Intensity-Modulated Radiotherapy Using Implanted Fiducial Markers With Daily Portal Imaging: Assessment of Prostate Organ Motion
- Department of Radiation Oncology, LDS Hospital, Salt Lake City, UT (United States)
- Statistical Data Center, Intermountain Health Care, Salt Lake City, UT (United States)
Purpose: To assess our single institutional experience with daily localization, using fiducials for prostate radiotherapy. Methods and Materials: From January 2004 to September 2005, 33 patients were treated with 1,097 intensity-modulated radiation treatments, using three implanted fiducials. Daily portal images were obtained before treatments. Shifts were made for deviations {>=}3 mm in the left-right (LR), superior-inferior (SI), and anterior-posterior (AP) dimensions. Results: Of 1,097 treatments, 987 (90%) required shifts. Shifts were made in the LR, SI, and AP dimensions in 51%, 67%, and 58% of treatments, respectively. In the LR dimension, the median distance shifted was 5 mm. Of 739 shifts in the SI dimension, 73% were in the superior direction for a median distance of 6 mm, and 27% were shifted inferiorly for a median distance of 5 mm. The majority of shifts in the AP dimension were in the anterior direction (87%). Median distances shifted in the anterior and posterior directions were 5 mm and 4 mm, respectively. The median percentage of treatments requiring shifts per patient was 93% (range, 57-100%). Median deviations in the LR, SI, and AP dimensions were 3 mm, 4 mm, and 3 mm, respectively. Deviations in the SI and AP dimensions were more often in the superior rather than inferior (60% vs. 29%) and in the anterior rather than posterior (70% vs. 16%) directions. Conclusions: Interfraction prostate motion is significant. Daily portal imaging with implanted fiducials improves localization of the prostate, and is necessary for the reduction of treatment margins.
- OSTI ID:
- 20951723
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Vol. 68, Issue 3; Other Information: DOI: 10.1016/j.ijrobp.2007.02.024; PII: S0360-3016(07)00316-1; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
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