Not palpable? Role of radio-guided video-assisted thoracic surgery for nonpalpable solitary pulmonary nodules

Purpose: This study aimed to evaluate the effectiveness of radio-guided localization for thoracoscopic resection of small nonpalpable lung nodules. Methods: Nineteen patients with a solitary nodule were enrolled. Inclusion criteria were maximum nodule diameter <15 mm, distance from nearest pleural surface of 20-40 mm, nonsolid or partly solid nodule, and/or posterior location. Under computed tomography (CT) guidance, the nodule was identified and a needle was inserted to reach lesional or perilesional tissue. A solution of (99m)Tc macro-aggregates albumin diluted with iodized contrast medium was injected. After injection, CT and gamma scintigraphy were performed to confirm precise staining. Localization complications were minimal. Results: At thoracoscopy, the gamma detector probe allowed localization of nodules in all patients, with the radioactive signal being converted by the system into audio and visual numeric signals. Resection was performed, and suture margins were checked with the probe to search for residual hyperabsorption. All specimens underwent frozen section. Mean time to detect nodules with the gamma probe was 6 min (range 3-9 min). Frozen section revealed primary pulmonary tumors in eight cases, secondary lesions in four cases, and a benign nodule in the remaining seven cases. Conclusion: Radio-guided localization is a simple, safe procedure for localizing nonpalpable solitary pulmonary nodules.