Detection of distant metastasis and prognostic prediction of recurrent salivary gland carcinomas using 18 F‐FDG PET/CT

Objective To compare the diagnostic accuracy of 18 F‐ FDG PET / CT and conventional contrast‐enhanced CT for the re‐staging of recurrent salivary gland carcinoma ( SGC ). Materials and Methods This study included 58 consecutive patients who underwent recurrent SGC s after definitive treatment. The recurrences were evaluated by 18 F‐ FDG PET / CT and contrast‐enhanced CT of the neck and chest. McNemar's test was used to compare the diagnostic accuracy of 18 F‐ FDG PET / CT with standard neck and chest CT imaging, and a Cox proportional hazards model was used to assess the prognostic value of PET / CT . Results Of 58 patients with recurrent SGC s, 17 (29%) had a local recurrence, 17 (29%) had a regional recurrence, and 38 (66%) had a distant metastasis, with these classifications showing overlap. The sensitivity and accuracy of 18 F‐ FDG PET / CT for the detection of distant metastases were significantly higher than those of CT ( p  <   0.05), whereas, for detection of loco‐regional recurrences, they did not differ ( p  >   0.1). The 18 F‐ FDG PET / CT ‐positive findings at distant sites were predictors of poor progression‐free and overall survival outcome (all p  <   0.05). Conclusions 18 F‐ FDG PET / CT is a more effective method than CT for detecting distant site recurrences of SGC . This may lead to prognostic prediction for recurrent SGC s.