Inventi Impact: Radiology

Inventi:hrd/22837/17

FDG PET Using SUVmax for Preoperative T-Staging of Esophageal Squamous Cell Carcinoma with and\nwithout Neoadjuvant Chemoradiotherapy

Background: Accurate T-staging is pivotal for predicting prognosis and selecting appropriate therapies for\nesophageal squamous cell carcinoma (ESCC). The diagnostic performance of fluorodeoxyglucose (FDG) positron\nemission tomography/computed tomography (PET/CT) for its T-staging is uncertain. We investigated use of FDG\nPET/CT for preoperative T-staging of patients with ESCC.\nMethods: Patients with ESCC given preoperative FDG PET/CT scans, either with (CRT[+] group) or without (CRT[âË?â??]\ngroup) neoadjuvant chemoradiotherapy, were retrospectively reviewed. Maximal standardized uptake value\n(SUVmax) of the primary tumors on FDG PET/CT scans were measured, and histopathological results were used as\nthe reference standard. The associations between pathological T-stage and potential factors of age, tumor location,\ntumor grade, tumor size, and tumor SUVmax were analyzed. The cut-off levels of SUVmax for predicting different\nT-stages and for residual viable tumors after neoadjuvant chemoradiotherapy were determined using receiver\noperating characteristic analyses.\nResults: We enrolled 103 patients (45 in the CRT[âË?â??] group; 58 in the CRT[+] group). SUVmax, an independent predictive\nfactor, positively correlated with the pathological T-stage in both groups (CRT[âË?â??] group: ρ = 0.736, p < 0.001; and CRT[+]\ngroup: ρ = 0.792, p < 0.001). The overall accuracy of the PET/CT with thresholded SUVmax for predicting the pathological\nT-stage was 73.3% in the CRT[âË?â??] group (SUVmax of T0: 0ââ?¬â??1.9, T1: 2.0ââ?¬â??4.4, T2: 4.5ââ?¬â??6.5, T3: 6.6ââ?¬â??13.0, T4: >13.0) and 67.2% in\nthe CRT[+] group (SUVmax of T0: 0ââ?¬â??3.4, T1: 3.5ââ?¬â??3.9, T2: 4.0ââ?¬â??5.5, T3: 5.6ââ?¬â??6.2, T4: > 6.2). For CRT[âË?â??] group, the accuracy using\nan SUVmax cut-off of 4.4 to differentiate early (T0-1) from locally advanced disease (T2-4) was 82.2% (95% CI, 71.1ââ?¬â??93.\n4%). For CRT[+] group, the accuracy using an SUVmax cut-off of 3.4 to predict residual viable tumors (non-T0) after\ncompletion of chemoradiotherapy was 82.8% (95% CI, 73.0ââ?¬â??92.5%).\nConclusions: The FDG avidity of a primary esophageal tumor significantly positively correlated with the pathological\nT-stage. PET/CT with thresholded SUVmax was useful for predicting T-stage and differentiating residual viable tumors.