Multimodality program involving stereotactic surgery in brain tumor management.

Stereotactic and image guided surgery is becoming increasingly important in the management of brain tumors. Although there are several stereotactic modalities that have been reported to be of value, it is the combination of techniques in a multimodality approach that seems to show the most promise. Both frame-based and frameless guidance may facilitate glioma resection, allowing the optimal amount of resection while permitting avoidance of surrounding eloquent areas. Not only does this optimize resection, but leaving a minimal amount of gross tumor may provide a better bed for intracavitary chemotherapy. Deep tumors may be localized and approached through a small channel. Surgical exposure may be minimized to protect uninvolved areas of the brain. There is increasing evidence that patients operated with imaging guidance have a more benign course and more rapid discharge, perhaps with a lower incidence of adverse neurological sequelae. Stereotactic conformal radiotherapy allows a higher tumor dose while sparing uninvolved brain from radiation more efficiently than conventional radiation. Residual tumor may be treated with a boost of stereotactic radiotherapy. Stereotactic instillation of radioisotope may be used to treat cystic tumors. Stereotactic insertion of cannulae or radioisotope seeds permits efficient brachytherapy. Stereotactic surgery has moved beyond a subspeciality, so that every neurosurgeon might benefit from using stereotactic techniques in brain tumor management.     

Use of positron emission tomography (PET) in stereotactic conditions for brain biopsy

Summary In order to take advantage of the metabolic information provided by positron emission tomography (PET) in cases of brain tumour, we have developed a technique to integrate PET images routinely in the planning of stereotactic brain biopsy. We used stereotactic PET with [¹⁸F]-labelled fluorodeoxyglucose (PET-FDG) in 38 patients undergoing brain biopsy. To evaluate the contribution of PET-FDG in guiding brain biopsy, we analyzed the diagnosis provided by the 78 Stereotactic trajectories obtained in these patients.We found that stereotactic PET-FDG seemed to provide more information in cases of anaplastic astrocytomas and glioblastomas than in low-grade gliomas. Our results also show that biopsy trajectories performed in areas where increased FDG uptake is found within the lesion boundaries always provide interpretable specimens; this was not the case for trajectories guided by CT only. Therefore, the routine integration PET-FDG in the planning of stereotactic brain biopsy may lead to a reduction in sampling. Recently, we also tested consecutive stereotactic PET with [¹¹C]-labelled methionine (PET-Met) and PET-FDG. This technique allowed us to compare accurately the tumoural glucose metabolism and protein synthesis.Our results suggest that stereotactic PET may increase the diagnostic yield of brain biopsy and may improve the understanding of PET in neuro-oncology.     

Frameless stereotactic neurosurgery using intraoperative magnetic resonance imaging: stereotactic brain biopsy

OBJECTIVE: To assess the application accuracy of intraoperative magnetic resonance imaging for frameless stereotactic surgery, and to evaluate the performance of intraoperative magnetic resonance imaging for the brain biopsy, a standard stereotactic procedure. METHODS: A series of spatial coordinate and phantom experiments were performed to analyze the application accuracy of the system. A prospective analysis of 68 consecutive patients undergoing stereotactic brain biopsy was then performed. RESULTS: The spatial coordinate experiments revealed a mean overall error in acquisition of 0.2 mm. The phantom experiments demonstrated a 1:1 correlation between the magnetic resonance image of a stereotactically guided probe and its relationship to a target and the actual relationship of the probe and target. Sixty-eight brain biopsies were successfully performed in all intracranial compartments except the sella. The radiographic abnormality was localized successfully in all patients (100%). Sixty-six (97.1%) of the biopsies yielded diagnostic tissue. Two biopsies (2.9%) were complicated by intraparenchymal hemorrhage. One expanding temporal lobe hemorrhage was evacuated by immediate craniotomy in the magnet with no postoperative sequelae. A deep hemorrhage from a lymphoma was managed conservatively with interval resolution of symptoms. There were no infections. There was no perioperative mortality. CONCLUSION: Intraoperative magnetic resonance imaging allows excellent target localization, provides true real-time imaging to account for anatomic changes during surgery, and permits intraoperative confirmation that the biopsy needle has reached the targeted lesion. Immediate postoperative imaging in the operating room allows assessment of adverse events and the potential for immediate management of hemorrhagic complications.     

