Perfusion CT allows prediction of therapy response in non-small cell lung cancer treated with conventional and anti-angiogenic chemotherapy.

OBJECTIVES

To determine whether CT can depict early perfusion changes in lung cancer treated by anti-angiogenic drugs, allowing prediction of response.

METHODS

Patients with non-small cell lung cancer, treated by conventional chemotherapy with (Group 1; n = 17) or without (Group 2; n = 23) anti-vascular endothelial growth factor (anti-VEGF) drug (bevacizumab) underwent CT perfusion before (TIME 0) and after 1 (TIME 1), 3 (TIME 2) and 6 (TIME 3) cycles of chemotherapy. The CT parameters evaluated included: (1) total tumour vascular volume (TVV) and total tumour extravascular flow (TEF); (2) RECIST (Response Evaluation Criteria in Solid Tumours) measurements. Tumour response was also assessed on the basis of the clinicians' overall evaluation.

RESULTS

In Group 1, significant reduction in perfusion was identified between baseline and: (1) TIME 1 (TVV, P = 0.0395; TEF, P = 0.015); (2) TIME 2 (TVV, P = 0.0043; TEF, P < 0.0001); (3) TIME 3 (TVV, P = 0.0034; TEF, P = 0.0005) without any significant change in Group 2. In Group 1: (1) the reduction in TVV at TIME 1 was significantly higher in responders versus non-responders at TIME 2 according to RECIST (P = 0.0128) and overall clinicians' evaluation (P = 0.0079); (2) all responders at TIME 2 had a concurrent decrease in TVV and TEF at TIME 1.

CONCLUSION

Perfusion CT demonstrates early changes in lung cancer vascularity under anti-angiogenic chemotherapy that may help predict therapeutic response.

KEY POINTS

• Perfusion CT has the potential of providing in vivo information about tumour vasculature. • CT depicts early and specific perfusion changes in NSCLC under anti-angiogenic drugs. • Specific therapeutic effects of anti-angiogenic drugs can be detected before tumour shrinkage. • Early perfusion changes can help predict therapeutic response to anti-angiogenic treatment. • Perfusion CT could be a non-invasive tool to monitor anti-angiogenic treatment.