Prognostic value of DCE-CT-derived blood volume and flow compared to core biopsy microvessel density in patients with metastatic renal cell carcinoma

Abstract

Background Angiogenesis is prominent in metastatic renal cell carcinoma (mRCC). We compared two angiogenesis assessment methods: dynamic contrast-enhanced computed tomography (DCE-CT)-derived blood volume (BV) and blood flow (BF) and core biopsy microvessel density (MVD). Methods As planned in DaRenCa Study-1 study, DCE-CT and core biopsy were performed from the same tumour/metastasis at baseline. MVD was assessed by CD34 immunostaining in tumour (CD34-index T ) or tumour including necrosis (CD34-index TN ). BV and BF were assessed using the DCE-CT software. Overall survival (OS) and progression-free survival (PFS) were assessed by Kaplan-Meier analysis. Spearman coefficient (rho) tested the correlation between MVD and BV, BF, or CT density (HU). Results At baseline, 25 patients had analysable scans and tissue. BV deconv , BV Patlak , and BF deconv > median were associated with favourable OS (43.2 versus 14.6 months, p = 0.002; 31.6 versus 20.2 months, p = 0.015; and 31.6 versus 24.5 months, p = 0.019). CD34-index T and CD34-index TN did not correlate with age ( p = 0.543), sex ( p = 0.225), treatment ( p = 0.848), International mRCC Database Consortium category ( p = 0.152), synchronous versus metachronous metastatic disease ( p = 0.378), or tumour volume ( p = 0.848). CD34-index T or CD34-index TN > median was not associated with PFS ( p = 0.441 and p = 0.854, respectively) or OS ( p = 0.987 and p =0.528, respectively). CD34-index T or CD34-index TN was not correlated with BV, BF, or HU (rho 0.20–0.26). Conclusions Differently from MVD, DCE-CT-derived BV and BF had prognostic impact and may better reflect angiogenesis in mRCC. Trial registration NCT01274273