Medicine and Health Sciences Commons^™

Anticancer Effects And Mechanisms Of Cfi-400945 And Radiation In Breast Cancer, Sierra M. Pellizzari

Electronic Thesis and Dissertation Repository

Breast cancer is a leading cause of death in women and development of new treatments is essential. Polo-like Kinase 4 (PLK4) controls centriole duplication and its inhibition by CFI-400945 induces genomic instability and aneuploidy. Radiation therapy (RT) also induces aneuploidy leading to cell death, although development of radioresistance is common. We hypothesized that CFI-400945 and RT act synergistically in breast cancer. Colony formation assays identified synergistic anticancer effects of CFI-400945 and RT, with combinatorial effects also observed for RT with either siRNA inhibition of PLK4 or with the PLK4 inhibitor Centrinone B. This suggests that the antiproliferative effect of these …

Radiation Oncology Quality And Safety Considerations In Low Resource Settings: A Medical Physics Perspective, Jacob Van Dyk, Ahmed Meghzifene

Oncology Publications

The last few years have seen a significant growth of interest in the global radiation therapy crisis. Various organizations have quantified the need and are providing aid in support of addressing the shortfalls existing in many low-to-middle income countries (LMICs). With the tremendous demand for new facilities, equipment and personnel, it is very important to recognize the quality and safety challenges and to address them directly. An examination of publications on quality and safety in radiation therapy indicates a consistency in a number of the recommendations; however, these authoritative reports were generally based on input from high-resourced contexts. Here we …

The Effects Of Field-Of-View And Patient Size On Ct Numbers From Cone-Beam Computed Tomography., Katrina Y T Seet, Arvand Barghi, Slav Yartsev, Jacob Van Dyk

Oncology Publications

Cone-beam computed tomography (CBCT) is used for patient alignment before treatment and is ideal for use in adaptive radiotherapy to account for tumor shrinkage, organ deformation and weight loss. However, CBCT images are prone to artifacts such as streaking and cupping effects, reducing image quality and CT number accuracy. Our goal was to determine the optimum combination of cone-beam imaging options to increase the accuracy of image CT numbers. Several phantoms with and without inserts of known relative electron densities were imaged using the Varian on-board imaging system. It was found that CT numbers are most influenced by the selection …

Effects Of Genistein Following Fractionated Lung Irradiation In Mice., Andrea E Para, Andrea Bezjak, Ivan W T Yeung, Jacob Van Dyk, Richard P Hill

Oncology Publications

BACKGROUND AND PURPOSE: This study investigated protection of lung injury by genistein following fractionated doses of radiation and its effect on tumor response.

MATERIAL AND METHODS: C3H/HeJ mice were irradiated (100 kVp X-rays) with 9 fractions of 3.1 Gy over 30 days (approximately equivalent to 10 Gy single dose) and were maintained on a genistein diet ( approximately 10mg/kg). Damage was assessed over 28 weeks in lung cells by a cytokinesis block micronucleus (MN) assay and by changes in breathing rate and histology. Tumor protection was assessed using a colony assay to determine cell survival following in situ irradiation of …

Consistency Check Of Planned Adaptive Option On Helical Tomotherapy., M Schirm, S Yartsev, G Bauman, Jerry J. Battista Dr., Jacob Van Dyk

Oncology Publications

This study aims to evaluate a new Planned Adaptive software (TomoTherapy Inc., Madison, WI) of the helical tomotherapy system by retrospective verification and adaptive re-planning of radiation treatment. Four patients with different disease sites (brain, nasal cavity, lungs, prostate) were planned in duplicate using the diagnostic planning kVCT data set and MVCT studies of the first treatment fraction with the same optimization parameters for both plan types. The dosimetric characteristics of minimum, maximum, and mean dose to the targets as well as to organs at risk were compared. Both sets of plans were used for calculation of dose distributions in …