......................................................................................................................... 3 Introduction...................................................................................................................4 The Problem...................................................................................................................6 Foundations and ...

The accuracy of the position measurements obtained by the radiation positioning system (RADPOS) was evaluated under static and dynamic conditions. In the static verifications, the RADPOS was fixed to the treatment couch in a photon treatment room and a proton treatment room, and was translocated with the treatment couch in x, y and z directions. Because the presence of magnetic and/or electrica...

aspartic proteases are a relatively small group of enzymes which express in various nematodes including onchocerca volvulus. an estimation of the gene copy number corresponding to the ov7a clone, which contains a cdna insert encoding approximately two-thirds of the entire coding sequence of aspartic protease of o. volvulus, was made by slot blot analysis in a closely related species o. gibsonig...

ID: 9678 Title: An analytical approach to prevent gantry-couch collision for linac-based radiosurgery Gantry-couch collision is a serious concern for the treatment planning of the linac-based stereotactic radiosurgery (SRS). The ability to detect collision at the planning time removes the need for backup plans and preserves the useful beam angles that would be deemed unsafe and discarded otherw...

The purpose of this study was to develop and evaluate filmless quality assurance (QA) tools for helical tomotherapy by using the signals from the on-board megavoltage computed tomography (MVCT) detector and applying a dedicated step-wedge phantom. The step-wedge phantom is a 15 cm long step-like aluminum block positioned on the couch. The phantom was moved through the slit beam and MVCT detecto...

Benjamin W. Chaffee, DDS, MPH, PhD; Jing Cheng, MD, MS, Elizabeth T. Couch, RDH, MS; Kristin S. Hoeft, Bonnie Halpern-Felsher, PhD

We present a quantitative methodology to measure head interfraction movements within intracranial masks of commercial immobilization devices used for proton radiotherapy. A three-points tracking (3PtTrack) method was developed to measure the mask location for each treatment field over an average of 10 fractions for seven patients. Five patients were treated in supine with the Qfix Base-of-Skull...

PURPOSE Clinical evaluation of a "virtual" methodology for providing 6 degrees of freedom (6DOF) patient set-up corrections and comparison to corrections facilitated by a 6DOF robotic couch. METHODS A total of 55 weekly in-room image-guidance computed tomographic (CT) scans were acquired using a CT-on-rails for 11 pelvic and head and neck cancer patients treated at our facility. Fusion of the...

The American sociologist Carl Couch titled his 1989 paper with a critical question which deserves far more attention than it has to date received. He asked: ‘Oral technologies: a cornerstone of ancient civilizations?’ (1989). Couch went on to write that ‘[i]f only a limited amount of information is available, a highly differentiated society cannot emerge nor be sustained’ (1989, p. 588). In a l...

The dosimetric impact from devices external to the patient is a complex combination of increased skin dose, reduced tumor dose, and altered dose distribution. Although small monitor unit or dose corrections are routinely made for blocking trays, ion chamber correction factors, e.g., accounting for temperature and pressure, or tissue inhomogeneities, the dose perturbation of the treatment couch ...