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Motohiro Hayashi, Mikhail F Chernov,
Samuel M Lipski,
Noriko Tamura,
Shoji Yomo,
Ayako Horiba,
Shyunsuke Tsuzuki,
Masahiro Izawa,
Yoshikazu Okada,
Yoshihiro Muragaki,
Hiroshi Iseki,
Pavel Ivanov,
Jean Régis,
Kintomo Takakura
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ABSTRACT: Background: Gamma Knife surgery (GKS) should be considered a standard treatment option for small and medium-sized vestibular schwannomas (VSs). It results in a tumor control rate similar to that seen with microsurgery and provides better preservation of facial nerve function and hearing. Methods: From December 2002 to April 2011, a total of 260 patients with VS underwent GKS using Leksell Gamma Knife model 4C with an automatic positioning system. There were 30 Koos stage I tumors, 112 stage II, 100 stage III, and 18 stage IV. All patients were treated with the use of high-resolution magnetic resonance imaging; creation of the highly precise conformal and selective multi-isocenter dose planning with small collimators, carefully sparing adjacent cranial nerves of any excessive irradiation; and creation of a wide 80 % isodose area within the tumor while applying a low marginal dose (mean 11.9 Gy) at the 50 % isodose line. Results: Among 182 patients who were followed for more than 3 years after treatment, the tumor control and shrinkage rates were 98.4 % and 76.4 %, respectively. Volume reduction of >50 % was marked in 54.9 % of VSs. Preservation of facial nerve function and hearing at the pretreatment level was noted in 97.8 % and 87.9 %, respectively. There was marked improvement of facial nerve function and hearing after GKS in 2.2 % and 3.8 %, respectively. There was no major morbidity. Conclusion: Due to contemporary technological and metho-dological achievements GKS can be focused not only on growth control but on shrinking the VS, with possible reversal of the neurological deficit.
Acta neurochirurgica. Supplement 01/2013; 116:25-36.
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Mikhail F Chernov,
Yuko Ono,
Kayoko Abe,
Masao Usukura,
Motohiro Hayashi,
Masahiro Izawa,
Sergey V Diment,
Pavel I Ivanov,
Yoshihiro Muragaki,
Hiroshi Iseki,
Tomokatsu Hori,
Yoshikazu Okada,
Kintomo Takakura
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ABSTRACT: A number of intracranial tumors demonstrate some degree of enlargement after stereotactic radiosurgery (SRS). It necessitates differentiation of their regrowth and various treatment-induced effects. Introduction of low-dose standards for SRS of benign neoplasms significantly decreased the risk of the radiation-induced necrosis after -management of schwannomas and meningiomas. Although in such cases a transient increase of the mass volume within several months after irradiation is rather common, it usually followed by spontaneous shrinkage. Nevertheless, distinguishing tumor recurrence from radiation injury is often required in cases of malignant parenchymal brain neoplasms, such as metastases and gliomas. The diagnosis is frequently complicated by histopathological heterogeneity of the lesion with coexistent viable tumor and treatment-related changes. Several neuroimaging modalities, namely structural magnetic resonance imaging (MRI), diffusion-weighted imaging, diffusion tensor imaging, perfusion computed tomography (CT) and MRI, single-voxel and multivoxel proton magnetic resonance spectroscopy as well as single photon emission CT and positron emission tomography with various radioisotope tracers, may provide valuable diagnostic information. Each of these methods has advantages and limitations that may influence its usefulness and accuracy. Therefore, use of a multimodal radiological approach seems reasonable. Addition of functional and metabolic neuroimaging to regular structural MRI investigations during follow-up after SRS of parenchymal brain neoplasms may permit detailed evaluation of the treatment effects and early prediction of the response. If tissue sampling of irradiated intracranial lesions is required, it is preferably performed with the use of metabolic guidance. In conclusion, differentiation of tumor progression and radiation-induced effects after intracranial SRS is challenging. It should be based on a complex evaluation of the multiple clinical, radiosurgical, and radiological factors.
Acta neurochirurgica. Supplement 01/2013; 116:193-210.
