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

Animals ; Macaca mulatta ; surgery ; Magnetic Resonance Imaging ; Neuronavigation ; standards ; Stereotaxic Techniques ; standards

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

An 18-year-old left-handed male harbored intractable medial temporal lobe epilepsy (MTLE) underwent fractionated gamma knife surgery (GKS) instead of open surgery, considering the mental retardation and diffuse cerebral dysfunction. GKS treatment parameters were: target volume, 8.8 cm3; total marginal dose, 24 Gy in 3 fractionations at the 50% isodose line. The patient has been free from seizures since 9 months after GKS, with notable improvement in cognitive outcome. Fractionated GKS could be considered as a safe tool for seizure control and neuropsychological improvement in patients with MTLE.
Adolescent ; Epilepsy ; Epilepsy, Temporal Lobe* ; Humans ; Intellectual Disability ; Male ; Radiosurgery* ; Seizures ; Stereotaxic Techniques ; Temporal Lobe*

An 18-year-old left-handed male harbored intractable medial temporal lobe epilepsy (MTLE) underwent fractionated gamma knife surgery (GKS) instead of open surgery, considering the mental retardation and diffuse cerebral dysfunction. GKS treatment parameters were: target volume, 8.8 cm3; total marginal dose, 24 Gy in 3 fractionations at the 50% isodose line. The patient has been free from seizures since 9 months after GKS, with notable improvement in cognitive outcome. Fractionated GKS could be considered as a safe tool for seizure control and neuropsychological improvement in patients with MTLE.
Adolescent ; Epilepsy ; Epilepsy, Temporal Lobe* ; Humans ; Intellectual Disability ; Male ; Radiosurgery* ; Seizures ; Stereotaxic Techniques ; Temporal Lobe*

Surgical navigation system is a system that processes medical images by computer graphics and image processing technique, reconstructs 2D or 3D medical image models. It builds a real-time loop among the eyes of doctor, the surgical device and the head of patient by several of space localization technique, so that to realize displaying the localization of surgical devices real-time. The history and research status of surgical navigation system is summarized and the system configuration and the key techniques are expatiated emphatically in this paper. The key techniques include localization in space, image processing and displaying technique, system registration technique and head location technique. At last the progress direction of navigation systems is given.
Computer Graphics ; Humans ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional ; Neuronavigation ; methods ; Stereotaxic Techniques ; Surgery, Computer-Assisted ; methods

In this paper, we introduce a slip-coordinate system that applied in the extra-cranial stereotactic radiosurgery treatment system (by the name of extra-cranial X-Knife), and make an analysis about the correlative formula.
Equipment Design ; Humans ; Immobilization ; Radiosurgery ; instrumentation ; methods ; Radiotherapy, Computer-Assisted ; Stereotaxic Techniques ; instrumentation ; Tomography, X-Ray Computed

In order to analyze the image noise effect on the results of Gamma knife dosimetry parameter test, we tested the dosimetry parameters of the Gamma knives according to GBZ 168-2005. Radiological protection standards of X (gamma)-ray stereotactic radiosurgery for head treatment. Dose analysis software was applied to examine the testing film before and after image denoising, and SPSS 11.0 software was used for statistical analysis. The results showed that there was a significant difference in the results of the maximum deviation between radiation field size and its nominal value (t = 7.600, P < 0.01) and the radiation field's penumbra region width of collimators also had significantly different sizes (t = 5.334, P < 0.01) before and after image denoising. This study indicated that the image noise could influence the results of testing Gamma knife dosimetry parameters, so as to cause deviations.
Algorithms ; Artifacts ; Gamma Rays ; Head ; surgery ; Humans ; Radiometry ; instrumentation ; Radiosurgery ; instrumentation ; Radiotherapy Planning, Computer-Assisted ; methods ; Stereotaxic Techniques

OBJECTIVETo evaluate the clinical value of stereotactic radiosurgery (SRS) for uveal melanoma.

METHODSFrom Jan, 1996 to March, 2004, 16 patients with uveal melanoma were treated with SRS, two by one session (35 Gy, 25 Gy) and fourteen by fractionated SRS (30-55 Gy/2-4F/4-16D). The follow-up period ranged from 3 to 100 months (median: 66 months).

RESULTSAll 16 patients were still alive though all were blind in the diseased eye during recent follow-up. Local control rate was 93.4%, 5-year survival rate of 13 patients who have been followed for more than 5 years, was 100% (13/13). However, 7 patients received eyeball enucleation due to corneal ulcer (n = 2), suspicion for uncontrolled tumor (n = 2) and secondary glaucoma (n = 3). One patient developed distant metastasis, though still alive.

CONCLUSIONFractionated radiosurgery is safe and effective for uveal melanoma. It is indicated for lesions of limited size (longest diameter < 20 mm, depth < 15 mm) located in the posterior pole or behind the equator at the back of the eyeball.

Adult ; Aged ; Eye Enucleation ; methods ; Female ; Humans ; Male ; Melanoma ; surgery ; Middle Aged ; Radiosurgery ; Stereotaxic Techniques ; Uveal Neoplasms ; surgery

Image guided surgery (IGS) means that computers are used for modeling the position of patients and providing the surgeons with image guidance for invasive procedures. In this paper, we introduce the composition and the work flow of IGS, analyze the process and principle of Registration, which is regarded as a process to combine the actual position of patients and the visual position of models. Seeing that the precision of the registration determines the precision of the IGS system directly, we conduct a study on the registration algorithm precision, feasibility as well as robustness. Combined with the actual requirements in clinical IGS, we also analyze the influence of changes in the number and position of markers on registration precision.
Algorithms ; Humans ; Image Processing, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; methods ; Neuronavigation ; Pattern Recognition, Automated ; methods ; Stereotaxic Techniques ; Surgery, Computer-Assisted