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Title: Poster — Thur Eve — 16: 4DCT simulation with synchronized contrast injection of liver SBRT patients

Stereotactic body radiation therapy (SBRT) has recently emerged as a valid option for treating liver metastases. SBRT delivers highly conformai dose over a small number of fractions. As such it is particularly sensitive to the accuracy of target volume delineation by the radiation oncologist. However, contouring liver metastases remains challenging for the following reasons. First, the liver usually undergoes significant motion due to respiration. Second, liver metastases are often nearly indistinguishable from the surrounding tissue when using computed tomography (CT) for imaging making it difficult to identify and delineate them. Both problems can be overcome by using four dimensional CT (4DCT) synchronized with intravenous contrast injection. We describe a novel CT simulation process which involves two 4DCT scans. The first scan captures the tumor and immediately surrounding tissue which in turn reduces the 4DCT scan time so that it can be optimally timed with intravenous contrast injection. The second 4DCT scan covers a larger volume and is used as the primary CT dataset for dose calculation, as well as patient setup verification on the treatment unit. The combination of two 4DCT scans, short and long, allows visualization of the liver metastases over all phases of breathing cycle while simultaneously acquiringmore » long enough 4DCT dataset suitable for planning and patient setup verification.« less
Authors:
;  [1] ;  [2] ; ;  [3] ;  [4] ;  [5]
  1. Department of Medical Physics, Odette Cancer Center, Sunnybrook Health Sciences Center, Toronto, ON (Canada)
  2. Department of Medical Imaging, Sunnybrook Health Sciences Center, Toronto, ON (Canada)
  3. Department of Radiation Oncology, Odette Cancer Center, Sunnybrook Health Sciences Center, Toronto, ON (Canada)
  4. (Canada)
  5. Department of Radiation Therapy, Odette Cancer Center, Sunnybrook Health Sciences Center, Toronto, ON (Canada)
Publication Date:
OSTI Identifier:
22407640
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 41; Journal Issue: 8; 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; ACCURACY; COMPUTERIZED TOMOGRAPHY; CONTRAST MEDIA; INJECTION; LIVER; METASTASES; NEOPLASMS; PATIENTS; PLANNING; RADIATION DOSES; RADIOTHERAPY; RESPIRATION; VERIFICATION