Patients with B-ALL (Ph +ve) acute lymphoblastic leukemia are at high risk of relapse and mortality. We seek to establish a mechano-biological testing technique to assess biophysical properties of cell motility, potentiating the ability to distinguish between high and low risk leukemia populations and behaviors. Two experiments were performed to test the mechano-biological behavior of B-ALL using the ThorLabs modular optical tweezers and a microfluid chemotaxis chamber. The first experiment measured the relative mechanical energy carried by a cell in the optical trap, which was performed on B-ALL in control conditions and under SDF1 chemotaxis. The relative mechanical energy was found through an extension of the back-focal-plane calibration method for optical tweezers, and assumed that increased cellular activity manifests as random movements. There was no discernable difference in the relative mechanical energies between the control B-ALL, B-ALL under SDF1 chemotaxis, and B-ALL in the presence of mesenchymal stem cells. The second experiment quantified the real-time migrational force of B-ALL under SDF1 chemotaxis. This was found through prior calibration of the optical tweezers through determination of the terms κ and β. Of the viable measurements, 3 of 8 cells exhibited a significant force towards the SDF1 gradient. Further experimentation is necessary to normalize the experimental set-up conditions, and increase the number of viable measurements during cell migration.
Cerenkov light is created in clinical applications involving high-energy radiation such as in radiation therapy. There is considerable interest in using Cerenkov light as a means to perform in vivo dosimetry during radiation therapy; however, a better understanding of the light-to-dose relationship is needed. One such method to solve this relationship is that of a deconvolution formulation, which relies on the Cerenkov scatter function (CSF). The CSF describes the creation of Cerenkov photons by a pencil beam of high-energy radiation, and the subsequent scattering that occurs before emission from the irradiated medium surface. This study investigated the dependence of the CSF on common radiation beam parameters (beam energy and incident angle) and the type of irradiated medium. An analytical equation with fitting coefficients of the CSF was obtained for common beam energies in a stratified skin model and optical phantom. Perturbation analysis was performed to investigate the dependence of the deconvolved Cerenkov images on the full-width at half-maximum and amplitude of the CSF. The irradiated material and beam angle had a large impact on the deconvolution process, whereas the beam energy had little effect.
Cherenkov light is created in clinical applications involving high-energy radiation such as in radiation therapy. Due to improvements in camera sensitivity, we are now able to detect and measure Cherenkov light created during radiation therapy using linear accelerators (linacs). However, no method currently exists for using Cherenkov light to estimate the absolute radiation dose delivered to irradiated tissues. We have developed a technique to perform dosimetry with images of Cherenkov emission using deconvolution imaging techniques. The deconvolution technique relies upon the Cherenkov Scatter Function (CSF), a function that describes the scattering of Cherenkov light as it is generated by the treatment photons and propagated through tissue to the surface of the skin. In this study, the CSF was generated through Monte Carlo for 6 MV, 10 MV, and 18 MV photon beams in light, medium, dark skin, and optical tissue phantom materials. Functional dependence of on incident treatment beam angle is shown. The CSFs generated are parameterized using a double-Gaussian distribution and fit coefficients are given. Basic formulation of the deconvolution imaging equation is given to show the relationship of the CSF to x-ray beam flux.
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