Post-treatment FDG-PET scans show promise for predicting the prognosis of patients with inoperable non-small cell lung cancer, the principal investigator of a major clinical trial reported today at the American Society for Radiation Oncology (ASTRO) Annual Meeting in Miami Beach, Fla.
The prognosis for patients with stage 2 and 3 inoperable non-small cell lung cancer (NSCLC) is poor, with only about 15 percent of patients surviving at five years post-treatment for the disease. While new treatment strategies are being intensely studied, timely assessment of their efficacy has proven difficult.
“These results are encouraging,” said Mitchell Machtay, MD, principal investigator of the ACRIN 6668/RTOG 0235 trial. “Definitive prognostic information after a patient completes therapy has not been available for making decisions about further treatment options, and these preliminary results suggest that FDG-PET may play an important role in that regard.”
Twenty ACRIN and RTOG participating sites enrolled 251 patients into the phase III trial that gathered pre- and post-treatment FDG-PET (F-18 fluorodeoxyglucose-positron emission tomography) scans. Their treatment included both chemotherapy and radiation therapy. Investigators wondered if the standardized uptake value (SUV) — a quantitative measure of how rapidly tumor cells are using the glucose-based FDG radiotracer — was predictive of a patient’s survival. SUV was obtained on post-treatment FDG-PET scans.
Patients with high levels of FDG uptake after treatment had more aggressive tumors that were more likely to recur, Machtay said.
“The higher the SUV measure in the primary tumor, the greater the recurrence rate and the lower a patient’s corresponding survival outlook,” he added.
“The results announced today suggest that FDG-PET has a role in helping physicians make more informed treatment decisions, such as starting a patient on a new chemotherapy program,” said Barry Siegel, MD, ACRIN co-deputy chair and medical director of the ACR PET Imaging Core Laboratory, “and helping investigators determine whether a treatment regimen is worthy of further study before long-term survival data are available.”