Skip to main content
Journal cover image

Extension of the NCAT phantom for the investigation of intra-fraction respiratory motion in IMRT using 4D Monte Carlo.

Publication ,  Journal Article
McGurk, R; Seco, J; Riboldi, M; Wolfgang, J; Segars, P; Paganetti, H
Published in: Phys Med Biol
March 7, 2010

The purpose of this work was to create a computational platform for studying motion in intensity modulated radiotherapy (IMRT). Specifically, the non-uniform rational B-spline (NURB) cardiac and torso (NCAT) phantom was modified for use in a four-dimensional Monte Carlo (4D-MC) simulation system to investigate the effect of respiratory-induced intra-fraction organ motion on IMRT dose distributions as a function of diaphragm motion, lesion size and lung density. Treatment plans for four clinical scenarios were designed: diaphragm peak-to-peak amplitude of 1 cm and 3 cm, and two lesion sizes--2 cm and 4 cm diameter placed in the lower lobe of the right lung. Lung density was changed for each phase using a conservation of mass calculation. Further, a new heterogeneous lung model was implemented and tested. Each lesion had an internal target volume (ITV) subsequently expanded by 15 mm isotropically to give the planning target volume (PTV). The PTV was prescribed to receive 72 Gy in 40 fractions. The MLC leaf sequence defined by the planning system for each patient was exported and used as input into the MC system. MC simulations using the dose planning method (DPM) code together with deformable image registration based on the NCAT deformation field were used to find a composite dose distribution for each phantom. These composite distributions were subsequently analyzed using information from the dose volume histograms (DVH). Lesion motion amplitude has the largest effect on the dose distribution. Tumor size was found to have a smaller effect and can be mitigated by ensuring the planning constraints are optimized for the tumor size. The use of a dynamic or heterogeneous lung density model over a respiratory cycle does not appear to be an important factor with a

Duke Scholars

Published In

Phys Med Biol

DOI

EISSN

1361-6560

Publication Date

March 7, 2010

Volume

55

Issue

5

Start / End Page

1475 / 1490

Location

England

Related Subject Headings

  • Thorax
  • Respiration
  • Radiotherapy, Intensity-Modulated
  • Radiotherapy Planning, Computer-Assisted
  • Radiotherapy Dosage
  • Radiometry
  • Phantoms, Imaging
  • Nuclear Medicine & Medical Imaging
  • Movement
  • Monte Carlo Method
 

Citation

APA
Chicago
ICMJE
MLA
NLM
McGurk, R., Seco, J., Riboldi, M., Wolfgang, J., Segars, P., & Paganetti, H. (2010). Extension of the NCAT phantom for the investigation of intra-fraction respiratory motion in IMRT using 4D Monte Carlo. Phys Med Biol, 55(5), 1475–1490. https://doi.org/10.1088/0031-9155/55/5/014
McGurk, Ross, Joao Seco, Marco Riboldi, John Wolfgang, Paul Segars, and Harald Paganetti. “Extension of the NCAT phantom for the investigation of intra-fraction respiratory motion in IMRT using 4D Monte Carlo.Phys Med Biol 55, no. 5 (March 7, 2010): 1475–90. https://doi.org/10.1088/0031-9155/55/5/014.
McGurk R, Seco J, Riboldi M, Wolfgang J, Segars P, Paganetti H. Extension of the NCAT phantom for the investigation of intra-fraction respiratory motion in IMRT using 4D Monte Carlo. Phys Med Biol. 2010 Mar 7;55(5):1475–90.
McGurk, Ross, et al. “Extension of the NCAT phantom for the investigation of intra-fraction respiratory motion in IMRT using 4D Monte Carlo.Phys Med Biol, vol. 55, no. 5, Mar. 2010, pp. 1475–90. Pubmed, doi:10.1088/0031-9155/55/5/014.
McGurk R, Seco J, Riboldi M, Wolfgang J, Segars P, Paganetti H. Extension of the NCAT phantom for the investigation of intra-fraction respiratory motion in IMRT using 4D Monte Carlo. Phys Med Biol. 2010 Mar 7;55(5):1475–1490.
Journal cover image

Published In

Phys Med Biol

DOI

EISSN

1361-6560

Publication Date

March 7, 2010

Volume

55

Issue

5

Start / End Page

1475 / 1490

Location

England

Related Subject Headings

  • Thorax
  • Respiration
  • Radiotherapy, Intensity-Modulated
  • Radiotherapy Planning, Computer-Assisted
  • Radiotherapy Dosage
  • Radiometry
  • Phantoms, Imaging
  • Nuclear Medicine & Medical Imaging
  • Movement
  • Monte Carlo Method