Tracking System May Improve Prostate Radiotherapy Treatment

Researchers and clinicians in Australia are leading a clinical trial to test a GPS-like device that tracks the position of the prostate as it moves during radiotherapy.

AsianScientist (Dec. 4, 2013) – Researchers and clinicians from the University of Sydney and the Northern Sydney Cancer Center are leading a clinical trial to test a tracking system for use during prostate cancer radiotherapy treatment.

The multileaf collimator (MLC) tracking system uses a GPS-like device called the Calypso system to track the position of the prostate as it moves during therapy, so as to continuously target the tumor with sub-millimeter accuracy.

A prostate can move up to 1.5 centimeters during a radiation treatment session and in current practice the tumor is positioned before treatment, but this motion is not monitored or corrected for during treatment.

MLC is a computer-controlled device with numerous narrow slats or leaves that can be moved in and out to create apertures of different sizes. This tool is used to shape and reshape the radiotherapy treatment beam during treatment to match the three-dimensional shape of the area being targeted.

In addition to shaping the treatment beam, the MLC responds to signals from a tiny set of transponders implanted into the prostate to follow the tumor as it moves.

The trial’s lead clinician Dr. Tom Eade said the use of MLC tracking will potentially improve the accuracy of radiation delivery and reduce the impact on surrounding healthy tissue and sensitive structures such as the rectum and bladder.

“This breakthrough may potentially change the paradigm of prostate cancer treatments, opening the opportunity for patients to have their cancer cured with radiation in just 1-2 weeks of treatment with very low side effects,” he said.

University of Sydney Medical School’s Professor Paul Keall said having a radiation beam continuously target the prostate means that the prostate will receive more than 98 percent of the radiation dose planned.

“We are recording the estimated treatment improvements with MLC tracking, as well as recording the actual patient outcomes. Based on prior data we estimate that tumor dose misses, which can be up to 30 percent in current practice, can be reduced to below two percent,” said Professor Keall.

The researchers say that the tracking system also has the potential to reduce prostate cancer radiation therapy from an eight week program to just five days, as the greater level of accuracy could make it possible to safely deliver higher doses across fewer treatment sessions.

“This shorter treatment course is better for patients and more cost-efficient,” said Dr. Eade.

——

Source: University of Sydney; Photo: HowardLake/Flickr/CC.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

Related Stories from Asian Scientist