Biopsia Estereotáxica de tumores de tronco en pediatría. Indicaciones actuales y perspectivas futuras / Stereotaxic biopsy of trunk tumors in pediatrics. Current indications and future prospects

Introducción: Los tumores de tronco constituyen neoplasias frecuentes en pediatría. Durante las últimas décadas y con el avance de los métodos de estudios por imágenes fueron desarrolladas clasificaciones con implicancias diagnósticas y terapéuticas. Hoy en día la biopsia estereotáxica es un tema controversial especialmente en las lesiones difusas.El objetivo del presente artículo es realizar una actualización de las indicaciones de este tipo de procedimiento en pediatría analizando también perspectivas futuras. Desarrollo: En la actualidad las biopsias estereotáxicas en tumores de tronco tienen indicaciones precisas ante tumores sin indicación quirúrgica o en casos no quirúrgicos. En pacientes con lesiones atípicas definida por imagen, presentación clínica o edad fuera del rango habitual se torna necesario el diagnóstico por anatomía patológica. El avance del estudio oncológico por biología molecular despertó interés en los gliomas difusos de la protuberancia. Hoy en día es aceptada la realización de esta cirugía en caso de protocolos de investigación, aunque la misma no tenga relevancia en la evolución del paciente. La toma de tejido para determinar la aplicación de tratamientos blanco junto a técnicas que posibilitan la aplicación de fármacos por microcatéteres colocados directamente en la lesión son posibles futuras aplicaciones de la estereotaxia para este tipo de tumores. Conclusiones: Los tumores de tronco en pediatría, por ser una patología frecuente, requieren un capítulo especial. Los avances en la clasificación de estos junto con los nuevos métodos de estudio de biología molecular tornan necesario definir las indicaciones de biopsia estereotáxica en este tipo de lesiones pudiendo cambiar el paradigma en un futuro cercano.

Introduction: Brainstem tumors are frequent neoplasms in pediatrics. During the last decades and with the advancement of imaging methods, classifications with diagnostic and therapeutic implications were developed. Today the stereotaxic biopsy is a controversial topic especially in diffuse lesions. Objectives: To update the indications for this type of procedure in pediatrics, also analyzing future perspectives. Discussion: At the present, stereotaxic biopsies in brainstem tumors have precise indications for tumors without surgical indication or in non-surgical cases. In patients with atypical lesions defined by MRI, clinical presentation or age outside the usual range, diagnosis by pathological anatomy becomes necessary.Advances in molecular biology in oncology have sparked interest in diffuse gliomas of the pons. Nowadays, the performance of this surgery is accepted in the case of research protocols, although it has no relevance in the patient`s outcome.Taking tissue to determine the application of target treatments together with techniques that allow the application of drugs by microcatheters placed directly in the lesion are possible future applications of stereotaxy for this type of tumors. Conclusions: Brainstem tumors in pediatrics, as they are a frequent pathology, require a special chapter. Advances in the classification of these, together with new molecular biology study methods make it necessary to define the indications for stereotaxic biopsy for this type of lesion, which may change the paradigm in the future.

Suspicious amorphous microcalcifications detected on full-field digital mammography: correlation with histopathology / Microcalcificações amorfas suspeitas detectadas na mamografia digital: correlação histológica

Abstract Objective: To evaluate suspicious amorphous calcifications diagnosed on full-field digital mammography (FFDM) and establish correlations with histopathology findings. Materials and Methods: This was a retrospective study of 78 suspicious amorphous calcifications (all classified as BI-RADS® 4) detected on FFDM. Vacuum-assisted breast biopsy (VABB) was performed. The histopathological classification of VABB core samples was as follows: pB2 (benign); pB3 (uncertain malignant potential); pB4 (suspicion of malignancy); and pB5 (malignant). Treatment was recommended for pB5 lesions. To rule out malignancy, surgical excision was recommended for pB3 and pB4 lesions. Patients not submitted to surgery were followed for at least 6 months. Results: Among the 78 amorphous calcifications evaluated, the histopathological analysis indicated that 8 (10.3%) were malignant/suspicious (6 classified as pB5 and 2 classified as pB4) and 36 (46.2%) were benign (classified as pB2). The remaining 34 lesions (43.6%) were classified as pB3: 33.3% were precursor lesions (atypical ductal hyperplasia, lobular neoplasia, or flat epithelial atypia) and 10.3% were high-risk lesions. For the pB3 lesions, the underestimation rate was zero. Conclusion: The diagnosis of precursor lesions (excluding atypical ductal hyperplasia, which can be pB4 depending on the severity and extent of the lesion) should not necessarily be considered indicative of underestimation of malignancy. Suspicious amorphous calcifications correlated more often with precursor lesions than with malignant lesions, at a ratio of 3:1.

