[Evaluating the short-term effect of gefitinib in advanced lung adenocarcinoma with positive EGFR-mutant by dual source volume perfusion CT].

Objective: To investigate tumor vascularity by dual source volume perfusion computed tomography (VPCT) in advanced lung adenocarcinoma with positive EGFR-mutant and determine whether any of the VPCT parameters would predict the tumor response to gefitinib.

Methods: Twelve patients (5 males and 7 females, Median age: 53 years, range: 36 - 69 years) with advanced lung adenocarcinoma received VPCT scan. All patients with positive EGFR-mutant were confirmed by pathological biopsy. After a 6-week therapy of gefitinib, VPCT was repeated and the short-term effect evaluated by the RECIST criteria. The VPCT parameters (blood volume, blood flow and permeability surface) of 12 patients were compared with their differentiation grade and short-term effect.

Results: Short-term effects were poor in those cases in whom BF increased after a 6-week of targeted therapy (P = 0.030). BF and PS at pre-therapy were negatively correlated with differentiation grade (r = -0.603, -0.694, P = 0.038, 0.012). There was a negative correlation between the rate of BF decline and differentiation grade (r = -0.686, P = 0.029); a negative correlation existed between the trend of BF and RECIST criteria (r = -0.707, P = 0.010). But there was no significant correlation with differentiation grade (P = 0.059). If the BF decline was considered effective, the dual source VPCT could predict the effect of RECIST criteria. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of VPCT was 100%, 66.7%, 83.3%, 75% and 100% respectively.

Conclusion: Dual source VPCT of advanced lung adenocarcinoma can assess effectively tumor vascularity and perfusion changes after the therapy of gefitinib. It is important in evaluating the response of targeted therapy in lung cancer.