Clinical value of [18-F] fluorodeoxyglucose positron emission tomography imaging in soft tissue sarcomas

Objective To evaluate positron emission tomography (PET) using 2-fluoro-2-deoxy-D-glu cose (FDG) for clinical application in soft tissue sarcomas. Summary and Background Data FDG PET is a promising noninvasive method for the preoperative assessment o f soft tissue sarcomas and may complement radiologic tomography. Methods Data from 50 consecutive patients with 59 masses, either suspicious for pri mary or locally recurrent soft tissue sarcoma, were prospectively gathered. The semiquantitative FDG uptake (standardized uptake values [SUVs]) was ca lculated in tumor and normal tissue (muscle). Histopathology of surgical sp ecimens and follow-up data were used as control criteria. Results In primary soft tissue sarcomas, PET displayed a sensitivity of 91% and a s pecificity of 88%. Local recurrence was detected with a sensitivity of 88% and a specificity of 92%, All intermediate-grade and high-grade soft tissue sarcomas (primary and locally recurrent) were Visualized with a precise di fferentiation from muscle, Fifty percent of the low-grade sarcomas showed a n FDG uptake equivalent to muscle (false-negative results in one primary an d three recurrent soft tissue sarcomas). Benign soft tissue tumors (e.g., l ipoma, leiomyoma, ganglion) did not accumulate FDG. inflammation resulted i n an increased FDG uptake. The semiquantitative FDG uptake (SUVs) correlate d with tumor grade but not with size and histologic type. Conclusion High-grade and intermediate-grade soft tissue sarcomas are amenable to PET imaging, whereas low-grade lesions may not be depicted, SUVs for FDG correl ate with tumor grade in soft tissue sarcomas, Benign soft tissue tumors are differentiated from higher-grade soft tissue sarcomas. These data show tha t FDG-PET can complement preoperative radiologic assessment for soft tissue sarcomas and that FDG-PET is a powerful diagnostic toot for detecting high -grade and intermediate-grade local recurrence.