Establishing a framework to implement 4D XCAT phantom for 4D radiotherapy research.

AIMS To establish a framework to implement the 4D integrated extended cardiac torso (XCAT) digital phantom for 4D radiotherapy (RT) research. MATERIALS AND METHODS A computer program was developed to facilitate the characterization and implementation of the 4D XCAT phantom. The program can (1) generate 4D XCAT images with customized parameter files; (2) review 4D XCAT images; (3) generate composite images from 4D XCAT images; (4) track motion of selected region-of-interested (ROI); (5) convert XCAT raw binary images into DICOM format; (6) analyse clinically acquired 4DCT images and real-time position management (RPM) respiratory signal. Motion tracking algorithm was validated by comparing with manual method. Major characteristics of the 4D XCAT phantom were studied. RESULTS The comparison between motion tracking and manual measurements of lesion motion trajectory showed a small difference between them (mean difference in motion amplitude: 1.2 mm). The maximum lesion motion decreased nearly linearly (R 2 = 0.97) as its distance to the diaphragm (DD) increased. At any given DD, lesion motion amplitude increased nearly linearly (R 2 range: 0.89 to 0.95) as the inputted diaphragm motion increased. For a given diaphragm motion, the lesion motion is independent of the lesion size at any given DD. The 4D XCAT phantom can closely reproduce irregular breathing profile. The end-to-end test showed that clinically comparable treatment plans can be generated successfully based on 4D XCAT images. CONCLUSIONS An integrated computer program has been developed to generate, review, analyse, process, and export the 4D XCAT images. A framework has been established to implement the 4D XCAT phantom for 4D RT research.

[1]  Deanna Hasenauer,et al.  Hybrid computational phantoms of the male and female newborn patient: NURBS-based whole-body models , 2007, Physics in medicine and biology.

[2]  G Starkschall,et al.  Respiratory-driven lung tumor motion is independent of tumor size, tumor location, and pulmonary function. , 2001, International journal of radiation oncology, biology, physics.

[3]  W P Segars,et al.  Realistic CT simulation using the 4D XCAT phantom. , 2008, Medical physics.

[4]  Steve B. Jiang,et al.  The management of respiratory motion in radiation oncology report of AAPM Task Group 76. , 2006, Medical physics.

[5]  H Chen,et al.  A review on the clinical implementation of respiratory-gated radiation therapy , 2007, Biomedical imaging and intervention journal.

[6]  W. Segars,et al.  4D XCAT phantom for multimodality imaging research. , 2010, Medical physics.

[7]  P B Hoffer,et al.  Computerized three-dimensional segmented human anatomy. , 1994, Medical physics.

[8]  Hiroki Shirato,et al.  Phase I study of concurrent real-time tumor-tracking thoracic radiation therapy with paclitaxel and carboplatin in locally advanced non-small cell lung cancer. , 2011, Lung cancer.

[9]  Rebecca Fahrig,et al.  Characterization of a novel anthropomorphic plastinated lung phantom. , 2008 .

[10]  Shinichi Shimizu,et al.  Intrafractional tumor motion: lung and liver. , 2004, Seminars in radiation oncology.

[11]  Bilal A Tahir,et al.  Dosimetric evaluation of inspiration and expiration breath-hold for intensity-modulated radiotherapy planning of non-small cell lung cancer. , 2010, Physics in medicine and biology.

[12]  E. Larsen,et al.  A method for incorporating organ motion due to breathing into 3D dose calculations. , 1999, Medical physics.

[13]  George Starkschall,et al.  A novel platform simulating irregular motion to enhance assessment of respiration‐correlated radiation therapy procedures , 2005, Journal of applied clinical medical physics.

[14]  Shinichi Shimizu,et al.  Three-dimensional intrafractional movement of prostate measured during real-time tumor-tracking radiotherapy in supine and prone treatment positions. , 2002, International journal of radiation oncology, biology, physics.

[15]  Philip M Evans,et al.  Feasibility of the use of the Active Breathing Co ordinator (ABC) in patients receiving radical radiotherapy for non-small cell lung cancer (NSCLC). , 2009, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.