Radiation Biology Shared Resource

Marjan Boerma, Ph.D.

Radiation Biology Shared Resource Director

Marjan Boerma, Ph.D., is a Professor of Pharmaceutical Sciences in the UAMS College of Pharmacy, where she directs the Division of Radiation Health. She serves as Associate Director of Basic Science and Director of the Radiation Biology Shared Resource. Boerma has over 20 years of experience in radiation biology, and her research interests focus on normal tissue injury from ionizing radiation and cancer therapy. She oversees the overall administration of the Radiation Biology Shared Resource and ensures radiation safety and animal research compliance regulations are met.

• Rupak Pathak, PhD, Project Coordinator –  Pathak is an Associate Professor of Pharmaceutical Sciences in the College of Pharmacy, Division of Radiation Health. In the past 18 years, his research has focused on the effects of ionizing radiation on chromosomal damage, endothelial biology, platelet-immune interaction, and normal tissue response. He assists investigators at UAMS in designing and validating their radiation research models and trains research staff and students in operating radiation equipment.
• Kimberly Krager, PhD, Core Manager – Krager is an Assistant Staff Scientist in the College of Pharmacy, Division of Radiation Health. She has worked extensively in the radiation biology field for the past 20 years, with ten of those years at UAMS. She oversees the maintenance of equipment, helps plan experiments, and operates the irradiators and the MRI instrument.
• Tatiana Wolfe, PhD, Medical Physicist -Wolfe is an Assistant Professor of Psychiatry in the College of Medicine and a Medical Imaging Physicist with the UAMS Brain Imaging Research Center. She has over a decade of experience in MRI physics and technology, focused on translational pre- and clinical research. She develops MRI protocols as needed for Radiation Biology Shared Resource users and oversees the work performed on the 7T MRI instrument.

The Radiation Biology Shared Resource performs maintenance of radiation equipment and radiation dosimetry, provides consultation in design and development of new animal and cell culture radiation models, and performs whole-body or localized irradiation of animal models and cell cultures. While the services provided by the Radiation Biology Shared Resource are mainly related to radiation therapy, the shared resource also assists with a range of other research studies, including the irradiation of small laboratory animals in preparation for bone marrow transplantation and for studies that develop medical countermeasures for scenarios of accidental radiation exposure.

The Radiation Biology Shared Resource performs radiation dosimetry to ensure that the output of the radiation equipment is accurate. Radiation dosimetry is performed at least twice a year with chromatographic film and properly calibrated ionization chambers. In addition, phantom-based dosimetry is performed to confirm absorbed radiation dose in individual animal models. Radiation dosimetry is performed in collaboration with the manufacturers of the radiation equipment and with assistance of board-certified medical physicists in the UAMS Department of Radiation Oncology.

The Radiation Biology Shared Resource maintains and operates equipment and facilities to deliver ionizing radiation for research use. The shared resource can deliver X- and γ-rays at a broad range of dose rates and radiation field sizes for a variety of purposes, such as irradiation of cell cultures, animal whole-body irradiation, localized irradiation in animal tumor models, or other (image-guided) partial-body irradiation. Equipment is located in the Winthrop P. Rockefeller Cancer Institute and includes a self-contained g-ray irradiator.(Mark 1, model 68A, J.L. Shepherd), an X-ray cabinet (X-Rad 320, Precision X-ray), and a small-animal radiation research platform (SARRP, Xstrahl). The Radiation Biology Shared Resource also maintains and operates a 7T MRI system (PharmaScan, Bruker).

• g-ray irradiator  – This is a self-contained irradiator (J.L. Shepherd) designed for mouse whole-body and partial-body and cell culture exposures to γ-rays. A turntable ensures an even exposure of the animal or sample. Radiation dose rate can be adjusted by attenuators and distance to the source. Animal partial-body irradiation is performed with the help of shielding material.
• Precision X-Ray X-Rad320 – The Precision X-Ray, X-Rad320, is a self-contained X-ray system used for mouse and rat whole-body and partial-body and cell culture exposures to X-rays (maximum output voltage: 320 kV). A turntable ensures an even exposure of the sample. Radiation dose rate can be adjusted by attenuators and distance to the source. Animal partial-body irradiation is performed with the help of collimators or shielding material.
• Xstrahl SARRP – The Xstrahl SARRP incorporates cone-beam computed tomography (CBCT) imaging and radiation planning software (MuriPlan) to deliver precise X-ray beams (maximum output voltage: 220 kV) down to 1 mm diameter to anatomical targets (tumors and normal tissues) of mice and rats, similar to clinical radiation therapy. The SARRP has fixed collimators, a motorized variable collimator, and a respiration gating system. For added precision in radiation targeting, additional animal imaging data can be imported into the planning software for image fusion with the CBCT.
• Bruker PharmaScan 7T – The PharmaScan 7T provides high-resolution non-invasive imaging of mice, rats, and other small animals in a wide range of applications. The PharmaScan 7T is used for the quantification of tumors and normal tissue structures in small-animal models, as well as functional imaging, such as in the brain. Imaging modalities include T1- and T2-weighted imaging, diffusion tensor imaging, and proton magnetic resonance spectroscopy.