[A diagnostic strategy for isolated pulmonary nodules less than 2 cm in diameter].

The object of this study is to determine the best diagnostic strategy for isolated pulmonary nodules less than 2 cm in diameter starting from decision analysis. The diagnostic pathway included strategies: 1. Observation with a thoracic tomodensitometry (TDM) every 3 months. 2. Percutaneous needle biopsy. 3. Video-assisted thoracoscopic surgery (VATS) resection. 4. Resection by thoracotomy. Observation was the best strategy for non-smokers in their 40's with a cost of 57-69 Francs per year of life gained. Needle biopsy was the best strategy for a 1 cm nodule in patients of 50 years, smokers and non-smokers (life expectancy 29.38 and 24.44 years). The best strategy for a 2 cm nodule was needle biopsy in 40 year old smokers (life expectancy 34.18 years) and in non-smokers aged 50-60 years with a life expectancy from 20.0 to 28.2 years. VATS was the best strategy for a 1 cm nodule in smokers over the age of 60 for a 2 cm nodule over the age of 50. The costs were 1 811, 3 214, 1 873, 1 811 and 6 093 Francs respectively per year of life gained. During the sensitivity analysis VATS remained the best strategy provided the post-operative mortality remained below 2%. When the risk of malignancy is only moderate needle biopsy may be recommended but when the risk of malignancy is high it is preferable to advise VATS as the method of diagnosis.