A Comparison of Soft-Tissue Implanted Markers and Bony Anatomy Alignments for Image-Guided Treatments of Head-and-Neck Cancers Omar A. Zeidan, Ph.D., Adam J. Huddleston, M.D., Choonik Lee, Ph.D., Katja M. Langen, Ph.D., Patrick A. Kupelian, M.D., Sanford L. Meeks, Ph.D., Rafael R. Manon, M.D. International Journal of Radiation Oncology • Biology • Physics Volume 76, Issue 3, Pages 767-774 (March 2010) DOI: 10.1016/j.ijrobp.2009.02.060 Copyright © 2010 Elsevier Inc. Terms and Conditions
Fig. 1 Axial megavoltage computed tomographic images that show marker positions at different locations for the 5 patients in our study. Marker positions are indicated by white arrows. International Journal of Radiation Oncology • Biology • Physics 2010 76, 767-774DOI: (10.1016/j.ijrobp.2009.02.060) Copyright © 2010 Elsevier Inc. Terms and Conditions
Fig. 2 Illustration of an image registration of a planning kilovoltage computed tomographic image set with TomoTherapy megavoltage computed tomography (MVCT) in the sagittal view. The dark grey area outlined by arrows represents the inferior–superior extent of a daily MVCT image data set. International Journal of Radiation Oncology • Biology • Physics 2010 76, 767-774DOI: (10.1016/j.ijrobp.2009.02.060) Copyright © 2010 Elsevier Inc. Terms and Conditions
Fig. 3 An overlay of transverse images from megavoltage computed tomographic and kilovoltage computed tomographic images before alignment (a), after alignment based on markers (b), and after alignment based on bony anatomy (c). The white ellipsoid encompasses the region where two markers are implanted. The rod-like structure that appears in the oral cavity is a bite plate depressor. International Journal of Radiation Oncology • Biology • Physics 2010 76, 767-774DOI: (10.1016/j.ijrobp.2009.02.060) Copyright © 2010 Elsevier Inc. Terms and Conditions
Fig. 4 Scatterplots of differences between bony-based and marker-based alignment in the lateral (LAT), longitudinal (LNG), and vertical (VRT) directions. Each scatter point on the plot is simply the difference (bone shift − marker shift) for that fraction. International Journal of Radiation Oncology • Biology • Physics 2010 76, 767-774DOI: (10.1016/j.ijrobp.2009.02.060) Copyright © 2010 Elsevier Inc. Terms and Conditions
Fig. 5 Scatterplots of fractional vector shift per patient. The fractional mean of the vector shifts for all patients is shown as a solid curve. International Journal of Radiation Oncology • Biology • Physics 2010 76, 767-774DOI: (10.1016/j.ijrobp.2009.02.060) Copyright © 2010 Elsevier Inc. Terms and Conditions
Fig. 6 Intermarker distances as measured from daily megavoltage computed tomographic images for 4 of the 5 patients. Patient 1 has only one marker, and no distance is tracked. Patient 4 has three markers (A, B, and C), with three intermarker distances tracked. International Journal of Radiation Oncology • Biology • Physics 2010 76, 767-774DOI: (10.1016/j.ijrobp.2009.02.060) Copyright © 2010 Elsevier Inc. Terms and Conditions
Fig. 7 Percentage dose difference of the D95 for the primary planning target volume (PTV) and clinical target volume (CTV) with respect to the treatment plan D95 for both alignment techniques. International Journal of Radiation Oncology • Biology • Physics 2010 76, 767-774DOI: (10.1016/j.ijrobp.2009.02.060) Copyright © 2010 Elsevier Inc. Terms and Conditions