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ABSTRACT: The availability of advanced computer-aided robotized devices for the Gamma Knife (i.e., an automatic positioning system and PerfeXion) resulted in significant changes in radiosurgical treatment strategy. The possibility of applying irradiation precisely and the significantly improved software for treatment planning led to the development of the original concept of robotic Gamma Knife microradiosurgery, which is comprised of the following: (1) precise irradiation of the lesion with regard to conformity and selectivity; (2) intentional avoidance of excessive irradiation of functionally important anatomical structures, particularly cranial nerves, located both within the target and in its vicinity; (3) delivery of sufficient radiation energy to the tumor with a goal of shrinking it while keeping the dose at the margins low enough to prevent complications. Realization of such treatment principles requires detailed evaluation of the microanatomy of the target area, which is achieved with an advanced neuroimaging protocol. From 2003, we applied the described microradiosurgical concept in our clinic for patients with benign skull base tumors. Overall, 75 % of neoplasms demonstrated shrinkage, and 47 % showed ≥50 % and more volume reduction. Treatment-related complications were encountered in only 6 % of patients and were mainly related to transient cranial nerve palsy. Just 2 % of neoplasms showed regrowth after irradiation. In conclusion, applying the microradiosurgical principles based on advanced neuroimaging and highly precise treatment planning is beneficial for patients, providing a high rate of tumor shrinkage and a low morbidity rate.
Acta neurochirurgica. Supplement 01/2013; 116:5-15.
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Motohiro Hayashi, Mikhail F Chernov,
Noriko Tamura,
Shoji Yomo,
Manabu Tamura,
Ayako Horiba,
Masahiro Izawa,
Yoshihiro Muragaki,
Hiroshi Iseki,
Yoshikazu Okada,
Pavel Ivanov,
Jean Régis,
Kintomo Takakura
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ABSTRACT: Background: Gamma Knife radiosurgery (GKS) is currently performed with 0.1 mm preciseness, which can be designated microradiosurgery. It requires advanced methods for visualizing the target, which can be effectively attained by a neuroimaging protocol based on plain and gadolinium-enhanced constructive interference in steady state (CISS) images. Methods: Since 2003, the following thin-sliced images are routinely obtained before GKS of skull base lesions in our practice: axial CISS, gadolinium-enhanced axial CISS, gadolinium-enhanced axial modified time-of-flight (TOF), and axial computed tomography (CT). Fusion of "bone window" CT and magnetic resonance imaging (MRI), and detailed three-dimensional (3D) delineation of the anatomical structures are performed with the Leksell GammaPlan (Elekta Instruments AB). Recently, a similar technique has been also applied to evaluate neuroanatomy before open microsurgical procedures. Results: Plain CISS images permit clear visualization of the cranial nerves in the subarachnoid space. Gadolinium-enhanced CISS images make the tumor "lucid" but do not affect the signal intensity of the cranial nerves, so they can be clearly delineated in the vicinity to the lesion. Gadolinium-enhanced TOF images are useful for 3D evaluation of the interrelations between the neoplasm and adjacent vessels. Fusion of "bone window" CT and MRI scans permits simultaneous assessment of both soft tissue and bone structures and allows 3D estimation and correction of MRI distortion artifacts. Conclusion: Detailed understanding of the neuroanatomy based on application of the advanced neuroimaging protocol permits performance of highly conformal and selective radiosurgical treatment. It also allows precise planning of the microsurgical procedures for skull base tumors.
Acta neurochirurgica. Supplement 01/2013; 116:167-178.
