Department of Radiation Medicine

Nina Mayr, MD, Chair

Radiation Medicine serves cancer patients through applied medical research, education of medical specialists and personalized use of the latest radiation technology and treatments. The 73-member team includes five attending physicians, five medical physicists, four radiation oncology residents, two physics residents and a support staff of radiation dosimetrists, therapists, nurses and students. They work in a 33,000-square-foot facility that is housed in Ohio State’s James Cancer Hospital and Solove Research Institute and includes a treatment planning CT (computed tomography) simulator, access to molecular imaging-based therapy planning with positron emission tomography/computed tomography (PET/CT), and 3-dimensional treatment planning for conformal and intensity modulated radiation therapy and stereotactic radiosurgery. It also has two dual energy and two 6 MV linear accelerators, one with single-fraction stereotactic radiosurgery and fractionated central nervous system stereotactic radiotherapy capabilities, an intraoperative electron beam linear accelerator, and an upgraded gamma knife. The Brachytherapy Program offers permanent or temporary applications as well as intraoperative procedures and novel radionuclide therapies.

Ongoing Research Programs

The Department’s research programs have focused on the use of anatomical and functional tumor imaging for radiation therapy planning and therapy-response monitoring, and on radiation therapy targeting delineation for radiation therapy delivery, outcome prediction and tumor-response modeling of radiation therapy and multimodality cancer therapy.

Research Accomplishments of 2006

Functional and anatomical imaging-based tumor outcome prediction – Work has continued on this National Institutes of Health-funded research that focuses on developing an imaging-based predictive assay for cervical cancer (PI: Nina Mayr, MD). Scientists made five presentations on the subject in 2006, including three at the Annual Scientific Meeting of the American Society of Therapeutic Radiology and Oncology. Presenting were Mayr, Jian Wang, PhD, John Grecula, MD, and Hualin Zhang, PhD. Updated results were presented in a Special Focus Session titled “Cancer: Early Predictors of Tumor Responses” at the 2006 Annual Scientific Meeting of the Radiological Society of North America. This pioneering work, published in the American Journal of Roentgenology, demonstrated for the first time that tumor regression occurs in non-linear fashion and supported the use of three-dimensional imagingbased tumor volumetry instead of simple diameter- based measurements for response assessment and outcome prediction in cervical cancer.
Radiation Medicine established further collaborations with the departments of Radiology, Pathology, and Obstetrics and Gynecology, along with the College of Public Health, to develop a personalized multimodality algorithm for response monitoring and prediction of tumor response to cytotoxic therapy in patients with cervical cancer. The Department also is expanding this concept with other tumors. John Grecula, MD, has applied for a grant to help develop imaging-based predictive paradigms in lung cancer therapy. The research focuses on radiation therapy targeting and includes the continuation of tumor target delineation (Nilendu Gupta, PhD) with the development of an anatomical atlas for target delineation in radiation therapy. Manual and automated methods, as well as standardization of delineation techniques for tumor targets and normal tissue volumes, are being intensively investigated and developed in Radiation Medicine.
The team further concentrated on computational methods of radiation therapy optimization, including more effective dose prescription in highly focused radiation therapy for brain lesions treated with the Gamma Knife (Simon Lo, MD, and Joseph Montebello, MD) and other technologies (Nina Mayr, MD). Work on novel methodologies of Gamma Knife dosimetry planning, which can reduce the dose to normal brain tissue, was presented at the 2006 Annual Meeting of the Society of Neuro-Oncology. Results on the use of radiation grid therapy, a novel modality to improve dose delivery in treating melanoma and debulking large tumors, was presented at the Annual Meeting of the American Society of Therapeutic Radiology and Oncology by Hualin Zhang, PhD.
Research by Jian Wang, PhD, on response modeling expanded after his initial pioneering work on theoretical radiobiological modeling studies of prostate cancer response. The model with parameters established by Wang provides the most consistent interpretation of clinical data available for prostate cancer. It also provides a unifying hypothesis for resolving longstanding controversies regarding radio sensitivity and extremely low clonogen numbers in prostate cancer, with full consideration of various clinical effects. The Department has published two articles and presented several abstracts at national conferences regarding this work, which has expanded to include serial imaging-based tumor outcome databases in cervical cancer to model biophysical aspects of tumor response. High correlations have been found between temporal tumor response dynamics and ultimate tumor control and treatment outcome. A kinetic model has been developed to describe the tumor radiosensitivity and regression process of cervical cancer during radiation therapy. Abstracts have been presented on the subject at the American Society of Therapeutic Radiology and Oncology, the Annual Biomedical Imaging Research Opportunity Workshop, and the International Society for Magnetic Resonance Imaging in Medicine.