| 1. |
- Antonsson, Johan, et al.
(författare)
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Diffuse reflectance spectroscopy measurements for tissue type discrimination during deep brain stimulation
- 2008
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Ingår i: Journal of neural engineering. - : IOP Publishing. - 1741-2560 .- 1741-2552. ; 5:2, s. 185-190
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Tidskriftsartikel (refereegranskat)abstract
- Diffuse reflectance spectroscopy as a method for improving intracerebral guidance during functional neurosurgery has been investigated. An optical probe was developed for measurements during stereotactic and functional neurosurgery in man. The aim of the study was to investigate the spectral differences between white and grey matter and between white matter and functional targets. Diffuse reflectance spectroscopy measurements in ten patients were recorded at incremental steps towards and in three different functional targets (STN, GPi and Zi). The recorded spectra along the trajectory were sorted into white or grey matter, based on preoperative MRI images or the recorded spectral shape and intensity. The difference between tissue types was calculated as a quotient. Significant intensity differences between white and grey matter were found to be at least 14% (p < 0.05) and 20% (p < 0.0001) for MRI and spectral-sorted data respectively. The reflectance difference between white matter and the functional targets of GPi was higher than for STN and Zi. The results indicate that diffuse reflectance spectroscopy has a potential to be developed to a suitable complement to other intracerebral guidance methods.
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| 2. |
- Bergenheim, A Tommy, et al.
(författare)
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Diplopia after balloon compression of retrogasserian ganglion rootlets for trigeminal neuralgia : technical case report.
- 2008
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Ingår i: Neurosurgery. - : Ovid Technologies (Wolters Kluwer Health). - 1524-4040 .- 0148-396X. ; 62:2, s. E533-4; discussion E534
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Balloon compression of the rootlets behind the trigeminal ganglion for the treatment of trigeminal neuralgia has become an increasingly popular method among neurosurgeons. However, the method has recognized complications, including double vision. Although occurring infrequently, diplopia may cause the patient significant disability. To minimize the risk for this complication, we analyzed our patients with respect to the surgical technique. METHODS: We reviewed our joint consecutive series of 193 patients with trigeminal neuralgia treated with balloon compression. The medical records and the intraoperative x-ray images were analyzed. RESULTS: We identified six patients with double vision postoperatively. In analyzing these occurrences, we found that the balloon was inflated outside Meckel's cave in four patients, the balloon was initially inflated too deeply in one patient, and the anatomy of Meckel's cave was probably aberrant in one patient. In five of the six patients, the symptoms resolved within 5 months. CONCLUSION: By meticulous surgical technique with close attention to the anatomic position and the shape of the inflated balloon, most cases of postcompression diplopia should be avoided.
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| 3. |
- Bjoreland, Anders, et al.
(författare)
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Liquid ionization chamber calibrated gel dosimetry in conformal stereotactic radiotherapy of brain lesions
- 2008
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 47:6, s. 1099-1109
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Tidskriftsartikel (refereegranskat)abstract
- Hypofractionated conformal stereotactic radiotherapy (HCSRT) is an established method of treating brain lesions such as arteriovenous malformations (AVMs) and brain metastases. The aim of this study was to investigate the reliability of treatment plans in the terms of dose distribution and absorbed dose for HCSRT. Methods and materials. Treatment plans for three different clinical intracerebral targets, AVMs, were transferred to a CT study of a spherical water filled phantom simulating the human head and recalculated for the phantom geometry using a standard treatment planning system utilizing a pencil beam algorithm for dose calculation. The calculated absorbed dose, relative three dimensional (3D) dose distribution and dose conformity were investigated using gel dosimetry normalized to liquid ionization chamber (LIC) measurements. Results. The measured absorbed dose to the dose reference point was found to be within 2% of the calculated dose for all three targets. The measured dose distribution was found to be within 3% and 2 mm of the calculated dose for more than 93% of all points in the target volume for all three targets. Conclusions. The results show that the investigated standard treatment planning system can correctly predict the absorbed dose and dose distribution in different types of intracerebral targets and that the treatment can be delivered according to the plan.
