American Journal of Roentgenology, Vol 167, 1211-1215, Copyright © 1996 by American Roentgen Ray Society

ARTICLES

Accuracy of MR imaging for estimating intraosseous extent of osteosarcoma

E Onikul, BD Fletcher, DM Parham and G Chen
Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis TN 38105, USA.

OBJECTIVE: We compared how well T1-weighted and short inversion time inversion recovery (STIR) MR images obtained before and after preoperative chemotherapy reveal the extent of longitudinal intraosseous tumor involvement in osteosarcoma of children. MATERIALS AND METHODS: MR images were obtained at diagnosis and after preoperative multiagent chemotherapy in 20 children with osteosarcoma arising in the long bones. Images were reviewed to determine the length of the abnormal intraosseous signal intensity on paired longitudinal T1- weighted and STIR images taken at diagnosis and after chemotherapy. These measurements were compared with those made during a review of similarly oriented pathologic sections of the resected bone. Median differences were calculated and analyzed using Wilcoxon's signed-rank test. RESULTS: Abnormalities detected on T1-weighted images corresponded more closely to pathologic findings than did abnormalities detected on STIR images. On STIR images, readers overestimated tumor extent in 73% of both pre- and postchemotherapy studies. Readers overestimated tumor length on 29 of the 40 STIR images and on 13 of the 40 T1-weighted images. Readers underestimated tumor length on five STIR images and 11 T1-weighted images. Median differences between measurements made at the pathologic examination and on STIR images were statistically significant, both for imaging at diagnosis (p = .001) and for imaging after chemotherapy (p = .005); however, no significant differences were found between measurements made at the pathologic examination and measurements made on T1-weighted images. Measurements of tumor length on either type of imaging did not change significantly after chemotherapy. MR imaging showed 100% sensitivity for epiphyseal tumor spread but poor specificity. False-positive readings occurred in seven of 13 patients with abnormal signal intensity that extended into the adjacent epiphyses. CONCLUSION: Readers estimated intraosseous tumor extent more accurately on T1-weighted images than on STIR images. Readers overestimated tumor length on STIR images. T1-weighted longitudinal images taken before chemotherapy can be used for early planning of surgical approaches to osteosarcoma in children.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. S. Kim, S.-Y. Lee, W. H. Cho, W. S. Song, J.-S. Koh, J. A. Lee, J. Y. Yoo, and D.-G. Jeon Tumor Necrosis Rate Adjusted by Tumor Volume Change Is a Better Predictor of Survival of Localized Osteosarcoma Patients Ann. Surg. Oncol., March 1, 2008; 15(3): 906 - 914. [Abstract] [Full Text] [PDF]

				T. Zwaga, J. V. M. G. Bovee, and H. M. Kroon Best Cases from the AFIP: Osteosarcoma of the Femur with Skip, Lymph Node, and Lung Metastases RadioGraphics, January 1, 2008; 28(1): 277 - 283. [Full Text] [PDF]

				D. L. Muscolo, M. A. Ayerza, L. A. Aponte-Tinao, and M. Ranalletta Partial Epiphyseal Preservation and Intercalary Allograft Reconstruction in High-Grade Metaphyseal Osteosarcoma of the Knee J. Bone Joint Surg. Am., December 1, 2004; 86(12): 2686 - 2693. [Abstract] [Full Text] [PDF]

				D. A. Elias, L. M. White, D. J. Simpson, R. A. Kandel, G. Tomlinson, R. S. Bell, and J. S. Wunder Osseous Invasion by Soft-Tissue Sarcoma: Assessment with MR Imaging Radiology, October 1, 2003; 229(1): 145 - 152. [Abstract] [Full Text] [PDF]

				H. E. Daldrup-Link, C. Franzius, T. M. Link, D. Laukamp, J. Sciuk, H. Jurgens, O. Schober, and E. J. Rummeny Whole-Body MR Imaging for Detection of Bone Metastases in Children and Young Adults: Comparison with Skeletal Scintigraphy and FDG PET Am. J. Roentgenol., July 1, 2001; 177(1): 229 - 236. [Abstract] [Full Text] [PDF]