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ABSTRACT: From 1993 to 2011, a total of 3,095 patients with brain metastases underwent Gamma Knife radiosurgery (GKS) at Tokyo Women's Medical University. Follow-up information on 2,283 of these patients was available for retrospective analysis. The cases were separated into three groups according to the treatment period, the model of the Gamma Knife used, main goals of treatment, and technical nuances of radiosurgery. In the latest cohort of patients treated with the Leksell Gamma Knife model 4C with automatic positioning system, an optimized treatment strategy was applied. It was based on highly selective dose planning, with the use of multiple small isocenters located within the bulk of the mass, which was done for prevention of the excessive irradiation of the perilesional brain and avoidance of its posttreatment edema. In cases of large cystic tumors, selective coverage of the contrast-enhancing capsule with chain-like application of multiple small isocenters was done. Introduction of the new treatment strategy did not affect the 1-year tumor control rate, which was consistently >90 %. However, it did result in a statistically significant reduction of severe posttreatment peritumoral brain edema (from 15.5 % to 6.3 %; P < 0.0001). In conclusion, recent technical and methodological achievements of GKS seemingly do not affect its high efficacy in cases of brain metastasis with regard to tumor control. However, it may result in a prominent reduction of treatment-associated -morbidity, which is particularly important in patients with large and/or critically located neoplasm.
Acta neurochirurgica. Supplement 01/2013; 116:63-69.
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ABSTRACT: Background: Optimal management of metastatic brain disease requires precise detection and detailed characterization of all intracranial lesions. Methods: We analyzed an experience with 3200 brain MRI investigations performed at 1.5 T and 3.0 T for identification and/or evaluation of intracranial metastases. Usually axial T1- and T2-weighted images and contrast-enhanced T1-weighted images in axial and coronal and/or sagittal projections were obtained. Fluid-attenuated inversion recovery and diffusion-weighted imaging were sometimes used as well. Routinely, 0.2 mmol/kg of gadoteridol (ProHance®) was administered intravenously, but the dose was reduced to 0.1 mmol/kg in elderly patients or in patients with mild renal dysfunction. Findings: Magnetic resonance imaging (MRI) provided excellent information on tumor location; interrelations with functionally important intracranial structures; type of growth; vascularity; recent, old or multiple hemorrhages within or in the vicinity of the mass; presence of peritumoral edema; necrotic changes; subarachnoid dissemination; meningeal carcinomatosis. However, without administration of gado-teridol or without contrast enhancement, small metastatic tumors could not be reliably distinguished from brain lacunes. Some metastases (malignant melanoma, thyroid cancer, endocrine carcinoma, small cell lung carcinoma) may demonstrate specific neuroimaging features. Non-metastatic -multiple brain lesions caused by vascular, inflammatory, demyelinative or lymphoproliferative diseases require a thorough differential diagnosis with metastatic brain tumors based not only on neuroimaging but on additional analysis of various clinical data. Conclusion: Contemporary MRI techniques provide excellent options for detection, detailed characterization, and differential diagnosis of metastatic brain tumors, which is extremely important when choosing the optimal treatment strategy, particularly with Gamma Knife radiosurgery.
Acta neurochirurgica. Supplement 01/2013; 116:159-166.
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Mikhail F Chernov,
Hidetoshi Kasuya,
Kotaro Nakaya,
Koichi Kato,
Yuko Ono,
Shigetoshi Yoshida,
Yoshihiro Muragaki,
Takashi Suzuki,
Hiroshi Iseki,
Osami Kubo,
Tomokatsu Hori,
Yoshikazu Okada,
Kintomo Takakura
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ABSTRACT: The main goal of the present study was evaluation of proton magnetic resonance spectroscopy (¹H-MRS) in diagnosis of histopathologically aggressive intracranial meningiomas.
Single-voxel ¹H-MRS of 100 intracranial meningiomas was performed before their surgical resection. Investigated metabolites included mobile lipids, lactate, alanine, N-acetylaspartate (NAA), and choline-containing compounds (Cho). According to criteria of World Health Organization (WHO) 82 meningiomas were assigned histopathological grade I, 11 grade II, and 7 grade III. The MIB-1 index varied from 0% to 27.3% (median, 1.6%). In 43 cases tight adhesion of the tumor to the pia mater or brain tissue was macroscopically identified at surgery. The consistency of 49 meningiomas was characterized as soft, 26 as hard, and 25 as mixed.
