Radio-Guided Localization and Resection of Small or Ill-Defined Pulmonary Lesions

Screening programs have increased the identification of small or indistinct pulmonary lesions that are difficult to localize. We report our experience in their preoperative localization by radiotracer and resection.

Patients with pulmonary nodules of subsolid morphology or smaller than 1 cm, deeper 1 cm below the visceral pleura, or both underwent computed tomography (CT)-guided injection of radiotracer technetium 99m macroaggregates in the vicinity of the lesion. During the operation, a handheld gamma probe was used to detect the hot spot where the radioactive tracer was localized, and this area was resected.

From November 2007 to May 2013, 112 patients (58 men; median age 62 years) underwent preoperative radiotracer injection with a successful marking in all patients. Adverse events included 33 (29.4%) pneumothoraces (one requiring chest tube placement), 23 (20.5%) parenchymal hemorrhage suffusions, and 1 (0.9%) allergic reaction to contrast medium. In all cases except two, the gamma probe revealed pulmonary lesions. Overall, 123 pulmonary nodules were localized and resected. The mean distance from the pleura was 12 mm (range, 0 to 39 mm). Pulmonary resection was performed by thoracoscopy in 70 (62.5%) cases, thoracotomy in 36 (32.1%), and conversion of thoracoscopy to thoracotomy in 6 (5.4%). The mean nodule size was 9 mm (range, 3 to 24 mm). Histology showed 14 (11.4%) benign lesions and 109 (88.6%) malignant lesions (85 primary lung cancers and 24 metastases).

Radiotracer localization of pulmonary lesions is a simple and feasible procedure with a high rate of success. Optimal candidates are patients with suspicious-looking nodules detected by screening or incidental CT resulting frm the high rate of nonsolid morphology and small size.