Resumo Objetivo: Correlacionar o achado mamográfico de calcificações amorfas suspeitas diagnosticadas na mamografia digital com seus diagnósticos anatomopatológicos. Materiais e Métodos: Setenta e oito casos de calcificações amorfas suspeitas (todas classificadas como BI-RADS® 4) detectadas na mamografia digital e submetidas a biópsia percutânea assistida à vácuo foram retrospectivamente avaliados. A classificação anatomopatológica utilizada na biópsia foi: pB2 para lesão benigna, pB3 para lesão com potencial incerto de malignidade, pB4 para lesão suspeita, e pB5 para lesão considerada maligna. O tratamento foi recomendado para as lesões pB5, a exérese cirúrgica foi indicada para lesões pB3 e pB4, para descartar malignidade, e o seguimento evolutivo foi adotado para as demais pacientes. Resultados: A histologia demonstrou 8 (10,3%) casos malignos (6 lesões pB5 e 2 lesões pB4) e 36 (46,2%) casos benignos (pB2). As demais 34 (43,6%) lesões foram classificadas como pB3 (33,3% foram lesões precursoras - hiperplasia ductal atípica, neoplasia lobular ou atipia epitelial plana - e 10,3% foram lesões de alto risco). A taxa de subestimação das lesões pB3 foi zero. Conclusão: O diagnóstico de lesões precursoras (excluindo hiperplasia ductal atípica, que pode corresponder a lesão pB4 dependendo da severidade e extensão dos achados) na biópsia percutânea assistida à vácuo por calcificações amorfas suspeitas não necessariamente representa lesão subestimada. Calcificações amorfas suspeitas se associaram a lesões precursoras numa proporção de 3:1 em relação às lesões malignas.

Procedimientos neuroquirúrgicoscerebrales guiados por estereotaxiarealizados en el Hospital Universitario de San Ignacio (HUSI): evolución a corto y mediano plazo / Neurosurgical Brain Estereotactic- Guided Procedures Performed at Hospital Universitario San Ignacio (HUSI): Development in the Short and Medium Term

Objetivo: Describir los resultados postoperatorios de los pacientes a los que se lesrealizaron procedimientos neuroquirúrgicos cerebrales guiados por estereotaxia enel Hospital Universitario de San Ignacio durante el periodo julio del 2009-julio del2011. Materiales y métodos: Se revisaron las historias clínicas de 78 pacientes,sus características clínicas, la localización de las lesiones en las neuroimágenes,el tipo de procedimiento, los resultados funcionales y los desenlaces a corto ymediano plazo. Resultados: 78 pacientes tuvieron procedimientos neuroquirúrgicosguiados por estereotaxia entre julio del 2009 y julio del 2011. El 64,1 % (n = 50)eran hombres. La localización de las lesiones fue en orden de frecuencia: gangliossubtalámicos, lóbulo frontal, lóbulo temporal, tálamo, unión córtico-subcortical, tallocerebral, ubicación frontotemporal, lóbulo occipital, ubicación parieto-occipital ybase del cráneo. Discusión: La implementación de procedimientos neuroquirúrgicosguiados por estereotaxia sigue siendo una de las mejores opciones en el abordaje depatologías cerebrales profundas o de difícil acceso. Tanto en Colombia como en elresto del mundo son procedimientos con una baja tasa de morbilidad y mortalidad.Conclusiones: Independientemente del tipo de procedimiento guiado por estereotaxiala tasa de complicaciones no excede el 5 %, tasas similares a las obtenidas en laliteratura mundial...