No one metabolic parameter had statistically significant association with histopathological grade and subtype, invasive growth, and consistency of meningioma. Univariate statistical analysis revealed greater ¹H-MRS-detected Cho content (P=0.0444) and lower normalized NAA/Cho ratio (P=0.0203) in tumors with MIB-1 index 5% and more. However, both parameters lost their statistical significance during evaluation in the multivariate model along with other clinical and radiological variables. It was revealed that non-benign histopathology of meningioma (WHO grade II/III) is mainly predicted by irregular shape (P=0.0076) and large size (P=0.0316), increased proliferative activity by irregular shape (P=0.0056), and macroscopically invasive growth by prominent peritumoral edema (P=0.0021).
While ¹H-MRS may be potentially used for the identification of meningiomas with high proliferative activity, it, seemingly, could not add substantial diagnostic information to other radiological predictors of malignancy in these tumors.
Clinical neurology and neurosurgery 12/2010; 113(3):202-12. · 1.30 Impact Factor
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Mikhail F Chernov,
Taku Ochiai,
Yuko Ono,
Yoshihiro Muragaki,
Fumitaka Yamane,
Takaomi Taira,
Takashi Maruyama,
Masahiko Tanaka,
Hiroshi Iseki,
Osami Kubo,
Yoshikazu Okada,
Tomokatsu Hori,
Kintomo Takakura
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ABSTRACT: A retrospective study was conducted for evaluation of the role of single-voxel proton magnetic resonance spectroscopy (1H-MRS) in preoperative investigation of patients with mesial temporal lobe epilepsy (MTLE). Eighteen cases, including both non-lesional and lesional MTLE, were analyzed. Selective amygdalohippocampectomy was performed in 8 cases, selective amygdalohippocampectomy combined with lesionectomy in 6 cases, lesionectomy in 3 cases, and anterior temporal lobe resection in one case. The length of follow-up varied from 24 to 71 months (median, 35 months). Before surgery, (1)H-MRS disclosed decrease of N-acetylaspartate (NAA) content (P=0.01) and more frequent (P=0.07) presence of lactate (Lac) on the side of the epileptogenic zone. Decrease of NAA content below 0.75 and/or unilateral presence of Lac provided 86% (95% CI: 68%-100%) lateralization accuracy. Metabolic parameters did not differ in subgroups with hippocampal sclerosis and brain tumors. On the long-term follow-up 12 patients (67%) were free of disabling seizures. There was a trend (P=0.05) for worse seizure outcome in cases with significant bilateral metabolic alterations characterized by predominance of choline-containing compounds' peak on 1H-MR spectra on both sides. In conclusion, 1H-MRS-detected reduction of NAA content and unilateral presence of Lac in the mesial temporal lobe structures may serve as additional diagnostic clues for lateralization of the epileptogenic zone in MTLE. Metabolic imaging has limited usefulness for differentiation of the hippocampal sclerosis and low-grade intraaxial brain tumor. Presence of significant bilateral metabolic alterations in the mesial temporal lobe structures is associated with worse postoperative seizure control.
Journal of the neurological sciences 08/2009; 285(1-2):212-9. · 2.32 Impact Factor
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Mikhail F Chernov,
Kotaro Nakaya,
Hidetoshi Kasuya,
Koichi Kato,
Yuko Ono,
Shigetoshi Yoshida,
Ryoichi Nakamura,
Takashi Suzuki,
Yoshihiro Muragaki,
Hiroshi Iseki,
Osami Kubo,
Tomokatsu Hori,
Kintomo Takakura
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ABSTRACT: The objective of the present study was metabolic characterization of the peritumoral brain in the vicinity of meningiomas using proton magnetic resonance spectroscopy ((1)H-MRS). Data of long-echo (TR: 2000 ms, TE: 136 ms) single-voxel spectroscopic investigations were obtained during preoperative examination of 81 patients (19 men and 62 women; mean age, 56.5 years). Twenty-seven neoplasms were disclosed incidentally. Moderate-to-severe peritumoral edema was presented in 20 cases. Invasive growth of the tumor was macroscopically identified during surgery in 35 cases. Analyzed metabolites included N-acetylaspartate (NAA), choline-containing compounds (Cho), mobile lipids (Lip) and lactate (Lac). Compared to distant normal-appearing white matter (1)H-MRS of the brain in the vicinity of meningiomas disclosed statistically significant decrease of NAA content (P=0.0019). Investigated metabolic parameters depended on the presence of invasive tumor growth and prominent peritumoral edema, as well as on the size of the neoplasm, its location, and the patient's age. More severe (1)H-MRS-detected peritumoral metabolic abnormalities associated with invasive growth of meningioma might be used for its prediction. The presence of meningioma-related neurological symptoms was mainly determined by the size of the tumor, while might be also associated with lower normalized NAA/Cho ratio and more frequent presence of a Lip peak in the peritumoral brain. In conclusion, decrease of NAA content constitutes the most prominent (1)H-MRS-detected brain abnormality in the vicinity of intracranial meningiomas. Peritumoral spectroscopic alterations are determined by a variety of factors, can be predictive for invasive tumor growth and may correspond to presented neurological symptoms.
