Differential diagnosis between tumoural and non-tumoural intracranial lesions in children: a stereotactic approach

Frameless stereotaxy with scalp-applied fiducial markers for brain biopsy procedures: experience in 218 cases

OBJECT

The goal of this study was to develop and assess the use and limitations of performing brain biopsy procedures by using image-guided surgical navigation systems (SNSs; that is, frameless stereotactic systems) with scalp-applied fiducial markers.

METHODS

Two hundred eighteen percutaneous brain biopsies were performed in 213 patients by using a frameless stereotactic SNS that operated with either sonic or optical digitizer technology and scalp-applied fiducial markers for the purpose of registering image space with operating room space. Common neurosurgical and stereotactic instrumentation was adapted for use with a localizing wand, and recently developed target and trajectory guidance software was used. Eight (3.7%) of the 218 biopsy specimens were nondiagnostic; five of these (2.4%) were obtained during procedures in 208 supratentorial lesions and three were obtained during procedures in 10 infratentorial lesions (30%; p < 0.001). Complications related to the biopsy procedure occurred in eight patients (seven of whom had supratentorial lesions and one of whom had an infratentorial lesion, p > 0.25). Five complications were intracerebral hemorrhages (two of which required craniotomy), two were infections, and one was wound breakdown after instillation of intratumoral carmustine following biopsy. There were only three cases of sustained morbidity, and there were two deaths and one delayed deterioration due to disease progression. Two surgeons performed the majority of the procedures (193 cases). The three surgeons who performed more than 10 biopsies had complication rates lower than 5%, whereas two of the remaining four surgeons had complication rates greater than 10% (p = 0.15). Twenty-three additional procedures were performed in conjunction with the biopsies: nine brachytherapies; five computer-assisted endoscopies; four cyst aspirations; two instillations of carmustine; two placements of Ommaya reservoirs; and one craniotomy.

CONCLUSIONS

Brain biopsy procedures in which guidance is provided by a frameless stereotactic SNS with scalp-applied fiducial markers represents a safe and effective alternative to frame-based stereotactic procedures for supratentorial lesions. There were comparable low rates of morbidity and a high degree of diagnostic success. Strategies for performing posterior fossa biopsies are suggested.

The safety and efficacy of stereotactic biopsy for intracranial lesions

BACKGROUND

Stereotactic brain biopsy is considered by many physicians to have significant morbidity and mortality rates with a high risk of sampling error resulting in misdiagnosis. The technical aspects necessary to perform the procedure safely and effectively are unfamiliar to most physicians.

METHODS

After reporting his initial results with stereotactic brain biopsy, several modifications were implemented by the author to improve the morbidity, mortality, and diagnostic yield rates, including complex surgical planning with regard to patient selection, biopsy trajectory, imaging technique, target choice, and intraoperative pathologic review. The results of implementing these modifications were examined retrospectively in 134 consecutive brain biopsies.

RESULTS

One hundred and thirty-four stereotactic brain biopsies were performed in 122 patients. Computed tomography guidance was used in 85 patients (63%) and magnetic resonance imaging was used in 49 patients (37%). Sixty-four lesions (48%) were located in the right hemisphere, 61 (45%) in the left, and 9 (7%) in the midline. The most common diagnoses included 62 malignant brain tumors (46%), 24 benign brain tumors (18%), 23 neurologic disorders (17%), and 20 infections (15%). Five biopsies (4%) did not demonstrate a pathologic process for an overall diagnostic yield of 96%. Reasons for diagnostic failure included lesion location adjacent to the ventricular system, inaccurate targeting, and the inability to penetrate the tumor. One patient sustained a neurologic deficit after the biopsy for a morbidity rate of 0.7% and one sustained a fatal hemorrhage during the biopsy of a vascular tumor for a mortality rate of 0.7%. These results are comparable to those reported in 7471 biopsies (current series included) in which the morbidity rate was 3.5%, the mortality rate was 0.7%, and the diagnostic yield was 91%.

CONCLUSIONS

Stereotactic brain biopsy is an extremely safe and effective procedure for evaluating intracranial lesions. Complex surgical planning can decrease the risk of potential complications and the use of intraoperative pathologic examination can improve the diagnostic yield for this procedure.