Objective: Retrospective description of postoperativeoutcomes of patients who underwentneurosurgical brain stereotactic guided proceduresat the Hospital Universitario San Ignacioduring the period July 2009-July 2011. Materialsand Methods: A review of medical recordsof 78 patients who were taken to neurosurgicalstereotactic guided procedures at the HospitalUniversitario San Ignaci. We reviewed the clinicalcharacteristics of patients, the location of thelesions on neuroimaging, management, type ofprocedure of each patient, functional results andoutcomes in the short and medium term. Results:78 patients who underwent neurosurgical brainstereotactic guided procedures between July2009 to July 2011 at the Hospital UniversitarioSan Ignacio. The 64.1 % (n = 50) were men. Thelocation of the lesions were in order of frequencysub-thalamic ganglia, frontal lobe, temporallobe, thalamus, cortico-subcortical junction, brainstem,fronto-temporal location, occipital lobe,parieto-occipital location, and at the skull’s base.Discussion: Implementing guided stereotacticneurosurgical procedures remains one of the bestoptions in dealing with deep brain pathologies ordifficult access. In both Colombia and the rest ofthe world, these are procedures with low morbidityand mortality. It must, however, developmulticenter studies that allow us to observe thedevelopment of stereotactic neurosurgery in ourcountry, also develop studies with a larger continuityto assess the long-term outcomes. Conclusions:Whatever type of stereotactic guidedprocedure the rate of complications does not exceed5 %, similar rates to those obtained from theglobal literature...

Observing thermal injury of rabbit brain in laser interstitial themotherapy and evaluating changed structure of Mood brain barrier in acute stage / 中华急诊医学杂志

Objective To observe ultramicro pathologic change of rabbit brain central damaged tissue and peripheral tissue after LOT, to evaluate the changed structure of blood brain barrier (BBB) of peripheral tissue in acute stage. Method Seventy Newzealand rabbits were randomly screened from Zhejiang University Animal Experiment Center. By stereotaxic technique, semiconductor surgica laser fibers were inserted into right frontal lobes and heat treated to randomly build LITT Group A (2 W, 600 s, n = 20) and LITT Group B (15 W, 100 s, n = 20) brain damaged models successfully. Other 15 nomal rabbits were randomly distributed as mannitol perfusion group and fake operation group. The ultramicro structures in central thermodamaged tissue were observed with transmission electro microscope after LITT 3 h,6 h,12 h,24 h. In peripheral tissue, ultramicro morphologic changes of brain vessels and BBB were evaluated. S100B protein in serum and BBB indexe were measured at different stages post LITT. Experimental data were treated as one-factor analysis of variance and q test. Results The brain damage center connected the tip of laser fiber and turn into thermodamage tissue. The main structure changes were cytoclasis, damnification of cell membrum, swelling of cell organelle such as mitochondrion, endoplasmic reticulurn,disappearance of mitochondrion and sparseness of cytoplasm in local tissure. Heat energy conducted to damage peripheral tissue, some cells occured apoptosis in different stage. In acute stage after LITT, contracted capillary vessel, oncreted red cell, swell endothelium cell, broken base membrum, wide around clearance and destroyed aperture structure were identified. The levels of serum S100B and BBB indexe dramatically rised. The opening time of BBB in peripheral tissue was longer than mannital perfusion group. However at 24 h post LITT, they began to recover in Group A. The difference of serum S100B and BBB indexe between Group A and Group B has statistical significance ( P =0.0087). Conclusions With semiconductor laser heat treatment and stereotaxic techniqe, definite cells cytoclasis, cell membrance structures and chondriosome damage could be performed obviously in rabbit brain thermotherapy point. Apoptosis could be found in peripheral tissue, BBB could be opened in an acute stage. The opening time course of BBB was shortened in those LITT cases with small power. It shew us a new method to perform a safe and exact damage zone of brain for functional neurosurgery.

