Radiation is delivered in less than two minutes as the RapidArc™ moves in a continuous revolution around prostate cancer patient Zack Washington of San Antonio.
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A faster, more precise way to kill cancer cells and shrink tumors with radiation was used on a patient for the first time in San Antonio at the Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio.

It took less than two minutes on April 22 to deliver the high-energy X-rays to 67-year-old Air Force veteran Zack Washington, who has early stage prostate cancer. “I didn’t feel a thing,” Washington told CTRC faculty and staff after his first treatment with the new Varian Trilogy™ linear accelerator with RapidArc™ technology.

Pencil-tip precision
The machine makes a single revolution around the patient while aiming very small radiation beams — the size of a pencil tip — at the tumor with varying levels of intensity and from multiple angles. Typical radiation therapy of this type, known as IMRT or intensity-modulated radiation therapy, takes about 10 minutes, because the machine has to stop at numerous intervals as it rotates around the patient.

Quicker treaments promote accuracy
“A two-minute treatment time means patients do not have to hold still for long, thus reducing the likelihood that patients’ movements could compromise the pinpoint accuracy of the radiation dose,” said Chul S. Ha, M.D., professor and chairman of the Department of Radiation Oncology at the UT Health Science Center. He added that the reduction in treatment time provides more comfort for the patient.

After five days of treatment, Washington reported no side effects and expressed confidence about a good outcome. More than 90 percent of patients with early stage prostate cancer are cured by radiation therapy.

Technology allows beam to be shaped to tumor's size and position
RapidArc high-definition technology makes treatments more precise by shaping the radiation beam so that it conforms closely to the tumor’s three-dimensional shape. Right before treatment, technicians use imaging equipment to view the tumor’s exact location, size and shape. The patient lies on a robotically controlled table that can be adjusted by touching a button and will align the patient on as many as six different planes (up and down, front and back, left and right) to the precise treatment position.

“Our goal is to deliver the lowest dose possible to the healthy tissue surrounding the tumor, while maximizing the radiation to the cancerous cells of the tumor,” says medical physicist Nikos Papanikolaou, Ph.D., professor of radiation oncology at the UT Health Science Center and chief of the radiation physics division. “RapidArc is a revolutionary way to deliver efficient and painless radiation treatments. We are very excited to offer this technology to South Texas,” he said.

RapidArc will be used to treat several types of cancer
The CTRC purchased the multi-million-dollar linear accelerator “as part of its continuing investment in state-of-the-art technology to provide hope for the people of South Texas battling cancer,” Dr. Ha said. RapidArc will be used to treat not only prostate cancer but also cancers of the brain, spine, liver and lung.