A pilot study of the role of TC-99 radionuclide in localization of pulmonary nodular lesions for thoracoscopic resection

Objective: Video-assisted thoracic surgery (VATS) is an interesting and eme rging procedure for diagnosis and treatment of peripheral pulmonary nodules . However, thoracoscopy has limits in the detection of small nodules, below the pleural surface, deep in the lung parenchyma, which cannot be seen as much as palpated. Methods to localize such lesions, including the methylene blue injection or the introduction of a hooked-wire under the radiological vision, have some advantages but a lot of limitations. We are developing a new technique for the detection of pulmonary nodules smaller than 2 cm, de ep in the lung parenchyma. Methods: The technique consisted of a intra-lesi onal injection of 0.3 mi of solution of 99m Tc-labelled human serum albumin microspheres (5-10 MBq) under the CT-scan guide, 2 h before surgery. Durin g thoracoscopy a 11 mm diameter-collimated probe connected to a gamma ray d etector (Scinti Probe MR 100 - Pol.hi.tech.. Aquila - Italy), is introduced by a 11.5 mm trocar and the pleural surface of the suspected area was scan ned. A hot-spot indicated the presence of the injected nodule and as a cons equence, the area to be resected. Results: from June 1997 to June 1999 we t reated 39 patients with small pulmonary nodules. The patients were 27 men a nd 12 women with a mean age of 60.8 years (range: 13-80). In 19 cases the a namnesis was positive for synchronous or metachronous malignant neoplasm. T he mean surgical procedure length was 50 min (range 20-100 min). In all the cases the nodule was resected and the resection margins were pathologicall y free of tumour. The mean post-operative hospital stay was 3 days (range 2 -6 days). Histological examination showed 21 benign lesions and 18 malignan t lesions (seven metastases and 11 primary lung cancers). Nine pts with pri mary lung carcinoma underwent a completion lobectomy by open surgery. Concl usions: Radiolocalization by gamma-probe allows the detection and exeresis of small nodules in a easy and safe way. Future and predictable advances in radio-marked monoclonal antibodies, as well as in the development of endos copic beta-detector probe, will offer a more effective method for detection of primary and metastatic rumours, targets of thoracoscopic resections. (C ) 2000 Elsevier Science B.V. All rights reserved.