立体定向脑内病灶活检的临床意义

目的 探讨先进图像引导立体定向脑组织活检术方法 ,明确其在神经系统疾病诊断中的意义.方法 回顾性分析1987年12月至2009年1月立体定向脑内病灶活检的1187例病历资料,其中男性694例(58.5%),女性493例(41.5%);年龄1～85岁(平均39.7岁).CT(含正电子发射断层扫描)引导活检607例,MRI(含氢质子磁共振波谱成像)引导活检580例;采用常规框架立体定向活检手术726例,采用无框架立体定向机器人活检手术461例(含定向引导神经内镜活检).早期450例立体定向手术定位,采用CT或MRI图像测量靶点坐标方法 ,不能立体显示穿刺途径;后期737例立体定向手术定位,采用计算机三维重建病灶方法 ,能够立体显示穿刺路径.结果 活检明确组织病理学诊断1156例(活检阳性诊断率97.4%).本组中983例(82.8%)获得肿瘤学病理诊断,主要包括神经胶质瘤、转移性肿瘤、原发性淋巴瘤、生殖细胞瘤等;173例(14.6%)为非肿瘤性病变,其中包括多发硬化和瘤样脱髓鞘病变、神经变性疾病、炎性病变、寄生虫病等.活检穿刺手术并发少量血肿(<10 ml)而无神经功能障碍20例(1.7%),较大血肿(>10ml)需要外科处理(置管引流或开颅血肿清除)9例(0.8%);活检出血导致死亡3例(0.3%).本组无颅内感染病例.结论 先进影像技术引导的立体定向脑组织活检术是一种微侵袭、可靠的脑内疾病确定诊断手段.生化成像、功能成像技术的发展,为立体定向引导的活检技术赋予了崭新的内容.     

Development and clinical usefulness of a new neuroendoscope system for CT-guided stereotactic brain surgery.

Since computed tomography (CT)-guided stereotactic surgery is essentially blind surgery, it always involves the risk of injuring viable brain tissue and vessels, and it is difficult to obtain a sufficient amount of biopsy specimen from cystic or necrotic lesions. Moreover, the direct observation of the lesion would provide extremely valuable information. The authors have therefore developed a new subminiature rigid endoscope and an ultrasonic aspirator for use in stereotactic surgery, as well as a new micromanipulative system to attach the equipment to the stereotactic frame so that they can be accurately inserted into the optimum position from any direction. The new neuroendoscope includes a graded refractive index glass rod only 1.0 mm in diameter (Selfoc, Nippon Sheet Glass Co., Osaka), which provides a focal depth from 1 mm to infinity, as well as an extremely bright and wide visual field with an angle of 70 degrees. Furthermore, because the outer probe and endoscopic sheath share the outer rigid metal tube 4.5 mm in outer diameter, a large internal channel of 2.1 mm in diameter allows the introduction of various microinstruments such as an ultrasonic aspirator probe, laser probe, and biopsy forceps. When a miniaturized video camera is attached, the surgical procedures can be controlled using the video monitor and photographed. The new probe for the ultrasonic aspirator has been developed in various types suitable for fragmentation and aspiration of hematomas and brain tumors, so under endoscopic control even the harder coagulants and tumors can be removed.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of computerized tomography-guided stereotactic and ultrasound-guided techniques for brain biopsy

Forty-one patients with brain lesions underwent brain biopsy using either a computerized tomography (CT)-guided stereotactic approach or an ultrasound-guided technique. The cases were selected according to location and size of the mass lesion. Lesions 15 mm or less in diameter and those in the posterior fossa were biopsied by a CT-guided stereotactic technique (18 patients). Supratentorial lesions with a diameter larger than 15 mm were approached using ultrasound guidance (23 patients). These criteria for procedure selection provided a diagnostic yield of 94% for the CT-guided procedures and 91% for those guided by ultrasound. Safety for the two procedures was similar. The ultrasound procedure was more rapid, simpler, and less costly to perform. It is concluded that, with the protocol described, CT-guided stereotactic procedures could be reserved for cases in which absolute accuracy is mandatory.     

