FDG PET/CT Assesses the Risk of Femoral Pathological Fractures in Patients With Metastatic Breast Cancer.
OBJECTIVE
Assessment of pathological fracture risk is critical to optimize the use of prophylactic orthopedic fixation to prevent pathological fractures. Better prediction of pathological fracture risk is needed. We evaluated if quantitative measures of FDG avidity can assess femoral pathological fracture risk in patients with metastatic breast cancer (MBC).


METHODS
A Health Insurance Portability and Accountability Act-compliant retrospective case-control study was performed under institutional review board waiver. Patients with MBC who received an FDG PET/CT from January 2008 to December 2014 and had pathological fracture of the proximal femur within 3 months of PET/CT were selected as cases. Patients with MBC who had an FDG PET/CT in 2013 were sequentially screened in reverse chronological order to identify patients with proximal femoral metastases on PET/CT but no subsequent pathological fracture to serve as a control group. The prespecified goal was to have twice the number of controls as cases. Target lesions in the proximal femur, from femoral head to 5 cm below the lesser trochanter, were analyzed on FDG PET/CT for SUVmax, SUVmean, metabolic tumor volume, and total lesion glycolysis. Wilcoxon rank sum test was used to compare continuous variables in cases and controls. A nonparametric receiver operating characteristic analysis was performed to assess the ability of quantitative FDG measurements to differentiate between cases and controls.


RESULTS
In 27 cases with pathological fracture and 55 controls without pathological fracture, all 4 quantitative measures of FDG avidity were statistically different between cases and controls (P < 0.001). A total lesion glycolysis of 81 could differentiate between fracture and nonfracture patients with accuracy, sensitivity, and specificity of 0.83, 0.85, and 0.80, respectively.


CONCLUSIONS
Quantitative measures of FDG avidity may help identify breast cancer patients at high risk of subsequent pathological fracture of the proximal femur.
From the *Department of Radiology, Memorial Sloan Kettering Cancer Center, New York; †Department of Radiology, Weill Cornell Medical College, New York; ‡Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY; §Department of Orthopaedics, Cooper University Hospital, Camden, NJ; ∥Department of Surgery, Memorial Sloan Kettering Cancer Center, New York; and ¶Department of Surgery, Weill Cornell Medical College, New York, NY.
Gary A
GA
Ulaner
Alexandra M
AM
Zindman
Junting
J
Zheng
Tae Won B
TW
Kim
John H
JH
Healey
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D001943:Breast Neoplasms / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D019788:Fluorodeoxyglucose F18; D005598:Fractures, Spontaneous / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18