Is manual palpation of the lung necessary in patients undergoing pulmonary metastasectomy?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether manual palpation of the lung is necessary in patients undergoing pulmonary metastasectomy. In total, 56 articles were found using the described search strategy. After screening these articles and their references, 18 publications represented the best evidence to answer the clinical question. No randomized controlled trial addressing the three-part question was available. The authors, journal, date and country of publication, patient group, study type, relevant outcomes and results of these papers were tabulated. The studies reported on 1472 patients with different primary cancers. The patients underwent more than 1630 pulmonary metastasectomies between 1990 and 2014 after the treatment of primary cancer. Almost three quarters of patients underwent open procedures like thoracotomy or sternotomy. Most frequently, helical CT with a slice thickness ranging between 1 and 10 mm was used for preoperative imaging. The sensitivity in detecting pulmonary nodules ranged from 34 to 97%. The corresponding sensitivity rates for PET-CT were 66-67.5 and 75% for high-resolution CT. The positive predictive value for lesions detected by helical CT varied from 47 to 96%. Helical CT reached a specificity between 54 and 93% in detecting pulmonary nodules. The surgeons identified more nodules by meticulous palpation than helical CT. It is noteworthy that up to 48.5% of these palpated nodules were benign lesions (false-positive). Patients with smaller imaged nodules, multiple imaged nodules or primary mesenchymal tumour are more likely to have occult pulmonary nodules. We conclude that not all palpable pulmonary nodules can be imaged preoperatively. Thoracotomy allows the manual palpation of the ipsilateral hemithorax and might be superior to video-assisted thoracic surgery regarding radical resection. However, not all palpable nodules are malignant, and the impact of non-resected pulmonary metastases on patient survival is not clearly evaluated.