Stereotactic Minimally Invasive Aspiration for Small Thalamic Hemorrhage A Clinical Study / 国际脑血管病杂志

Objective:To explore the feasibilitv of stereotactic minimally invasive aspiration of small thalamic bemorrhage.Methods:Twenty-two patients with small thalamic hemowhage(5 to 10 mL)were divided into two groups:a stereotactic group(n=10)and a control group(n= 12).The patients in the stereotactic group received stereomctic minimally invasive puncture and drainage of hematomas.According to the condition,repeated infusion of urokinase(10-20 kU) into the hematoma cavities were administered 12 hours after the procedure,and the hematomas were irrigated and drained so as to removal of them completely after retaining for 2-4 hours, The appropriate symptomatic treatment was administered in the patients in both groups.National Institutes of Health Stroke Scale(NIHSS)scores were determined 14 and 30 days before and after the treatment in all the patients.The reductiom of the NIJSS scores (as compared with those before treatment)were calculated at day 14 and 30 respectively after the treatment. Results:The reductiom of the NIHSS scores in the stereotactic group at day 14 and 30 were significantly higher than those in the control group.It was suggested that the neurological functional recovery of the patients was faster after stereotmtic minimally invasive puncture and drainage of intracranial hematorna in the stereotactic group.Concision:The stereotactic minimally invasive puncture and drainage of intracranial hematoma may significantly improve the outcome in patients with small thalamic hemorrhage.

Stereotactic Core-Needle Biopsy of Non-Mass Calcifications: Outcome and Accuracy at Long-Term Follow-Up

OBJECTIVE: To determine, by means of long-term follow-up evaluation, the outcome and accuracy of stereotactic core-needle biopsy (SCNB) of non-mass calcifications observed at mammography, and to analyze the factors contributing to false-negative findings. MATERIALS AND METHODS: Using a 14-gauge needle, SCNB was performed in cases involving 271 non-mass calcified lesions observed at mammography in 267 patients aged 23 72 (mean, 47) years. We compared the SCNB results with those of long-term follow-up which included surgery, mammography performed for at least six months, and reference to Korean Cancer Registry listings. We investigated the retrieval rate for calcifications observed at specimen mammography and histologic evaluation, and determined the incidence rate of cancer, sensitivity, and the underestimation rate for SCNB. False-negative cases were evaluated in terms of their mammographic findings, the effect of the operators' experience, and the retrieval rate for calcifications. RESULTS: For specimen mammography and histologic evaluation of SCNB, the retrieval rate for calcifications was, respectively, 84% and 77%. At SCNB, 54 of 271 lesions (19.9%) were malignant [carcinoma in situ, 45/54 (83%) ], 16 were borderline, and 201 were benign. SCNB showed that the incidence of cancer was 5.0% (6/120) in the benign mammographic category and 31.8% (48/151) in the malignant category. The findings revealed by immediate surgery and by longterm follow-up showed, respectively, that the sensitivity of SCNB was 90% and 82%. For borderline lesions, the underestimation rate was 10%. For false-negative cases, which were more frequent among the first ten cases we studied (p = 0.01), the most frequent mammographic finding was clustered amorphous calcifications. For true-negative and false-negative cases, the retrieval rate for calcifications was similar at specimen mammography (83% and 67%, respectively; p = 0.14) and histologic evaluation (79% and 75%, respectively; p = 0.47). CONCLUSION: In this study group, most diagnosed cancers were in-situ lesions, and long-term follow-up showed that the sensitivity of SCNB was 82%. Falsenegative findings were frequent during the operators' learning period.

Stereotactic Endoscopic Evacuation of Intraventricular Hematomas

Over the last decades, the use of endoscope in neurosurgery gradually gained importance. Although the major indication of neuroendoscopic procedure is intraventricular procedures, the experience of neuroendoscopic intervention of intraventricular hemathoma is rather small. The authors present our experience of four patients with acute ventricular dilatation with intraventricular hematoma through frame-based stereotactic guidance. Through neuroendoscopic intervention, the clot was removed more than 80% each procedure. After the procedure, the silastic catheter was left for continuous intraventricular pressure monitoring. Neither thrombolytic agent nor hyperosmolar treatment was needed postoperatively. There was no mortality or morbidity directly related to endoscopic procedure itself. Brief overview of this technique is given.

