The role of radiolabeled choline (Cho) in pts with biochemical recurrence after radical treatment for prostate cancer (PCa) is well established. Its widespread clinical use has prompted the depiction of incidentalomas, unusual sites of metastatic lesions, as well as false positive and negative cases. We evaluated all patients affected by biochemical recurrence of PCa who performed a 18F-Cho PET/CT resulted suspected for a second malignancy.
18F-Cho PET/CT was performed in patients with biochemical PCa recurrence. We identified 7 patients in which PET/CT resulted suspected for a second malignancy. Histology was used as reference standard for final diagnosis. One patient was excluded from the present analysis since final radiological diagnosis was consistent with benign meningioma. All values are expressed as median and range.
Considering the 6 patients with biochemical PCa recurrence evaluable (72 years, 66-84 years), 5/6 were treated with surgery while the remaining patient was only treated with radiotherapy with curative intent. Median value of PSA at the time of PET/CT was 2,01 ng/mL (0,4-8,77). The median time between PCa diagnosis and PET/CT was 11 years (6-12 years). In 2 cases a second malignancy was diagnosed 12 (lung cancer) and 6 (cutaneous basocellular carcinoma) after PCa, respectively. 18F-Cho PET/CT identified 13 sites of 18F-Cho uptake (lung=5, lymph node=7, bone=1). Final histological diagnosis was consistent with lung cancer in 5/6 cases (first diagnosis = 4/5, recurrence = 1/5) and with nodal metastasis from melanoma in the remaining case. In this latter case, the diagnosis of melanoma was subsequent to PET/CT and primary site of disease remained unknown.
18F-Cho PET/CT indication in prostate cancer detection is well know, however it may be an added value since the diagnosis of a second tumor has a significant impact on the therapeutic management of patients.