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Access Type
WSU Access
Date of Award
January 2023
Degree Type
Dissertation
Degree Name
Ph.D.
Department
Biomedical Engineering
First Advisor
Mohammad Mehrmohammadi
Abstract
As of 2022, the lifetime risk of a woman in the U.S. developing breast cancer is 12.9% - demonstrating a 3.8% increase when compared to 1975. Although the breast cancer mortality rate has been decreasing since 1998, implying an improvement in standard of care, the total number of deaths per year continues to rise with an aging population. There are two approaches for improving clinical outcomes for women with breast cancer: improving imaging methods for increased detectability of cancer and improving therapies for treating the cancer after detection.Current imaging modalities such as magnetic resonance imaging (MRI), handheld B-mode ultrasound (US), and mammography fall short of fully meeting the diagnostic need. For instance, mammography has limited detectability of malignancies in dense breast cases. These same women face increased predisposition of developing breast cancer. Ultrasound and photoacoustic tomography (UST and PAT respectively) offer an attractive alternative to current diagnostic tools. UST advances traditional handheld US and offers quantitative estimates of acoustic parameters like sound speed (SS) and attenuation, while also being operator independent. PAT on the other hand is a natural complement to UST – sharing similar hardware – and derives its contrast from various endogenous and exogenous chromophores. PAT is also able to provide functional and molecular information, which allows one to visualize the underlying processes of cancer (e.g. hypoxia, angiogenesis, etc). However, certain assumptions are made when measuring parameters such as blood oxygenation, an important marker for cancer, like ignoring optical fluence and SS variation. Both assumptions introduce biases into quantitative measurements and must be accounted for to improve the accuracy of oxygenation, etc measurements. Here, I propose to develop PAT reconstruction algorithm using priori knowledge acquired from UST to model optical diffusion and acoustic variation and to correct these biases. Treatments of breast cancer include surgery, chemo- and radiation therapies. Each treatment method has its respective limitations, however concerning all is the need to limit damage to surrounding healthy tissue. Mild hyperthermia therapy (MHTh) has been used as an adjunct to chemo- and radiation therapies and has been shown to increase their effectiveness while reducing their dosage requirements. This typically requires a cumbersome MRI + microwave system. UST has applications in MHTh and can fulfill the role of both heat induction - via high intensity ultrasound (HIFU), and temperature monitoring – through the close relationship between SS and temperature. While MRI-guided RF heat induction has been introduced and used for breast cancer, it is possible to implement both heat induction and temperature guidance into a single acoustic device as such we propose an all-acoustic UST MHTh system.
Recommended Citation
Pattyn, Alexander, "Improved Breast Cancer Theranostics Using Photoacoustic And Ultrasound Tomography" (2023). Wayne State University Dissertations. 3781.
https://digitalcommons.wayne.edu/oa_dissertations/3781