ASSESSMENT OF TUMOR VASCULARITY BY MEANS OF DOPPLER SONGRAPHY

Tumor vessels are structurally and functionally abnormal. The degree o f vascularity determines a tumor's aggressiveness, as well as its radi osensitivity and chemosensitivity. Assessing tumor vascularity may hel p in differential diagnosis and assist therapy monitoring. Together wi th other imaging methods, Doppler sonography has been evaluated for th e assessment of tumor vascularity but has proven to be difficult to ev aluate. Using quantitative analysis methods, Doppler sonography was sh own to carry differential diagnostic and prognostic information as wel l as to reflect vascular changes during radiotherapy. Its clinical rol e, however, remains to be determined. With current technology, neither blood volume flow nor microvessel density can be reliably assessed in a tumor using Doppler sonography, because it is insensitive to capill ary blood flow. Upcoming developments such as harmonic imaging and con trast media that generate stimulated acoustic emissions are expected t o significantly improve sensitivity.