• Perfusion CT in Patients With Metastatic Renal Cell Carcinoma Treated With Interferon

    AJR:194, January 2010

    Chaan S. Ng, Xiaohong Wang, Silvana C. Faria, E. Lin, Chusilp Charnsangavej, Nizar M.Tannir

    OBJECTIVE. The objective of our study was to assess the potential value of tumor per­fusion parameters measured by perfusion CT as possible biomarkers of prognosis and early indicator of treatment efficacy in patients with metastatic conventional renal cell carcinoma (RCC) treated with interferon.


    MATERIALS AND METHODS. This study comprised 37 patients with metastatic RCC who were enrolled in a larger (n = 118) randomized clinical trial of intermediate- ver­sus low-dose interferon. Tumor perfusion parameters—that is, tumor blood flow, blood vol­ume, mean transit time (MTT), and permeability-surface area product—of index metastatic lesions were obtained at baseline and at 8-week follow-up. Baseline perfusion parameters and changes at follow-up were compared, and their associations with patient progression-free sur­vival were estimated. Univariate and multivariate analyses were performed.


    RESULTS. Twenty-eight patients were assessable. Median progression-free survival was 5.3 months (95% CI, 2.4-7.4 months), with one partial response. Tumor blood flow at base-line was inversely associated with patient progression-free survival in both univariate (hazard ratio [HR] = 1.006, p = 0.025) and multivariate (HR = 1.007, p = 0.012) analyses. There were significant increases in tumor blood flow and reductions in MTT on follow-up scans com­pared with baseline scans (both, p = 0.04), but no association between changes in perfusion parameters and progression-free survival was detected.


    CONCLUSION. Patients with highly vascularized metastatic RCC as shown by high baseline tumor blood flow appear to have a worse prognosis than those who do not. Tumor perfusion may be a useful biomarker of prognosis and additionally, in the future, may assist in treatment stratification. The potential utility of perfusion CT as an early response indicator was probably inadequately assessed in this study because of the limited antiangiogenic activ­ity of interferon in metastatic RCC.