PET Scans More Effective than Standard Technique at Accurately Staging Lung Cancer
Classic "TNM" staging in lung cancer (an assessment of primary Tumor, regional lymph Node involvement, distant Metastasis) has only been partially effective at accurately predicting patient survival. Now, researchers at the University Hospital Gasthuisberg, Belgium, have examined the use of PET imaging to provide a more accurate, and individualized, prognosis to help in treatment decisions.
The advance is based on improved understanding of the molecular biology of non-small-cell lung cancers (NSCLC), which make up 80 percent of lung cancer cases. The investigators knew that the speed by which tumors proliferated could be measured by how quickly the cancerous tissue used an energy-rich glucose solution given to patients during PET imaging. That imaging technique looks at metabolism within tissues. This study aimed to determine whether the Standardized Uptake Value (SUV), a measurement of glucose use, could help predict a patient's prognosis.
The research team, led by Dr. Johan Vansteenkiste, looked at several completed PET imaging studies to examine SUV rates in 125 potentially operable NSCLC patients. They found that glucose-uptake did have an important prognostic value and that a value of "7" or less, indicating slower metabolic turnover, was an independent variable associated with improved survival. Patients with a tumor of less than 3 centimeters that had been removed had an expected 2-year survival of 86% if the SUV was below 7, and 60% if above 7. Nearly all tumors greater than 3 centimeters had SUV's of more than 7, and an expected 2-year survival of 43%.