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| 4. |
- Henriksson, Roger, et al.
(författare)
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Boron neutron capture therapy (BNCT) for glioblastoma multiforme : a phase II study evaluating a prolonged high-dose of boronophenylalanine (BPA)
- 2008
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 88:2, s. 183-91
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: To evaluate the efficacy and safety of boron neutron capture therapy (BNCT) for glioblastoma multiforme (GBM) using a novel protocol for the boronophenylalanine-fructose (BPA-F) infusion. PATIENT AND METHODS: This phase II study included 30 patients, 26-69 years old, with a good performance status of which 27 have undergone debulking surgery. BPA-F (900 mg BPA/kg body weight) was given i.v. over 6h. Neutron irradiation started 2h after the completion of the infusion. Follow-up reports were monitored by an independent clinical research institute. RESULTS: The boron-blood concentration during irradiation was 15.2-33.7 microg/g. The average weighted absorbed dose to normal brain was 3.2-6.1 Gy (W). The minimum dose to the tumour volume ranged from 15.4 to 54.3 Gy (W). Seven patients suffered from seizures, 8 from skin/mucous problem, 5 patients were stricken by thromboembolism and 4 from abdominal disturbances in close relation to BNCT. Four patients displayed 9 episodes of grade 3-4 events (WHO). At the time for follow-up, minimum ten months, 23 out of the 29 evaluable patients were dead. The median time from BNCT treatment to tumour progression was 5.8 months and the median survival time after BNCT was 14.2 months. Following progression, 13 patients were given temozolomide, two patients were re-irradiated, and two were re-operated. Patients treated with temozolomide lived considerably longer (17.7 vs. 11.6 months). The quality of life analysis demonstrated a progressive deterioration after BNCT. CONCLUSION: Although, the efficacy of BNCT in the present protocol seems to be comparable with conventional radiotherapy and the treatment time is shorter, the observed side effects and the requirement of complex infrastructure and higher resources emphasize the need of further phase I and II studies, especially directed to improve the accumulation of (10)B in tumour cells.
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| 5. |
- Lindvall, Peter, et al.
(författare)
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Cerebral metabolism during air transport of patients after surgery for malignant glioma
- 2008
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Ingår i: Aviation, Space and Environmental Medicine. - 0095-6562 .- 1943-4448. ; 79:7, s. 700-703
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Post-operative air transport of patients following an intracranial procedure is not uncommon. The transport itself may pose a risk, and if there are harmful effects to the brain this should be reflected in the brain metabolism. The aim of this study was to analyze possible alterations in cerebral metabolism that could be caused by air transport.METHODS: Four patients with glioblastomas were operated with a biopsy or a craniotomy. During this procedure microdialysis catheters were placed in tumor tissue or brain adjacent to tumor and in normal cerebral tissue. In this study we have analyzed cerebral glucose metabolites (glucose, lactate / pyruvate ratio), glycerol, and glutamate at five time points during a 24-h period including air transport.RESULTS: Analyzing mean values, there was a small but significant increase in the lactate/pyruvate ratio from 45.18 to 47.78 in normal cerebral tissue after air transport compared to a previous fasting sample. For tumor tissue there was a small decrease in glucose from 1.04 to 0.92 mmol L(-1) and an increase in glutamate from 13.08 to 19.06 micromol L(-1). There were no other significant differences in the analyzed cerebral metabolites after air transport.DISCUSSION: There were only minor differences in levels of cerebral metabolites after air transport compared to a previous fasting sample. Thus it seems that air transportation of the four reported patients did not cause any major cellular damage or metabolic changes as assessed by extracellular glucose, lactate/pyruvate ratio, glycerol, or glutamate.
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| 6. |
- Lindvall, Peter, et al.
