Daniel Harrington, Medical Physics Residency, Arizona

October 28, 2014

When staff plan radiation therapy for a patient, the planning target volume (PTV) is the area they define to receive treatment. Within the PTV is the clinical target volume (CTV). That’s the area that covers the tumor to be treated and any possible microscopic expansion of the tumor that might not be visible.

Harrington’s research examined whether the PTV area was large enough to account for any shift in the patient during treatment. His investigation included 10 radiation therapy cases in the head and neck region.

What he found

The research showed that PTV does properly cover the area that needs treatment, even if a shift occurs.

Why it matters

PTV dictates the area of the body that will receive radiation treatment. PTV is at the core of effective therapy for these patients.

“This is not a controversial topic. PTV and CTV are fundamental in radiation treatment planning,” says Harrington. “We all assume the concept researched here to be accurate. But, there is not much evidence for that assumption. The findings confirmed that it is true. That’s important for the way radiation therapy is conducted.”

Presentation

• American Association of Physicists in Medicine 56th-Annual Meeting and Exhibition, July 2014
• 53rd-Annual Conference of the Particle Therapy Co-operative Group, June 2014