SU‐FF‐J‐79: Markerless Lung Tumor Tracking in Rotational Radiotherapy

J. Lewis, R. Li, T. Watkins, L. Cerviño, J. Lawson, W. Song, S. Jiang

Research output: Contribution to journalArticle

Abstract

Purpose: To develop a method to track lung tumors in rotational cone beam projections during rotational radiotherapy and cone beam CT scanning. Method and Materials: A multiple template based tracking algorithm was developed and used to track tumors in rotational cone beam projections. Templates were generated by creating DRRs of ten phases of 4DCT. These templates were generated for a sequential set of angles matching the projections of a CBCT scan. The position of the tumor in each template was derived from contours drawn on 4DCT. Shifting of the templates was used to allow for a greater tumor motion ranges. The mutual information between projections and templates was computed and used as one parameter in a probability function used to track tumor position. Tumor distance traveled and phase change between successive projections were also incorporated into the probability function. This output was compared to physician specified tumor locations on each cone beam projection. In addition to a patient study, the method was tested on a respiratory motion phantom programmed to exhibit sinusoidal motion in the SI direction. Results: In the phantom study, the SI motion of the tumor was tracked with a mean absolute error (MAE) ranging from 1.2mm to 1.6mm and a 95th percentile absolute error (P95) ranging from 3.2mm to 3.7mm. For the patient study, the SI motion was tracked with MAE ranging from 1.7mm to 1.9mm and P95 ranging from 3.4mm to 3.9mm. Conclusion: The algorithm has demonstrated the feasibility of tracking tumors in rotational x‐ray images. Further development is needed in order to achieve accuracy similar to that of fixed gantry fluoroscopic tracking.

Original languageEnglish (US)
Number of pages1
JournalMedical Physics
Volume36
Issue number6
DOIs
StatePublished - 2009

Fingerprint

Radiotherapy
Lung
Neoplasms
Cone-Beam Computed Tomography
Articular Range of Motion
X-Rays
Physicians

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging

Cite this

SU‐FF‐J‐79 : Markerless Lung Tumor Tracking in Rotational Radiotherapy. / Lewis, J.; Li, R.; Watkins, T.; Cerviño, L.; Lawson, J.; Song, W.; Jiang, S.

In: Medical Physics, Vol. 36, No. 6, 2009.

Research output: Contribution to journalArticle

Lewis, J. ; Li, R. ; Watkins, T. ; Cerviño, L. ; Lawson, J. ; Song, W. ; Jiang, S. / SU‐FF‐J‐79 : Markerless Lung Tumor Tracking in Rotational Radiotherapy. In: Medical Physics. 2009 ; Vol. 36, No. 6.
@article{eb2024d63cf54f8982f1db95b6146324,
title = "SU‐FF‐J‐79: Markerless Lung Tumor Tracking in Rotational Radiotherapy",
abstract = "Purpose: To develop a method to track lung tumors in rotational cone beam projections during rotational radiotherapy and cone beam CT scanning. Method and Materials: A multiple template based tracking algorithm was developed and used to track tumors in rotational cone beam projections. Templates were generated by creating DRRs of ten phases of 4DCT. These templates were generated for a sequential set of angles matching the projections of a CBCT scan. The position of the tumor in each template was derived from contours drawn on 4DCT. Shifting of the templates was used to allow for a greater tumor motion ranges. The mutual information between projections and templates was computed and used as one parameter in a probability function used to track tumor position. Tumor distance traveled and phase change between successive projections were also incorporated into the probability function. This output was compared to physician specified tumor locations on each cone beam projection. In addition to a patient study, the method was tested on a respiratory motion phantom programmed to exhibit sinusoidal motion in the SI direction. Results: In the phantom study, the SI motion of the tumor was tracked with a mean absolute error (MAE) ranging from 1.2mm to 1.6mm and a 95th percentile absolute error (P95) ranging from 3.2mm to 3.7mm. For the patient study, the SI motion was tracked with MAE ranging from 1.7mm to 1.9mm and P95 ranging from 3.4mm to 3.9mm. Conclusion: The algorithm has demonstrated the feasibility of tracking tumors in rotational x‐ray images. Further development is needed in order to achieve accuracy similar to that of fixed gantry fluoroscopic tracking.",
author = "J. Lewis and R. Li and T. Watkins and L. Cervi{\~n}o and J. Lawson and W. Song and S. Jiang",
year = "2009",
doi = "10.1118/1.3181371",
language = "English (US)",
volume = "36",
journal = "Medical Physics",
issn = "0094-2405",
publisher = "AAPM - American Association of Physicists in Medicine",
number = "6",

