In the past 10 years, modern technology has made deep seated obscure lesions visible. With development of computer technology and various stereotaxic techniques, many new procedures, refinement of old procedures, and development of new applications are possible. The authors are intended to provide a detailed description of our experience with the Brown-Roberts-Wells (BRW) stereotactic system in the evaluation and management of 90 patients with intracranial lesions, and to provide cases presentation of various inaccessible intracranial lesions.
Humans ; Stereotaxic Techniques

Radiation therapy has played a key role, together with surgery and systemic chemotherapy, in treating in all stages of non-small cell lung cancer. We have witnessed remarkable improvements in radiation therapy techniques, with the innovations in hardware and software. Stereotactic ablative radiation therapy, which can deliver high radiation dose focused to small target volume, represents one of the state-of-the-art radiation therapy techniques. The technical development of radiation therapy and the role of stereotactic ablative radiation therapy in treating inoperable stage I non-small cell lung cancer are briefly reviewed.
Carcinoma, Non-Small-Cell Lung* ; Drug Therapy ; Radiotherapy ; Stereotaxic Techniques

Stereotactic vacuum-assisted breast biopsy (VAB) has been used to evaluate microcalcifications or non-palpable breast lesions on mammography. Although stereotactic VAB is usually performed in a prone or upright position, an expensive prone table is necessary and vasovagal reactions often occur during the procedure. For these reasons, the lateral decubitus position can be applied for stereotactic VAB, and true lateral mammography can be used to detect the lesion. We report on 15 cases of lateral decubitus positioning for stereotactic VAB with true lateral mammography for non-palpable breast lesions or microcalcifications. The mean procedure time was approximately 30.1 minutes, and no complications occurred during the procedures. Fourteen cases had benign breast lesions and one case had a ductal carcinoma in situ. The lateral decubitus stereotactic VAB with true lateral mammography can be applied for microcalcifications or non-palpable breast lesions and helps to minimize anxiety and vasovagal reactions in patients.
Anxiety ; Biopsy ; Breast ; Carcinoma, Intraductal, Noninfiltrating ; Humans ; Mammography ; Stereotaxic Techniques

The treatment modality of patients with spontaneous intracerebral hematoma is still controversial. With remarkable development of CT-guided stereotactic techniques, stereotactic evacuation is preferable to conventional craniotomy due to local anesthesia and minimal brain damage. We reviewed 60 patients with hypertensive intracerebral hematoma, treated with CT-guided stereotactic aspiration and conventional craniotomy from Jan. 1995 to Dec. 1995. The patients were divided into three groups. Group I included the patients who had hematoma less than 30cc in volume and treated stereotactically using a single catheter. Group II was consisted of patients who had hematoma more than 30cc and treated stereotactically using 2 or more catheters. Group III was composed of the patients who showed neurologically rapid progression and treated with conventional craniotomy. We compared the results of the three groups of therapeutic modalities and made conclusions. Most of the spontaneous intracranial hematomas were removed com pletely within 5 days by the stereotactic method. This method was feasible to the patients, who had large volume of hematomas using multiple catheters.
Anesthesia, Local ; Brain ; Catheters* ; Craniotomy ; Hematoma* ; Humans ; Stereotaxic Techniques

The treatment modality of patients with spontaneous intracerebral hematoma is still controversial. With remarkable development of CT-guided stereotactic techniques, stereotactic evacuation is preferable to conventional craniotomy due to local anesthesia and minimal brain damage. We reviewed 60 patients with hypertensive intracerebral hematoma, treated with CT-guided stereotactic aspiration and conventional craniotomy from Jan. 1995 to Dec. 1995. The patients were divided into three groups. Group I included the patients who had hematoma less than 30cc in volume and treated stereotactically using a single catheter. Group II was consisted of patients who had hematoma more than 30cc and treated stereotactically using 2 or more catheters. Group III was composed of the patients who showed neurologically rapid progression and treated with conventional craniotomy. We compared the results of the three groups of therapeutic modalities and made conclusions. Most of the spontaneous intracranial hematomas were removed com pletely within 5 days by the stereotactic method. This method was feasible to the patients, who had large volume of hematomas using multiple catheters.
Anesthesia, Local ; Brain ; Catheters* ; Craniotomy ; Hematoma* ; Humans ; Stereotaxic Techniques

The neurophysiological study has been widely used in search of the relationship between brain and behavior. The basic techniques for the animal experiments of this kind such as stereotaxic techniques, lesioning methods the methods the methods of electrical stimulation and recording and confirmation of histological location were briefly reviewed. Nevertheless the importance of complementary neurochemical, neuroanatomical and behavioral studies can not be neglected.
Animal Experimentation* ; Animals* ; Brain ; Electric Stimulation ; Stereotaxic Techniques

