Prognostic value of SUVmax in regional lymph node equal to or greater than SUVmax in the primary tumor on pre-therapy 18F-FDG PET/CT for patients with stage III non-small cell lung cancer

Objectives We evaluated survival outcome of stage III non-small cell lung cancer (NSCLC) patients with maximum standardized uptake value (SUVmax) in any regional lymph nodes (LN) equal to or greater than that in the primary tumor (PT) on pre-therapy 18F-FDG PET/CT.

Methods From 2006 to 2011, all patients with non-resectable stage III NSCLC who had 18F-FDG PET/CT (median 1 month, range 0-3.3 months) prior to definitive chemoradiation therapy were reviewed. We compared overall survival (OS) of the patients with the highest SUVmax in the PT with OS of those with SUVmax of LN ≥ SUVmax of PT (rounded to nearest whole number). OS was calculated from the date of pre-therapy PET/CT to death from any cause. Patients who were alive were censored at the date of last known alive. Survival curves were estimated using the method of Kaplan-Meier and compared by the log-rank test. We also assessed the correlation between SUVmax and OS using Cox proportional hazards model..

Results 44 patients (F/M=13/31; Age=27-84 yo) were studied. The median OS of patients with highest SUVmax in PT (n=29, average SUVmax of PT=18) and that of patients with SUVmax of LN ≥ SUVmax of PT (n=15, average highest SUVmax of LN=16) are 25.6 (95% CI: 13.3-35.9) and 14.3 (95% CI: 7.0-20.2) months respectively (p=0.05). There is no significant correlation between overall survival and SUVmax using SUVmax of PT of all patients (p=0.53), SUVmax of PT of patients with the highest SUVmax in PT (p=0.44), or the highest SUVmax among PT and LN of all patients (p=0.48).

Conclusions This study showed a trend of worse overall survival of stage III NSCLC patients with SUVmax in any regional lymph nodes equal to or greater than SUVmax in the primary tumor on pre-therapy 18F-FDG PET/CT. This information may help to identify patients with poor prognosis and for whom additional or modified treatments may be designed accordingly. This study showed no prognostic value of SUVmax alone on pre-therapy 18F-FDG PET/CT for overall survival.