A prospective study to determine the incidence of non-imaged malignant pulmonary nodules in patients who undergo metastasectomy by thoracotomy with lung palpation.

BACKGROUND

To prospectively assess the incidence of non-imaged malignant nodules in patients who undergo thoracotomy for metastasectomy with bimanual lung palpation.

METHODS

This is a prospective cohort study of patients who underwent open metastasectomy by thoracotomy. All patients had metastatic lung lesions, underwent 64-slice helical computed tomographic (CT) scan with intravenous contrast using 5-mm collimated cuts, and most had integrated PET (positron emission tomography)-CT. Unsuspected malignant pulmonary nodules that were palpated and removed, and that were not imaged preoperatively, were recorded.

RESULTS

From January 2006 to March 2010, 152 patients underwent metastasectomy by rib-sparing, nerve-sparing thoracotomy by 1 surgeon. Fifty-one (34%) patients had 57 pulmonary nodules that were not imaged preoperatively and 32 of the 57 (56%) nodules were malignant. Thirty patients had non-imaged malignant nodules that were palpated and removed. There were 15 malignant nodules that were in different lobes than the imaged nodules. The 3 most commonly missed malignant nodules occurred in patients with colorectal cancer, renal cell, and sarcoma.

CONCLUSIONS

Metastasectomy by thoracotomy, which affords bimanual palpation of the entire lung, discovers ipsilateral non-imaged malignant pulmonary metastases in 1 of 5 patients who had at least 1 imaged metastatic pulmonary lesion. This is true despite preoperative, fine cut chest CT scan with contrast, and integrated 18F-fluorodeoxyglucose-PET-CT scanning. The clinical significance of these non-imaged, resected malignant nodules is unknown, nor is the added morbidity of resecting benign nodules.