PT  - JOURNAL ARTICLE
AU  - Seo, Ji Hyoung
AU  - Song, Bong Il
AU  - Lee, Hong Je
AU  - Kang, Sungmin
AU  - Jeong, Shin Young
AU  - Lee, Sang-Woo
AU  - Ahn, Byeong-Cheol
AU  - Lee, Jaetae
TI  - Significance of focal hypermetabolic lesions of the parotid gland on F-18 FDG PET/CT
DP  - 2010 May 01
TA  - Journal of Nuclear Medicine
PG  - 1236--1236
VI  - 51
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/51/supplement_2/1236.short
4100  - http://jnm.snmjournals.org/content/51/supplement_2/1236.full
SO  - J Nucl Med2010 May 01; 51
AB  - 1236 Objectives Focal FDG uptake of parotid glands is occasionally found on F-18 FDG PET/CT (PET/CT). We have evaluated clinical significance of focal hypermetabolic lesions of parotid gland. Methods Fifty six focal parotid hypermetabolic cases (male 41, mean age 65.5 ± 11.5 yrs) found on 9867 PET/CT scans, performed between 2005 and 2007, were retrospectively reviewed. SUVmax was measured for all focal hypermetabolic lesions. Among these, total 42 cases which were further evaluated either with radiologic studies (n=28) such as USG or CT, or clinical follow-up (n=14), were included. Results Mean SUVmax of focal hypermetabolic parotid lesions was 7.2 ± 4.2 (range 2.5 - 19.0). Eleven cases out of 42 were malignant (26.2%), and the rest 31 cases benign (73.8%). Eight of 11 malignant cases were primary parotid cancers, and the rest 3 lymphomas. Benign cases were Warthin’s tumor (n=1), pleomorphic adenoma (n=2), other benign lesions such as focal sialadenitis, reactive lymphadenopathy, cyst, etc. (n=8), and there were 4 cases which demonstrated no diagnostic abnormalities on further radiologic studies. Sixteen cases were diagnosed as benign, as follow-up PET/CT revealed no significant interval change or decreased FDG uptake. There was no statistical difference in SUVmax between malignant and benign cases (8.2 ± 4.9, 7.3 ± 3.9, p=0.239), and among benign lesions (p=0.385). In 7 patients who underwent PET/CT for parotid tumor evaluation, all were diagnosed as primary parotid cancer. Among 35 patients who underwent PET/CT for other than parotid tumor evaluation, 4 cases (11.4%) of incidentally found focal parotid uptake were diagnosed as malignancy. Three of them were lymphomas and one primary parotid cancer. Conclusions Focal parotid FDG uptake findings were found in variable benign or malignant lesions, and their SUVmax values were not statistically different. About 11% of incidentally found focal parotid hypermetabolic lesions were diagnosed as malignancy, suggesting further meticulous evaluation for differential diagnosis of the malignancy