Frameless Fractionated Gamma Knife Radiosurgery with ICON™ for Large Metastatic Brain Tumors

BACKGROUND: Recently, a new generation of gamma knife radiosurgery (GKRS) equipped with a frameless immobilization system has encouraged the use of fractionated GKRS as an increasingly favorable treatment option. We investigated the preliminary outcome of efficacy and toxicity associated with frameless fractionated gamma knife radiosurgery (FF GKRS) for the treatment of large metastatic brain tumors. METHODS: Fifteen patients with 17 lesions were treated using FF GKRS and included in this study, because of the large tumor size of more than 10 cm3. FF GKRS was performed based on a thermoplastic mask system for 3 to 5 consecutive days. RESULTS: The mean duration of clinical follow-up was 12 months (range, 4–24), and the local control rate was 100%. Tumor volume decreased in 13 lesions (76.5%), and remained stable in 4 lesions (23.5%). One patient was classified as new lesion development because of the occurrence of leptomeningeal seeding regardless of the tumor volume change. Compared with the initial volume at the time of FF GKRS, tumor volume change at the last follow-up was 62.32% ± 29.80%. Cumulative survival rate at 12 months was 93.3% ± 6.4%. One patient died during the follow-up period because of the progression of the primary disease. No patient showed radiation necrosis on the follow-up images. CONCLUSION: Daily FF GKRS by gamma knife ICON™ revealed satisfactory tumor control rate and low morbidity, despite the short follow-up period. Further prospective studies and a longer follow-up of a large cohort of patients diagnosed with brain metastases are required to elucidate the effect of FF GKRS in brain metastases.

Application of ExacTrac X-ray image guidance system to frameless stereotactic radiosurgery of intracranial tumor / 医疗卫生装备

Objective To study the setup accuracy and other factors during frameless stereotactic radiosurgery (SRS) of intracraial tumor using ExacTrac X-ray image guide system.Methods Totally 119 intracranial tumor patients from August 2014 to February 2016 underwent auto setup with infrared marker.Bilateral oblique cross field images were obtained with ExacTrac X-ray system,and went through comparison,registration and correction with the digitally reconstructed ones of the planning system.Then the translation accuracy errors at LAT,LNG and VRT directions and corresponding rotational accuracy errors were acquired,and the errors experienced extended analysis.Results The translation errors at LAT,LNG and VRT directions acquired with ExacTrac X-ray image guidance system and 6DOF couch were (0.16±0.13) mm,(0.17±0.14) mm and (0.15±0.11) mm respectively,the corresponding rotational errors were (0.21±0.15),(0.18±0.15),(0.18±0.14)° respectively,and the vector error was (0.32±0.16) mm.All of 3 translation and 3 rotational errors were in the SRS error range.Conclusion ExacTrac X-ray image guidance system combined with 6 degrees-of-freedom couch increases the treatment accuracy during frameless SRS,and thus is worthy promoting practically.

Analysis of translational errors in frame-based and frameless cranial radiosurgery using an anthropomorphic phantom / Análise dos erros de posicionamento translacionais em radiocirurgia craniana frame e frameless com uso de objeto simulador antropomórfico

Abstract Objective: To evaluate three-dimensional translational setup errors and residual errors in image-guided radiosurgery, comparing frameless and frame-based techniques, using an anthropomorphic phantom. Materials and Methods: We initially used specific phantoms for the calibration and quality control of the image-guided system. For the hidden target test, we used an Alderson Radiation Therapy (ART)-210 anthropomorphic head phantom, into which we inserted four 5mm metal balls to simulate target treatment volumes. Computed tomography images were the taken with the head phantom properly positioned for frameless and frame-based radiosurgery. Results: For the frameless technique, the mean error magnitude was 0.22 ± 0.04 mm for setup errors and 0.14 ± 0.02 mm for residual errors, the combined uncertainty being 0.28 mm and 0.16 mm, respectively. For the frame-based technique, the mean error magnitude was 0.73 ± 0.14 mm for setup errors and 0.31 ± 0.04 mm for residual errors, the combined uncertainty being 1.15 mm and 0.63 mm, respectively. Conclusion: The mean values, standard deviations, and combined uncertainties showed no evidence of a significant differences between the two techniques when the head phantom ART-210 was used.

Resumo Objetivo: Comparar os erros de posicionamento e erros residuais translacionais tridimensionais de uma radiocirurgia guiada por imagem, frame versus frameless, com uso de um objeto simulador antropomórfico. Materiais e Métodos: Para a calibração e qualidade do sistema de imagem foram utilizados objetos simuladores específicos. Para o teste hidden target foi utilizado o crânio do objeto simulador antropomórfico Alderson Radiation Therapy (ART)-210, dentro do qual foram inseridas quatro esferas metálicas de 5 mm de diâmetro como volumes alvos de tratamento. Imagens tomográficas foram realizadas com o ART-210 devidamente posicionado para ambos os métodos de imobilização. Resultados: Para o método frameless, a média foi 0,22 ± 0,04 mm para os erros setup e 0,14 ± 0,02 mm para os erros residuais, apresentando uma incerteza combinada de 0,28 mm e 0,16 mm, respectivamente. Para o método frame, a média foi 0,73 ± 0,14 mm para os erros setup e 0,31 ± 0,04 mm para os erros residuais, apresentando uma incerteza combinada de 1,15 mm e 0,63 mm, respectivamente. Conclusão: Com base nas médias, desvios-padrão e incertezas combinadas, os resultados mostraram não haver evidências de diferença significativa entre as técnicas em questão quando utilizado um objeto simulador antropomórfico craniano ART-210.