Journal of the neurological sciences 07/2009; 284(1-2):168-74. · 2.32 Impact Factor
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Mikhail F Chernov,
Yoshihiro Muragaki,
Taku Ochiai,
Takaomi Taira,
Yuko Ono,
Masao Usukura,
Takashi Maruyama,
Kotaro Nakaya,
Ryoichi Nakamura,
Hiroshi Iseki,
Osami Kubo,
Tomokatsu Hori,
Kintomo Takakura
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ABSTRACT: Comparative evaluation of diagnostic efficacy of stereotactic brain biopsy performed with and without additional use of spectroscopic imaging ((1)H-MRS) for target selection was done.
From 2002 to 2006, 30 patients with parenchymal brain lesions underwent (1)H-MRS-supported frame-based stereotactic biopsy, whereas in 39 others MRI-guided technique was used. Comparison of diagnostic yield of the procedure in these two groups was performed. Additionally, the diagnostic accuracy was evaluated in 37 lesions, which were surgically resected within 1 month thereafter.
Stereotactic biopsy permitted establishment of a definitive histopathological diagnosis in 57 cases and diagnosis of low-grade glioma without specific tumor typing in 8 cases. In 4 cases tissue sampling was non-diagnostic. In 5 out of 8 cases with incomplete diagnosis and in all non-diagnostic cases target selection was performed without the use of (1)H-MRS (P=0.2073). The diagnostic yields of (1)H-MRS-supported and MRI-guided procedures were 100% and 90%, respectively (P=0.1268). Comparison of the histopathological diagnoses after stereotactic biopsy and surgical resection revealed complete diagnostic agreement in 13 cases, minor disagreement in 14 cases, and major disagreement in 10 cases. Among these last 10 cases, initial undergrading of non-enhancing WHO grade III gliomas was the most common (7 cases). The diagnostic accuracy of (1)H-MRS-supported and MRI-guided procedures was 67% and 79%, respectively (P=0.4756).
While in the present study the diagnostic yield of (1)H-MRS-supported frame-based stereotactic brain biopsy was 100%, its statistically significant diagnostic advantages over MRI-guided technique were not proved. Optimal selection of the spectroscopic target for tissue sampling remains unclear.
Clinical neurology and neurosurgery 06/2009; 111(6):527-35. · 1.30 Impact Factor
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Motohiro Hayashi, Mikhail F Chernov,
Takaomi Taira,
Taku Ochiai,
Kotaro Nakaya,
Noriko Tamura,
Shinichi Goto,
Shoji Yomo,
Nobuo Kouyama,
Yoko Katayama,
Yoriko Kawakami,
Masahiro Izawa,
Yoshihiro Muragaki,
Ryoichi Nakamura,
Hiroshi Iseki,
Tomokatsu Hori,
Kintomo Takakura
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ABSTRACT: To evaluate outcomes after pituitary radiosurgery in patients with post-stroke thalamic pain syndrome.
From 2002 to 2006, 24 patients with thalamic pain syndrome underwent pituitary radiosurgery at Tokyo Women's Medical University and were followed at least 12 months thereafter. The radiosurgical target was defined as the pituitary gland and its connection with the pituitary stalk. The maximum dose varied from 140 to 180 Gy. Mean follow-up after treatment was 35 months (range, 12-48 months).
