4 Clinical Trials for Various Conditions
Standard planning constraints for liver SBRT incorporate strict dose-volume limits for normal liver parenchyma to minimize the risk of radiation-induced liver disease. The presence of diurnal and fasting/fed variations in liver volume therefore carry substantial potential for introducing errors into estimates of dose-volume distribution within normal liver tissue, as well as affecting day-to-day setup fidelity and organ alignment for treatment. This prospective study will examine how diurnal and fast-fed variations in liver volume affect treatment planning for abdominal SBRT.
Motion during radiation therapy can be categorized as inter-fraction (changes in anatomy that occur between treatment days) and intra-fraction (changes that occur during the "beam on" window of treatment delivery). Inter-fraction motion is managed by adaptive radiotherapy (ART), the process of making changes in the treatment plan while the patient remains on the treatment table. This is now a standard-of-care therapy within Washington University's clinic. Intra-fraction motion is managed by gated and non-gated delivery techniques. Varian Medical Systems has integrated the necessary components into a CT-guided radiotherapy device (ETHOS). In the ETHOS, Varian has built a device that integrates on-board cone beam CT imaging capable of delineating target and organ-at-risk positions and a dedicated artificial intelligence-driven treatment planning system for inter-fraction motion management as well as a paired optical surface image guidance system for intra-fraction motion management. Although online ART is a standard-of-care practice in the clinic and has previously been shown to be feasible, use of surface-guidance for intra-fraction gating of abdominal and thoracic SBRT on ETHOS is novel. Therefore, in this study, the investigators propose to evaluate the feasibility and safety of using a novel surface guidance beam-gating system, incorporated with a CBCT-guided adaptive radiotherapy platform, to manage respiratory motion during delivery of CT-guided stereotactic radiotherapy. To best assess the utility of this technology to manage respiratory motion, the investigators will focus on disease sites that are highly affected by respiratory motion: upper abdominal or lower thoracic malignancies.
This is Pilot study that investigates the CBCT(Cone beam computed tomography) image quality improvement provided by the 2D antiscatter grid technology. The primary objective is to assess the improvement in tissue visualization in an observer study, which will be conducted in a blinded fashion.
The purposes of this study are: 1. To assess the maximum tolerated dose of low-dose UART(Upper Abdominal Radiation Therapy ) or WART(Whole Abdominal Radiation Therapy) given in combination with standard fixed dose-rate Gemcitabine in patients with advanced gastrointestinal (GI) or ovarian tumors (Phase I). 2. To assess response rate and survival in advanced upper GI tumors following completion of therapy (Phase II).