Frameless Stereotactic Aspiration for Spontaneous Intracerebral Hemorrhage and Subsequent Fibrinolysis Using Urokinase

OBJECTIVES: The optimal management of patients with spontaneous intracerebral hemorrhage (ICH) remains controversial. The aim of this study was to evaluate technical results and clinical outcomes of frameless stereotactic aspiration and fibrinolysis using urokinase performed in a single center. MATERIALS AND METHODS: The subjects of this study were 62 consecutive patients with spontaneous ICH who were treated with frameless stereotactic aspiration and subsequent fibrinolysis using urokinase between February 2009 and June 2010 in our hospital. The surgical results, procedure-related complications, and clinical outcomes were evaluated. RESULTS: A total of 62 patients were enrolled in the study. The median age was 54 years (range, 32-86). The mean initial Glasgow coma scale score was 7.7 (range 5-11). The mean initial hemorrhage volume was 43 cm3 (range 30-70). Seven patients (11.2%) died of respiratory failure (four patients), postoperative edema (two patients), and heart disease (one patient). There were seven cases of procedure-related complications (11.2%), including malpositioning of catheters (two patients), pneumocephalus (one patient), and rebleeding (four patients, 6.4%). At the three-month follow-up, a good outcome (three-month Glasgow outcome scale > 3) was noted in 32 patients (51.6%). CONCLUSIONS: Frameless stereotactic aspiration and subsequent fibrinolytic thearpy using urokinase for spontaneous ICH is a simple and safe procedure with low mortality and rebleeding rate.

Sistema auxiliar para colocar el marco estereotactico en el craneo / Auxiliary system for positioning the stereotactic frame to the skull

En neurocirugía funcional y radioneurocirugía estereotáctica, la fijación de un marco en el cráneo, permite el establecimiento de un sistema tridimensional de coordenadas, para localizar y definir con precisión los objetivos en el cerebro. El montaje se basa en la experiencia y la percepción visual del médico, pero los resultados son subjetivos y la calibración de las coordenadas del marco con respecto al cráneo no siempre es la óptima para el desarrollo del procedimiento quirúrgico. Este estudio evalúa la eficacia y la funcionalidad de un sistema auxiliar diseñado para colocar el marco estereotáctico en el cráneo. La evaluación se realiza por medio de un estudio comparativo de dos grupos de 7 pacientes cada uno sometidos a tratamiento de radioneurocirugía. En el primer grupo no es utilizado el sistema, solo en el segundo, se tomaron 165 imágenes (IRM) en promedio por cada estudio. El empleo del sistema auxiliar disminuye la variación de la inclinación y la rotación del marco con respecto al cráneo hasta un 64%, la apreciación subjetiva del médico es sustituida por una medición objetiva, obteniéndose certidumbre al posicionar el marco sobre el cráneo. Los resultados muestran que el sistema auxiliar diseñado es eficaz y funcional.

In functional neurosurgery and stereotactic radioneurosurgery, the fixation of a frame to the skull allows the establishment of a three-dimensional coordinate system, to locate and precisely defined objectives in the brain. The montage is based on experience and visual perception the doctor, the results obtained and the calibration of the coordinates of the frame with respect to the skull is not always the optimal for developing the surgical procedure. This study evaluates the effectiveness and functionality of an auxiliary system designed to collocate the stereotactic frame to the skull. The evaluation is done by means of a comparative study of two groups of 7 patients each underwent radioneurosurgery treatment. The first group is not using the system, only in the second, were performed on average 165 images (MRI) for each study. The use of auxiliary system reduces the variation of the inclination and rotation of the frame with respect to the skull by 64%, the subjective appreciation the doctor is substituted by an objective measure, thus obtaining certainty to position the frame on the skull. The results show that the auxiliary system designed is effective and functional.