Fusion of MR and CT Images of the Head:Applications in Planning X-knife Treatment for Intracranial Lesions(A Report of 25 Cases) / 实用放射学杂志

Objective To study the application of fusion of CT and MRI images in X-knife treatment for intracranial lesions.Methods Total 25 patients included:3 gliomas,3 acoustic neuroma,2 pituitary adenoma,one craniopharygioma to be remained or recurred postoperatily,2 pituitary micro-adenoma,5 AVM,4 cavernous angioma,3 metastatic tumour,one neoplasm located pituitary stem and midbrain respectively.Before the fusion of CT and MRI images MRI scan and CT scan for location of X-knife were performed respectively,then MR and CT image were transferred to workstation for the fusion of images.Results All lesions were showed clearly on fusional images and more nodules were observed in 3 metastatic tumour.Skull,soft tissue constructures and the profile of lesions were completely overlaped on overlaped images of CT and MR with an error less 1.0 mm.Conclusion CT and MRI images of head can be accurately registered.The images can show the radiologic informations more clearly than conventional CT image.It provides a safe,effective and little harmful method for X-knife treatment of intracranial lesions.

Diagnostic Value of Mammography with X-ray Stereotaxic Puncture in Early Breast Cancer / 实用放射学杂志

Objective To evaluate the value of X-ray stereotaxic puncture in the diagnosis of early breast cancer.Methods The X-ray manifestations of 53 cases of early breast cancer verified by pathology were analysed.Results In 53 cases,there were 23 cases of lumps,17 were simple calcification,8 nodes with calcification,12 asymmetry improved density with disorder structue,15 stellatesign,18 augmentation blood,3 conduit breakag.Conclusion Mammography with X-ray stereotaxic localized puncture is the first useful method in diagnosing the early stage of breast cancer.

Nucleotratotomia trigeminal estereotáxica no tratamento da dor facial atípica / Stereotactic trigeminal nucleotractotomy for treatment of atypical facial pain

As características funcionais e morfológicas da face, aliadas à complexidade do fenômeno doloroso, tornam favorável a existência de inúmeras fontes de dor facial, como procuraram demonstrar as várias classificações existentes a respeito. A nucleotratotomia trigeminal consistena ablação cirúrgica de núcleos trigeminais de segunda ordem e tratos.Dois casos de dor facial atípica refratários ao tratamento medicamentoso ou a outras formas nãooperatórias são discutidos. A intensidade da dor pré e pós-operatória foi avaliada pela Escala Visual Analógica. A técnica operatória é descrita. Os resultados imediatos foram satisfatórios em ambos os casos. Um doente teve recidiva da dor, com menor intensidade, dois meses após o procedimento e o outro estava assintomático oitomeses depois. Um doente apresentou ataxia transitória que regrediu em dois meses; o outro teve meningite bacteriana no pós-operatório. Aspectos terapêuticos e as bases fisiopatológicas da indicação cirúrgica são apresentados.

The functional and morphologic peculiarities of the face justify the occurrence of varied sources of pain. The trigeminal nucleotractotomy consists in a surgical lesion of secundary trigeminal nuclei and tracts.Two cases of atypical facial pain refractory to clinical treatments are discussed. The intensity of pain was evaluated by the Visual Analogic Scale. The surgical technique is described. The immediate results were satisfactory. One patient developed recurrent pain two months later,and the other was asymptomatic for eight months. One patient presented transitory ataxia and the other developed bacterial meningitis. The physiopathological basis of this procedure is discussed.

Assessment of Spacial Distortion in Digital Subtraction Angiogra phy for Stereotactic Radiosurge ry: An Experimental Study with Phantom

PURPOSE: In stereotactic radiosurgery, awareness of the precise localization and volumetry of tumors and of critical organs, and the planning of the treatment field are important. The purpose of this study was to determine the degree of distortion in images obtained by digital subtraction angiography(DSA) and to assess whether DSA is a suitable may substitute for MRI in the planning of stereotactic radiosurgery. MATERIALS AND METHODS: After designing DSA phantoms we obtained images under variable conditions and analyzed image distortion using an image analysis program. RESULT: DSA imaging distortion increased as intensifying tube size became greater and the distance between tube and object decreased. CONCLUSION: Images obtained by DSA imaging were very distorted, and in the planning of stereotactic radio-surgery DSA is not, therefore, a suitable substitute for MRI.

