Optimal image-guidance scenario with cone-beam computed tomography in conventionally fractionated radiotherapy for lung tumors
| Autor: | Anneyuko I. Saito, Jonathan G. Li, Wenyin Shi, Sanjiv Samant, Heather E. Newlin, A Chvetsov, Anamaria R. Yeung, Jatinder R. Palta, Christopher G. Morris, Chihray Liu, Kenneth R. Olivier |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Cancer Research medicine.medical_specialty Cone beam computed tomography Lung Neoplasms Fractionated radiotherapy medicine.medical_treatment Computed tomography Residual Imaging Three-Dimensional medicine Humans Computer Simulation Four-Dimensional Computed Tomography Image guidance Aged Aged 80 and over medicine.diagnostic_test business.industry Radiotherapy Planning Computer-Assisted Dose fractionation Cone-Beam Computed Tomography Middle Aged Radiation therapy Oncology Radiographic Image Interpretation Computer-Assisted Female Radiology Dose Fractionation Radiation Radiotherapy Intensity-Modulated Radiotherapy Conformal Nuclear medicine business |
| Zdroj: | American journal of clinical oncology. 33(3) |
| ISSN: | 1537-453X |
| Popis: | Purpose To determine the residual setup errors of several image guidance scenarios, using cone-beam computed tomography (CBCT) in conventionally fractionated radiotherapy for lung tumors. Methods Thirteen lung cancer patients were treated with conventionally fractionated radiotherapy, using daily image guidance with CBCT, resulting in 389 CBCT scans which were registered to the planning scan using automated soft-tissue registration. Using the resulting daily alignment data, 4 imaging frequency scenarios were analyzed: (A) no imaging; (B) weekly imaging with a 3-mm threshold; (C) first 5 fractions imaged, then weekly imaging with a patient-specific threshold; and (D) imaging every other day. Results The systematic setup error (Sigma) was reduced with increasing frequency of imaging from 3.4 mm for no imaging to 1.0 mm for imaging every other day. Random setup error (sigma), however, varied little regardless of the frequency of imaging: 2.9, 3.0, 3.4, and 3.2 mm for scenarios A, B, C, and D, respectively. The setup margins required to account for the residual error of each imaging scenario were 1 to 1.6 cm for scenario A, 4 to 6 mm for scenarios B and C, and 4 to 5 mm for scenario D. As the residual error of daily CBCT was not included in this analysis, these margins compare with a margin of zero for daily CBCT. Conclusions Daily image guidance is ideal as the setup margin can be reduced by about 5 mm versus a nondaily imaging scenario. However, if daily image guidance is not possible, there is little benefit in imaging more often than once a week. |
| Databáze: | OpenAIRE |
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