(författare)
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Reproducibility and geometric accuracy of the Fixster system during hypofractionated stereotactic radiotherapy
- 2008
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Ingår i: Radiation Oncology. - 1748-717X. ; 3:16
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Hypofractionated radiotherapy has been used for the treatment of AVMs and brain metastases. Hypofractionation necessitates the use of a relocatable stereotactic frame that has to be applied on several occasions. The stereotactic frame needs to have a high degree of reproducibility, and patient positioning is crucial to achieve a high accuracy of the treatment.METHODS:In this study we have, by radiological means, evaluated the reproducibility of the isocenter in consecutive treatment sessions using the Fixster frame. Deviations in the X, Y and Z-axis were measured in 10 patients treated with hypofractionated radiotherapy.RESULTS:The mean deviation in the X-axis was 0.4 mm (range -2.1 - 2.1, median 0.7 mm) and in the Y-axis -0.3 mm (range -1.4 - 0.7, median -0.2 mm). The mean deviation in the Z-axis was -0.6 (range -1.4 - 1.4, median 0.0 mm).CONCLUSION:There is a high degree of reproducibility of the isocenter during successive treatment sessions with HCSRT using the Fixster frame for stereotactic targeting. The high reducibility enables a safe treatment using hypofractionated stereotactic radiotherapy.
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| 7. |
- Sandström, Maria, et al.
(författare)
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Effects of the VEGFR inhibitor ZD6474 in combination with radiotherapy and temozolomide in an orthotopic glioma model.
- 2008
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Ingår i: Journal of Neuro-Oncology. - : Springer Science and Business Media LLC. - 0167-594X .- 1573-7373. ; 88:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- AIM OF THE STUDY:The extensive neovascularisation of malignant glioma is mainly influenced by vascular endothelial growth factor (VEGF). The effect of ZD6474, a potent inhibitor of VEGF-receptor-2, was evaluated in combination with either radiotherapy or temozolomide.METHODS:The effects on glioma growth were investigated in the intracerebral BT4C rat glioma model. ZD6474 30 mg/kg was given alone or in combination with radiotherapy 12 Gy x 1 or with temozolomide 100 mg/kg for 3 days. Two different experiments were performed comparing ZD6474 to radiotherapy or temozolomide. For each experiment 28 animals were randomized into four groups.RESULTS:ZD6474 in combination with radiotherapy significantly decreased tumour area by 66% compared with controls whereas the combination with temozolomide decreased tumour area by 74%.CONCLUSIONS:ZD6474 in combination with two standard modalities in the treatment of malignant glioma, radiotherapy and chemotherapy, markedly decreased the growth of an intracerebral experimental glioma. These results justify further investigations of these therapies in combination.
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| 8. |
- Tabatabaei, Pedram, et al.
(författare)
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Glucose metabolites, glutamate and glycerol in malignant glioma tumours during radiotherapy
- 2008
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Ingår i: Journal of Neuro-Oncology. - : Springer. - 0167-594X .- 1573-7373. ; 90:1, s. 35-39
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The metabolism of malignant glioma was studied in 13 patients. The main objective was to perform a study of the metabolic pattern of glucose, lactate, pyruvate, glutamate and glycerol in tumour tissue during base-line conditions and to detect any changes in the metabolism during radiotherapy.METHOD: During a stereotactic biopsy, two microdialysis catheters were implanted: one in tumour and one in peri-tumoural tissue. Fasting samples were analysed daily, before and during 5 days of radiotherapy given with 2 Gy fractions.RESULTS: Base-line levels of glucose and pyruvate were significantly lower in tumour compared to peri-tumoural tissue (P = 0.04 and 0.023, respectively). The lactate/pyruvate ratio was significantly higher in tumour tissue (P = 0.022). In general, the levels of lactate, glutamate and glycerol were higher in tumour tissue, although not statistically significant. Further, we could not detect any significant changes during the 5 days of radiotherapy in any of the metabolites analysed.CONCLUSION: Radiotherapy up to 10 Gy given in five fractions does not influence the glucose metabolism nor does it induce any acute cytotoxic effect detected with glutamate or glycerol in malignant glioma, as assessed by microdialysis. The study confirms the glycolytic properties of glucose metabolism in malignant glioma.
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