment, the exact location, size, and shape of the patient's tumor is visually observed through a simple two-minute imaging procedure using the machine's On-Board Imager or Cone Beam CT.
RapidArc Positioning
After imaging is completed, the images are reviewed by the therapist and the patient's position can be adjusted so that an accurate treatment can be delivered. The patient does not need to move off the treatment couch for this process-all adjustments are made automatically by the treatment couch.
Treatment
A RapidArc radiotherapy treatment is delivered quickly-usually in less than two minutes and with just one turn of the machine around the patient. RapidArc shapes and modulates a highly focused treatment beam so that it targets the tumor precisely, sparing surrounding healthy tissues. It treats the entire tumor with pinpoint accuracy and is easier on the patient, who does not have to hold still for long periods of time.
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Benefits to the Patient
RapidArc™ radiotherapy technology represents a new revolution in cancer care. RapidArc enables your clinician to treat some types of cancer with great precision in significantly less time.
RapidArc is delivered with a medical linear accelerator, which is a large machine that generates high-powered X-rays and rotates around you as you lie on a treatment couch, delivering the beams from many angles. With RapidArc, the entire treatment is completed with a single rotation of the machine.
RapidArc is a new approach to delivering image-guided, intensity-modulated radiation therapy (IG-IMRT). Image guidance improves tumor targeting, and IMRT shapes the radiation dose so that it conforms closely to the three-dimensional shape of the tumor. That means more radiation is delivered to the tumor and less to surrounding healthy tissues.
The treatments are fast. That makes it easier on you-you don't have to hold still for long, and you're in and out in a matter of minutes each day. With RapidArc, the treatment time is reduced by about 80%.
A RapidArc radiotherapy system incorporates technology that makes it possible for your treatment team to position you for treatment with sub-millimeter accuracy. An On-Board Imager® kV imaging system or a CBCT (Cone Beam CT) mounted on the treatment machine provides high-resolution X-ray or CT images of the targeted area just before each daily treatment.
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Frequently Asked Questions
What is RapidArc?
RapidArc™ radiotherapy technology is a new form of image-guided, intensity-modulated radiation therapy (IMRT). Image guidance improves tumor targeting, and IMRT shapes the radiation dose so that it conforms closely to the three-dimensional shape of the tumor. This means more dose to the tumor, and less to surrounding healthy tissue.
RapidArc quickly delivers a complete IMRT treatment with a single rotation of the treatment machine around the patient. The entire tumor volume receives the radiation dose during this one revolution of the machine. RapidArc involves varying (or modulating) the intensity of the radiation (in this case, high-energy X-rays) being used as therapy for cancer.
To administer a RapidArc treatment, clinicians use computer-generated images to plan and then deliver tightly focused radiation beams to cancerous tumors. Using RapidArc technology, clinicians can deliver a precise radiation dose that conforms to the shape of the tumor, while limiting the amount of radiation that reaches surrounding healthy tissues.
A significant benefit provided by RapidArc is the speed of a treatment. A RapidArc treatment is delivered with a single 360-degree rotation of the linear accelerator, which takes less than two minutes.
Why would I want to be treated with RapidArc?
RapidArc is an extremely fast and precise form of radiation therapy. It allows clinicians to quickly and accurately deliver radiation to cancer cells while keeping the dose to surrounding tissues as low as possible.
Faster treatments are not only more comfortable, they may also be more accurate. Since a patient will spend less time holding still, it will be easier to avoid movements that could compromise the accuracy of the treatment. RapidArc delivers treatments two to eight times faster than earlier forms of radiotherapy.
What kind of radiation is used in RapidArc?
Photons (X-rays) are used to deliver RapidArc. The radiation is generated by a machine called a medical linear accelerator. This machine stands approximately nine feet tall, is nearly 15 feet long and can be rotated around the patient with amazing precision. Operationally, microwave energy, similar to that used in satellite television transmission, is used to accelerate electrons to nearly the speed of light. As they reach maximum speed they collide with a tungsten target, which in turn releases photons, or X-rays.
Very small beams with varying intensities can be aimed at a tumor from multiple angles to attack the target in a complete three-dimensional manner. In fact, RapidArc can be delivered with beams the size of 2.5 x 5-millimeter pixels-the size of a pencil tip-each with varying intensity. The idea is to deliver the lowest dose possible to the surrounding healthy tissue, while still delivering the maximum dose to the tumor.
What happens when a person is treated with RapidArc?
RapidArc treatment involves three basic steps: diagnosis, treatment planning and delivery. As part of diagnosis, the medical team generates three-dimensional diagnostic images (usually CT or MRI) of the patient's anatomy and uses these images to specify the dose of radiation needed to treat the tumor. In some cases, treatment planning includes a simulation session to further localize the cancer and finalize the radiation treatment plan.
Patients receive RapidArc treatments according to various schedules, usually five days a week for six or seven weeks. During a RapidArc treatment, the linear accelerator rotates around the patient to deliver the radiation from nearly every angle. The radiation is shaped and reshaped as it is continuously delivered from virtually every angle in a 360-degree revolution around the patient. Treatment consisting of a 360-degree revolution takes less than two minutes.
What is the RapidArc treatment process like?
The RapidArc process is similar to a typical radiation treatment. Be certain to ask your treatment team any questions you may have since the individual processes may vary slightly based on your individual situation.
How long is a course of RapidArc treatment?
Treatments vary depending on your diagnosis, ask your medical professional for information about your specific diagnosis. Generally, radiation therapy usually is given five days a week for six or seven weeks. When radiation is used to alleviate pain or other symptoms, the course of treatment lasts for two to three weeks. For each radiation therapy session, the patient is in the treatment room for about 10 minutes. These types of schedules, which use small amounts of daily radiation rather than a few large doses, help protect normal body tissues in the treatment area. Weekend rest breaks allow normal cells to recover. The total dose of radiation and the number of treatments a patient needs depend on the size and location of the cancer, the type of tumor, the patient's general health and other factors.
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