PET Imaging Effective in Predicting Lung Cancer Outcomes

Advanced imaging with positron emission tomography (PET) scans shows great potential in predicting which patients with inoperable lung cancer have more aggressive tumors and need additional treatment following standard chemotherapy/radiation therapy, according to new findings.

Mitch Machtay, MD, from the Seidman Cancer Center at University Hospitals (UH) Case Medical Center (Cleveland, OH, USA), and lead investigator for the study, presented the data October 6, 2011, at the annual meeting of the American Society for Radiation Oncology (ASTRO) in Miami Beach (FL, USA). The US National Cancer Institute (Bethesda, MD, USA) -funded trial, led by the American College of Radiology Imaging Network (ACRIN; Reston, VA, USA) in collaboration with Radiation Therapy Oncology Group (RTOG), enrolled 251 patients at 60 cancer centers around the United States.

“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,” said Dr. Machtay, chairman of radiation oncology at UH Case Medical Center and Case Western Reserve University School of Medicine (Cleveland, OH, USA). “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.”

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 fluorodeoxyglucose [FDG]). Since most cancer cells take up glucose 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 findings 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,” explained 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.”

Related Links:
Seidman Cancer Center at University Hospitals Case Medical Center