Tumor angiogenesis at baseline identified by 18F-Alfatide II PET/CT may predict survival among patients with locally advanced non-small cell lung cancer treated with concurrent chemoradiotherapy

Background The study investigated the predictive value of tumor angiogenesis observed by F-18-ALF-NOTA-PRGD2 II (denoted as F-18-Alfatide II) positron emission tomography (PET)/computed tomography (CT) before concurrent chemoradiotherapy (CCRT) for treatment response and survival among patients with locally advanced non-small cell lung cancer (LA-NSCLC). Methods Patients with unresectable stage IIIA or IIIB NSCLC (AJCC Cancer Staging 7th Edition) who received CCRT were included in this prospective study. All patients had undergone F-18-Alfatide PET/CT scanning before CCRT, and analyzed parameters included maximum uptake values (SUVmax) of primary tumor (SUVP) and metastatic lymph nodes (SUVLN) and mean uptake value of blood pool (SUVblood). Tumor-to-background ratios (TBRs) and changes in tumor diameter before and after CCRT (Delta D) were calculated. The ratios of SUVP to SUVblood, SUVLN to SUVblood, and SUVP to SUVLN were denoted as TBRP, TBRLN, and T/LN. Short-term treatment response, progression-free survival (PFS), and overall survival (OS) were evaluated. Results Of 38 enrolled patients, 28 completed CCRT. SUVP, SUVLN, TBRP, TBRLN and T/LN showed significant correlation with PFS (all P < 0.05). SUVP was negatively correlated with OS (P = 0.005). SUVP and TBRP were higher in non-responders than in responders (6.55 +/- 2.74 vs. 4.61 +/- 1.94, P = 0.039; 10.49 +/- 7.58 vs. 7.73 +/- 6.09, P = 0.023). Delta D was significantly greater in responders (2.78 +/- 1.37) than in non-responders (-0.16 +/- 1.33, P < 0.001). Exploratory receiver operating characteristic curve analysis identified TBRP (area under the curve [AUC] = 0.764, P = 0.018), with a cutoff value of 6.52, as the only parameter significantly predictive of the response to CCRT, with sensitivity, specificity, and accuracy values of 71.43%, 78.57%, and 75.00%, respectively. ROC curve analysis also identified SUVP (AUC = 0.942, P < 0.001, cutoff value 4.64) and TBRP (AUC = 0.895, P = 0.001, cutoff value 4.95) as predictive of OS with high sensitivity (84.21%, 93.75%), specificity (100.00%, 66.67%), and accuracy (89.29%, 82.14%). Conclusions Evaluation of tumor angiogenesis by F-18-Alfatide II at baseline may be useful in predicting the short-term response to CCRT as well as PFS and OS in patients with LA-NSCLC.