Four-dimensional computed tomographic analysis of esophageal mobility during normal respiration
- Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands)
- Department of Bioinformatics, Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)
Background: Chemo-radiotherapy for thoracic tumors can result in high-grade radiation esophagitis. Treatment planning to reduce esophageal irradiation requires organ motion to be accounted for. In this study, esophageal mobility was assessed using four-dimensional computed tomography (4DCT). Methods and Materials: Thoracic 4DCT scans were acquired on a 16-slice CT scanner in 29 patients. The outer esophageal wall was contoured in two extreme phases of respiration in 9 patients with nonesophageal malignancies. The displacement of the center of contour was measured at 2-cm intervals. In 20 additional patients with Stage I lung cancer, the esophagus was contoured in all 10 phases of each 4DCT at five defined anatomic levels. Both approaches were then applied to 4DCT scans of 4 patients who each had two repeat scans performed. A linear mixed effects model was constructed with fixed effects: measurement direction, measurement type, and measurement location along the cranio-caudal axis. Results: Measurement location and direction were significant descriptive parameters (Wald F-tests, p < 0.001), and the interaction term between the two was significant (p = 0.02). Medio-lateral mobility exceeded dorso-ventral mobility in the lower half of the esophagus but was of a similar magnitude in the upper half. Margins that would have incorporated all movement in medio-lateral and dorso-ventral directions were 5 mm proximally, 7 mm and 6 mm respectively in the mid-esophagus, and 9 mm and 8 mm respectively in the distal esophagus. Conclusions: The distal esophagus shows more mobility. Margins for mobility that can encompass all movement were derived for use in treatment planning, particularly for stereotactic radiotherapy.
- OSTI ID:
- 20944728
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 3 Vol. 67; ISSN IOBPD3; ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
Similar Records
SU-F-J-128: Dosimetric Impact of Esophagus Motion in Spine Stereotactic Body Radiotherapy
Detection of Esophageal Fiducial Marker Displacement During Radiation Therapy With a 2-dimensional On-board Imager: Analysis of Internal Margin for Esophageal Cancer