Risk factors for cancellation of stereotactic large core needle biopsy on a prone biopsy table

Among patients undergoing stereotactic needle biopsy of the breast on a pro ne biopsy table, a substantial proportion of planned procedures are termina ted prematurely. This study was undertaken to identify risk factors for can cellation of these procedures and to derive a clinical rule for predicting cancellation. Risk factors for cancellation were assessed in a group of 476 consecutive patients with non-palpable lesions planned for large core need le biopsy. 64 (13%) of these planned procedures were cancelled. Multivariat e regression analysis was applied to identify independent risk factors for cancellation. Validation took place by applying the logistic rule on a vali dation set, including 5 cancelled and 35 successful biopsy procedures. Mamm ograms that were difficult to interpret owing to extremely dense breast tis sue, axillary location of the non-palpable lesion, body mass index below 20 , less than 15 min distance from the lesion to the chest wall or the presen ce of more than one non-palpable lesion were identified as independent risk factors. The logistic rule discriminated patients with successful and canc elled biopsy procedures with a receiver operator characteristic (ROC) area of 0.72. In the validation set, the area under the ROC curve was 0.92. The prediction rule, based on mammographic and clinical findings, discriminated patients with successful and cancelled needle biopsy procedures to a certa in extent. The risk of cancellation of the stereotacic biopsy procedure is considerable in cases of very dense breast tissue or the presence of multip le risk factors.