Bone metastases in patients with metastatic breast cancer: morphologic and metabolic monitoring of response to systemic therapy with integrated PET/CT.
OBJECTIVE
To retrospectively compare morphologic and metabolic changes in bone metastases in response to systemic therapy in patients with metastatic breast cancer (MBC) with integrated positron emission tomography (PET)/computed tomography (CT).


METHODS
The institutional review board waived the requirement for informed consent and approved this HIPAA-compliant study. A retrospective analysis was performed with 102 women (mean age, 55 years) with MBC who received systemic treatment. All patients underwent integrated PET/CT before and after treatment. Two reviewers analyzed the images in consensus. Morphologic changes, including morphologic patterns, and lesion attenuation were evaluated. Standardized uptake value (SUV) and total lesion glycolysis (TLG) were analyzed to evaluate metabolic changes. Uni- and multivariate analyses were performed to identify factors that enabled response duration (RD) to be predicted.


RESULTS
At baseline, the morphologic patterns of the target lesions were lytic (n = 33), sclerotic (n = 22), mixed (n = 42), and unclassified (n = 5). Progression of sclerotic change after treatment was identified in 49 patients (48%). After treatment, the mean attenuation of the lesion increased, whereas the mean SUV and TLG decreased. Increases in attenuation correlated significantly with decreases in SUV (r = -0.510, P < .001) and TLG (r = -0.491, P < . 001). Univariate analysis revealed that the increase in attenuation and the decrease in SUV were potential predictors of RD. Multivariate analysis revealed that an increase in the change in SUV was a significant predictor of RD (relative risk, 2.4; P = .003).


CONCLUSIONS
A decrease in SUV after treatment was an independent predictor of RD in patients with MBC who had bone metastases.
Tateishi
Ukihide
U
Department of Nuclear Medicine, University of Texas M.D. Anderson Cancer Center, Unit 1263, 1515 Holcombe Blvd, Houston, TX 77030, USA. utateish@ncc.go.jp
Gamez
Cristina
C
Dawood
Shaheenah
S
Yeung
Henry W D
HW
Cristofanilli
Massimo
M
Macapinlac
Homer A
HA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000556:secondary*; D001943:Breast Neoplasms / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000556:secondary; D018275:Carcinoma, Lobular / Q000556:secondary; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18