We report on our initial experience with daily image guidance for the treatment of a patient with a basal cell carcinoma of the nasal dorsum using bolus electron conformal therapy. We describe our approach to daily alignment using treatment machine-integrated megavoltage (MV) planar imaging in conjunction with cone beam CT (CBCT) volumetric imaging to ensure the best possible setup reproducibility. Based on MV imaging, beam aperture misalignment with the intended treatment region was as large as 0.5 cm in the coronal plane. Four of the five fractions analyzed show induced shifts when compared to digitally reconstructed radiographs (DRR), in the range of 0.2-0.5 cm. Daily inspection of CBCT images show that the bolus device can have significant tilt in any given direction by as much as 13° with respect to beam axis. In addition, we show that CBCT images reveal air gaps between bolus and skin that vary from day to day, and can potentially degrade surface dose coverage. Retrospective dose calculation on CBCT image sets shows that when daily shifts based on MV imaging are not corrected, geometrical miss of the planning target volume (PTV) can cause an underdosing as large as 14% based on DVH analysis of the dose to the 90% of the PTV volume.
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http://dx.doi.org/10.1120/jacmp.v12i1.3311 | DOI Listing |
Biomed Phys Eng Express
December 2024
Department of Radiation Oncology, Northwest Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, United States of America.
. Electron beam treatment often requires bolus to augment surface dose to nearly 100%. There are no optimum bolus materials and hence a high-Z based clothlike material is investigated to reduce air column in treatment that provides optimum surface dose.
View Article and Find Full Text PDFMol Imaging Biol
December 2024
Oxygen Measurement Core, O2M Technologies, Chicago, IL, 60612, USA.
Purpose: Type 1 diabetes (T1D) is an autoimmune disease that leads to the loss of insulin-producing pancreatic beta cells. Beta cell replacement devices or bioartificial pancreas (BAP) have shown promise in curing T1D and providing long-term insulin independence without the need for immunosuppressants. Hypoxia in BAP devices damages cells and imposes limitations on device dimensions.
View Article and Find Full Text PDFNeurol Int
November 2024
Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
Glioblastomas (GBMs) are dreadful brain tumors with abysmal survival outcomes. GBM extracellular vesicles (EVs) dramatically affect normal brain cells (largely astrocytes) constituting the tumor microenvironment (TME). We asked if EVs from different GBM patient-derived spheroid lines would differentially alter recipient brain cell phenotypes.
View Article and Find Full Text PDFBMC Vet Res
November 2024
Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt.
Biomed Phys Eng Express
October 2024
Department of Radiation Oncology, Northwestern University, Chicago, IL, 60611, United States of America.
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