Economic analyses on the use of positron emission tomography for the work-up of solitary pulmonary nodules and for staging patients with non-small-cell-lung-cancer in Italy.

AIM: Increasing ageing of the population and tumor incidence, along with worldwide rationing of the resources for public health systems, spur the use of economic analyses for the choice of strategies and technologies in the assessment and management of cancer patients. Incidence and clinical managing of tumors vary in different countries even if positron emission tomography (PET) with 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) is becoming a routine clinical method for diagnosis, staging, treatment monitoring and follow-up in a variety of tumors. Available data indicate that PET can be considered a superior alternative or complementary tool to other well-established methods. However, in spite of the above and of the rapidly increasing number of PET centers in Europe, USA and Japan, only a few studies have dealt with some of the economic aspects raised by the clinical use of PET because of differences in values of reimbursements and health costs. The main aim of this study is to propose and discuss an economic model of analysis for PET applications in the field of detection and management of pulmonary tumors. METHODS: In this study 2 assessments were performed by decision tree analysis on the economic impact of the availability of PET on decision-making processes for 2 conditions: solitary pulmonary nodules assessment and non-small-cell lung cancer (NSCLC) staging. In order to define a methodology consistent with the system of reimbursement and the prevalent clinical views of the Italian National Health Service, data on costs, death probability, and life expectancy were gathered from the literature and from the Italian system of reimbursement (ROD-DRGs). RESULTS: The results of the cost minimization analysis demonstrate that the use of PET in the diagnostic path for the workup of patients with SPN reduces the overall diagnostic costs, by approximately 50 Euro per patient, by reducing inappropriate invasive diagnostic investigation and their complications. The results of the cost effectiveness analysis demonstrate that the use of PET in the diagnostic path for the staging of patients with NSCLC reduces the overall diagnostic costs by approximately 108 Euro for added year, by reducing inappropriate surgical interventions and their complications. CONCLUSION: Both analyses are based on standard methods used in the literature, so our conclusions can be compared with results and assessments of similar studies in different countries and health care systems. Also in the Italian case, the use of an economic assessment provides relevant information on the efficacy and effectiveness of PET.

Anatomical and biochemical investigation of primary brain tumours.

Cancerous transformation entails major biochemical changes including modifications of the energy metabolism of the cell, e.g. utilisation of glucose and other substrates, protein synthesis, and expression of receptors and antigens. Tumour growth also leads to heterogeneity in blood flow owing to focal necrosis, angiogenesis and metabolic demands, as well as disruption of transport mechanisms of substrates across cell membranes and other physiological boundaries such as the blood-brain barrier. All these biochemical, histological and anatomical changes can be assessed with emission tomography, X-ray computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Whereas anatomical imaging is aimed at the diagnosis of brain tumours, biochemical imaging is better suited for tissue characterisation. The identification of a tumoural mass and the assessment of its size and vascularisation are best achieved with X-ray CT and MRI, while biochemical imaging can provide additional information that is crucial for tumour classification, differential diagnosis and follow-up. As the assessment of variables such as water content, appearance of cystic lesions and location of the tumour are largely irrelevant for tissue characterisation, a number of probes have been employed for the assessment of the biochemical features of tumours. Since biochemical changes may be related to the growth rate of cancer cells, they can be thought of as markers of tumour cell proliferation. Biochemical imaging with radionuclides of processes that occur at a cellular level provides information that complements findings obtained by anatomical imaging aimed at depicting structural, vascular and histological changes. This review focusses on the clinical application of anatomical brain imaging and biochemical assessment with positron emission tomography, single-photon emission tomography and MRS in the diagnosis of primary brain tumours, as well as in follow-up.