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Title: SU-E-T-306: Study of the Reduction Technique for the Secondary Cancer Risk Due to Cone Beam CT in Image Guided Radiotherapy

Purpose: This study evaluated the effectiveness of a thin lead sheet based simple shielding method for imaging doses from cone beam computed tomography (CBCT) in image-guided radiotherapy (IGRT). Methods: The entire body, except for the region scanned by CBCT, was shielded by wrapping in a 2 mm lead sheet. Reduction of secondary doses from CBCT was measured using a radio-photoluminescence glass dosimeter (RPLGD) placed inside an anthropomorphic phantom and changes in secondary cancer risk due to the shielding effect were estimated using BEIR VII model. Results: Doses to out-of-field organs for head-and-neck, chest, and pelvis scans were decreased 15∼100 %, 23∼90 %, and 23∼98 %, respectively, and the average reductions in lifetime secondary cancer risk due to the 2 mm lead shielding were 1.61, 10.4, and 12.8 persons per 100,000, respectively. Conclusion: This study suggests that a simple thin lead sheet based shielding method results in a non-negligible reduction of secondary doses to out-of-field regions for CBCT.
Authors:
 [1] ;  [2] ; ; ;  [3] ; ; ;  [1]
  1. Korea University, Seoul (Korea, Republic of)
  2. (Korea, Republic of)
  3. Kyung Hee University Hospital at Gangdong, Seoul (Korea, Republic of)
Publication Date:
OSTI Identifier:
22355865
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:
60 APPLIED LIFE SCIENCES; CHEST; COMPUTERIZED TOMOGRAPHY; DOSEMETERS; DOSES; HAZARDS; HEAD; IMAGES; LEAD; NECK; NEOPLASMS; ORGANS; PELVIS; PHANTOMS; PHOTOLUMINESCENCE; RADIOTHERAPY; REDUCTION; SHEETS; SHIELDING