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 (ΔPE) and of the sum of longest tumor diameters (ΔLTD) 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 ΔPE and the median PFS (rp=0.809; p=0.015); no significant correlation was found between the median ΔLTD 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 ΔPE (rp=0.218; p=0.60) or with the median ΔLTD (rp=0.012; p=0.98). Conclusion: The ΔPE but not the ΔLTD 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.