Abstract
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Objectives Aim of our study was to describe some abnormal, unexpected focal FC findings, unrelated to PC, that are not rare and consequently must be kept in mind for correct scan interpretation.
Methods We analyzed 573 consecutive FC scan, in large majority done for restaging, following biochemical recurrence of PC, after primary treatment and in a minority of cases for staging of advanced disease
Results We found abnormal and unexpected PET findings not related to PC localizations in 138/573 pts (24%). Our findings were: a. inflammation in 104/138 pts (75 %); in detail: - 93 pts (67%) in lymph nodes, at mediastinal, inguinal and cervical sites (1 had pulmonary sarcoidosis) - 10 pts (7%) in pulmonary thickening consistent with pneumonia - 1 pt in an iliac muscle abscess b. benign nodular diseases in 20/138 pts (14%) - 10 pts (7%) in thyroid adenomas - 9 pts (7%) in adrenal glands adenomas - 1 pt in a hemangioma of the liver c. malignant disease in 8/138 pts (6%), - 5/8 pts (4%) in the lungs (4 adenocarcinomas and 1 bronchial alveolar carcinoma) - 3/8 pts (2%) in the liver (all HCC) d. Paget disease in 3 pts (2%) with intense 18F-choline bone uptake and CT abnormalities not consistent for metastases that allowed correct scan interpretation e. miscellaneous CNS diseases in 3 pts (2%) with : - 2 pts had meningiomas with intense focal tracer uptake - 1 pt had cortical uptake in the right occipital lobe, probably due to brain barrier interruption in the site of a recent cortical stroke
Conclusions FC, being more sensitive than 18F-FDG in PC pts, is widely used, especially in case of restage for biochemical recurrence; nevertheless it must be known that the radiopharmaceutical is not specific for prostate cancer as in almost 25% of pts unexpected focal findings, not related to PC can be found. This can happen more frequently in case of inflammatory and other benign diseases, but malignant neoplasms cannot be excluded, as over reported.