Dynamic contrast-enhanced magnetic resonance imaging in the early evaluation of anti-angiogenic therapy in metastatic renal cell carcinoma.

Aim: To evaluate the efficacy of dynamic contrast-enhanced magnetic resonance (DCE-MR) in the response to anti-angiogenic-targeted agents in patients with metastatic renal cell cancer (mRCC). Patients and Methods: Twenty-eight consecutive patients with sub-diaphragmatic metastases from mRCC were included in the protocol after signed informed consent. Baseline characteristics were collected and patients were first evaluated with a baseline computed tomography (CT) and DCE-MR, subsequently with a new DCE-MRI after 28 days of therapy and followed-up with CT until progression. Treatments were administered at standard doses. The changes of peak enhancement (Delta PE) and of the sum of longest tumor diameters (Delta LTD) were related to progression-free survival (PFS) and overall survival (OS). Results: The median PFS was 11.4 months [95% Confidence Interval (CI): 7.9-14.7 months) and the parametric two-tailed Pearson's test showed a positive correlation between the median Delta PE and the median PFS (rp=0.809; p=0.015); no significant correlation was found between the median Delta LTD and the median PFS (rp=-0.446; p=0.27). The median OS was 23.3 months (95% CI: 13.6-33.0 months) and no significant correlation was found with the median Delta PE (rp=0.218; p=0.60) or with the median Delta LTD (rp=0.012; p=0.98). Conclusion: The APE but not the Delta LTD was found to be significantly related to PFS; these preliminary results suggest extending the number of patients and investigating the possible relationship with other tumor characteristics and MRI parameters.