Cortical Localization of Scalp Electrodes on Three-Dimensional Brain Surface Using Frameless Stereotactic Image Guidance System

BACKGROUND: The purpose of this study was to localize the cortical regions reflected by overlying scalp electrodes. METHODS: We enrolled 10 patients with epilepsy (5 males, mean age 29.7 years old). Thin slice coronal T1 weighted MR images were obtained and then scalp EEG electrodes were placed based on an international 10-20 system. Cortical locations of scalp electrodes were determined using a real-time frameless stereotactic image guidance system, Brainsight(R). RESULTS: The locations of 19 scalp electrodes were marked on the 3D rendered cortical surface of one representative patient's MRI; Fp1 (Fp2) on the anterior pole of the middle frontal gyrus, Fz on the mid-point of the interhemispheric fissure in the frontal lobe, F3 (F4) on the mid-portion of the middle frontal gyrus, F7 (F8) on the pars triangularis of the inferior frontal gyrus, Cz on the interhemispheric fissure where a lateral precentral gyrus starts, C3 (C4) scattered around postcentral gyrus, T3 (T4) on the middle temporal gyrus, P3 (P4) on the angular gyrus, Pz on the mid-point of the interhemispheric fissure in the parietal lobe, T5 (T6) on the posterior part of the inferior temporal gyrus, and O1 (O2) on the occipital pole. CONCLUSIONS: The locations of scalp electrodes were well correlated with conventional concepts of their cortical locations. The individual differences of the scalp electrode locations may be due to the different sizes and morphologies of the brains in each of the patients. Real time cortical localization of scalp electrodes using the Frameless Stereotactic Image Guidance System may provide useful information for more accurate localization of focal cerebral activity in partial epilepsy patients.

Comparative Study on Frameless Stereotactic Hematoma Aspiration versus Frame-Based Stereotactic Hematoma Aspiration in Deep Seated Intracerebral Hemorrhage: A Clinical Article / 대한뇌혈관외과학회지

OBJECTIVE: We compare the frameless stereotactic hematoma aspiration (FSA) with frame-based stereotactic hematoma aspiration (FBSA) in intracerebral hemorrhage (ICH) about operative advantage and result. MATERIAL AND METHODS: Between January 2002 and December 2002, we surgically treated 30 patients presenting with spontaneous ICH at our hospital. 15 patients underwent FBSA via Codman-Roberts-Wells system and catheter placement with urokinase infusion and drainage, and 15 patients underwent FSA and catheter placement via neuronavigator with urokinase infusion and drainage. RESULTS: The amount of remaining hematoma and removal rate were from 1 to 26 and 76% in FSA and from 2 to 55 and 60.4% in FBSA. The entry point was selected within 2.03+/-0.85 cm in a frontal direction from Kocher's point and 2.86+/-0.57 cm in lateral direction from Kocher's point and the trajectory was selected toward the distal margin of hematoma along the long axis of hematoma in FSA but the entry point was restricted within Kocher's point and the trajectory was selected toward the center of the maximum axial section of hematoma in FBSA. The mean time of operative preparation was mean 61 minutes in FSA and 78 minutes in FBSA. The number of patients not required with infusion of urokinase was 10 in FSA and 7 in FBSA. The mean duration of urokinase infusion was 3.6 day in FSA and 4.1 day in FBSA. CONCLUSION: FSA is fast, simple and effective procedure. In comparison with FBSA, FSA has advantage in selecting the entry point and the trajectory for hematoma aspiration and catheter placement, and in a less time-consuming procedure.

Fractionated Stereotactic Radiation Therapy Using Linear Accolerator in Brain Tumor and Arteriovenous Malformation

With a frame-based system, stereotactic dose of radiation is delivered to the target in one day. The patient is uncomfortable with a frame based system and the staff is forced to produce a treatment plan under time pressure. And then a single dose of radiation is delivered. Our frameless fractionated conformal stereotactic radiotherapy system uses markers, permanently placed in the head. There is more time to prepare and perform the treatment. The point reference system is a frameless system, allowing a separation in time between all of the steps in a stereotactic procedure. And these reference points allow physician precisely to set up the patient again and again. Our system is made to spare normal cells within target volume by fractionating the tumor dose. We have treated 43 patients with multifraction regimen using 6-MV linear accelerator. All patient tolerated the treatment well and no significant complication were seen. Although small in number experienced, this technique seems to be feasible and safe for treating brain tumor and vascular malformation.

Clinical Application of Frameless Stereotaxy "Viewing Wand": Its Usefulness and Limitation

The Viewing Wand is a frameless stereotactic device to provide image-based intraoperative navigation, allowing accurate neurosurgical planning and procedures. The authors applied the frameless stereotactic device called "ISG Viewing Wand" to 30 cases of intracranial lesions and evaluated for its usefulness and limitation. The Viewing Wand was used in 3 cases in conjunction with CT and 27 cases with MRI. The actual error of this system after the registration was judged by the operating surgeon to be less than 2mm in CT or MR image. The useful registrations were possible in 25(83%) out of 30 cases. But it was not useful in 5 cases, because of movement of fiducial markers in 2 cases and head movement after registration in 3 cases. In 25 cases having useful registration, the wand was helpful to localize the lesion for designing the scalp incision and bone flap, as well as the extent of surgical resection of lesions. As a whole, the viewing wand was found to be reliable and accurate. The system is a useful navigational aid that allows a direct approach to intracranial pathology without the drawbacks of application and the limitations of a frame-based stereotactic device.