The lab pursues two main avenues of research. The first involves developing and applying new methods of high resolution 3D dosimetry. A range of uniquely capable state-of-the-art 3D dosimetry systems have been developed with funding support from the National Institute of Health. These systems are currently being applied to a diverse range of challenges in both the clinical (radiation therapy) and research domains. The second direction focuses on developing the new optical bio-imaging techniques of optical-computed-tomography (optical-CT), and optical-emission-computed-tomography (optical-ECT). These techniques have the potential to provide uniquely useful information on biological processes in bulk tumor and tissue samples.
High Resolution 3D Dosimetry
In the past few years, the Duke 3D Dosimetry Lab has established itself as one of the leading 3D dosimetry groups in the world. The Lab has received NIH R01 funding to develop optical imaging techniques for 3D dosimetry. Key aims of the Lab include (i) elevating the state-of-the-art for verification of advanced and new radiation therapy treatments, (ii) developing powerful new 3D dosimetry tools for diverse applications including proton-therapy, micro-beam therapy, pre-clinical cancer research, and the nuclear industry. Our research has demonstrated that the PRESAGE/optical-CT 3D dosimetry system can achieve these aims. The research involves a 3-party consortium combining expertise in 3D dosimetry (Duke) with clinical trials credentialing experience (Geoffery Ibbott at the RPC/MDACC), and radiochromic materials expertise (John Adamovics at Rider University). Recent projects are highlighted in the table below, and include the first comprehensive 3D investigations of the accuracy of IMRT deliveries in a cohorts of patients.
Separate from the work on 3D dosimetry, the lab also has a long-term collaboration with Dr. Mark Dewhirst’s group at Duke, which is focused on novel techniques for optical bio-imaging. Specifically, applying optical tomographic techniques to imaging unsectioned tissue samples. The primary aim is to investigate and optimize the new techniques of optical-computed-tomography (optical-CT) and optical-emission-tomography (optical-ECT), and establish their capability as powerful new tools of pre-clinical cancer biology. Optical-CT/ECT are the optical analogues of x-ray-CT and SPECT respectively. In conjunction with new techniques for rendering bulk tissue samples transparent to visible light, optical-CT/ECT can yield unique data unattainable by other modalities. Principally: high-spatial resolution (potentially 10-20µm), high contrast, precisely co-registered, three-dimensional (3D) images of the distribution of fluorescent reporter proteins and absorbing contrast agents in large un-sectioned tissue samples (up to ~8cc). This capability is of significant interest to cancer researchers because it provides, for the first time, data similar to that obtained from influential window-chamber studies, but in much larger tumors. Optical-CT/ECT have potential for very diverse application. Our initial work builds on funded work in Dr. Dewhirst's lab investigating novel therapeutics to reduce a critical cause of radiation and chemotherapy treatment failure: hypoxic-tumor resistance. We aim to image the 3D distribution of vasculature, HIF-1 and viable tumor in much larger tumors than has been possible before. Successful completion will establish optical-CT/ECT as powerful new tools of pre-clinical cancer biology, with diverse applicability, capable of providing unique data on key biological characteristics in larger tumors. The 'proof of principle' is to evaluate novel therapeutics for hypoxic-tumor-resistance. The results may help determine a new and effective therapeutic approach to this critical cause of radiation and chemotherapy treatment failure. Two papers from this research collaboration were selected for Phys Med Biol Highlights Edition in 2008 and 2010, and one was short-listed for the Robert’s Prize from the IOP.