Percutaneous stereotactic brain tumour biopsy and cyst aspiration with a non-invasive frame

A non-invasive Stereoadapter was used for stereotactic CT-guided percutaneous brain biopsy in 18 patients with 16 solid tumours and four cysts. The Stereoadapter was mounted on the patient's head using ear plugs and a nasion support. After the CT study, the Stereoadapter was detached. The target was simulated on a phantom base and a probe carrier attached to the Stereoadapter. For surgery, the Stereoadapter with the probe carrier was remounted to the patient's head. Local anaesthesia was mainly used. Tissue samples were aspirated with a 2 mm diameter Sedan-Nashold biopsy cannula, introduced through a twist drill hole. Conclusive histological/cytological diagnosis was obtained in 16 of the 20 lesions. The new method proved to be reliable and quick. Since the imaging study and the surgery could be separated in time and place, the biopsy procedure was less time-consuming than previous methods of stereotactic biopsy using an invasive frame.     

CT-guided stereotactic surgery of brain abscess

Seven patients with brain abscess underwent CT-guided stereotactic aspiration using Iseki's stereotactic apparatus. Three of them were under the age of fifteen and four were older than thirty. The lesions were single and round in four cases, multilobular in two and multiple in one patient. Operations were performed after systemic administration of antibiotics for more than two weeks and after capsule formation was confirmed on CTs. Preoperative volume of the abscesses was estimated from CTs. The target point chosen was the center of the ring of the largest diameter in the enhanced lesion. Abscess was aspirated under monitoring with intraoperative CT scan. No continuous drainage was performed and no antibiotics were given directly into the abscess cavity. In all cases the center of the abscess was punctured with a single trial. Average volume of the preoperative brain abscesses was 18.8ml. Aspirated volume at the time of the operation averaged 16.9ml and all the abscesses decreased to unmeasurable size on CTs. In five of seven patients abscesses were cured after a single aspiration, and in one case after the second operation. One case required extirpation of the lesion. During the follow-up period of four months to five and a half years six patients showed no recurrence. One patient died of unrelated cause four and a half years after the operation. No operative complication was noted. There was no operative morbidity or mortality. Using a CT guided stereotactic method, brain abscess is punctured so accurately, regardless of its location and size, that damage to the surrounding brain during operation can be minimized. Therefore it is highly possible to aspirate abscesses completely.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stereotactic support in the excision of brain tumors. Technical note

The surgical resection of deep-seated brain tumors may be facilitated by CT guided stereotactic methods. The Authors present a procedure of preoperative localisation and delimitation of the border of a neoplastic mass facing important functional areas. Ideally tumor excision should not be extended beyond that boundary which for this reason is targeted and is stereotactically labeled using non diffusible dyes.     

A probe for simultaneous sampling in stereotactic brain biopsy

Summary A probe for stereotactic brain biopsy which allows to obtain two different samples along a single trajectory tract is presented. It consists of a cylindrical stainless steel probe which has two separate grooves. The pieces of tissue are shredded from the lesion by sliding a polyethylene cannula that fits around the probe.     

The risk of haemorrhage after image guided stereotactic biopsy of intra-axial brain tumours--a prospective study

OBJECTIVE: To analyze prospectively the frequency and the risk of symptomatic and asymptomatic haemorrhage after image guided stereotactic biopsy of intra-axial brain tumours. METHODS: The study was conducted within a time frame of 24 months (April 1998-April 2000). 326 patients (150 males, 176 females; mean age 56.8 years) were included and 345 computerized tomography (CT)-guided stereotactic biopsies were performed/supervised by a specialized stereotactic neurosurgeon. A modified Riechert Stereotaxy System and a workstation for multiplanar trajectory planning were used in all patients. Serial biopsies (median, 5 samples) were done with small forceps (diameter 1 mm), smear preparations of the biopsy specimens were intra-operatively examined. Frequency, size, and location of any detectable bleeding were analyzed by post-biopsy CT-scan investigation. For risk estimation, logistic regression analysis was performed. The chi-square statistic was used for comparative analysis of the study results with available data from the literature. RESULTS: A conclusive tissue diagnosis could be achieved in 98%. Overall treatment morbidity was 3.1%. There was no mortality. Haemorrhage related morbidity was 0.9%. Age, Karnofsky score, mass effect of the tumour, tumour histology, tumour location and the number of specimens taken did not have any prognostic significance. The clinically silent bleeding rate was 9.6% and more often seen in patients with high grade gliomas (p = 0.03). Both the silent and non-silent bleeding rate were significantly lower as compared to available prospective data in the literature (p < 0.01). CONCLUSION: Using multiplanar image guided trajectory planning, small biopsy forceps and intra-operative smear preparations the risk of major haemorrhage related morbidity after stereotactic brain tumour biopsy is extremely low (<1%) in experienced hands.     

