Nondiagnostic CT-guided stereotactic biopsies in a series of 407 cases: influence of CT morphology and operator experience

Abstract

Nondiagnostic biopsies were analyzed in a consecutive series of 407 patients undergoing computerized tomography (CT)-guided stereotactic biopsies. These were categorized as either negative biopsies, when normal tissue or nonspecific pathology was found, or inconclusive, when a definitive diagnosis could not be made although representative tissue was obtained. Nineteen biopsies (4.7%) were negative and 10 (2.4%) were inconclusive, giving an overall nondiagnostic biopsy rate of 7.1% (29 of the 407 cases). Suspected neoplastic masses (390 cases) were classified on the basis of their CT morphology into four groups: Group 1 included purely hypodense nonenhancing masses; Group 2 included isodense nonenhancing masses; Group 3 included ring-enhancing masses; and Group 4 included mixed-density enhancing masses. Although a higher proportion of hypodense nonenhancing masses (six of 56, or 10.7%) yielded a negative result, there was no statistically significant difference in the negative biopsy rates for the different CT categories (p = 0.06). The negative biopsy rates for the 6 years of the study, 1987 to 1992 (1987 being an incomplete year) were as follows: 13.3%, 6%, 3.2%, 3%, 5.8%, and 2.7%. There was no significant decrease in the negative biopsy rate as experience with this procedure increased (p = 0.20). A total of eight surgeons independently performed the biopsies. There was no significant difference (p = 0.24) in the negative biopsy rate of the surgeon with the most experience (124 biopsies, 2.4% negative biopsy rate) compared with that of the seven other surgeons combined (283 biopsies; 5.7% negative biopsy rate). These findings suggest that the yield in a stereotactic biopsy is independent of the CT appearance of the mass. Adherence to certain basic principles in patient and target selection will ensure a reasonable percentage of positive yield with stereotactic biopsy procedures even if the surgeon is relatively inexperienced. There does not appear to be a learning curve in the performance of CT-guided stereotactic biopsies. The management of patients with nondiagnostic biopsies is discussed.

Evaluation of 126 consecutive cases of stereotactic procedures: brain biopsy, diagnostic yield, accuracy, non-diagnostic results, hemorrhagic complications and follow up.

“…It is a fact that intraoperative bleeding through the biopsy needle seriously increases the surgeon's anxiety and reluctance to proceed with any further biopsy. Ranjan et al (29) found no significant difference between the most experienced and other surgeons regarding negative biopsies. Two non-diagnostic cases were the 94 th and 125 th procedures in the present study.…”

“…There are few studies on the management and follow up of non-diagnostic biopsy cases in the literature (1,13,23,29,39). The institution of empirical treatments after a presumptive diagnosis using serial imaging was advised for patients with non-diagnostic biopsies (1,39).…”

Correlation among magnetic resonance imaging findings, prognostic factors for survival, and histological diagnosis of intrinsic brainstem lesions in children

“…Additionally, heterogeneity often requires multiple sampling, which is potentially dangerous in the brainstem. 16 Even in the most recent study by Kesari et al,7 published in 2008 and involving a large series, a histological diagnosis was obtained in only 53% of the patients. Many authors claim a very restrictive indication for radiologically unclear lesions due to the presumed high-risk profile.…”

Confounding Factors in Diagnostics of <b><i>MGMT</i></b> Promoter Methylation Status in Glioblastomas in Stereotactic Biopsies

“…4c), a higher rate of specimens being located in areas with neuroradiologically confirmed contrast medium uptake was related to an increasing number of conclusive diagnoses for MGMT promoter methylation status. Since the computed tomography era it is well known that stereotactic biopsies of intracerebral lesions are most likely to yield a histopathological diagnosis if the contrast-enhanced portion of the lesion is targeted in preference to the necrotic part [30,31,32,33]. On the other hand, targeting contrast-enhanced tissues only might decrease diagnostic accuracy [30].…”