There are some limitations in the localization of epileptogenic zone commonly used by human eyes to identify abnormal discharges of intracranial electroencephalography in epilepsy. However, at present, the accuracy of the localization of epileptogenic zone by extracting intracranial electroencephalography features needs to be further improved. As a new method using dynamic network model, neural fragility has potential application value in the localization of epileptogenic zone. In this paper, the neural fragility analysis method was used to analyze the stereoelectroencephalography signals of 35 seizures in 20 patients, and then the epileptogenic zone electrodes were classified using the random forest model, and the classification results were compared with the time-frequency characteristics of six different frequency bands extracted by short-time Fourier transform. The results showed that the area under curve (AUC) of epileptic focus electrodes based on time-frequency analysis was 0.870 (delta) to 0.956 (high gamma), and its classification accuracy increased with the increase of frequency band, while the AUC by using neural fragility could reach 0.957. After fusing the neural fragility and the time-frequency characteristics of the γ and high γ band, the AUC could be further increased to 0.969, which was improved on the original basis. This paper verifies the effectiveness of neural fragility in identifying epileptogenic zone, and provides a theoretical reference for its further clinical application.
Humans ; Electroencephalography/methods* ; Epilepsy/diagnosis* ; Seizures ; Stereotaxic Techniques

External beam radiotherapy can be used to treat cutaneous squamous cell carcinomas (SCC). Acute skin toxicity is the most common adverse event. In this case study we report on an elderly patient with nasal root cutaneous SCC treated with stereotactic technique using a dedicated linear accelerator (CyberKnife system). Grade 3 skin toxicity was observed but it was resolved after 6 weeks. The use of stereotactic radiotherapy permitted a clinical remission of SCC with good cosmetic results.
Aged ; Carcinoma, Squamous Cell* ; Humans ; Particle Accelerators ; Radiosurgery ; Radiotherapy ; Skin ; Skin Neoplasms ; Stereotaxic Techniques* ; Vitamin E

Various systems of computer-assisted orthopaedic surgery (CAOS) in total hip arthroplasty (THA) were reviewed. The first clinically applied system was an active robotic system (ROBODOC), which performed femoral implant cavity preparation as programmed preoperatively. Several reports on cementless THA with ROBODOC showed better stem alignment and less variance in limb-length inequality on radiographic evaluation, less incidence of pulmonary embolic events on transesophageal cardioechogram, and less stress shielding on the dual energy X-ray absorptiometry analysis than conventional manual methods. On the other hand, some studies raise issues with active systems, including a steep learning curve, muscle and nerve damage, and technical complications, such as a procedure stop due to a bone motion during cutting, requiring re-registration and registration failure. Semi-active robotic systems, such as Acrobot and Rio, were developed for ease of surgeon acceptance. The drill bit at the tip of the robotic arm is moved by a surgeon's hand, but it does not move outside of a milling path boundary, which is defined according to three-dimensional (3D) image-based preoperative planning. However, there are still few reports on THA with these semi-active systems. Thanks to the advancements in 3D sensor technology, navigation systems were developed. Navigation is a passive system, which does not perform any actions on patients. It only provides information and guidance to the surgeon who still uses conventional tools to perform the surgery. There are three types of navigation: computed tomography (CT)-based navigation, imageless navigation, and fluoro-navigation. CT-based navigation is the most accurate, but the preoperative planning on CT images takes time that increases cost and radiation exposure. Imageless navigation does not use CT images, but its accuracy depends on the technique of landmark pointing, and it does not take into account the individual uniqueness of the anatomy. Fluoroscopic navigation is good for trauma and spine surgeries, but its benefits are limited in the hip and knee reconstruction surgeries. Several studies have shown that the cup alignment with navigation is more precise than that of the conventional mechanical instruments, and that it is useful for optimizing limb length, range of motion, and stability. Recently, patient specific templates, based on CT images, have attracted attention and some early reports on cup placement, and resurfacing showed improved accuracy of the procedures. These various CAOS systems have pros and cons. Nonetheless, CAOS is a useful tool to help surgeons perform accurately what surgeons want to do in order to better achieve their clinical objectives. Thus, it is important that the surgeon fully understands what he or she should be trying to achieve in THA for each patient.
Arthroplasty, Replacement, Hip/instrumentation/*methods ; Humans ; *Robotics ; Stereotaxic Techniques ; *Surgery, Computer-Assisted

BACKGROUND: In discography performed during percutaneous endoscopic lumbar discectomy (PELD) via the posterolateral approach, it is difficult to create a fluoroscopic tunnel view because a long needle is required for discography and the guide-wire used for consecutive PELD interrupts rotation of fluoroscope. A stereotactic system was designed to facilitate the determination of the needle entry point, and the feasibility of this system was evaluated during interventional spine procedures. METHODS: A newly designed stereotactic guidance system underwent a field test application for PELD. Sixty patients who underwent single-level PELD at L4-L5 were randomly divided into conventional or stereotactic groups. PELD was performed via the posterolateral approach using the entry point on the skin determined by premeasured distance from the midline and angles according to preoperative magnetic resonance imaging (MRI) findings. Needle entry accuracy provided by the two groups was determined by comparing the distance and angle measured by postoperative computed tomography with those measured by preoperative MRI. The duration and radiation exposure for determining the entry point were measured in the groups. RESULTS: The new stereotactic guidance system and the conventional method provided similarly accurate entry points for discography and consecutive PELD. However, the new stereotactic guidance system lowered the duration and radiation exposure for determining the entry point. CONCLUSIONS: The new stereotactic guidance system under fluoroscopy provided a reliable needle entry point for discography and consecutive PELD. Furthermore, it reduced the duration and radiation exposure associated with determining needle entry.
Diskectomy ; Diskectomy, Percutaneous ; Equipment Design ; Fluoroscopy ; Humans ; Magnetic Resonance Imaging ; Needles ; Skin ; Spine ; Stereotaxic Techniques