Investigation of Linac-Based Image-Guided Hypofractionated Prostate Radiotherapy

Journal Article · Sun Jul 01 04:00:00 EDT 2007 · Medical Dosimetry

DOI:https://doi.org/10.1016/j.meddos.2007.01.004· OSTI ID:20975203

Pawlicki, Todd ^[1]; Kim, Gwe-Ya ^[1]; Hsu, Annie ^[1]; Cotrutz, Cristian ^[1]; Boyer, Arthur L ^[1]; Lei, Xing ^[1]; King, Christopher R ^[1]; Luxton, Gary ^[1]

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1. Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)

A hypofractionation treatment protocol for prostate cancer was initiated in our department in December 2003. The treatment regimen consists of a total dose of 36.25 Gy delivered at 7.25 Gy per fraction over 10 days. We discuss the rationale for such a prostate hypofractionation protocol and the need for frequent prostate imaging during treatment. The CyberKnife (Accuray Inc., Sunnyvale, CA), a linear accelerator mounted on a robotic arm, is currently being used as the radiation delivery device for this protocol, due to its incorporation of near real-time kV imaging of the prostate via 3 gold fiducial seeds. Recently introduced conventional linac kV imaging with intensity modulated planning and delivery may add a new option for these hypofractionated treatments. The purpose of this work is to investigate the use of intensity modulated radiotherapy (IMRT) and the Varian Trilogy Accelerator with on-board kV imaging (Varian Medical Systems Inc., Palo Alto, CA) for treatment of our hypofractionated prostate patients. The dose-volume histograms and dose statistics of 2 patients previously treated on the CyberKnife were compared to 7-field IMRT plans. A process of acquiring images to observe intrafraction prostate motion was achieved in an average time of about 1 minute and 40 seconds, and IMRT beam delivery takes about 40 seconds per field. A complete 7-field IMRT plan can therefore be imaged and delivered in 10 to 17 minutes. The Varian Trilogy Accelerator with on-board imaging and IMRT is well suited for image-guided hypofractionated prostate treatments. During this study, we have also uncovered opportunities for improvement of the on-board imaging hardware/software implementation that would further enhance performance in this regard.

• OSTI ID: 20975203
• Journal Information: Medical Dosimetry, Journal Name: Medical Dosimetry Journal Issue: 2 Vol. 32; ISSN 0958-3947; ISSN MEDOEJ
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CARCINOMAS
COMPUTER CODES
IMAGES
LINEAR ACCELERATORS
PATIENTS
PERFORMANCE
PROSTATE
RADIATION DOSES
RADIOTHERAPY
STATISTICS