Mitsuo Satake MD, Presenter: Nothing to Disclose

Ukihide Tateishi MD, PhD, Abstract Co-Author: Nothing to Disclose

Tetsuo Maeda MD, Abstract Co-Author: Nothing to Disclose

Yasuaki Arai MD, Abstract Co-Author: Nothing to Disclose

There are great variations in histologic type and grade in soft tissue sarcomas. This study was conducted to assess the validity of diagnosis of tumor grade prior to treatment using FDG PET/CT fused images in patients with soft tissue sarcomas.

FDG PET/CT fused images of 53 cases (mean age: 62 years old; range 42-78 years) in patients with soft tissue tumors were analyzed prospectively. We excluded 7 patients with pathologically confirmed benign tumors form data analysis. Pathologic diagnosis was obtained by surgical specimens in 46 malignant tumors: Pleomorphic sarcoma undifferentiated subtype (n=8), osteosarcoma (n=8), Ewing’s sarcoma/primitive neuroectodermal tumor (PNET; n=8), synovial sarcoma (n=6), liposarcoma (n=5), rhabdomyosarcoma (n=5), chondrosarcoma (n=3), and others (n=3). Maximum and average standardized uptake value (SUV) of the primary and metastatic lesions were compared to pathologic variables including tumor differentiation, the presence of necrosis, MIB-1 score, mitotic score, p53 overexpression, MIB-1 grade, and mitotic grade. The Pearson correlation coefficients were conducted between maximum and average SUV and pathologic variables. The multiple stepwise regression analysis was also performed.

Significant correlations were found in 46 primary lesions between maximum SUV and MIB-1 grade (r=.613, P<.001), mitotic grade (r=0.579, P<.001), MIB-1 score (r=.511, P<.001), tumor differentiation (r=.427, P=.003), and mitotic score (r=.412, P=.004). There were also significant correlations between average SUV and tumor differentiation, MIB-1 score, mitotic score, MIB-1 grade, and mitotic grade in primary lesions. In the multiple stepwise regression analysis, MIB-1 grade was only significant to correlate with maximum and average SUV (P<.0001) in the primary lesions. However, no significant correlation was identified in 20 metastatic lesions between maximum SUV and tumor differentiation, MIB-1 score, mitotic score, MIB-1 grade, and mitotic grade.

Maximum and average SUV of the primary lesions on FDG PET/CT fused images reflects MIB-1 grade of soft tissue sarcomas prior to treatment.

Satake, M, Tateishi, U, Maeda, T, Arai, Y, Validity of Tumor Grade Using FDG PET/CT Fused Images: A Prospective Analysis in Patients with Soft Tissue Sarcomas.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4409590.html