Efficacy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography as a predictor of response in locally advanced non-small-cell carcinoma of the lung.

OBJECTIVE: The study assessed the role of (18)F-fluorodeoxyglucose ((18)F-FDG) Positron emission tomography (PET)/computed tomography (CT) in evaluating the prognostic value of metabolic response for progression-free survival (PFS) and overall survival (OS) in patients with locally advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS: Thirty patients with locally advanced NSCLC were enrolled in this prospective study and randomly allocated to one of two treatment arms. Arm A (n=15) received two cycles of neoadjuvant chemotherapy [paclitaxel (200 mg/m(2)) and carboplatin (AUC5)] and external beam radiotherapy (60 Gy/30 fractions/6 weeks). Arm B (n=15) received the same neoadjuvant chemotherapy followed by external beam radiotherapy (48 Gy/20 fractions/4 weeks) with concomitant cisplatin 30 mg/m(2) weekly. Patients underwent (18)F-FDG PET/CT at baseline and after 6 weeks of completion of intended treatment. Pretreatment and post-treatment maximum standardized uptake values (SUVmax) were noted. Patients with a reduction of SUVmax more than 50% were considered to be metabolic responders and those with a reduction 50% or less as nonresponders. Median follow-up was 18.98 months.

RESULTS: Twenty-one patients completed the intended treatment. The median pretreatment and post-treatment SUVmax values were 14 and 6.4 for arm A and 15.3 and 3.5 for arm B, respectively. Significant decrease in SUVmax was observed in both arms. Metabolic response in arm A and arm B was 50 and 64%, respectively. The median PFS and OS of the responders were 22.31 and 24.73 months and those for nonresponders were 7.83 and 8.26 months, respectively. No significant difference in OS and PFS was observed between responders and nonresponders in the two arms.

CONCLUSION: PET/CT distinguishes responders from nonresponders early after completion of chemoradiation in patients with locally advanced NSCLC, but did not provide any prognostic significance.