Dr. Sadeghi is Chief of Medical Physics at Arizona Breast Cancer Specialists and Associate Professor with the University of Texas. He received his Ph.D. in Medical Physics from the University of Texas Health Science Center at San Antonio, Texas.

Dr. Sadeghi has over 15 years of experience in clinical physics in Radiation therapy. Prior to joining

Arizona Breast Cancer Specialists,

Dr. Sadeghi was a chief of Medical Physics at Texas Cancer Clinic and the clinical chief of medical physics at Cancer Therapy and Research Center where he was directly involved with some of the first patient treatments with Partial Breast Irradiation, real time prostate HDR and Stereotactic Radiosurgery. Dr. Sadeghi's extensive work with high dose rate brachytherapy, mostly with breast and prostate cancer, has lead to his providing an exclusive training program to radiation oncology residents through the American Brachytherapy Society. He has also formed a residency program for post graduate students in Medical Physics and graduate students through the University of Texas in San Antonio and the University of Arizona in Tucson. He is a member of the American Society for Therapeutic Radiology and American Brachytherapy Society.

Joy Witzel has worked as a Health Physicist for three years at the Audie L. Murphy VA Hospital in San Antonio Texas while obtaining her Master's Degree in Medical Health Physics. She then transferred to the CyberKnife clinic working for the South Texas Oncology Hematology group as a temporarily licensed Medical Radiation Oncology Physicist for several years.

Joy was accepted into our Medical Physics Residency Program in May 2011.

Greg Kohlhapp earned his Bachelor's of Science degree in radiation therapy from the University of Wisconsin - La Crosse. After working briefly as a radiation therapist, he was intrigued by the treatment planning involved with radiation treatments. He found the basic principles of radiation biology and radiation physics fascinating, so he decided to pursue a career in medical dosimetry.

Greg earned his Master's of Science degree in medical dosimetry from the University of Wisconsin - La Crosse. He works with both External Treatment Planning and Brachytherapy. He really enjoys working in radiation oncology and has had the opportunity to work with state-of-the-art technology on a daily basis and utilize this technology to fight cancer.