Abstract: Background and purpose: Clinical data show that Endostar, a recombinant human endostatin, has the therapeutic benefit for patients with non-small cell lung cancer (NSCLC) while combined with chemotherapy or radiotherapy. However, the microenvironment changes induced by Endostar monotherapy in NSCLC is not yet clear. The purpose of this study was to prospectively study tumor vascular effects of Endostar monotherapy in patients with locally advanced or advanced NSCLC by dynamic contrast-enhanced perfusion computed tomography (CT perfusion, CT-p). Methods: Previously untreated patients with histologically or cytologically confirmed locally advanced or advanced NSCLC were eligible. All patients received daily Endostar (7.5 mg⁄m²) for 14 days. CT-p scans were acquired at the baseline and post-treatment. CT-p parameters, such as blood flow (BF), blood volume (BV) and permeability surface PS (area product), were measured in all patients. Results: Of all 7 patients enrolled, four were staged as ⅢB and three as stage Ⅳ (2 with malignant pleural effusion, 1 with brain metastasis). The median BF, BV and PS values of baseline and post-treatment were 27.1/48.9 mL/100 mL/min, 86.8/84.8 mL/100 mL and 45.0/54.0 mL/100 mL/min, respectively. After administration of Endostar for 14 days , BF showed a significant increase compared with that at baseline (P=0.028), whereas no significant changes were found in BV (P=0.398) and PS (P=0.237) values. Conclusion: Our results suggest that Endostar monotherapy induces a significant increase in BF whereas no significant difference in BV and PS.

Key words: Non-small cell lung cancer, Endostatin, CT perfusion, Microenvironment