The diagnostic efficacy of FDG-PET in the local recurrence of hilar bile duct cancer

Background/Purpose. It is frequently difficult to make an accurate diagnosis of the local recurrence of hilar bile duct cancer (HBC). We assessed the efficacy of fluorodeoxyglucose-positron emission tomography (FDG-PET) in diagnosing the local recurrence of HBC. Methods. Among 18 patients who had previously undergone resection of HBC, 5 were suspected of having a recurrence. These 5 patients were examined for recurrence by computed tomography (CT) and FDG-PET. A definitive diagnosis was determined either by pathological studies or by clinical follow-up. Results. Whereas CT showed a recurrent mass in only 1 patient, FDG-PET revealed the high uptake of FDG in all patients. Histopathological and/or cytological examinations confirmed the local recurrence of HBC in 4 patients. One false-positive result occurred in a patient with reflux cholangitis. One patient with a recurrent tumor was followed by FDG-PET after irradiation therapy. The high level of FDG uptake, which had been seen in that patient before irradiation, completely disappeared after treatment. Conclusions. When used in combination with other modalities. FDG-PET offered useful information for the diagnosis of a local recurrence of HBC. This highly sensitive imaging approach also appeared to be useful for follow-up examination after irradiation therapy.