Lung cancer requires especially precise radiation treatment, so MSK doctors are testing a GPS-type system to guide radiation.
Radiation therapy for lung cancer is challenging, but MSK radiation oncologists are testing a system called Calypso® GPS for the Body that continuously tracks the location of lung tumors at all times. The system causes radiation to automatically shut off if the tumor moves outside a very small field. This spares healthy tissue from receiving radiation and allows higher radiation doses to be used safely.
Radiation therapy is a highly effective treatment for lung cancer, but it can be challenging to deliver consistently to lung tumors, which move as a patient breathes. To make this treatment more precise, Memorial Sloan Kettering radiation oncologists are testing a sophisticated positioning system using tiny markers that are implanted in the lungs and act as beacons. The markers signal to a tracking system made up of an antenna plate hovering over the patient and three cameras installed in the ceiling of the treatment room. The markers produce a 3-D representation of the tumor’s location at all times.
“It operates the same way satellite-based GPS pinpoints a location on earth,” MSK radiation oncologist Andreas Rimner says. “Here, the cameras are the satellites.”
MSK is among a handful of centers performing the first clinical trials for lung cancer testing this system. The technology has been used for years with great success to treat people with prostate cancer, and it is already approved by the FDA for use in several other locations in the body. As a patient breathes, the lungs expand and contract, which makes the tumor a moving target and increases the chance that the radiation may miss the cancer cells and damage normal tissue.
The tumor-tracking system, called Calypso® GPS for the Body, continuously monitors the tumor’s location during the treatment session. If the tumor moves outside of a very small field — like when the patient breathes — the machine delivering the radiation automatically switches off, preventing healthy tissue from being damaged. “We’re pleased to be giving our patients access to this technology, which is otherwise not available prior to FDA approval,” says Dr. Rimner, who is leading one of the trials.