PURPOSE: Cone-beam computed tomography (CBCT) is a new image-guided radiation therapy (IGRT) technique for patient alignment in radiotherapy. The CBCT x-ray volume imaging system from Elekta allows for a variety of alignment methods. The aim of this study is to assess the accuracy of soft-tissue-based automatic alignment as compared with manual alignment using intraprostatic fiducials. METHODS AND MATERIALS: All patients were treated on an Elekta Synergy S linear accelerator with kilovoltage CBCT. All alignments were performed using the x-ray volume imaging system and associated software. Automatic alignment with gray-value-based registration and manual alignment to fiducial markers were performed. Transitional corrections along each axis as well as 3-dimensional vectors were compared with evaluate the accuracy of gray-value-based registration compared with fiducials. RESULTS: The distribution of the 3-dimensional vectors between gray-value and fiducial registrations demonstrated notable differences. The mean summed vector was 0.75 cm, with a standard deviation (SD) of 0.52 cm and range from 0.04 to 2.06 cm. There was minimal difference along the lateral direction, with a mean ± SD of -0.02 cm ± 0.13 cm. However, there were large discrepancies along the superior-inferior and anterior-posterior direction alignments, with mean ± SD values of -0.55 ± 0.48 cm and -0.31 ± 0.43 cm, respectively. CONCLUSIONS: CBCT with soft-tissue-based automatic corrections is not an accurate alignment compared with manual alignment to fiducial markers for prostate IGRT. We have concluded that a daily manual alignment to fiducials is one of the most reliable methods to maintain accuracy in prostate IGRT.
PURPOSE: Cone-beam computed tomography (CBCT) is a new image-guided radiation therapy (IGRT) technique for patient alignment in radiotherapy. The CBCT x-ray volume imaging system from Elekta allows for a variety of alignment methods. The aim of this study is to assess the accuracy of soft-tissue-based automatic alignment as compared with manual alignment using intraprostatic fiducials. METHODS AND MATERIALS: All patients were treated on an Elekta Synergy S linear accelerator with kilovoltage CBCT. All alignments were performed using the x-ray volume imaging system and associated software. Automatic alignment with gray-value-based registration and manual alignment to fiducial markers were performed. Transitional corrections along each axis as well as 3-dimensional vectors were compared with evaluate the accuracy of gray-value-based registration compared with fiducials. RESULTS: The distribution of the 3-dimensional vectors between gray-value and fiducial registrations demonstrated notable differences. The mean summed vector was 0.75 cm, with a standard deviation (SD) of 0.52 cm and range from 0.04 to 2.06 cm. There was minimal difference along the lateral direction, with a mean ± SD of -0.02 cm ± 0.13 cm. However, there were large discrepancies along the superior-inferior and anterior-posterior direction alignments, with mean ± SD values of -0.55 ± 0.48 cm and -0.31 ± 0.43 cm, respectively. CONCLUSIONS: CBCT with soft-tissue-based automatic corrections is not an accurate alignment compared with manual alignment to fiducial markers for prostate IGRT. We have concluded that a daily manual alignment to fiducials is one of the most reliable methods to maintain accuracy in prostate IGRT.
Authors: B A Jereczek-Fossa; C Pobbiati; L Santoro; C Fodor; P Fanti; S Vigorito; G Baroni; D Zerini; O De Cobelli; R Orecchia Journal: Strahlenther Onkol Date: 2013-08-17 Impact factor: 3.621
Authors: Petr Paluska; Josef Hanus; Jana Sefrova; Lucie Rouskova; Jakub Grepl; Jan Jansa; Linda Kasaova; Miroslav Hodek; Milan Zouhar; Milan Vosmik; Jiri Petera Journal: J Appl Clin Med Phys Date: 2013-05-06 Impact factor: 2.102
Authors: Nicholas G Zaorsky; Timothy N Showalter; Gary A Ezzell; Paul L Nguyen; Dean G Assimos; Anthony V D'Amico; Alexander R Gottschalk; Gary S Gustafson; Sameer R Keole; Stanley L Liauw; Shane Lloyd; Patrick W McLaughlin; Benjamin Movsas; Bradley R Prestidge; Al V Taira; Neha Vapiwala; Brian J Davis Journal: Adv Radiat Oncol Date: 2017-03-20