Accurate setup of paraspinal patients using a noninvasive patient immobilization cradle and portal imaging
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, 10021 (United States)
Because of the proximity of the spinal cord, effective radiotherapy of paraspinal tumors to high doses requires highly conformal dose distributions, accurate patient setup, setup verification, and patient immobilization. An immobilization cradle has been designed to facilitate the rapid setup and radiation treatment of patients with paraspinal disease. For all treatments, patients were set up to within 2.5 mm of the design using an amorphous silicon portal imager. Setup reproducibility of the target using the cradle and associated clinical procedures was assessed by measuring the setup error prior to any correction. From 350 anterior/posterior images, and 303 lateral images, the standard deviations, as determined by the imaging procedure, were 1.3 m, 1.6 m, and 2.1 in the ant/post, right/left, and superior/inferior directions. Immobilization was assessed by measuring patient shifts between localization images taken before and after treatment. From 67 ant/post image pairs and 49 lateral image pairs, the standard deviations were found to be less than 1 mm in all directions. Careful patient positioning and immobilization has enabled us to develop a successful clinical program of high dose, conformal radiotherapy of paraspinal disease using a conventional Linac equipped with dynamic multileaf collimation and an amorphous silicon portal imager.
- OSTI ID:
- 20726274
- Journal Information:
- Medical Physics, Vol. 32, Issue 8; Other Information: DOI: 10.1118/1.1951042; (c) 2005 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
- Country of Publication:
- United States
- Language:
- English
Similar Records
Comparison of Kilovoltage Cone-Beam Computed Tomography With Megavoltage Projection Pairs for Paraspinal Radiosurgery Patient Alignment and Position Verification
Image-guided radiotherapy using megavoltage cone-beam computed tomography for treatment of paraspinous tumors in the presence of orthopedic hardware