Stereotactic Resection of the Brain Tumor Using 'Tailed Bullets': Technical Note

The interactive image-guided stereotactic system can provide a real-time surgical localization and guidance for complete removal of the tumor. However, this system has limitation with respect to the resection of deepseated tumors because once the tumor is removed, the brain and the margin of tumors shift toward the area previously occupied by the tumor. We present a new operative technique for determining the resection margin of deep-seated tumors using a visual marker called a 'tailed bullet' to overcome the problem mentioned above. Preoperative enhanced computed tomograms or magnetic resonance imagings were performed with the aid of the Leksell frame. The enhancing margin of the tumor was defined as a resection margin. Several points(10-15) of the tumor margin on the enhanced imaging were chosen and localized. After usual craniotomy, multiple tailed bullets were inserted into the target point just before the opening of the dura. As the tumor was removed, the brain began to move along with the tailed bullets, thus enable us to continue tracking the tumor margin by following the bullet's location. There are substantial benefits of this surgical technique. It can be easily applied to any kind of stereotactic frame without incurring other expenses and it is more cost-efficient than the neuronavigation system. This surgical procedure is also safe and simple to use for overcoming the limitation of neuronavigation system, since the movement of the bullets with the brain can be easily traced thus lowering the mortality and morbidity of brain tumor resection. This surgical technique is especially useful in glioma surgery.

Usefulness of Stereotactic Localization of Nonpalpable Breast Lesions

PURPOSE: To evaluate the usefulness of stereoscopic localization of nonpalpable breast lesions. MATERIALS AND METHODS: The authors retrospectively analyzed 60 cases of stereotactic localization performed for lesions whichwere mammographically visible but not palpable. Each case was reviewed for chief complaint, indication oflocalization on a mammograph, location of the lesion, pathological diagnosis, and complications during and afterthe procedure. RESULTS: Most patients(75%) had no specific complaint. Among the 60 cases, microcalcification,mass and combined lesions were found in 34(57%), 12(20%), and 14 cases(23%), respectively. The most commonlocation of the lesion was the upper outer quadrant(29 cases). A histopathologic report was available in 56 of 60cases. Among 43 benign cases(76.8%), fibrocystic disease was most common(38 cases, 67.9%), while among 13malignant cases, ductal carcinoma was most common(9 cases, 16.1%). In four of 56 cases(7.1%), failure to removethe target lesion was identified. Retrospective analysis suggests that movement of the patient during theprocedure is the most likely cause of failure. There were no major complications. CONCLUSION: Stereotacticlocalization is simple and accurate, and compared with the conventional method, requires less experience on thepart of the practitioner. Movement of the patient during the procedure may be the major cause of failure.

Clinical Analysis of Stereotactic Thalamotomy for Medically Intractable Essential Tremor

Stereotactic ventrolateral thalamotomy has been successful in treating a wide spectrum of involuntary movement disorders. But very little has been reported concerning their application in essential tremor. Twenty three patients with medically refractory disabling essential tremor underwent ventralis(VL) thalamotomies. The procedure was unilateral in twenty three cases. Contralateral tremor remained abscent or markedly reduced in 22 patients at the time of the most recent follow-up examinations at a mean of 2.9 months after surgery. Disability was determined by a modified form of an estabilished rating scale for termor reported by Fahn and was reduced from a mean score of 11 to 3(p<0.0001) after the operation. Persistent surgical morbidity was limited to three patients with mild dysarthria and two with a mild cognitive impairment. There were no surgically related deaths. It is concluded that stereotactic VL thalamotomy is a treatment option for medically intractable disabling essential tremor.

CT-Guided Stereotaxis of Intracranial Mass Lesions: Its Complications and Diagnostic Accuracy of Biopsy

