Researchers will also report on a new technique to reduce toxicity at the highest levels of radiation therapy. Because pulmonary tumors move when patients breathe, doctors have previously had to treat a wider area to hit this moving target in order to ensure that the lung tumors receive the ideal dose of radiation, increasing the side effects of treatment. However, physicians at Memorial Sloan-Kettering have discovered a way to immobilize the lung tumors during radiation treatment using a method called the deep inspiration breath hold, which decreases lung density and has allowed doctors to more safely treat patients at higher doses than ever.
The approach is used when free breathing with three-dimensional conformal radiation therapy does not allow for safe treatment at a high dose. It requires the patient to hold his or her breath for 10 seconds at a time to make sure the lung tumor stays still during treatment. This is repeated five or six times during each treatment episode. The individual must be at exactly the same breath level for each treatment, which is measured with a device called a spirometer. The therapy is only administered when the patient can maintain the same breath level as the last treatment.
The deep inspiration breath hold allows for more targeted and thus safer treatment for large lung tumors that would otherwise not be eligible for dose escalation, said Ken Rosenzweig, MD, a radiation oncologist with expertise in the treatment of lung cancer and who developed the technique at Memorial Sloan-Kettering. Our findings show that high-dose radiation treatment can effectively control the rate of tumor growth with little toxicity despite locally advanced disease in the majority of patients, said Dr. Rosenzweig. To date, 20 patients have completed high dose rad
Contact: Esther Carver
Memorial Sloan-Kettering Cancer Center