Seeking ways to move proton therapy forward

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When it comes to prepping and treating a patient for cancer, technology can only take you so far. Sometimes you need a little help from the patient.

This is particularly true of lung tumors, which often move position each time a patient breathes. Today’s proton therapy machines are good at compensating for this shifting target, but Niek Schreuder, Provision’s chief medical physicist, is working toward the next advancement in focusing proton therapy even further.

With the help of a summer intern and some Provision employees, he created test to monitor and guide patient breathing. This could help to improve the quality of time based CT scans, referred to as 4D CT scans that is used to delineate the target in the patient’s lung. Better 4D CT scans ultimately will result in even more effective lung cancer treatments.

The team developed a smart phone app to accurately measure breath rate while the device lay on a test participant’s chest. In an experiment with 13 former patients, the team measured each individual’s normal breathing rate. They then provided audio feedback and monitored breathing rates at both a faster and slower pace than normal. They also measured the patients’ ability to hold their breath.

The participants really got into the project, Schreuder said. One even went home and developed a visual breathing guide using a laser taped to the phone—an alternative to audio cues.

“If we can assist in controlling a patient’s breathing, it will help us obtain better 4D CT scans, in particular, of the tumor site,” he said. “The second, longer term phase of the project, would be to work with patient breathing during treatment itself.”

Currently, proton therapy machines are programmed to take a patient’s breathing patterns into account while applying the layers of protons to the tumor site. But the next step in technology developing, Schreuder said, is actually synchronizing the proton therapy machine with a patient’s breathing in order to customize treatment even further.

The next step, he said, is to find a company to create an app that includes both monitoring and guidance capabilities. This would allow the patient to practice breathing techniques before a CT scan or treatment and for caregivers to assess a patient’s ability to assist in this way.

Such breathing control is more widely used with conventional radiation therapy but is still in development stages for proton treatment.

“The most underutilized resource in the treatment room is the patients themselves,” Schreuder said. “What we’re exploring is not rocket science. It’s really simple.”