image_pdfimage_print

Listening to Dr. Heinz-Otto Peitgen talk about the recent developments in breast cancer diagnosis and treatment on which he and Dr. Kathy Schilling have collaborated, you are awed by how far they have advanced the state of the art. By combining their expertise, Dr. Peitgen is a mathematician and Dr. Schilling is a radiologist, they have developed new, more effective ways to uncover breast cancers and optimize their treatment compared to more conventional approaches such as mammography.

The research started in 1995 by looking at the body, a natural, living system, in mathematical terms. According to Dr. Peitgen, “Fractals in particular deal with the geometry of nature.” Applying fractal geometry as the initial basis for his work, Dr. Peitgen has been able to work with Dr. Schilling to enhance the use of MRI imaging as a potent tool for the detection of breast cancer.

Contrast enhanced MRI of breast showing multiple lesions in three dimensions. Two dimensional mammography would likely not identify all the lesions seen in MRI.

Fractal geometry is an area of mathematics which is used to describe shapes that are ‘self-similar’. Look at a tree and its repeating branching structure or vegetables such as broccoli and cauliflower. Notice the similarity of the whole vegetable to the smaller parts of which it is made. These are examples of how fractals can be used to study natural geometric shapes including ductal and vascular systems within our bodies such as a breast, our liver, other organs or tumors.

Dr. Peitgen has been working with Dr. Kathy Schilling at Boca Raton Community Hospital to test and refine a new approach to diagnosing and treating breast cancer. Dr. Schilling reports, “With the use of the DynaCAD system, developed by the scientists at MeVis, under the direction of Dr. Peitgen, we are able to confidently review the hundreds of MRI images generated during each breast exam. We have found that we are able to detect 32% more cancer than detected with mammography, ultrasound and physical exam in patients with recently diagnosed breast cancer.”

Enhanced MRI images of the breast provide radiologists with a detailed, three-dimensional view of the breast and tumors compared to the two dimensional view produced by mammograms. In two-dimensional views, some tumors inside the breast can be hidden behind other tumors or structures. For example a large tumor may hide the existence of additional smaller tumors depending upon the projected view produced by the mammogram. Unaware of the additional tumors, follow up biopsies may not be targeted well enough to uncover other cancer sites resulting in less than optimal treatment.

Focusing on the larger tumor, a lumpectomy may be selected as the course of treatment. However, smaller cancer sites may remain undetected and untreated and at a later time result in what may be considered a ‘reoccurrence’ of the cancer when in fact it was always there, just not detected.

The Peitgen-Schilling team is further enhancing the MRI’s diagnostic effectiveness with the use of contrast agents. Contrast agents are special dyes given to the patient to enhance the visualization of the cancer sites throughout the breast. According to Dr. Peitgen, cancers have some very unique properties such as massive angiogenesis, or the formation of large masses of new blood vessels to feed the growing tumor. Different from normal blood vessels, the blood vessels feeding the cancerous tumor tend to have vessel walls which leak more blood into the surrounding cellular mass. He says, “Two things happen when you have cancer, a new vascular system grows around a cancer and these new vascular systems are very leaky versus non-cancerous vascular systems.” Taking advantage of this unique property and using specialized software developed by Dr. Peitgen’s technical team, the flow of the contrast agents are tracked by MRI every few minutes as they flow through the breast being studied. The images produced show a full, three dimensional image of the breast with the contrast agents highlighting the cancerous areas.

Contrast enhanced MRI of a breast with lesions undergoing chemotherapy. The red regions are still active, while the blue ones appear to be necrotic.

The new MRI tool can better target locations for taking samples for biopsy. The MRI tool helps guide the needle to the exact locations in the breast where cancer is suspected. This results in much more accurate targeting of the biopsy samples and resulting surgery. Commenting on the benefits of this new approach, Dr. Schilling said, “As a result of using this new system we are able to direct the surgeon appropriately so all disease is removed at the initial surgery. This should result in a decrease in recurrence rate in the future.” Dr. Schilling continued, “Additionally, in 9% of patients we found unsuspected breast cancer in the opposite breast. Thus this new tool will significantly enhance the surgical planning.”

Not only can these enhanced MRI images detect the presence of cancers, but amazingly they can show if some cancerous areas are more active than others. This has led Drs. Schilling and Peitgen to investigate how they can use these images to assess the effectiveness of chemotherapy on the cancer. Historically, physicians relied only on the size of a tumor to judge how well the chemotherapy was working. If the tumor was reduced in size, they concluded the chemotherapy was working. However, in some cases the cancer can become inactive or necrotic and not change in size. Since the new MRI tool can measure the activity of the cancer, it can assess the effect of chemotherapy on each specific cancer area independent of its increasing or decreasing size. This will allow physicians to more accurately and effectively administer cancer killing therapies.

A new direction being explored by the Peitgen-Schilling team involves the potential for using fractal geometry to analyze the shape, pattern and roughness of the cancer to determine the stage of its development. “However, this has not been proven yet,” comments Dr. Peitgen.

Currently, about 150 sites are using enhanced MRI imaging systems to better diagnose and treat breast cancer. Summarizing the positive results of the development of these new systems, Dr. Schilling said, ” We believe through the use of this new imaging modality we will be able to detect cancers in patients at high risk for developing breast cancer, at an earlier and more treatable stage thus reducing suffering and saving lives.”

Dr. Peitgen is currently a professor of Mathematics and Biomedical Sciences at Florida Atlantic University and the University of Bremen in Germany. Dr. Peitgen is also the founder and president of MeVis – Center for Medical Diagnostic Systems and Visualization, GmbH in Bremen, Germany. On February 21, 2006 he and the father of fractal geometry, Benoit Mandelbrot, were inducted as fellows into the Hall of Fame at Florida Atlantic University’s Charles E. Schmidt College of Sciences for their world-class work and achievements involving fractals. Dr. Kathy Schilling is a radiologist and Medical Director of Breast Imaging and Intervention at the Center for Breast Care at Boca Raton Community Hospital.