Faculty Collaboration Database

Gated treatment delivery verification with on-line megavoltage fluoroscopy. Int J Radiat Oncol Biol Phys 2010 Apr;76(5):1592-8

Date

02/06/2010

Pubmed ID

20133069

DOI

10.1016/j.ijrobp.2009.08.005

Scopus ID

2-s2.0-77949569698 (requires institutional sign-in at Scopus site)   16 Citations

Abstract

PURPOSE: To develop and clinically demonstrate the use of on-line real-time megavoltage (MV) fluoroscopy for gated treatment delivery verification.

METHODS AND MATERIALS: Megavoltage fluoroscopy (MVF) image sequences were acquired using a flat panel equipped for MV cone-beam CT in synchrony with the respiratory signal obtained from the Anzai gating device. The MVF images can be obtained immediately before or during gated treatment delivery. A prototype software tool (named RTReg4D) was developed to register MVF images with phase-sequenced digitally reconstructed radiograph images generated from the treatment planning system based on four-dimensional CT. The image registration can be used to reposition the patient before or during treatment delivery. To demonstrate the reliability and clinical usefulness, the system was first tested using a thoracic phantom and then prospectively in actual patient treatments under an institutional review board-approved protocol.

RESULTS: The quality of the MVF images for lung tumors is adequate for image registration with phase-sequenced digitally reconstructed radiographs. The MVF was found to be useful for monitoring inter- and intrafractional variations of tumor positions. With the planning target volume contour displayed on the MVF images, the system can verify whether the moving target stays within the planning target volume margin during gated delivery.

CONCLUSIONS: The use of MVF images was found to be clinically effective in detecting discrepancies in tumor location before and during respiration-gated treatment delivery. The tools and process developed can be useful for gated treatment delivery verification.

Author List

Tai A, Christensen JD, Gore E, Khamene A, Boettger T, Li XA

Authors

Elizabeth M. Gore MD Professor in the Radiation Oncology department at Medical College of Wisconsin
An Tai PhD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Cone-Beam Computed Tomography
Fluoroscopy
Four-Dimensional Computed Tomography
Humans
Lung Neoplasms
Phantoms, Imaging
Prospective Studies
Radiotherapy Planning, Computer-Assisted
Respiration
Respiratory-Gated Imaging Techniques
Software
Spine