OBJECTIVETo study the significance of intra-tumoral cavitation in the patients with advanced NSCLC treated by rh-endostatin plus NP chemotherapy.

METHODSFifty-seven patients with advanced NSCLC were randomly assigned to receive chemotherapy with rh-endostatin plus NP or NP alone. The numbers of activated circulating endothelial cells (aCECs) were measured by flow cytometry. Chest computed tomography was performed to evaluate the efficacy after 2 cycles of chemotherapy.

RESULTSCavitation occurred in 5 of 29 patients in the rh-endostatin plus NP group, but not in any case of the NP group. Of the 5 patients, there were 2 males and 3 females, with pathological types of 3 adenocarcinomas, 1 adenosquamous cell carcinoma and 1 sarcomatoid carcinoma. All of these 5 cases had a peripherally located tumor in the CT scan. There was only one cavity in each case and most of these were roundish. Four cavities were situated in the center of the tumor and another one was eccentric. There were 3 cavities with thin wall and 2 with thick wall. Their average diameter was 2.7 cm. No hemoptysis occurred in these 5 patients. The blood-supply of the tumors showed by perfusion CT images was inhibited in 3 cases after treatment. The average number of aCECs decreased from 323.2/10(5) to 33.0/10(5) after treatment.

CONCLUSIONIntratumoral cavitation is a peculiar imaging characteristics after anti-angiogenic therapy, which may be caused by inhibition of blood-supply to the tumor. CT perfusion imaging and measurement of activated circulating endothelial cells may be helpful to predict the efficacy of anti-angiogenic therapy combined with chemotherapy.