Research
The Bioheat Transfer Laboratory broadly engages in improving thermal therapies for the treatment of cancer and other disorders. Focused research areas include characterization of human tissue properties and bioheat transfer modeling for magnetic resonance-guided focused ultrasound (MRgFUS) thermal therapies. The lab aims to generate collaborative opportunities within and external to BYU, provide opportunities for undergraduate and graduate students to participate in basic to clinical research, and advance therapies with enormous potential for improving cancer treatment outcomes and patients’ quality of life.
Ongoing Research Projects
Why thermal therapies?
Therapies that ablate diseased tissue by the deposition of thermal energy can eliminate scalpel-driven surgical procedures, reducing both risk for infection and patient recovery times. They exclude ionizing radiation. In cases of recurrence, thermal therapies can be repeated without negative cumulative effects. Many vehicles for delivering thermal energy are in use and development, including FUS, radiofrequency (RF) ablation, laser treatments, and cryotherapy. If such therapies were consistently efficacious, cancer treatment paradigms could change radically.
Lab goals
While thermal therapies achieve their effect by driving energy into the target tissue, blood perfusion can simultaneously draw heat away, negating the treatment. Further, cancerous tumors and other pathologies exhibit highly variable vascularity, which is difficult to quantify and predict. When unaccounted for or poorly modeled, heat transport via these vessels increases thermal therapy unpredictability and can decrease the treatment’s benefit to the patient. The Bioheat Transfer Laboratory aims to address these issues with the goals described below. Our success will lead to accurate personalized treatment planning, improved consistency and safety of treatments, and greater clinical acceptance for thermal therapies.
Our group has previously developed a novel technique that uses 3D MRI temperature data to quantify perfusion-related thermal energy losses. However, in the pretreatment setting, the technique’s required heating is unacceptable. Recent MRI developments in perfusion quantification have opened the possibility of finding a link between non-heating perfusion measurements and the perfusion-related losses we can quantify. Establishing this link is a primary goal of the Bioheat Transfer Laboratory and will advance the goal of personalized and accurate treatment planning.
This technique for quantifying perfusion-related losses can also be used to evaluate models of bioheat transfer. A second Bioheat Transfer Laboratory goal includes the first study to use fully three-dimensional temperature data to critically evaluate the Pennes bioheat transfer equation (the most commonly applied biothermal model) and its spatiotemporal approximations. Future efforts include the development of a new equation to describe general bioheat transfer that would embrace the benefits of the Pennes model for diffuse capillary flow while addressing its limitations with improved local vascular modeling using convective vessel networks.
Subcutaneous fat negatively impacts FUS treatment efficiency by absorbing ultrasonic energy before it has reached the target tissue. Additionally, an unexpected change in fat’s MRI signal intensity has been observed to occur during treatments just before FUS efficiency drops quickly. Despite its clear impact on FUS treatments, fat’s dynamic properties are not clearly understood. The Bioheat Transfer Laboratory is developing tools to systematically measure the thermal, acoustic, and MRI properties of fat as a function of temperature. The characterization of these properties will progress from ex vivo fat samples to a small animal model, and finally to clinical implementation with ongoing collaborators at institutions currently performing MRgFUS treatments.