Perfusion CT: A biomarker for soft tissue tumors of extremities

The aim of the work: To assess the perfusion CT characteristics of soft tissue tumors of extremities and evaluate its feasibility as a functional imaging technique in detecting, characterization, surgical planning and therapy monitoring of soft tissue tumors. Patients & methods: 31 cases with soft tissue tumor of extremities underwent PCT. Patients were 20 males and 11 females; age ranged from 17 to 74 years, mean age was 47.3 years. The final pathological results revealed three benign and 28 malignant soft tissue tumors, included 25 primary malignant tumors and three secondary tumors (metastasis). All cases underwent first-pass perfusion imaging with a 64-detector row CT scanner. Perfusion (BF), peak enhancement intensity (PEI), time to peak (TTP) and blood volume (BV) were measured in both tumor area and surrounding normal muscles then statistically compared. Results: Qualitative analysis of color-coded PCT maps efficiently differentiated areas of active tumor/tumor residue from normal tissue. Quantitative analysis demonstrated that mean BF, PEI and BV were significantly higher in malignant tumors compared with surrounding healthy muscles (p < 0.05), but mean value of TTP was not found to be statistically significantly different. Receiver operating characteristic (ROC) curve analysis showed that malignant tissue can be differentiated well from normal muscle with BF greater than 12.9 ml/min/100 gm tissue, PEI higher than 22.8 HU or BV larger than 19.75 ml per 100 g tissue. Conclusion: Preliminary results suggest a good value of PCT in detecting, characterization and therapy monitoring of soft tissue tumors of extremities. (C) 2013 Production and hosting by Elsevier B.V. on behalf of Egyptian Society of Radiology and Nuclear Medicine. Open access under CC BY-NC-ND license.