Early 2'-deoxy-2'-[18F]fluoro-D-glucose PET metabolic response after corticosteroid therapy to differentiate cancer from sarcoidosis and sarcoid-like lesions.
OBJECTIVE
We aimed at investigating whether early metabolic response to corticosteroid therapy may be used as a diagnostic tool to discriminate between cancer and sarcoidosis, a well-known cause of false-positive 2-deoxy-2-[F-18]fluoro-D: -glucose-positron emission tomography (FDG-PET) findings in oncology.


METHODS
Two cancer patients with biopsy-proven sarcoidosis or sarcoid-like reaction had multiple thoracic FDG foci. After infectious disease had been excluded, patients received oral corticosteroids for 16 and 14 days, respectively, and underwent posttherapeutic FDG-PET examination.


RESULTS
Posttreatment PET revealed a complete metabolic response in both patients, and clinical and imaging follow-up showed no sign of cancer progression.


CONCLUSIONS
Early metabolic response to systemic corticosteroid treatment may be used as a tool in the establishment of final diagnosis when sarcoidosis is suspected in a cancer patient and could be capable of differentiating cancer from sarcoidosis in the case of coexisting diseases.
Aide
Nicolas
N
Nuclear Medicine Department, François Baclesse Comprehensive Cancer Centre, Caen, France. n.aide@baclesse.fr
Allouache
Djelila
D
Ollivier
Yann
Y
de Raucourt
Sixtine
S
Switsers
Odile
O
Bardet
Stéphane
S