Objective: PET became a successful method in preoperative evaluation of patients with cancer. We question whether PET scan can answer critical surgeons’ requests such as distinguish benign and malign lesions, evaluation of cancer dissemination, evaluation of the pleural effusions, and also to detect early cancer recurrence. Methods: Between September 1999 and December 2001, 39 patients underwent a PET scan and we evaluated its benefit in further treatment of patients. Standard PET techniques were used. Results: In 20 patients (52%) results of PET scan were in correlation of clinical diagnosis and stage of cancer disease, partial difference between FDG-PET and clinical diagnosis was in 8 patients (20%), next treatment was changed in 11 patients (28%) Conclusion: We conclude, that dedicated PET could be valuable tool in the diagnosis and staging of cancer disease, especially in verifying cancer dissemination, recurrence of the cancer. PET scan can be misleading in evaluation of the mediastinal lymphnodes and pleural effusions.

        Key words: PET – oncology – diagnostic methods – indication