Professor Emeritus

In addition to general radiation oncology, Dr. Peter Mahler has a strong interest in palliative care. Approximately one half of all radiation oncology patients are treated with palliative intent. A significant fraction of those treated with curative intent develop recurrence months to years after their initial therapy and become palliative patients. Therefore, it is incumbent upon radiation oncologists to have well-honed palliative care skills in order to best serve their patients.

Dr. Ritter is a professor emeritus of Human Oncology and Medical Physics at the University of Wisconsin–Madison. Although he retired from active clinical service in 2018, he is still engaged in research, teaching and mentoring. My translational and clinical research focuses on genitourinary and gastrointestinal oncology. He has long-standing interests in the impact of tumor kinetics on tumor treatment response, exploring molecular and imaging biomarkers that predict or serve as surrogates for radiation response and investigating the impact of radiation hypofractionation on tumor response, particularly for prostate cancer.

The Rapraeger Lab was the first to demonstrate that syndecans contain “cell binding” motifs in their extracellular domains. The importance of this finding soon became clear when it was realized that such sites are critical for the signaling by growth factor receptor tyrosine kinases (RTKs) in tumor cells. RTKs and integrins have well-established roles in tumor cell proliferation, invasion and survival, often functioning in a coordinated fashion at sites of cell-matrix adhesion.

I am a professor emeritus in the Departments of Human Oncology and Medical Physics. I am engaged in clinical physics activities, focusing primarily on emerging applications of magnetic resonance imaging (MRI) in radiation therapy. My work is focused on understanding the impact of MRI-integrated radiation therapy systems on the delivery of radiation therapy. Real-time MR imaging provides high-quality images with superior soft-tissue contrast. This ability has contributed to innovative approaches to managing respiratory and cardiac motion as well as the impact of gastrointestinal processes. New MR acquisition techniques reduce imaging times and provide 3D MR images with a large field of view (FOV) for short breath hold. Image-based breath-hold management for gating promises to be relatively superior to operator guidance.