Radiotherapy Delivery Up to Eight Times Faster, Accuracy Improved with Less Time for Movement

A new radiotherapy technique can turn a 20-minute radiotherapy session into a 90-second session for selected patients.

The University of Alabama at Birmingham (UAB) in May 2008 became the first U.S. medical center to offer a faster cancer radiation therapy. Moreover, the new therapy saves healthy human tissue from unwanted radiation exposure at rates that are the same or better than other radiotherapy techniques, according to doctors at the UAB Comprehensive Cancer Center.

The new therapy is called RapidArc, which is the next-generation of intensity-modulated radiation therapy (IMRT). Conventional IMRT was introduced in the 1990s as a way to deliver multiple beams of radiation to a tumor, and minimize damage to neighboring healthy tissues. RapidArc is an advancement on the earlier technology with radiation delivery up to eight times faster than conventional IMRT, according to the system's manufacturer Varian Medical Systems, Inc (Palo Alto, CA, USA).

"RapidArc is an important advance for us and our patients,” said John Fiveash, M.D., an associate professor of radiation oncology at UAB and Cancer Center scientist. "Knowing that we can reduce delivery times to less than two minutes per day is important considering what cancer care involves emotionally and physically.”

Varian technicians added the RapidArc capability to UAB's existing IMRT machine during the last week of April 2008. The upgrades serve as a kind of guidance system, similar to a jet's automatic pilot, so that IMRT delivery can happen during a single rotation of the machine's arm around the patient.

The first U.S. patient to be given the new therapy is an Alabama man with early-stage prostate cancer whose treatment started May 6, 2008, according to Dr. Fiveash. Faster radiation delivery times reduce the chances that a slight move will affect the accuracy of the radiotherapy targeting. In addition, he reported that it means patients spend less time and feel less discomfort in the treatment room.

"We presently treat many patients with very complex treatment plans,” said John Brinkerhoff, R.Ph., M.B.A., C.M.P.E., executive administrator of UAB's department of radiation oncology. "We have a head and neck cancer plan that would normally require a patient to lie still for 20 minutes with their face in a cushioned stability mask. With RapidArc, they are required to remain still for only 90 seconds.”

The new system incorporates powerful computers to help clinicians arrive at a radiotherapy treatment strategy after studying thousands of biologic and mathematical variables, including medical scans of each patient's tumor.


Related Links:
University of Alabama at Birmingham
Varian Medical Systems