FDG PET/ CT predicts survival in non-small cell lung cancer patients

A quantitative PET measurement known as total lesion glycolysis (TLG) could help clinicians make informed prognoses for patients with a stage of non-small lung cancer (NSCLC), according to a study published online Dec. 18 in the Journal of Nuclear Medicine.

NSCLC makes up as much as 85 percent of lung cancer cases and chance of recurrence is significant—up to 30 percent. With lung cancer being the number one cause of worldwide cancer deaths, finding ways to predict patient response to therapy and improve prognosis is a major priority, especially since the incidence of lung cancer is creeping up due to better low-dose lung cancer screening.  

Usually clinicians pay particular attention to tumor type, lymph node involvement and the development of metastatic disease, wrote Seong Yong Park, MD, assistant professor, department of thoracic and cardiovascular surgery at the Ajou University School of Medicine in Suwon, Korea, and colleagues. “However, tumor- and patient-specific factors vary even within the same disease stage, creating a heterogeneous population of patients each with an individual prognosis that requires consideration of patient- and tumor-specific factors for best estimation.”

The researchers retrospectively reviewed 248 patients with a mean age of about 63, all classified in two stages of NSCLC. The two classes were type 1A or 1B, as indicated by the size of primary tumor (smaller or larger than two centimeters). All subjects had undergone FDG PET/CT, to determine if TLG was predictive of overall survival at follow-up.

All subjects had undergone surgery and complete resection of lymph nodes following PET/CT imaging. Researchers chose a region of interest from the primary lesion as well as metabolic parameters such as tumor volume and maximum standardized uptake volume and TLG.

Results of the study showed that FDG PET/CT found 129 stage 1A tumors and 119 tumors that were stage 1B. After a median follow-up of three years and six months, recurrence was found in 15 patients. Five-year overall survival was gauged at 93.7 percent and 78.3 percent for patients who had registered as having low-TLG and high-TLG following PET/CT, respectively. There was a better correlation between TLG and overall survival than with other parameters.

“Patients with high TLG should be closely observed for recurrence and might benefit from adjuvant therapy,” the researchers concluded.