Comparison of FDG-PET findings of brain metastasis from non-small-cell lung cancer and small-cell lung cancer.
OBJECTIVE
We compared the F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) findings of brain metastasis between patients with non-small-cell lung cancer (NSCLC) and small cell lung cancer (SCLC).


METHODS
A whole-body FDG and a brain PET were performed in 48 patients (31 men, 17 women; 57 +/- 9 years, 42 NSCLC, 6 SCLC), who had brain metastasis on magnetic resonance (MR). All primary lung lesions were detected by FDG-PET and confirmed pathologically. We analyzed the PET findings, lesion sizes, and the pathological result of primary lung cancer.


RESULTS
Of the 48 patients, 31 (64.6%) showed hypermetabolic lesions on FDG-PET of the brain image, and 14 (29.2%) showed hypometabolic lesions. Three patients (6.3%) had both hypermetabolic and hypometabolic lesions. On the lesion-based analysis, 74 lesions (67.3%) showed hypermetabolism on FDG-PET, and 36 lesions (32.7%) showed hypometabolism. All primary lung lesions were hypermetabolic on FDG-PET. When the FDG findings of metastatic brain lesions were analyzed with the pathological types of primary lung cancer, NSCLC was more frequently associated with hypermetabolic metastatic brain lesions than SCLC (80% and 26.7%, respectively, P < 0.01). On comparing the sizes of metastatic lesions between SCLC (1.3 +/- 1.2 cm) and NSCLC (1.8 +/- 1.2 cm), lesions of <1 cm were more frequent in SCLC than in NSCLC (P = 0.012). But no significant relationship was found between the size and PET finding of metastatic lesion (P = 0.412).


CONCLUSIONS
Even when the primary lesion of lung cancer showed hypermetabolism in FDG-PET, FDG accumulation in metastatic brain lesions was variable. One-third of brain metastases from lung cancer showed hypometabolism. NSCLC was more frequently associated with hypermetabolic metastatic brain lesions than SCLC. The PET findings of brain lesions were affected not only by the size of lesion but also by its biological characteristics.
Department of Nuclear Medicine, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, Korea.
Ho-Young
HY
Lee
June-Key
JK
Chung
Jae Min
JM
Jeong
Dong Soo
DS
Lee
Dong Gyu
DG
Kim
Hee Won
HW
Jung
Myung Chul
MC
Lee
D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000556:secondary; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging* / Q000556:secondary; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity; D014915:Whole-Body Counting
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18