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Title: SU-E-J-58: Dosimetric Verification of Metal Artifact Effects: Comparison of Dose Distributions Affected by Patient Teeth and Implants

Purpose: Implant-supported dentures seem particularly appropriate for the predicament of becoming edentulous and cancer patients are no exceptions. As the number of people having dental implants increased in different ages, critical dosimetric verification of metal artifact effects are required for the more accurate head and neck radiation therapy. The purpose of this study is to verify the theoretical analysis of the metal(streak and dark) artifact, and to evaluate dosimetric effect which cause by dental implants in CT images of patients with the patient teeth and implants inserted humanoid phantom. Methods: The phantom comprises cylinder which is shaped to simulate the anatomical structures of a human head and neck. Through applying various clinical cases, made phantom which is closely allied to human. Developed phantom can verify two classes: (i)closed mouth (ii)opened mouth. RapidArc plans of 4 cases were created in the Eclipse planning system. Total dose of 2000 cGy in 10 fractions is prescribed to the whole planning target volume (PTV) using 6MV photon beams. Acuros XB (AXB) advanced dose calculation algorithm, Analytical Anisotropic Algorithm (AAA) and progressive resolution optimizer were used in dose optimization and calculation. Results: In closed and opened mouth phantom, because dark artifacts formed extensively around themore » metal implants, dose variation was relatively higher than that of streak artifacts. As the PTV was delineated on the dark regions or large streak artifact regions, maximum 7.8% dose error and average 3.2% difference was observed. The averaged minimum dose to the PTV predicted by AAA was about 5.6% higher and OARs doses are also 5.2% higher compared to AXB. Conclusion: The results of this study showed that AXB dose calculation involving high-density materials is more accurate than AAA calculation, and AXB was superior to AAA in dose predictions beyond dark artifact/air cavity portion when compared against the measurements.« less
Authors:
; ; ;  [1] ;  [2] ;  [3] ;  [2] ;  [4] ;  [5] ;  [6] ;  [7] ;  [2]
  1. Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)
  2. (Korea, Republic of)
  3. Konkuk University Medical Center, Seoul (Korea, Republic of)
  4. Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea (Korea, Republic of)
  5. (United States)
  6. Department of Radiation Oncology, Ajou University School of Medicine, Suwon (Korea, Republic of)
  7. Research Institute of Health Science, Korea University, Seoul (Korea, Republic of)
Publication Date:
OSTI Identifier:
22325217
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 41; Journal Issue: 6; Other Information: (c) 2014 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; 60 APPLIED LIFE SCIENCES; ALGORITHMS; ANISOTROPY; CAT SCANNING; DENSITY; DOSES; EXCEPTIONS; HEAD; HUMAN POPULATIONS; IMPLANTS; METALS; NECK; NEOPLASMS; OPTIMIZATION; PATIENTS; PHANTOMS; PHOTON BEAMS; PLANNING; RADIATION DOSE DISTRIBUTIONS; RADIOTHERAPY; RESOLUTION; TEETH; VERIFICATION