RESUMO
AIM: Positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) can be performed using a dedicated PET scanner (PET-I) or a dual-head coincidence gamma camera (CGC-I). The aim of this study was to comparatively assess the impact of PET-I and CGC-I on clinical management in cancer patients. METHODS: From November 2000 to November 2002, PET-I and CGC-I were performed at an interval of 2 days in 151 patients with colorectal cancer (n=40), breast cancer (n=28), thyroid cancer (n=23), lung tumors (n=22), germ cell tumors (n=14), unknown primary cancer (n=7) and other cancers (n=17). PET-I and CGC-I were interpreted independently with knowledge of conventional imaging (CI). In June 2003, theoretical management, e.g. treatment modality/ies and treatment intent (curative or palliative), after CI, PET-I and CGC-I were stated during multidisciplinary sessions and were a posteriori considered as appropriate or inappropriate using pathological and follow-up data. RESULTS: The theoretical management proposed after PET-I and after CGC-I was similar in 112/151 (74%; 95% CI: 66-81%) patients. In 125 assessable patients, theoretical management after PET-I was appropriate in 86% (95% CI: 79-92%), significantly higher (P=0.0033) than after CGC-I (70%; 95% CI: 62-78%). Both proportions were also higher than after CI (46%; 95% CI: 37-56%), (P<0.0001). A similar trend for higher proportions of appropriate management after PET-I than after CGC-I was observed for each tumor localization. CONCLUSIONS: The clinical impact of PET-I is superior to that of CGC-I in a large series of cancer patients. Although CGC-I could be considered as an acceptable alternative, PET-I remains the standard and should preferably equip nuclear medicine departments.
