Algorithm Could Speed Up Radiation Therapy

Photo: CT of a prostate

"Intensity Modulated Radiation Therapy (IMRT) has exploded in popularity, but the technique can require hours of manual tuning to determine an effective radiation treatment for a given patient," said Richard Radke, assistant professor of electrical, computer, and systems engineering at Rensselaer Polytechnic Institute.

A subfield of artificial intelligence, machine learning is based on the development of algorithms that allow computers to learn relationships in large datasets from examples. Radke and his coworkers have tested their algorithm on 10 prostate cancer patients. They found that for 70 percent of the cases, the algorithm automatically determined an appropriate radiation therapy plan in about 10 minutes.

"The main goal of radiation therapy is to irradiate a tumor with a very high dose, while avoiding all of the healthy organs," Radke said. He described early versions of radiation therapy as a "fire hose" approach, applying a uniform stream of particles to overwhelm cancer cells with radiation.

IMRT adds nuance and flexibility to radiation therapy, increasing the likelihood of treating a tumor without endangering surrounding healthy tissue. Each IMRT beam is composed of thousands of tiny "beamlets" that can be individually modulated to deliver the right level of radiation precisely where it is needed.

The computer-based procedure was put to the test by developing radiation plans for 10 patients with prostate cancer. In all 10 cases the process took between five and 10 minutes, Radke said. Four cases would have been immediately acceptable in the clinic; three needed only minor "tweaking" by an expert to achieve an acceptable radiation plan; and three would have demanded more attention from a radiation planner.

Radke and his coworkers plan to develop a more robust prototype that can be installed on hospital computers and evaluated in a clinical setting. He hopes to see a clinical prototype in the next few years.; Source: Rensselaer Polytechnic Institute