Non image-guided core needle biopsies can be used safely to improve diagnostic efficiency for soft tissue tumors

Front-line biopsy remains the rule in the management of soft tissue mass syndromes. Although open biopsy has long been considered the gold standard, it has recently been shown that a percutaneous biopsy is associated with a reduction in the rate of complications and cost, while maintaining high diagnostic accuracy. Though there is much literature regarding the diagnostic accuracy of image-guided and open biopsies for soft tissue tumors, the accuracy of percutaneous non image-guided biopsies has not been well documented. The objective of this study was to compare the failure rate of non image-guided biopsies, image-guided biopsies and open biopsies for the diagnosis of soft tissue tumors. We also attempted to identify the failure risk factors for non image-guided biopsies and we compared the diagnostic delay of the three types of biopsy.

This was a continuous, single-center retrospective study. We reviewed the results from 337 patients managed with a biopsy (percutaneous or open) for a soft tissue tumor, all carried out in our center between January 2010 and December 2015. Biopsy technique was chosen by the treating orthopedic surgeon, according to the clinical and radiological characteristics of the mass. 141 patients (41.8%) had a non-image-guided biopsy as the first-line diagnostic procedure, 81 (24.0%) had an image-guided biopsy, and 115 (34.1%) an open biopsy. Diagnostic failure was defined either by a non-contributory biopsy, the need for repeat biopsy, or a major histological discordance obtained from the resected tumor piece. The risk factors studied were tumor characteristics, patient' characteristics and sampling modalities. Diagnostic delay was defined as the period between the day of the first external consultation at the hospital and the day of the notification of the diagnosis by the physician.

We obtained a failure rate of 9.9% (14 patients) for non image-guided biopsies. Eleven were non-contributive and three were considered as errors of diagnosis. The failure rate for image-guided biopsies was 18.5% (15 patients), with no significant difference compared with non image-guided biopsies. The open biopsies were associated with a failure rate of 6.9% (eight patients). We found no failure risk factors for non image-guided biopsies. Diagnostic delay was significantly shorter for non image-guided biopsies (p = 0.001).

When performed in a referral center by the patient's surgeon, a non-image-guided core needle biopsy is a safe procedure which ensures equivalent diagnostic accuracy for soft tissue tumors, while reducing the diagnostic delay.