Optimal use of imaging to guide treatment decisions for kidney cancer.
Treatment monitoring for solid tumors in general and for metastatic renal cancer in particular has been dominated by assessment of tumor burden via cross-sectional imaging. This poses a special problem for the mammalian target of rapamycin and vascular endothelial growth factor pathway-directed agents used in this disease. The standard RECIST metrics used to categorize "response" and "progression" are arbitrary and do not adequately capture the effect of these agents. Other approaches, including use of relative RECIST measures as a continuous variable, volumetric measurements, and functional assessments, such as dynamic contrast-enhanced magnetic resonance imaging-based quantitative variables and fluorodeoxyglucose-positron emission tomography, have been proposed as alternatives, but the data do not support their routine clinical use. Even fewer data are available on the use of baseline imaging characteristics to choose a specific therapy. Therefore, until further research on imaging predictive and intermediate biomarkers matures, a combination of standard cross-sectional imaging and clinical judgment is the most pragmatic option for treatment decision making for patients with metastatic renal cancer.
From the University of Chicago, Chicago, IL.
Walter M
WM
Stadler