The impact of positron emission tomography on clinical decision making in a university-based multidisciplinary lung cancer practice

Introduction: Positron emission tomography (PET) scanning has gained increasing application as a diagnostic and staging tool in the evaluation of lung cancer. Although PET scanning has been demonstrated to be a cost-effective adjunct to lung cancer diagnosis, its global impact on clinical decision making has not been assessed. Study objectives: To evaluate the impact of the systematic use of PET scanning on clinical decision making. Design: Retrospective study. Setting: A university-based multidisciplinary lung cancer practice. Patients: All patients undergoing diagnostic or staging PET scans from December 31, 2000, to December 31, 2002. Interventions: None. Measurements and results: One hundred ninety-eight patients underwent PET for diagnosis (161 patients) or staging (37 patients). PET scan results and clinical outcomes were retrospectively reviewed to determine the frequency with which PET scan findings (1) upstaged patients, (2) downstaged patients, (3) changed the diagnostic workup, (4) altered therapy, (5) resulted in a significant additional diagnosis, and (6) triggered evaluations that ultimately proved fruitless. PET upstaged 32 of 198 patients (16.2%) and downstaged 12 patients (6.1%), facilitating curative resection in 4 patients. Overall, PET scan findings changed the stage in 44 patients (22.2%). PET scan findings changed diagnostic management in 105 of 198 patients (53%), among whom biopsy was deferred in 65 patients (61.9%) and was triggered or guided in 40 patients (38.1%). PET scan findings altered treatment decisions in 38 patients (19.2%), leading to neoadjuvant therapy in 6 patients and resection in 5 patients, and forestalling noncurative thoracotomy in 6 patients. PET scan findings prompted or redirected chemotherapy or radiotherapy in the remainder of the patients. Overall, PET scan findings changed management in 143 patients (72.2%). PET scan findings triggered additional diagnostic testing in 32 patients (16.2%), resulting in no new diagnosis in 16 patients (50%) and a critical change in management in 7 patients (21.9%). PET scan findings were solely responsible for a significant non-lung cancer diagnosis in eight patients (4%). Conclusions: Systematically applied PET scanning has a significant impact on patient management, altering diagnostic or therapeutic interventions in 72.2% of patients, changing staging in 22.2% of patients, and identifying serious unsuspected diagnoses in 4.0% of patients, with potentially life-saving consequences in 2.0%.