Surgical resection may not be the appropriate first treatment for all intracranial mass lesions, especially for deep or midline lesions. And a precise histopathological diagnosis is mandatory to develop adequate and specific treatments. The advent of modern imaging and CT-compatible stereotactic frames has greatly simplified the performance of streotactic procedure for small and deep seated brain tumors. We present a 44-month experience on 94 stereotactic procedures of intracranial mass lesions, using Brown-Roberts-Wells(BRW) and Cosman-Roberts-Wells(CRW) system. Procedures were undertaken with the patient under the local anesthesia for biopsy(78 procedures), cyst aspiration and/or Ommaya reservoir insertion(9 procedures), and brachytherapy(5 procedures) and under the general anesthesia for stereotactic-guided microsurgery(2 procedures). Procedural objectives were satisfactorily accomplished with no mortality and an overall complication rate of 8.5%(8 of 94 procedures). The postoperative complications were transient and not seriour, except aggravation of obstructive hydrocephalus in two cases of lateral ventricular tumors. Specific and correct histological diagnoses were achieved in 73(94%) of 78 biopsy. We could not obtain a specific diagnosis in 3 cases(2 cases of reactive gliosis, 1 case of necrosis). And in two cases with a diagnosis of anaplastic astrocytoma and oligodendroglioma grade I on the basis of surgical specimens by craniotomy, stereotactic biopsy revealed astrocytoma grade II and nonspecific inflammation respectively. Our data suggest that CT-guided stereotactic biopsy is a reliable and safe method for histologic diagnosis of brain-tumoral conditions and the method of choice for deep-seated and midline lesions.

CT-Guided Stereotaxis of Intracranial Mass Lesions: Its Complications and Diagnostic Accuracy of Biopsy

Surgical resection may not be the appropriate first treatment for all intracranial mass lesions, especially for deep or midline lesions. And a precise histopathological diagnosis is mandatory to develop adequate and specific treatments. The advent of modern imaging and CT-compatible stereotactic frames has greatly simplified the performance of streotactic procedure for small and deep seated brain tumors. We present a 44-month experience on 94 stereotactic procedures of intracranial mass lesions, using Brown-Roberts-Wells(BRW) and Cosman-Roberts-Wells(CRW) system. Procedures were undertaken with the patient under the local anesthesia for biopsy(78 procedures), cyst aspiration and/or Ommaya reservoir insertion(9 procedures), and brachytherapy(5 procedures) and under the general anesthesia for stereotactic-guided microsurgery(2 procedures). Procedural objectives were satisfactorily accomplished with no mortality and an overall complication rate of 8.5%(8 of 94 procedures). The postoperative complications were transient and not seriour, except aggravation of obstructive hydrocephalus in two cases of lateral ventricular tumors. Specific and correct histological diagnoses were achieved in 73(94%) of 78 biopsy. We could not obtain a specific diagnosis in 3 cases(2 cases of reactive gliosis, 1 case of necrosis). And in two cases with a diagnosis of anaplastic astrocytoma and oligodendroglioma grade I on the basis of surgical specimens by craniotomy, stereotactic biopsy revealed astrocytoma grade II and nonspecific inflammation respectively. Our data suggest that CT-guided stereotactic biopsy is a reliable and safe method for histologic diagnosis of brain-tumoral conditions and the method of choice for deep-seated and midline lesions.

Delayed CT Guided Stereotaxic Evacuation of Hypertensive Intracerebral Hematoma

The authors analyzed 11 patients of hypertensive intracerebral hematoma who had undergone the delayed CT guided stereotaxic evacuation. this delayed stereotaxic evacuation seemed to be highly effective in improving the motor weakness rather than mental state. Such effect was appeared immediately after the procedures in most of the patients, even in very small amount of hematoma. In addition, we could shorten the total hospital periods. The most effective time of this delayed stereotaxic evacuation was seemed to be in around 2 weeks after the hemorrhage.

CT Guided Stereotaxic Biopsy for the Differential Diagnosis of Brain Lesions

Some intracranial masses are usually treated following a presumptive diagnosis based on the clinical picture and neurological studies but in some instances a proven histological diagnosis might alter the method of treatment as well as affect the prognosis. Open surgical biopsy however might cause serious neurological deficit in many of these patients however a stereotaxic approach might avoid such problems. For the correct three dimensional target localization on CT scan we developed nearly artifact free simplified CT interface frame that accurately interface between the CT scanner and the stereotasic instrument makes it possible to take biopsies at exact and with low risk. In 10 patients CT interfaced stereotaxic biopsy of brain lesions were performed. 100% accurate histological diagnosis was obtained and helped considerably in planning further therapy. The localization error was less than 0.04mm and no significant complications occured in these patients.