Author ORCID Identifier

https://orcid.org/0000-0002-0733-0278

Date of Award

Spring 4-15-2024

Document Type

Thesis (Ph.D.)

Department or Program

Engineering Sciences

First Advisor

David Gladstone, ScD

Second Advisor

Brian Pogue, PhD

Abstract

In the U.S. alone, nearly 2 million people will be diagnosed with cancer annually, and over half of them will receive radiation therapy throughout the course of their care. While widely regarded as safe, radiation therapy presents unique challenges that other procedures, such as surgery, lack. Namely, the invisible nature of the radiation itself makes it impossible to directly visualize treatment. Many immobilization and localization techniques exist to minimize the chance of incorrect radiation dose delivery, yet incidents still occur. Within the last decade, Cherenkov imaging has emerged as a new radiation therapy delivery verification technique. Cherenkov imaging is unique to other modalities because it allows for real-time visualization of beam delivery on the entire surface of the patient, showing light wherever dose is delivered. Beyond the ability to verify the extent of the treatment field, it has the potential to provide a 2D surrogate surface dose map. In this work, we exploit the unique nature of Cherenkov imaging for treatment delivery verification and incident detection in the radiation therapy clinic. This thesis focuses on several uses of Cherenkov imaging in the clinic, spanning from radiotherapy incident detection to quantitative in vivo dosimetry for diverse patient populations, independent of skin pigmentation. Cherenkov imaging is first explored as a tool for automatic incident detection during treatment, leveraging unique biological fiducials that are inherent to patient images. Expanding to quantitative in vivo dosimetry, the synergistic combination of Cherenkov imaging and scintillation dosimetry is presented as promising alternative to conventional dosimeters, with the unique ability to directly visualize measurement locations relative to the treatment field on the surface of the patient. Lastly, the longstanding concern regarding Cherenkov imaging for dark skin patients is addressed in a multi-institutional collaboration between Dartmouth Hitchcock Health and Moffitt Cancer Center, dedicated to imaging a diverse population, with the successful development of a patient-specific skin pigmentation calibration, a noteworthy advancement towards the realization of quantitative Cherenkov dosimetry.

Original Citation

Some chapters come from published works, including:

  • Decker, S.M., Alexander, D.A., Hachadorian, R.L., Zhang, R., Gladstone,

    D.J., Bruza, P., Pogue, B.W. “Estimation of diffuse Cherenkov optical

    emission from external beam radiation build-up in tissue.” J Biomed Opt.

    (2021) doi: 10.1117/1.JBO.26.9.098003

  • Alexander, D.A.†

    , Decker S.M.†, Jermyn M., Bruza P., Zhang R., Chen E.,

    McGlynn T.L., Rosselot R.A., Lee J., Rose M.L., Williams B.B., Pogue

    B.W., Gladstone D.J., Jarvis L.A. “One Year of Clinic Wide Cherenkov

    Imaging for Discovery of Quality Improvement Opportunities in Radiation22

    Therapy.” Practical Radiation Oncology. (2022) doi:

    1016/j.prro.2022.06.009

  • Decker S.M., Alexander, D.A., Bruza P., Zhang R., Chen E., Jarvis L.A.,

    Gladstone D.J., Pogue B.W. “Performance Comparison of Quantitative

    Metrics for Analysis of In Vivo Cherenkov Imaging Incident Detection

    During Radiotherapy.” British Journal of Radiology. (2022) doi:

    10.1259/bjr.20211346

  • Decker S.M., Bruza P., Zhang R., Williams, B.B., Jarvis L.A., Pogue B.W,

    Gladstone D.J. “Technical Note: Visual, rapid, scintillation point dosimetry

    for in vivo MV photon beam radiotherapy treatments.” Medical Physics.

    (2024) doi: 10.1002/mp.17071

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