Maximum standardized uptake value from staging FDG-PET/CT does not predict treatment outcome for early-stage non-small-cell lung cancer treated with stereotactic body radiotherapy

Abstract

Purpose: To perform a retrospective review to determine whether maximum standardized uptake values (SUV(max)) from staging 2-deoxy-2- [(18)F] fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) studies are associated with outcomes for early-stage non-small-cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT).

Methods and materials: Seventy-two medically inoperable patients were treated between October 17, 2003 and August 17, 2007 with SBRT for T1-2N0M0 NSCLC. SBRT was administered as 60 Gy in 3 fractions, 50 Gy in 5 fractions, or 50 Gy in 10 fractions using abdominal compression and image-guided SBRT. Cox proportional hazards regression was performed to determine whether PET SUV(max) and other variables influenced outcomes: mediastinal failure (MF), distant metastases (DM), and overall survival (OS).

Results: Biopsy was feasible in 49 patients (68.1%). Forty-nine patients had T1N0 disease, and 23 had T2N0 disease. Median SUV(max) was 6.55 (range, 1.5-21). Median follow-up was 16.9 months (range, 0.1-37.9 months). There were 3 local failures, 8 MF, 19 DM, and 30 deaths. Two-year local control, MF, DM, and OS rates were 94.0%, 10.4%, 30.1%, and 61.3%, respectively. In univariate analysis, PET/CT SUV(max), defined either as a continuous or dichotomous variable, did not predict for MF, DM, or OS. On multivariable analysis, the only predictors for overall survival were T1 stage (hazard ratio = 0.331 [95% confidence interval, 0.156-0.701], p = 0.0039) and smoking pack-year history (hazard ratio = 1.015 [95% confidence interval, 1.004-1.026], p = 0.0084).

Conclusions: Pretreatment PET SUV(max) did not predict for MF, DM, or OS in patients treated with SBRT for early-stage NSCLC.