Paper 533

Abstract Title:

CHAOTIC PATTERNS OF MALIGNANT AND NON-MALIGNANT BREAST TISSUE EXPRESSED BY FRACTAL DIMENSIONS OF BACKSCATTERED LIGHT  A NEW METHOD OF CANCER DIAGNOSIS

Authors:

F. Wierrani, M. S|ssenbacher , B. Spdngler, A. Kubin, W. Gr|nberger and R.H. Jindra

Institutions:

Rudolfstiftung Hospital, Vienna, AustriaLudwig Boltzmann Institute for Clinical Oncology and Photodynamic Therapy, Vienna, Austria

Key Words:

Abstract:

Chaotic run of events results in mechanisms developing fractal structures which are calculable using the chaos theory. Our objective was to determine differences of chaotic patterns of different breast conditions expressed by fractal dimensions [FD] calculated on time series of back scattered light with a specially established software.
Single measurements were made at one point as a function of time. Light provided by a laser [670 nm, 0.8 mW] backscattered from tissue, is converted into an electrical signal which is further amplified and displayed as a curve on an oscilloscope. FD is obtained by calculating the integral correlation function for increasing embedding dimensions [N = 2,.....8] which are depicted in a double logarithmic scale.
By means of 96 painless measurements on 12 healthy patients [confirmed by palpation and sonography] the average FD of healthy breast tissue was established as 2.37 1 0.18.
Tissue was defined pathological if the FD value was more than or equal to one standard deviation below the FD mean of healthy tissue [e.g. FD < 2.19]. This procedure was applied to seventeen patients with various breast conditions [previously diagnosed by palpation and imaging techniques and afterwards confirmed by histological examination of the exstirpated tumor]. Positive selection criterias required that the tumor was less than 2 cm under the surface of the breast because of the low penetration depth of the laserlight (670 nm) and that it4s diameter was more than one centimeter as shown by mammography and sonography.
Examination technique with backscattered light yielded a sensitivity of 83.3 % and a specifity of 72.7 %. In our study diagnostic results were comparable to modern imaging techniques. We have found that biological tissue acts in a chaotic mode visible by fractal response and that differentiation of healthy from malignant tissue is possible by the fractal dimension.