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In PVHMC’s ongoing commitment to excellence in cancer care, The Robert & Beverly Lewis Family Cancer Care Center is now offering RapidArc™ based radiation treatments for certain cancers. This revolutionary, new approach to image guided, intensity modulated radiation therapy
(IGRT/IMRT) delivers precise treatment in shorter times than traditional IMRT. Developed by Varian Medical Systems of Palo Alto, California our Trilogy Linear Accelerator was upgraded with this new treatment enhancement at the end of January 2009.
While IMRT has proved superior to traditional external beam radiation treatments for many types of cancer, it presented the clinicians and patients with a set of new challenges that needed refinement.
Specifically, IMRT treatments can be lengthy taking up to 30 minutes each day. Many patients find this protracted treatment time uncomfortable making patient cooperation difficult to achieve. Remaining perfectly still for over 15 minutes is challenging even for the most motivated and cooperative patient.
Another IMRT issue that needed to be improved was reducing the amount of radiation produced by the machine to give a single treatment. IMRT treatments were proving hard on the equipment which could lead to premature failure of expensive parts. When parts fail there is associated down time and missed treatments until the repair is complete.
It was also found that the amount of radiation to normal tissue could potentially be greater than is desirable. Researchers at Varian realized that an improved method of delivering IMRT was needed.
Using RapidArc technology to deliver treatments, the Linear Accelerator or linac gantry rotates 360 degrees around the patient while irradiating from every angle with very fine beams. The radiation beams are shaped and reshaped in addition to the intensity of the radiation being modulated during the machine rotation. This is quite different from the "static" IMRT treatments in that the linac is always emitting radiation as it moves around the patient so there is no starting and stopping of the radiation beam at specific angles. The time a patient spends on the treatment couch is greatly reduced with RapidArc. Since a patient will spend less time holding still, it will be easier to avoid movements that could compromise the accuracy of the treatment.
Like all 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. This is important as the less healthy tissue that is irradiated the less unwanted side effects the patient will experience.
Like conventional or static IMRT treatments Rapid Arc is preceded by image guidance (IGRT) to precisely aim the radiation beam at the intended target. Millimeter accuracy is crucial. On-Board Imager or Cone Beam CT images are obtained and compared to the planning images by the therapist. Needed corrections are automatically calculated by the sophisticated software and the treatment couch is adjusted. The patient does not need to move as the treatment couch does all the repositioning required.
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. RapidArc delivers treatments two to eight times faster than earlier forms of radiotherapy. Ask your Radiation Oncologist if RapidArc is right for you.
The Breast Health Center in Pomona has been awarded accreditation in Mammography, Stereotactic Breast Biopsy, Breast Ultrasound and Ultrasound-Guided Breast Biopsy as the result of a recent evaluation by the American College of Radiology (ACR). In recognition of this, the Breast Health Center has been designated as a Breast Imaging Center of Excellence by the ACR. "This designation shows that we have achieved high practice standards in image quality, personnel qualifications, facility equipment, quality control procedures and quality control program," states Dr. Paul Reisch, Medical Director of Breast Imaging.
The ACR began awarding accreditation for mammography in 1987, and our Center was only the third facility in the State of California to voluntarily submit our practice standards to the ACR’s peer-review evaluation and receive accreditation. In keeping with our commitment to the highest of quality standards, as the ACR added additional accreditation programs, we continued to submit our data for their review and have earned the designation of a Breast Imaging Center of Excellence.
We strive to remain a leader in technology and patient care. This new designation and accreditation is truly an honor, as our facility is the first to achieve it in our region. We want our patients to feel secure in their care, and to feel our commitment to their breast health.
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Treating some lung and abdominal tumors can be very challenging. They move as the patient breaths. There are several ways to address this problem. One way is to make the radiation field large enough so that even if the tumor moves with the breathing, it will stay in the radiation beam. This technique, however, treats more normal tissues than necessary. The more normal tissues are irradiated, the greater the chance of side effects. Several other techniques have evolved over time to solve this problem with the goal of treating the tumor properly but reducing the amount of normal tissues treated.
One such way is to restrict the diaphragm movement during the treatment by compressing the abdomen; this is referred to as “abdominal compression.” This technique can be difficult for some patients to follow. They may have compromised breathing already and this technique would aggravate that problem.
A second technique is what’s referred to as “breath hold” where patients are instructed to hold their breath for a certain period during the treatment. They are able to control when they hold their breath. This technique requires coaching and lengthens the time the patient is on the treatment table.
A third technique adopted at The Robert &
Respiratory gating, with radiation, is equivalent to loading a rifle, then holding it until the tumor or target appears in the cross-hair sight of the radiation beam before shooting. This “loading and shoot” is repeated until the tumor gets delivered the proper dose of radiation. This is a very similar to a shooting range where the shooter waits for the moving target to appear and then shoots. This treatment technique minimizes the normal tissues treated and allows the Radiation Oncologist to treat with higher doses of radiation.
Several steps are required for this process. A respiratory gated CT scan is followed by an evaluation of the amount of tumor movement with the breathing cycle. A portion of the breathing cycle is then selected where the tumor moves minimally and is reproducible. A computer treatment plan is developed using the same binned (or grouped) CT scan information. The patient is treated on a daily basis, by monitoring the breathing and the radiation beam on and off are timed automatically with the breathing.
Respiratory Gating is the most efficient way to treat moving tumors in the lung, abdomen and elsewhere where tumors move with the breathing.
Minimal normal tissues are irradiated thus reducing potential treatment side effects. That’s the goal of all treatments and respiratory gating now makes it possible.
Bouchaib Rabbani, Ph.D., Radiation Physicist
Pomona Valley Hospital Medical Center
1798 N. Garey Avenue | Pomona, California 91767
(909) 865-9500 | Contact Us
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