Pulmonary metastases: can accurate radiological evaluation avoid thoracotomic approach?

OBJECTIVES: To evaluate the effectiveness of radiological assessment (high-resolution CT (HRCT), helical CT (HCT) scan) of lung metastases and to verify if a complete manual exploration by thoracotomy is necessary. MATERIALS AND METHODS: From 1/96 to 1/00, 166 consecutive patients presenting with lung metastases were treated. Preoperative CT scan (HRCT in 78 patients, group A; HCT in 88 patients, group B) to assess the number, size and location of the lesions (slice thickness 5 mm; reconstruction interval 3-5 mm) was always performed. All patients underwent axillary thoracotomy (staged when lesions were bilateral); accurate palpation of the lung parenchyma was always performed to identify any undetected lesion. Non-metastatic lesions were excluded. RESULTS: We performed 356 wedge resections in 161 patients (113 monolateral, 70.2%; 48 bilateral, 29.8%) and five lobectomies. In group A, primary neoplasm was epithelial in 44 patients, sarcoma in 26 and germ cell in eight, and in group B, epithelial in 61 patients, sarcoma in 20 and germ cell in seven. Three hundred and sixty-one histologically proven metastases were resected (188 in group A and 173 in group B). HRCT correctly identified 142/188 lesions (sensitivity 75%); HCT revealed 142/173 metastases (sensitivity 82.1%). Sensitivity for lesions less than 6 mm in maximum diameter was 48% (30/58 false negative) in group A and 61.5% (20/52 false negative) in group B. CONCLUSIONS: The sensitivity of HCT exceeds that of HRCT. However, complete manual exploration by thoracotomy remains the procedure of choice for patients undergoing pulmonary metastasectomy, because of limitation in preoperative radiological assessment of lung lesions smaller than 6 mm.