Complications of CT-guided stereotactic biopsy of intra-axial brain lesions

A series of 300 consecutive stereotactic biopsies for intra-axial brain lesions performed by one neurosurgeon was critically analyzed regarding complications of the procedure. Complications were incurred by a total of 19 patients (6.3%). Five patients (1.7%) died following the procedure, all due to intracranial hypertension: one from subarachnoid hemorrhage, one from intracerebral hemorrhage, and three from increased edema without hemorrhage. The three patients who died without hemorrhage all had marked intracranial hypertension at the time of biopsy. All five patients who died harbored a glioblastoma multiforme. The surviving 14 patients (4.7%) with complications suffered increased neurological deficit due to hemorrhage. In 10 (3.3%), the deficit was mild and/or transient; in the other four (1.3%), a major deficit was incurred which markedly affected the remainder of the patient's life. Therefore, mortality or major morbidity was seen in 3.0% of patients and minor morbidity in 3.3%. Stereotactic biopsy is a very effective procedure with a complication rate significantly lower than that of craniotomy (particularly in the population of patients selected for stereotactic biopsy), but in a small number of patients the outcome is devastating.

CT-guided and computer assisted stereotactic biopsy. Technique, results, indications

On the base of a stereotactic device originally described by Riechert and Mundinger a three-dimensional localization and treatment planning system for CT-guided computer assisted stereotactic procedures has been developed. The experience with 338 patients, in which image guided stereotaxy has been used for the assessment of various intracerebral lesions, is presented. In 54 of these patients the cannula was introduced with a 20 MHz Doppler-probe positioned at the tip of the needle. A comparison of tissue specimens taken stereotactically with tissue material after tumour resection and/or autopsy was performed in 35 patients. The accuracy of the histological diagnosis was 88%. Bleeding as a complication due to the stereotactic intervention occurred in 8 patients (2.4%). Two of these patients had a fatal outcome (mortality: 0.6%). The morbidity (transient and permanent deterioration of the clinical status) was 1.2%.

Targeted brain biopsy: a comparison of freehand computed tomography-guided and stereotactic techniques

With computed tomography (CT) and magnetic resonance imaging stereotactic systems, biopsies of intracranial lesions can be made with safety and ease. Before the development of this technique, neurosurgeons often performed freehand brain biopsies under CT guidance. While stereotactic biopsy is the procedure of choice for small, deep lesions, few studies have compared the morbidity, mortality, and efficacy in obtaining a diagnosis associated with these two techniques for superficial lesions. A total of 167 consecutive CT-guided or stereotactic brain biopsies were performed in 154 patients. Fourteen of the stereotactic and 12 of the CT-guided biopsies were of deep lesions and were excluded from analysis. The results of 75 freehand CT-guided biopsies of superficial lesions in 69 patients were compared with those of 66 stereotactic biopsies (34 CT-guided and 32 MRI-guided) performed with the Brown-Roberts-Wells stereotactic system in 60 patients. Twenty-five of the lesions in the stereotactic biopsy group measured < or = 2 cm, as compared with 13 of those in the freehand CT-guided biopsy group. There were no biopsy-related deaths among the patients who underwent freehand CT-guided biopsy and one death among those who underwent stereotactic biopsy (1.5%). Freehand CT-guided biopsy was associated with 5% morbidity, compared with 6% morbidity for stereotactic biopsy. Seven CT-guided needle biopsies (9%) and 12 stereotactic biopsies (18%) were nondiagnostic. Statistical analysis showed no significant difference between morbidity and mortality in the two groups, but the rate of diagnostic failure was significant (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Stereotactic approach to intracranial lesions

The diagnostic and therapeutic approach to intracranial lesions must be different considering the different possibilities offered by the various methods. The diagnostic reliability and safety of stereotactic biopsy are often indispensable in order to optimize the subsequent therapy. The results obtained in selected pathologies allow us to propose the stereotactic approach to treat: -various kind of cysts by aspiration and/or Beta endocavitary radiation therapy; -blood or abscessual collections that can be aspirated in a similar way; -arterio venous malformations or tumours by radiosurgery; -tumours by brachicurietherapy or by computer assisted stereotactic surgery. We present some cases treated at the C.H.S.A. of Paris and at the C.H.R.U. of Grenoble utilizing Talairach methodology.