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Title: Dosimetry of an In-Line Kilovoltage Imaging System and Implementation in Treatment Planning

Purpose: To present the beam properties of the Siemens 70-kV and 121-kV linear accelerator-mounted imaging modalities and commissioning of the 121-kV beam in the Philips Pinnacle treatment planning system (TPS); measurements in an Alderson phantom were performed for verification of the model and to estimate the cone-beam CT (CBCT) imaging dose in the head and neck, thorax, and pelvis. Methods and Materials: The beam profiles and depth–dose curve were measured in an acrylic phantom using thermoluminescent dosimeters and a soft x-ray ionization chamber. Measurements were imported into the TPS, modeled, and verified by phantom measurements. Results: Modeling of the profiles and the depth–dose curve can be achieved with good quality. Comparison with the measurements in the Alderson phantom is generally good; only very close to bony structures is the dose underestimated by the TPS. For a 200° arc CBCT of the head and neck, a maximum dose of 7 mGy is measured; the thorax and pelvis 360° CBCTs give doses of 4-10 mGy and 7-15 mGy, respectively. Conclusions: Dosimetric characteristics of the Siemens kVision imaging modalities are presented and modeled in the Pinnacle TPS. Thermoluminescent dosimeter measurements in the Alderson phantom agree well with the calculated TPS dose, validating themore » model and providing an estimate of the imaging dose for different protocols.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ; ;  [1]
  1. Department of Radiation Oncology, Saarland University Medical Center, Homburg/Saar (Germany)
  2. Hochschule für Technik und Wirtschaft des Saarlandes, Saarbrücken (Germany)
  3. Department of Radiation Oncology, University of Minnesota, Minneapolis, Minnesota (United States)
Publication Date:
OSTI Identifier:
22416502
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 88; Journal Issue: 4; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BIOMEDICAL RADIOGRAPHY; CHEST; COMPARATIVE EVALUATIONS; COMPUTERIZED TOMOGRAPHY; DEPTH DOSE DISTRIBUTIONS; DOSIMETRY; HEAD; IONIZATION CHAMBERS; LINEAR ACCELERATORS; NECK; PELVIS; PHANTOMS; PLANNING; RADIATION DOSES; SOFT X RADIATION; THERMOLUMINESCENT DOSEMETERS; VERIFICATION