Advanced imaging with Positron Emission Tomography (PET) scans shows great promise in predicting which patients with inoperable lung cancer have more aggressive tumors and need additional treatment following standard chemotherapy/radiation therapy, according to new research.
Mitch Machtay, MD, of the Seidman Cancer Center at University Hospitals (UH) Case Medical Center and principle investigator for the study, presented the significant data today at 2 pm at the annual meeting of the American Society for Radiation Oncology (ASTRO) in Miami Beach, Fla. The National Cancer Institute-funded trial, led by the American College of Radiology Imaging Network (ACRIN) in collaboration with Radiation Therapy Oncology Group (RTOG), enrolled 251 patients at 60 cancer centers around the country.
"Lung cancer remains the number one cancer killer in the United States. These findings have the potential to give cancer physicians a new tool to more effectively tailor treatments for patients with locally advanced lung cancer," says Dr. Machtay, Chairman of Radiation Oncology at UH Case Medical Center and Case Western Reserve University School of Medicine. "This cooperative group study determined that the PET scan can show us which patients have the most aggressive tumors, potentially enabling us to intensify their treatment."
A PET scan is a unique type of imaging test that reveals physiologic processes in organs such as the lung. Unlike other types of medical imaging that display the body's structure, PET shows changes in metabolic and chemical activity caused by actively growing cancer cells. The scan visualizes areas of greater intensity, called "hot spots," and lights them up to help physicians pinpoint the disease.
In this study, stage III lung cancer patients had PET scans before and after a combined treatment regimen of chemotherapy and radiation therapy. They measured how rapidly tumors absorb a radioactive sugar molecule (known as FDG). Since most cancer cells take up sugar at a higher rate than normal cells, areas of tumor typically light up brightly on PET scans.
The researchers found that the post-treatment scan was predictive for patients' prognosis by identifying that patients with high levels of FDG uptake following treatment had more aggressive tumors that were more likely to recur. The researchers found that the higher the standard uptake value (SUV) for FDG in the primary tumor, the greater the recurrence rate and the lower the survival rate of patients.
The results also showed that there was a strong correlation between the radiation dose intensity and local control of the cancer, indicating that further research needs to be conducted in radiation technology for lung cancer
"This is one of the largest studies-of-its kind to show that PET scans have great potential in predicting the prognosis for patients with inoperable lung cancer," says Dr. Machtay. "It supports the theory that PET scans add an important new dimension to a physician's ability to determine which patients need additional cancer therapies to best manage their disease."
Among the nation's leading academic medical centers, University Hospitals Case Medical Center is the primary affiliate of Case Western Reserve University School of Medicine, a nationally recognized leader in medical research and education. National Cancer Institute-funded research is awarded through Case Western Reserve University.
Co-authors on the study are: F. Duan, B. Snyder, J. Gorelick, ACRIN Biostatistics Center/Brown University School of Medicine, Providence, RI; A. S. DeNittis, Main Line Health-Lankenau Institute for Medical Research, Wynnewood, PA; C. Chiles, Wake Forest University School of Medicine, Radiology, Winston-Salem, NC; I. Mahon, ACRIN, Philadelphia, PA; A. Alavi, University of Pennsylvania Medical School (Nuclear medicine/radiology), Philadelphia, PA; B. A. Siegel, Washington University (Nuclear Medicine/Radiology), St. Louis, MO; and J. D. Bradley, Washington University - Radiation Oncology, St. Louis, MO.
About University Hospitals
University Hospitals serves the needs of patients through an integrated network of hospitals, outpatient centers and primary care physicians. At the core of our health system is University Hospitals Case Medical Center. The primary affiliate of Case Western Reserve University School of Medicine, University Hospitals Case Medical Center is home to some of the most prestigious clinical and research centers of excellence in the nation and the world, including cancer, pediatrics, women's health, orthopedics and spine, radiology and radiation oncology, neurosurgery and neuroscience, cardiology and cardiovascular surgery, organ transplantation and human genetics. Its main campus includes the internationally celebrated UH Rainbow Babies & Children's Hospital, ranked among the top children's hospitals in the nation; UH MacDonald Women's Hospital, Ohio's only hospital for women; and UH Seidman Cancer Center, part of the NCI-designated Case Comprehensive Cancer Center. For more information, go to www.uhhospitals.org
The Radiation Therapy Oncology Group (RTOG) is a multi-institutional international clinical cooperative group funded primarily by National Cancer Institute. RTOG has 40 years of experience in conducting clinical trials and is comprised of over 300 major research institutions in the United States, Canada and internationally. The group currently is currently accruing to 40 studies that involve radiation therapy alone or in conjunction with surgery and/or chemotherapeutic drugs or which investigate quality of life issues and their effects on the cancer patient. For more information go to www.rtog.org