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Radonc/BME     Medical Image and
Computational Analysis Laboratory
Shruti Siva Kumar
MS, Biomedical Engineering from UF, 2016
PhD Graduate Student, Biomedical Engineering
expected graduation 2019


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  1. Honors and Awards
    -- Oct. 2017, National BMES Career Development Award ( link).
    -- Nov. 2016, UF College of Engineering Outstanding International Student award ( link).
    -- Dec. 2015, GE Industrial Remix Challenge award winner ( link).
  2. Research Overview

    1. MS Thesis: characterizing patterns of myocardial mechanical disfunction in women treated with radiation to the chest wall for breast cancer.


    Background and Significance
    Radiotherapy (RT) is a critical component of breast cancer management, yielding a substantial survival benefit. However, even with advanced technology for treating the tumor effectively, organs that are in close proximity to the breast, such as the heart, are highly prone to radiation exposure. Each 1 Gy heart dose increases risk of heart events by 7%. Compared with conventional photon (X-ray) therapy, proton therapy (PT) has shown improved target coverage and reduction of exposure of doses to organs at risk. By minimizing the radiation exposure to the heart PT is hypothesized to reduce cardiac toxicity but this effect has not been quantified in human subjects.

    Hypothesis
    Because cardiac injury is a late effect of radiation, early markers could be used to identify new techniques that would improve the therapeutic ratio of treatment within years rather than decades.


    Methods
    We are acquiring cardiac magnetic resonance (CMR) images in 12 patients with left-sided breast cancer undergoing breast or chest-wall photon or proton therapy. Our specific aims are to:
        i. Measure circumferential mechanical strain (percent muscle shortening) in myocardial sub-regions throughout the heart using MR cardiac tagging.
        ii. Measure left ventricle volume, ejection fraction, and perfusion using late gadolinium enhancement

    Results
        i. We have employed Myocardial Tagging technique to track the motion of LV heart wall.
        ii. We have segmented the LV of the heart from the above images using Active Contouring technique.
        iii. We have computed surface meshes and extracted those from the segmented images using mathematical transformations.
        iv. We have also computed strain maps to investigate the wall thickening between Pre-Radiation and Post- Radiation images. This has been done successfully for 2 patients each with an 8 month follow up scan.

    Future work
        i. We will be validating our results for strain computations using phantom heart with known tags and fitting parameters.
        ii. The 6 month datasets will be registered to the CT dataset used for treatment planning to facilitate pixel-wise assessment of dose versus strain and other cardiac parameters.
        iii. We will compare differences in CMR parameters from the 6 month time point to baseline data via a paired t-test.

    2. PhD Thesis: Modeling radiobiological correlations with lung radiation toxicity in breast cancer patients treated with either conventional X-ray versus proton radiation therapy.



  3. National Presentations
    O’Dell W, Siva Kumar S, Klassen C, Bradley J.
          Quantifying sub-clinical cardiac radiation toxicity in breast cancer patients
          63rd Annual Meeting of the Radiation Research Society, Cancun, Mexico,
          October 15-18, 2017

    Siva Kumar S, Waler A, Bradley J, Klassen C, O’Dell W.
          Determining Radiation-Induced Subclinical Cardiac Toxicity in Left Sided Breast Cancer Patients using Magnetic Resonance Imaging with Tagging
          BMES Annual Meeting,
          October 11-14, 2017 in Phoenix, AZ

    O’Dell W, Siva Kumar S.
          Determining prolate spheroidal modes of cardiac deformation directly from tagged heart images
          ISMRM 25th Annual Meeting & Exhibition, Hawaii,
          April 22-27, 2017
  4. Local Presentations
    S. Siva Kumar, A. Waler, J. Bradley, C. Klassen, W. O’Dell W.,
          Computing Myocardial Circumferential Strains In Pre And Post Radiation Treatment In Left-Sided Breast Cancer Patients
          UF Health Cancer Center Research Day Symposium. November, 2016
          and UF BME Research Day Symposium. November, 2016

    A. Gormaley, D. Prida, S. Siva Kumar, W. O'Dell
          Validation Of Sizing Of Pulmonary Vessels From 3D Medical Images
          UF Biomedical Engineering Research Day Symposium. November, 2016
          *Awarded most outstanding undergraduate poster

  5. Related MIACALab projects
    1. Myocardial MRI tagging
    2. Lung radiation dose response

  6. Close Research Collaborators
    1. W. O'Dell (Radiation Oncology Research)
    2. Dr. Julie Bradley
    3. Dr. Paul Okunieff