Transsulcal microsurgical approach for subcortical small brain lesions: technical note

We describe a transsulcal microsurgical approach for removal of small subcortical brain lesions, guided by frameless stereotaxy. This technique of simultaneous stereotactic localization of the subcortical lesion and its adjacent sulcus, before surgical approach, results in optimal surgical planning, leading to minimal brain tissue loss and excellent surgical outcome.     

Stereotactic implantation of deep brain electrodes using computed tomography

The selection of intracranial targets for stereotactic functional neurosurgical procedures traditionally has relied on information derived from pooled brain atlases and supplemented by contrast encephalographic or angiographic data from the individual patient. The integration of stereotaxy with computed tomography (CT) has permitted direct identification of intracranial targets based on multiplanar reformatted CT images from each individual patient. Four patients underwent the CT stereotactic implantation of a single deep brain electrode for the control of chronic pain (two cases) or of multiple depth electrodes for long term electroencephalographic recordings in the management of seizure disorders (two cases). In all patients, accurate and precise electrode placement was achieved from CT images alone. The use of CT permitted detailed anatomical stereotactic study of each patient's brain, the preplotting of electrode trajectories before probe insertion, and the rapid confirmation of precise electrode placement. Intraoperative contrast encephalography was not necessary. Functional neurosurgery was performed successfully and advantageously using CT stereotactic technique alone.     

Treatment of deep brain abscesses by stereotactic implantation of an intracavitary device for evacuation and local application of antibiotics

Summary Complete recovery from deep brain abscesses was achieved in four patients treated by a specialized stereotactic method. In one patient the lesion was in the right thalamus, in two patients within the brain stem and in one case in the right rolandic cortex. The technique consists in the stereotactic implantation of a chronic intracavitary catheter connected to a subcutaneous reservoir to allow postoperative multiple evacuations and local antibiotic irrigations. Serial CT scan examinations guided the timing of intracavitary treatment and the removal of the catheter. No recurrence developed. The diagnostic and therapeutic advantages of this stereotactic technique are emphasized.     

Multimodality program involving stereotactic surgery in brain tumor management

Stereotactic and image-guided surgery is becoming increasingly important in the management of brain tumors. Although there are several stereotactic modalities that have been reported to be of value, it is the combination of techniques in a multimodality approach that seems to show the most promise. Both frame-based and frameless guidance may facilitate glioma resection, allowing the optimal amount of resection while permitting avoidance of surrounding eloquent areas. Not only does this optimize resection, but leaving a minimal amount of gross tumor may provide a better bed for intracavitary chemotherapy. Deep tumors may be localized and approached through a small channel, and surgical exposure may be minimized to protect uninvolved areas of the brain. There is increasing evidence that patients operated with imaging guidance have a more benign course and more rapid discharge, perhaps with a lower incidence of adverse neurological sequelae. Stereotactic conformal radiotherapy allows a higher tumor dose while sparing uninvolved brain from radiation more efficiently than conventional techniques, and residual tumor may be treated with a boost of stereotactic radiotherapy. Stereotactic instillation of radioisotopes may be used to treat cystic tumors. Stereotactic insertion of cannulae or radioisotope seeds permit efficient brachytherapy. Stereotactic surgery has moved beyond a subspeciality, so that every neurosurgeon might benefit from using stereotactic techniques in brain tumor management.     

