Shao Dan MD, MD, Abstract Co-Author: Nothing to Disclose

Wang Shu-Xia MD,PhD, Presenter: Nothing to Disclose

Liang Chang-Hong MD,PhD, Abstract Co-Author: Nothing to Disclose

To investigate the clinical characteristics and FDG PET/CT findings of soft tissue (ST) metastasis.

The clinical and PET/CT data in 11 cases of soft tissue metastasis were analyzed retrospectively. The records of consecutive patients with available clinical data accord with the criteria between August 2007 and January 2009 were retrospectively reviewed. All studies were performed on Biography 16 HR PET/CT (SIEMENS, Germany). PET images were acquired during shallow breathing in the two-dimensional mode. Trunk PET scan was performed from the upper thighs to pharynx nasalis immediately after the CT scan was completed. Diagnostic CT scanning was performed followed. Enhanced scanning include arterial phase and venous phase. We scan epigastric region in arterial phase, then chest and abdomen in venous phase.

In the primary lesions, lung carcinoma was encountered in 9 of the 11 cases and represented as the most frequent neoplasms with ST metastasis, the remaining 2 patients had the primary lesion in kidney and mammary glands.All patients complaint of the presence of a painful mass. Those 11 patients had a total of 16 ST lesions, 13 lesions out of 16 ST lesions in the muscles.All ST metastatic lesions were FDG avid, the SUVmax of the ST metastatic lesions ranged from 2.5 to 13.9 (mean 6.49±2.38), the SUVmax of the liver being between 1.4 and 2.5 (mean 2.06±0.38), all lesions had more FDG uptake than in the liver, no lesion presented with SUVmax lower than in the liver. The CT size of the lesions were within 0.8～3.6cm (mean 2.18±1.7cm). In those 3 subcutaneous lesions, they were all hyperdense, more intense than the subcutaneous sites surrounding the lesions. Muscle lesions were hypodense (to compare with the muscles surrounding the lesions) in 5/16 and isodense in 8/16, and all lesions had well circumscribed margins and showed no calcification.

ST metastasis were mostly occurred in muscles, such as hip muscles and dorsal muscles, the primary lesions were most frequently located in lung. 18F-FDG PET/CT is sensitive and specific in discovering of the primary lesion and diagnosis of soft tissue metastasis, PET/CT has a significant diagnostic and differentiated diagnostic value on ST metastasis.

18F-FDG PET/CT is sensitive and specific in discovering of the primary lesion and diagnosis of soft tissue metastasis.

Dan, S, Shu-Xia, W, Chang-Hong, L, Application of 18F-FDG PET/CT Imaging in Soft Tissue Metastasis.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8007879.html