Initial pain reduction, usually within 48 h after radiosurgery, was marked in 17 patients (71%). However, in the majority of cases the pain recurred within 6 months after treatment, and at the time of the last follow-up examination durable pain control was marked in only 5 patients (21%). Ten patients (42%) had treatment-associated side effects. Anterior pituitary abnormalities were marked in 8 cases and required hormonal replacement therapy in 3; transient diabetes insipidus was observed in 2 cases, transient hyponatremia in 1, and clinical deterioration due to increase of the numbness severity despite significant reduction of pain was seen once.
Pituitary radiosurgery for thalamic pain results in a high rate of initial efficacy and is accompanied by acceptable morbidity. It can be used as a primary minimally invasive management option for patients with post-stroke thalamic pain resistant to medical therapy. However, in the majority of cases pain recurrence occurs within 1 year after treatment.
International Journal of Radiation OncologyBiologyPhysics 12/2007; 69(3):852-7. · 4.11 Impact Factor
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ABSTRACT: Outcome of urgent reoperation for major regional complication after removal of intracranial tumor was evaluated retrospectively in 100 consecutive patients treated since 1983. Urgent reoperation was performed from 3 to 240 hours (mean 74 hours) after primary surgery for 32 meningiomas, 23 pituitary adenomas, 22 gliomas, 13 vestibular schwannomas, and 10 other intracranial neoplasms. Mean Glasgow Coma Scale (GCS) score before reoperation was 8. Brain edema was the most frequent operative finding at reoperation (31 patients), followed by extradural hematoma (25) and brain ischemia (24). Removal of various types of intracranial hematomas was the most common surgical procedure at reoperation (47 cases). Final outcome was considered favorable in 54 patients, who were discharged without major neurological deficit, and unfavorable in 46, with severe disability or vegetative state in four and death in 42. Multivariate analysis showed statistically significant association with the outcome for histological type of the tumor (p < 0.0001), clinical state at admission (p < 0.001), GCS score before urgent reoperation (p = 0.001), time interval between primary surgery and urgent reoperation (p < 0.01), and patient age (p < 0.05). Therefore, the outcome after urgent reoperation due to major regional complications after removal of intracranial tumor is determined mainly by the clinical condition of the patient and characteristics of the tumor, and less influenced by the type of complication.
Neurologia medico-chirurgica 06/2007; 47(6):243-8; discussion 248-9. · 0.61 Impact Factor
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ABSTRACT: The objective of this retrospective study was evaluation of the outcome after stereotactic radiosurgery (SRS) in patients with intracranial metastases and poor performance status.
Forty consecutive patients with metastatic brain tumors and Karnofsky performance scale (KPS) scores < or =50 (mean, 43 +/- 8; median, 40) treated with SRS were analyzed. Poor performance status was caused by presence of intracranial metastases in 28 cases (70%) and resulted from uncontrolled extracerebral disease in 12 (30%).
Survival after SRS varied from 3 days to 11.5 months (mean, 3.8 +/- 2.9 months; median, 3.3 months). Survival probability constituted 0.50 +/- 0.07 at 3 months and 0.20 +/- 0.05 at 6 months posttreatment. Cause of low KPS score (p = 0.0173) and presence of distant metastases beside the brain (p = 0.0308) showed statistically significant associations with overall survival in multivariate Cox proportional hazards regression analysis. Median survival was 6.0 months if low KPS score was caused by cerebral disease and distant metastases in regions beyond the brain were absent, 3.3 months if low KPS score was caused by cerebral disease and distant metastases in regions beyond the brain were present, and 1.0 month if poor performance status resulted from extracerebral disease.
Identification of the cause of low KPS score (cerebral vs. extracerebral) in patients with metastatic brain tumor(s) may be important for prediction of the outcome after radiosurgical treatment. If poor patient performance status without surgical indications is caused by intracranial tumor(s), SRS may be a reasonable treatment option.
International Journal of Radiation OncologyBiologyPhysics 04/2007; 67(5):1492-8. · 4.11 Impact Factor
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ABSTRACT: Spectroscopic imaging can be helpful for the noninvasive identification of parenchymal brain tumors. The objective of the present study was the characterization of the metabolic profile of intracranial metastases, based on proton magnetic resonance spectroscopy (MRS).
