Abstract No. 527 Diagnostic accuracy of image-guided biopsy of hepatic lesions

To examine factors associated with false negative results of image-guided targeted percutaneous biopsy of hepatic lesions. Retrospective review of 1161 consecutive percutaneous biopsies (1054 patients) of hepatic lesions suspicious for malignancy between 2010 and 2018. Biopsies were performed both with final needle aspiration (FNA) and core biopsy techniques at the discretion of the radiologist. Malignant histopathologic diagnosis of the biopsy specimen defined true positive, benign histopathology and 2 year benign clinical or imaging follow-up defined true negative, and imaging or repeat positive pathology specimen defined false negative. All inpatient biopsies had point-of-care cytology analysis performed. Biopsies with anticipated low difficulty were performed outpatient without on-site cytology confirmation. Univariate and multivariate logistic regression analysis were performed. Of the biopsies, 79% (n = 922) were true positive for malignancy (TP), 14% (165) true negative benign (TN), 4% (43) false negative for malignant lesion (FN), and 3% (31) lost to follow-up (sensitivity 96%, negative predictive value 79%). FN biopsy was associated in univariate analysis with smaller biopsied lesions (P <0.0001), FNA compared to core biopsy technique (P <0.0001), longer skin to lesion biopsy tract (P = 0.04), cirrhosis (P <0.0001), and high procedural difficulty reported in biopsy dictation (P <0.0001). These factors except for lesion depth were significant in multivariate logistic regression (P <0.001). FN in comparison to TP was associated with chemotherapy in the past year (P = 0.007). FN biopsy was not associated with patient age (P = 0.95), gender (P = 0.38), lesion echogenicity (P = 0.36), lack of on-site cytology confirmation (P = 0.17), tumor histology accounting for underlying cirrhosis, 18 versus 20-gauge core biopsy technique (P = 0.16), CT versus ultrasound procedural guidance (P = 0.18), or number of needle-passes (P = 0.95). Image-guided percutaneous biopsy of hepatic lesions had a FN rate of 4%. FN biopsy was associated with smaller lesion size, cirrhotic liver, operator reported procedural difficulty, recent chemotherapy administration and FNA compared to core biopsy technique.Tabled 1TP or TN (n)FN (n)P valueN92243Biopsied lesion size3.9cm, SD 2.52.6cm, SD 2.3