Accuracy of DOTATATE-positron emission tomography for preoperative nodal staging of carcinoid tumors of the lung.

Objective: DOTATATE-positron emission tomography (PET) scans use a radiotracer that binds somatostatin receptor 2 on neuroendocrine cells to identify carcinoid tumors. Use of DOTATATE-PET during preoperative evaluation of lung carcinoids is increasing, but the accuracy of DOTATATE-PET in nodal staging of pulmonary carcinoids is unknown. Methods: We reviewed patients with lung carcinoids undergoing DOTATATE-PET before surgical resection between November 2013 and 2023. Exclusions included non-avid primary tumors on DOTATATE-PET or absent pathologic lymph node assessment. Using surgical pathology as the gold standard, we assessed concordance between DOTATATE-PET-based clinical stage and postoperative pathologic stage. Sensitivity, specificity, negative predictive value, and positive predictive value were calculated, with χ2 and Mann-Whitney U test used for comparisons. Results: Among 58 patients undergoing resection of lung carcinoid tumors (48 typical, 10 atypical carcinoids), 15 (25.8%) had pathologic nodal involvement, but DOTATATE-PET detected only 3. For the 43 patients who were pathologic node-negative, DOTATATE-PET was negative in 42. This yielded 42 true negatives, 3 true positives, 12 false negatives, and 1 false positive, with sensitivity of 20%, specificity 97.7%, negative predictive value 77.8%, positive predictive value 75%, and overall accuracy of 77.6%. Larger tumor size was significantly associated with inaccurate DOTATATE-PET (P = .03). No other clinical characteristics significantly correlated with DOTATATE-PET accuracy. Conclusions: DOTATATE-PET has poor sensitivity for nodal disease in patients with pulmonary carcinoid tumors. Thorough pathologic lymph node evaluation is necessary regardless of DOTATATE-PET results when resecting carcinoid tumors. Given that primary surgery is indicated even if it were known there were positive lymph nodes, the utility of a DOTATATE-PET is likely limited.