One hundred and four metastatic brain tumors were evaluated by long-echo (TR, 2000 ms; TE, 136 ms) single-voxel volume-selected proton MRS. In 83 patients the tumor fraction within the MRS voxel constituted more than 50%.
Compared to normal brain, the tumors showed statistically significant decreases of N-acetylaspartate (P < 0.0001), creatine (P < 0.0001), and the [NAA]/choline-containing compounds ratio (P < 0.0001), increases of [Cho] (P < 0.0001) and the mobile lipids/[Cr] ratio (P < 0.0001) and the lactate/[Cr] ratio (P < 0.05), and the more frequent presence of [Lip] (P < 0.0001) and [Lac] (P < 0.0001) resonances. However, the majority of these differences were lost when data for patients whose tumor fraction within the MRS voxel constituted less than 50% were analyzed separately. Determination of the predominant metabolite peak on the MR spectrum [NAA, Cho, Lip] permitted us to define three general metabolic patterns of brain metastases, which, showed statistically significant associations with the size of the neoplasm (P < 0.001), type of its contrast enhancement (P < 0.01), and the extent of perilesional edema (P < 0.05).
Proton MRS can define metabolically different subsets of metastatic brain tumors, and these characteristics should be taken into consideration during the differential diagnosis of parenchymal brain lesions.
International Journal of Clinical Oncology 10/2006; 11(5):375-84. · 1.41 Impact Factor
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ABSTRACT: Evaluation of results of the neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle.
From 2001 to 2004, 23 patients (mean age, 30.6 yr) with tumors located in the pineal region or posterior third ventricle underwent neurofiberscopic biopsy with simultaneous third ventriculostomy. The procedure was indicated for verification of the histological diagnosis of the neoplasm, which was planned to be treated by radiotherapy and/or chemotherapy without open surgery (eight patients), establishment of the pathological diagnosis for further choice of the most appropriate treatment strategy (11 patients), differentiation of the recurrent neoplasm and radiation necrosis (two patients), and decompression of the large tumor-associated cyst (two patients). In six previously shunted patients, substitution of the ventriculoperitoneal shunt on the third ventricle stoma was performed.
There was no postoperative mortality or permanent morbidity. In all cases, the obtained tissue sample was sufficient for pathological diagnosis. Transient postoperative complications included fever (15 patients), nausea and vomiting (three patients), and diplopia (one patient). On the long-term follow-up, delayed third ventricular stoma failure caused by tumor regrowth and scar formation was found in one patient, and dissemination of the malignant glioma through the subarachnoid space was found in another patient.
Neurofiberscopic biopsy represents a useful method for sampling of tumors of the pineal region and posterior third ventricle, which can be effectively used in both previously shunted and shunt-free patients.
Neurosurgery 09/2006; 59(2):267-77; discussion 267-77. · 2.79 Impact Factor
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ABSTRACT: Various types of intracranial metastases exhibit different growth patterns, which can be reflected in their metabolic characteristics and investigated noninvasively by proton magnetic resonance spectroscopy (1H-MRS). The objective of the present study was comparison of the 1H-MRS-detected metabolic parameters in brain metastases of different origin. Twenty-five patients (15 men and 10 women; mean age, 62.0 years) with single, previously nontreated metastatic brain tumors were investigated by long-echo single-voxel volume-selected 1H-MRS. The primary cancer was located in the lungs (10 cases), colon and rectum (8 cases), breast (3 cases), kidney (2 cases), prostate (1 case), and cardiac muscle (1 case). Comparison of clinical and radiological variables, including type of tumor contrast enhancement and extension of peritumoral edema, did not disclose statistically significant differences in metastatic brain tumors of different origin. At the same time, comparison of 1H-MRS-detected metabolic characteristics revealed that metastases of colorectal carcinoma have greater content of mobile lipids (Lip) compared to other neoplasms. In conclusion, high Lip content in the viable brain metastases of colorectal carcinoma can be used as an additional diagnostic clue for noninvasive identification of these tumors and should be taken into consideration in cases of 1H-MRS-based differentiation of their recurrence and radiation-induced necrosis after radiosurgical or radiotherapeutic treatment.