}

TY - JOUR

T1 - SU‐FF‐J‐79

T2 - Markerless Lung Tumor Tracking in Rotational Radiotherapy

AU - Lewis, J.

AU - Li, R.

AU - Watkins, T.

AU - Cerviño, L.

AU - Lawson, J.

AU - Song, W.

AU - Jiang, S.

PY - 2009

Y1 - 2009

N2 - Purpose: To develop a method to track lung tumors in rotational cone beam projections during rotational radiotherapy and cone beam CT scanning. Method and Materials: A multiple template based tracking algorithm was developed and used to track tumors in rotational cone beam projections. Templates were generated by creating DRRs of ten phases of 4DCT. These templates were generated for a sequential set of angles matching the projections of a CBCT scan. The position of the tumor in each template was derived from contours drawn on 4DCT. Shifting of the templates was used to allow for a greater tumor motion ranges. The mutual information between projections and templates was computed and used as one parameter in a probability function used to track tumor position. Tumor distance traveled and phase change between successive projections were also incorporated into the probability function. This output was compared to physician specified tumor locations on each cone beam projection. In addition to a patient study, the method was tested on a respiratory motion phantom programmed to exhibit sinusoidal motion in the SI direction. Results: In the phantom study, the SI motion of the tumor was tracked with a mean absolute error (MAE) ranging from 1.2mm to 1.6mm and a 95th percentile absolute error (P95) ranging from 3.2mm to 3.7mm. For the patient study, the SI motion was tracked with MAE ranging from 1.7mm to 1.9mm and P95 ranging from 3.4mm to 3.9mm. Conclusion: The algorithm has demonstrated the feasibility of tracking tumors in rotational x‐ray images. Further development is needed in order to achieve accuracy similar to that of fixed gantry fluoroscopic tracking.

AB - Purpose: To develop a method to track lung tumors in rotational cone beam projections during rotational radiotherapy and cone beam CT scanning. Method and Materials: A multiple template based tracking algorithm was developed and used to track tumors in rotational cone beam projections. Templates were generated by creating DRRs of ten phases of 4DCT. These templates were generated for a sequential set of angles matching the projections of a CBCT scan. The position of the tumor in each template was derived from contours drawn on 4DCT. Shifting of the templates was used to allow for a greater tumor motion ranges. The mutual information between projections and templates was computed and used as one parameter in a probability function used to track tumor position. Tumor distance traveled and phase change between successive projections were also incorporated into the probability function. This output was compared to physician specified tumor locations on each cone beam projection. In addition to a patient study, the method was tested on a respiratory motion phantom programmed to exhibit sinusoidal motion in the SI direction. Results: In the phantom study, the SI motion of the tumor was tracked with a mean absolute error (MAE) ranging from 1.2mm to 1.6mm and a 95th percentile absolute error (P95) ranging from 3.2mm to 3.7mm. For the patient study, the SI motion was tracked with MAE ranging from 1.7mm to 1.9mm and P95 ranging from 3.4mm to 3.9mm. Conclusion: The algorithm has demonstrated the feasibility of tracking tumors in rotational x‐ray images. Further development is needed in order to achieve accuracy similar to that of fixed gantry fluoroscopic tracking.

UR - http://www.scopus.com/inward/record.url?scp=85024781899&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85024781899&partnerID=8YFLogxK

U2 - 10.1118/1.3181371

DO - 10.1118/1.3181371

M3 - Article

AN - SCOPUS:85024781899

VL - 36

JO - Medical Physics

JF - Medical Physics

SN - 0094-2405

IS - 6

ER -