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SU-E-J-209: A Simple Method to Minimize Uncertainty in ITV Delineation: Phantom Verification.

Publication ,  Journal Article
Turner, K; Cai, J; Yin, F; Zhang, Y; Vergalasova, I
Published in: Med Phys
June 2012

PURPOSE: Irregular breathing causes variation in delineation of internal target volume (ITV), which is typically generated in the maximum intensity projection (MIP) images [1]. Previous studies have shown that MIP-based ITV can underestimate true tumor range [2]. This study examines a simple method to reduce such errors by combining the GTV of 3D-CT with the ITV of MIP. METHODS: The Computerized Imaging Reference Systems (CIRS) Dynamic Thorax Phantom Model 008A (CIRS, Norfolk, VA) with CIRS motion control software was used to model 4 irregular patient respiratory profiles and one regular respiratory profile (sine wave). A 3 cm tumor insert was used as target. For each breathing profile, a 3D-CT and 3 repeated 4D-CT scans with random intervals within the breathing profile were performed on a 4-slice clinical scanner (Lightspeed, GE, WI). The RPM system (Varian, Palo Alto, CA) was used to track the respiratory profiles. GTV was contoured on 3D-CT, and ITV was contoured on each MIP (ITVMIP) using a consistent lung window by the same person. The new method of creating ITV was to combine the GTV and ITVMIP, namely ITVCOMB. To evaluate which ITV is more accurate, ITVCOMB and ITVMIP were compared to a 'ground truth' ITV (ITVGT) which was generated by combining the three ITVMIPs. RESULTS: For the regular profile, both ITVMIP (27.25 cm3 ) and ITVCOMB (28.12 cm3 ) were comparable to ITVGT (27.25 cm3 ). For irregular profiles, the mean absolute difference between ITVCOMB and ITVGT (6.3%±4.9) was significantly (p-value=0.0078) smaller than that between ITVMIP and ITVGT (18.1%±12.3). CONCLUSIONS: The results suggest that combining GTV of the 3D-CT with the ITV of the MIP is more accurate than the ITV of the MIP alone, and thus would be a simple method to reduce breathing irregularity induced errors in ITV delineation for treatment planning of lung cancer.

Duke Scholars

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

June 2012

Volume

39

Issue

6Part9

Start / End Page

3700 / 3701

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Turner, K., Cai, J., Yin, F., Zhang, Y., & Vergalasova, I. (2012). SU-E-J-209: A Simple Method to Minimize Uncertainty in ITV Delineation: Phantom Verification. Med Phys, 39(6Part9), 3700–3701. https://doi.org/10.1118/1.4735049
Turner, K., J. Cai, F. Yin, Y. Zhang, and I. Vergalasova. “SU-E-J-209: A Simple Method to Minimize Uncertainty in ITV Delineation: Phantom Verification.Med Phys 39, no. 6Part9 (June 2012): 3700–3701. https://doi.org/10.1118/1.4735049.
Turner K, Cai J, Yin F, Zhang Y, Vergalasova I. SU-E-J-209: A Simple Method to Minimize Uncertainty in ITV Delineation: Phantom Verification. Med Phys. 2012 Jun;39(6Part9):3700–1.
Turner, K., et al. “SU-E-J-209: A Simple Method to Minimize Uncertainty in ITV Delineation: Phantom Verification.Med Phys, vol. 39, no. 6Part9, June 2012, pp. 3700–01. Pubmed, doi:10.1118/1.4735049.
Turner K, Cai J, Yin F, Zhang Y, Vergalasova I. SU-E-J-209: A Simple Method to Minimize Uncertainty in ITV Delineation: Phantom Verification. Med Phys. 2012 Jun;39(6Part9):3700–3701.

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

June 2012

Volume

39

Issue

6Part9

Start / End Page

3700 / 3701

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences