A preliminary assessment of an ultrasonic Doppler method for the study of blood flow in human breast cancer.

A 10 MHz, continuous wave ultrasonic Doppler system was used to study the blood flow associated with normal and malignant mammary tissue in patients with breast cancer. Some patients were receiving endocrine therapy and were examined repeatedly over a period of months. each of 6 characteristics extracted from the time varying maximum Doppler-shift frequency were averaged over signals obtained from a number of sites in the vicinity of the tumour, and from corresponding sites in the normal breast. A method was devised to allow location of previously examined vessels for subsequent examinations. The preliminary results of analysing approx. 400 recordings of Doppler signals obtained from 16 patients (6 of whom received endocrine therapy) are presented. The most informative of the 6 characteristics were the maximum systolic frequency (A) and the "mean" frequency (M) (= A + B/2 where B is the maximum frequency during end diastole). The average values of A and M obtained from the tumourous breast were always greater than those obtained from the normal breast in the same patient. A and M were roughly proportional to tumour volume, with extrapolated values at zero volume only slightly greater than the corresponding mean values for normal breast tissue. On average, changes in the values of A and M obtained from tumour sites during endocrine therapy appeared to occur in association with, and possibly slightly in advance of, changes in the tumour volume.