MRI导向立体定向活检手术在颅内疑难病例诊断中的应用

目的 探讨MRI导向立体定向活检手术的准确性及其在颅内疑难病例诊断中的应用价值。方法 安装CRW立体定向框架,采用MRI容积扫描与多层重建技术,对26例临床表现不典型或CT扫描不能发现明确病灶的患者施行立体定向脑活检手术。结果 26例患者均未出现因活检手术而造成的出血、偏瘫等严重并发症。所有患者均得到明确的病理诊断及相应的治疗。结论 MRI导向立体定向活检手术在准确性上明显优于CT导向活检手术;对于颅内疑难病例的诊断,也是一种有效的手段。     

New radiofrequency coil integrated with a stereotactic frame for intraoperative MRI-controlled stereotactically guided brain surgery

Mislocalization errors caused by MR image distortions or brain shift are one of the main causes of complications after stereotactically guided neurosurgical procedures. A special device, which could ameliorate such effects and provide intraoperative acquisition of MR images of sufficient diagnostic accuracy, was developed. It is composed of a radiofrequency receiver coil integrated with a modified Komai stereotactic frame and a Sugita four-pin head holder. Clinical testing revealed that the use of the device during stereotactically guided procedures under the control of low magnetic field strength (0.3 T) intraoperative MRI ameliorates the effects of brain shift, and permits to obtain informative tissue samples and to perform aggressive removal of the lesion without any damage of the eloquent cerebral structures. The possibility of an easy shift from a stereotactically guided to a routine microneurosurgical procedure represents an additional benefit of the developed device.     

Stereotactic radiosurgery for pediatric brain tumors

Six papers from the recent literature are reviewed for outcomes after stereotactic radiosurgery used to treat pediatric brain tumors. Results indicate that radiosurgery is feasible in children with brain tumors. The efficacy is approximately 80% local control for benign astrocytomas. The local control is less effective in malignant tumors. Only 4 of 15 children with recurrent ependymoma were controlled. The complication rate of all the papers combined is approximately 11%. Permanent neurologic complication owing to stereotactic radiosurgery is approximately 5%. These complications are discussed.     

Positron emission tomography-guided stereotactic brain biopsy.

We describe a technique that allows target definition for stereotactic brain biopsy using coordinates calculated on stereotactic positron emission tomographic (PET) images. In this study, PET images were obtained using [18F]-labeled fluorodeoxyglucose, a marker for glucose metabolism. The difference between PET-calculated and actual stereotactic coordinates of simulated targets is within PET spatial resolution. Combined computed tomography- and PET-guided stereotactic biopsies were performed in 11 patients with brain tumors. In this report, we describe two representative patients who underwent stereotactic brain biopsy using the present technique. Because of the complementary role of PET and computed tomography, their integration in multimodality planning might optimize the target selection for stereotactic brain biopsies.     

Thallium SPECT-based stereotactic targeting for brain tumor biopsies. A technical note

MR or CT images acquired under stereotactic conditions are often used to plan and guide brain tumor biopsies. The objective of this study was to design and test a methodology to increase target selection reliability by acquiring stereotactic 201Tl-SPECT data and by integrating them into the surgical planning. The three-headed Philips gamma camera system (Prism 3000) was adapted to stereotactic acquisitions (patient pallet, headholder). A software was developed for the stereotactic target determination based on SPECT images (pixel with the highest metabolic activity inside the tumor). The whole system accuracy was tested with the Elekta phantom adapted to SPECT imaging. The methodology was applied to one brain tumor biopsy. Comparison of the specific phantom coordinates evaluated in SPECT with the theoretical ones did not reveal any significant difference. In this way, our methodology including our homemade software (identification of the stereotactic frame, determination of the pixel with highest metabolic activity within the tumor in the stereotactic coordinate system) was validated. No significant geometric deformations were detected. Clinical feasibility was confirmed in 1 patient with a brain glioma. This study illustrates the feasibility and the accuracy of SPECT acquisitions with the stereotactic Leksell G-frame. The clinical relevance of this methodology is under evaluation. This definition of the target, based on the point with the highest metabolic activity within the tumor, might lead to improved diagnosis in biopsies and patient management. Furthermore, it might prepare the future for therapy aimed at delivering a therapeutic agent within a tumor.