Hybrid registration of prostate and seminal vesicles for image guided radiation therapy
| Autor: | Johan de Boer, Floris J. Pos, Jan-Jakob Sonke, Marcel van Herk |
|---|---|
| Přispěvatelé: | Graduate School, Biomedical Engineering and Physics |
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Male
Cancer Research Cone beam computed tomography Radiation Rotation business.industry Movement Radiotherapy Planning Computer-Assisted Planning target volume Prostate Seminal Vesicles Cone-Beam Computed Tomography medicine.anatomical_structure Oncology Fiducial Markers Medicine Humans Radiology Nuclear Medicine and imaging business Nuclear medicine Fiducial marker Image-guided radiation therapy Radiotherapy Image-Guided Retrospective Studies |
| Zdroj: | International journal of radiation oncology, biology, physics, 86(1), 177-182. Elsevier Inc. |
| ISSN: | 0360-3016 |
| Popis: | Purpose Fiducial markers are a good surrogate for the prostate but provide little information on the position and orientation of the seminal vesicles (SVs). Therefore, a more advanced localization method is warranted if the SVs are part of the target volume. The purpose of this study was to develop a hybrid registration technique for the localization of the prostate and SVs. Methods and Materials Twenty prostate patients implanted with 2 or 3 elongated fiducial markers had cone beam computed tomography (CBCT) scans acquired at every fraction. The first step of the hybrid registration was to localize the prostate by CBCT-to-planning-CT alignment of the fiducial markers, allowing both translations and rotations. Using this marker registration as a starting point, the SVs were registered based on gray values, allowing only rotations around the lateral axis. We analyzed the differential rotation between the prostate and SVs and compared the required SV margins for 3 correction strategies. Results The SV registration had a precision of 2.7° (1 standard deviation) and was successful for 96% of the scans. Mean (M), systematic (Σ), and random (σ) differences between the orientation of the prostate and SV were M = −0.4°, Σ = 7.2°, and σ = 6.4°. Daily marker-based corrections required an SV margin of 11.4 mm (translations only) and 11.6 mm (translations + rotations). Rotation corrections of the SVs reduced the required margin to 8.2 mm. Conclusions We found substantial differences between the orientation of the prostate and SVs. The hybrid registration technique can accurately detect these rotations during treatment. Rotation correction of the SVs allows for margin reduction for the SVs. |
| Databáze: | OpenAIRE |
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