Cost-effectiveness of staging computed tomography of the chest in patients with T2 soft tissue sarcomas

BACKGROUND. Published practice guidelines recommend routine chest computed tomography (CT) scanning as part of the staging evaluation for patients with T2 soft tissue sarcomas (STS), although there is no direct evidence to support this practice. The objective of this study was to determine the yield and cost-effectiveness of routine versus selective chest CT scanning for the staging of patients with T2 STS and to identify any subgroups for whom a more selective approach to chest CT scanning could be considered. METHODS. Six hundred consecutive patients with primary, nonthoracic, T2 (> 5 cm) STS underwent both chest X-ray (CXR) and chest CT scanning to evaluate the presence of pulmonary metastatic disease (M1). The authors constructed a decision tree that modeled the outcomes of diagnostic testing for two hypothetical diagnostic strategies: 1) routine chest CT (rCT) or 2) CXR and selective chest CT (sCT). The yield and cost of each strategy were determined; the incremental cost-effectiveness ratio (ICER) was calculated as the cost per additional patient with pulmonary metastases identified by rCT versus sCT. RESULTS. The yield of rCT was higher than that of sCT (M1 disease identified in 19.2% vs. 16.0% of patients, respectively), but rCT was more costly ($1301 vs. $418 per patient, respectively). The ICER of rCT compared with sCT was $27,594 per patient identified with pulmonary metastasis. The expected yields, costs, and ICERs of the diagnostic strategies varied across patient subgroups based on grade, anatomic site, and tumor size. CONCLUSIONS. For patients with T2 STS, rCT was most cost-effective in patients with high-grade lesions or extremity lesions. The findings of this study do not support the routine use of chest CT scanning in all patients with T2 STS.