Custo-efetividade da tomografia de emissão de pósitron (PET scan) no diagnóstico diferencial do nódulo pulmonar solitário na perspectiva do Sistema Único de Saúde

Abstract

Solitary pulmonary nodules of unknown origin still represent a contemporary clinical challenge. Rapid identification and resection of malignant etiology of SPN is essential both to enable better patient survival, as to avoid unnecessary invasive diagnostic and potential surgical complications in patients with benign lesions. The PET scan has been suggested as a diagnostic tool useful for improving the diagnostic process of these nodules. We evaluated the cost-effectiveness of the addition of Positron Emission Tomography (18FDG-PET-CT) to diagnostic routine with Fine-Needle Aspiration Biopsy (FNAB) routinely used by the Unified Health System (SUS) for diagnosis differential Solitary Pulmonary Nodule (SPN). The analytical model of decision represented a hypothetical cohort of males, 60 years of age, smokers, with NPS indeterminate solid, 8-30 mm in diameter and peripheral location in upper lobe without calcification, spicules, mediastinal lymph nodes increased or evidence of distant metastases, and risk of intermediate malignancy (5-65%). The conventional strategy of detection was compared to the addition of 18FDG-PET-CT. The time horizon understood throughout the lifetime of the cohort. We used the perspective of the Unified Health System and as a measure of effectiveness, the years of life gained (AVG) diagnosed by the inclusion of PET. They considered only the direct medical costs. Costs and benefits were discounted at 5%. The deterministic sensitivity analysis (univariate and bivariate) and probabilistic were realized. Using 18FDG-PET-CT resulted in 10.1 years of life gained (AVG), at a cost of AVG R$ 1,599,306.93. The parameters of greater impact in the analysis were: pneumothorax rate, complications and death by lobectomy for open thoracotomy and patient survival with estadioT1N0M0. The costs of adding the PET-CT show is significant, and the result does not achieve its use on a national scale in the public health network, due to the small added benefit considering the high additional cost.