Image-guided radiotherapy using megavoltage cone-beam computed tomography for treatment of paraspinous tumors in the presence of orthopedic hardware

Journal Article · Sun Oct 01 00:00:00 EDT 2006 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2006.05.038· OSTI ID:20850101

Hansen, Eric K ^[1]; Larson, David A ^[1]; Aubin, Michele ^[1]; Chen, Josephine ^[1]; Descovich, Martina ^[1]; Gillis, Amy M ^[1]; Morin, Olivier ^[1]; Ping, Xia ^[1]; Pouliot, Jean ^[1]

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1. Department of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States)

Purpose: This report describes a new image-guided radiotherapy (IGRT) technique using megavoltage cone-beam computed tomography (MV-CBCT) to treat paraspinous tumors in the presence of orthopedic hardware. Methods and Materials: A patient with a resected paraspinous high-grade sarcoma was treated to 59.4 Gy with an IMRT plan. Daily MV-CBCT imaging was used to ensure accurate positioning. The displacement between MV-CBCT and planning CT images were determined daily and applied remotely to the treatment couch. The dose-volume histograms of the original and a hypothetical IMRT plan (shifted by the average daily setup errors) were compared to estimate the impact on dosimetry. Results: The mean setup corrections in the lateral, longitudinal, and vertical directions were 3.6 mm (95% CI, 2.6-4.6 mm), 4.1 mm (95% CI, 3.2-5.0 mm), and 1.0 mm (95% CI, 0.6-1.3 mm), respectively. Without corrected positioning, the dose to 0.1 cc of the spinal cord increased by 9.4 Gy, and the doses to 95% of clinical target volumes 1 and 2 were reduced by 4 Gy and 4.8 Gy, respectively. Conclusions: Megavoltage-CBCT provides a new alternative image-guided radiotherapy approach for treatment of paraspinous tumors in the presence of orthopedic hardware by providing 3D anatomic information in the treatment position, with clear imaging of metallic objects and without compromising soft-tissue information.

• OSTI ID: 20850101
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 66, Issue 2; Other Information: DOI: 10.1016/j.ijrobp.2006.05.038; PII: S0360-3016(06)00951-5; Copyright (c) 2006 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

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BEAMS
COMPUTERIZED TOMOGRAPHY
CORRECTIONS
DOSIMETRY
ERRORS
IMAGES
METASTASES
PATIENTS
PLANNING
RADIATION DOSES
RADIOTHERAPY
SARCOMAS
SPINAL CORD
VERTEBRAE