MRI-guided stereotactic brain biopsy: a review of 33 cases

Stereotactic brain biopsy: an audit of sampling reliabilityin a clinical case series

Stereotactic brain biopsy is the current gold standard procedure to obtain a neuropathological diagnosis. An audit of 207 stereotactic cases, between January 1997 and December 2000 was carried out. The aim was to determine the optimum number of target sites required to make the final diagnosis and thereby set up recommendations for future practice. The overall diagnostic success rate was 89.3%. A significant positive correlation between the number of targets taken and the probability of achieving the final diagnosis was seen. In a subset of glioblastoma cases 96.1% of the tumours could have been confidently diagnosed on the basis of any two of the targets chosen, although often more targets were taken than this. The recommendations made by the audit were: (i) in cases where it is suspected the lesion does not require grading, one target site should be taken and further sites should only be taken if the first proves to be non diagnostic; (ii) in suspected glial series tumours, two targets should be routinely taken, with further sites taken only if these prove inconclusive on intraoperative smear.

Freehand two-step CT-guided brain tumor biopsy: a fast and effective interventional procedure in selected patients

PURPOSE

To evaluate the efficacy and safety of CT-guided needle biopsy of brain lesions without a stereotactic device, and to determine the best possible indications for this technique.

METHODS

From February 2001 to February 2004, 20 patients (12 men, 8 women; age 61-82 years) underwent CT-guided brain lesion biopsy. The procedure started with a brain CT scan for lesion localization and for selection of the inlet for needle insertion. The patient was then transported to the operating room where cranioanatrisis was performed. Subsequently, the biopsy was performed under CT guidance using a 14G brain biopsy needle with a blind smooth end and lateral holes. At the end of the biopsy, the field was checked for possible complications with a CT scan.

RESULTS

Histopathologic results were: brain tumor in 16 patients (80%), inflammatory process in 3 (15%), and no conclusive diagnosis in 1 (5%). A repeat of the process was required in 2 patients. A minor complication of local hematoma was found in 1 patient (5%). There were no deaths or other serious complications.

CONCLUSION

CT-guided biopsy is a reliable method for histopathologic diagnosis of brain lesions in selected cases. It is a simple, fast, effective, low-cost procedure with minimal complications, indicated especially for superficial and large tumors.

Clinical validation of true frameless stereotactic biopsy: analysis of the first 125 consecutive cases

OBJECTIVE

A lockable guide device, adjustable for positioning, was used to obtain samples for tissue analysis during brain biopsy procedures performed using an interactive image guidance system. Clinical validation of this technique, which was developed for true frameless stereotactic biopsies, and analyses of the histological yield, complication rate, and patient demographic characteristics for a large series of frameless stereotactic biopsies were the purposes of this study.

METHODS

Demographic, radiological, surgical, and clinical data were prospectively collected for a series of 125 frameless stereotactic biopsies performed using the technique described in detail previously.

RESULTS

Eighty-six procedures were magnetic resonance imaging-directed and 39 were computed tomography-directed. The mean diameter of the biopsied lesions was 36 mm, and the mean distance from the skin was 35.8 mm. Sixteen percent of the patients harbored multiple lesions, and 5.6% of the biopsied lesions were infratentorial. The mean operative time (including the entire anesthetic time) was 1.5 hours. The smear examination findings were corroborated by conclusive histological results in 96% of the cases, and definitive positive diagnoses were obtained in 122 cases (97.6%). Ten patients experienced surgical complications, but the sustained morbidity rate was 2.4% (including the death of a patient who was in critical clinical condition preoperatively and who died 2 mo later as a result of a chest infection; mortality rate, 0.8%).

CONCLUSION

This true frameless stereotactic biopsy technique was associated with low morbidity and mortality rates and an excellent diagnostic yield, with overall results at least as good as those observed for frame-based stereotaxy. The excellent accuracy results demonstrated previously and statistically significant reductions in operative time, as well as improved image presentation, target selection, and simplicity, support the use of this frameless stereotactic technique in preference to frame-based biopsy techniques.