Brain Tumor Pathology 02/2006; 23(1):35-40. · 1.19 Impact Factor
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ABSTRACT: Multivoxel proton magnetic resonance spectroscopy (MRS) was used for differentiation of radiation-induced necrosis and tumor recurrence after gamma knife radiosurgery for intracranial metastases in 33 consecutive cases. All patients presented with enlargement of the treated lesion, increase of perilesional brain edema, and aggravation or appearance of neurological signs and symptoms on average 9.3 +/- 4.9 months after primary treatment. Metabolic imaging defined four types of lesions: pure tumor recurrence (11 cases), partial tumor recurrence (11 cases), radiation-induced tumor necrosis (10 cases), and radiation-induced necrosis of the peritumoral brain (1 case). In 1 patient, radiation-induced tumor necrosis was diagnosed 9 months after radiosurgery; however, partial tumor recurrence was identified 6 months later. With the exception of midline shift, which was found to be more typical for radiation-induced necrosis (P < 0.01), no one clinical, radiologic, or radiosurgical parameter either at the time of primary treatment or at the time of deterioration showed a statistically significant association with the type of the lesion. Proton MRS-based diagnosis was confirmed histologically in all surgically treated patients (7 cases) and corresponded well to the clinical course in others. In conclusion, multivoxel proton MRS is an effective diagnostic modality for identification of radiation-induced necrosis and tumor recurrence that can be used for monitoring of metabolic changes in intracranial neoplasms after radiosurgical treatment. It can be also helpful for differentiation of radiation-induced necrosis of the tumor and that of the peritumoral brain, which may have important clinical and medicolegal implications.
Brain Tumor Pathology 01/2006; 23(1):19-27. · 1.19 Impact Factor
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ABSTRACT: We have developed scaled suction to facilitate the measurement of aneurysm neck width and tumor size during operations.
We constructed a new suction device scaled every 1 mm from the tip to 3 cm and every 5 mm from 3 to 5 cm. The scaled suction devices have been used in 50 aneurysm and brain tumor operations.
The new suction device permits easy measurement of aneurysm neck width, tumor size, the extent of internal decompression of tumor, and depth from the surface of the brain to the lesion.
Our scaled suction device is a simple and useful navigator for continuously measuring intraoperative variables such as lesion size and distance between the lesion and the surrounding vital structures.
Neurosurgery 11/2005; 57(4 Suppl):E413; discussion E413. · 2.79 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate an original neurofiberscope-guided strategy for the management of slit-ventricle syndrome that occurs after shunt placement.
Between 1995 and 2003 15 patients with slit-ventricle syndrome (mean age 14.2 years) underwent endoscopic third ventriculostomy (ETV) and shunt removal. During the initial surgical procedure a neurofiberscope with a small outer diameter was inserted along the shunt tube into the collapsed ventricle for endoscopically controlled removal of the ventricular catheter and evaluation of brain compliance. If the latter was sufficiently preserved, primary ETV and shunt removal were performed (four cases). If brain compliance seemed to be significantly reduced, endoscopically controlled replacement of the ventricular catheter and implantation of the Codman-Hakim programmable valve shunt device were performed (11 cases). In these patients, delayed ETV and shunt removal were performed later (mean period of 16.3 months). No medical or surgical complications occurred in any case. Follow up ranged from 6 to 84 months (mean 31.1 months; median 22 months). All patients became shunt independent and 13 became symptom free. Overall, the size of the ventricles returned to normal in five cases, became slightly dilated in nine, and moderately dilated in one.
Neurofiberscope-guided treatment of slit-ventricle syndrome involving shunt removal and ETV appears to be beneficial; all patients in this series were symptom free and shunt independent at the end of follow up.
Journal of Neurosurgery 05/2005; 102(3 Suppl):260-7. · 2.96 Impact Factor
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Journal of Neurosurgery 03/2005; 102(2):402-3; author reply 403. · 2.96 Impact Factor
