Background and PurposeCerebral blood oxygenation level is critical for following the evolution of stroke patients. The purpose of this study was to investigate the feasibility of measuring changes in blood oxygen levels for patients with acute stroke using SWI and to compare these changes with the patient's recovery over time.Materials and MethodsA total 30 MRI scans was performed on 10 acute ischemic stroke patients. Every patient was followed at three time points: less than 24 hours; 2–3 weeks after stroke and 2 months after stroke. Both MRI scan and NIH stroke scale (NIHSS) were acquired for each patient at all three time points. Oxygen saturation changes were derived from phase values differences (Δφ) measured over 10 veins from each hemisphere for all 10 patients over 3 time points. The correlation of oxygen saturation and NIHSS was further evaluated.ResultsThe stroke affected side of the brain showed moderate (r = −0.62) to strong (r = −0.70) correlation between the oxygenation change and NIHSS change. The oxygen saturation change from the normal side of the brain had essentially no association with recovery (r = −0.02 and−0.31). The results suggest that increases in oxygen saturation correspond to improved outcome and reductions in oxygen saturation correspond to worse outcome.ConclusionHigh resolution SWI provided a novel method to measure changes in oxygenation change of the human brain in vivo. By using the phase values from the veins, both spatial and temporal information can be found that relates to patient outcome post stroke.

Application accuracy is a crucial factor for stereotactic surgical localization systems, in which space digitization camera systems are one of the most critical components. In this study we compared the effect of the OPTOTRAK 3020 space digitization system and the FlashPoint Model 3000 and 5000 3D digitizer systems on the application accuracy for interactive localization of intracranial lesions. A phantom was mounted with several implantable frameless markers which were randomly distributed on its surface. The target point was digitized and the coordinates were recorded and compared with reference points. The differences from the reference points represented the deviation from the "true point." The root mean square (RMS) was calculated to show the differences, and a paired t-test was used to analyze the results. The results with the phantom showed that, for 1-mm sections of CT scans, the RMS was 0.76 +/- 0. 54 mm for the OPTOTRAK system, 1.23 +/- 0.53 mm for the FlashPoint Model 3000 3D digitizer system, and 1.00 +/- 0.42 mm for the FlashPoint Model 5000 system. These preliminary results showed that there is no significant difference between the three tracking systems, and, from the quality point of view, they can all be used for image-guided surgery procedures.

Object. The purpose of this study was to clarify the effectiveness of gamma knife radiosurgery (GKS) in achieving a partial or complete remission of so-called radioresistant metastases from renal cell carcinoma (RCC) and to propose guidelines for optimal treatment Methods. During a 5-year period, 29 patients (19 male and 10 female) with 92 brain metastases from RCC underwent GKS. The median tumor volume was 4.7 cm3 (range 0.5–14.5 cm3). Fourteen patients (48%) also underwent whole-brain radiotherapy (WBRT) before GKS, and two patients (6.8%) after GKS. The mean GKS dose delivered to the 50% isodose at the tumor margin was 16.8 Gy (range 13–30 Gy). All cases were categorized according to the Recursive Partitioning Analysis (RPA) classification for brain metastases. Univariate analysis was performed to determine significant prognostic factors and survival. The overall median survival was 7 months after GKS treatment. Age, sex, Karnofsky Performance Scale score, and controlled primary disease were not predictors of survival. Combined WBRT/GKS resulted in median survival of 18, 8.5, and 5.3 months for RPA Classes I, II, and III, respectively, compared with the median survival 7.1, 4.2, and 2.3 months for patients treated with WBRT alone. Conclusions. These results suggest that WBRT combined with GKS may improve survival in patients with brain metastases from RCC. Furthermore, this improvement in survival was seen in all RPA classes.

IntroductionThe piriform cortex and cortical amygdala (PCA) and the orbitofrontal cortex (OFC) are considered olfactory-related brain regions. This study aims to elucidate the normal volumes of PCA and OFC of each age groups (20.0-70.0 year old), and whether the volumes of PCA and OFC decline with increasing age and diminishing olfactory function.MethodsOne hundred and eleven healthy right-handed participants (54 males, 57 females), age 20.0 to 70.0 years were recruited to join this study after excluding all the major causes of olfactory dysfunction. Volumetric measurements of PCA and OFC were performed using consecutive 1-mm thick coronal slices of high-resolution 3-D MRIs. A validated olfactory function test (Sniffin’ Sticks) assessed olfactory function, which measured odor threshold (THD), odor discrimination (DIS), and odor identification (ID) as well as their sum score (TDI).ResultsThe volume of OFC decreased with age and significantly correlated with age-related declines in olfactory function. The volume of OFC showed significant age-group differences, particularly after 40 years old (p < 0.001), while olfactory function decreased significantly after 60 years old (p < 0.001). Similar age-related volumetric changes were not found for PCA (p = 0.772). Additionally, there was significant correlation between OFC and DIS on the Right Side (p = 0.028) and between OFC and TDI on both sides (p < 0.05). There was no similar correlation for PCA.ConclusionsAging can have a great impact on the volume of OFC and olfactory function while it has much smaller effect on the volume of PCA. The result could be useful to establish normal volumes of PCA and OFC of each age group to assess neurological disorders that affect olfactory function.

Chordomas are rare tumors of the central nervous system and primarily occur in the extradural space. We report two patients with intracranial chordomas located in the region ofthe clivus that invaded the prepontine cisterns. The patients, 45 and 62 years old, had histories ofcranial neuropathies and headache, respectively. Petrosal approaches were performed in both with radical resection of the tumors. Anatomopathological studies confirmed the diagnosis ofchordoma. The symptoms of both patients resolved, and they have had no recurrence after 18 months of follow-up. Intradural chordomas or extradural chordomas that invade the intradural space are difficult to differentiate from ecchordoses physaliphorae, a non-neoplastic entity with similar radiological features. MBI-1 studies were therefore performed to confirm the diagnosis ofchordoma. The differential diagnosis for these two entities, the different modalities of treatment, and prognosis are reviewed.

Background: This study evaluates prognostic factors influencing survival outcomes for 60 patients with permanent iodine-125 implants in the primary treatment of non-glioblastoma multiforme (GBM) high-grade gliomas. Methods: Stereotactic treatment planning aimed to encompass the contrast-enhancing rim of the tumor visualized by CT, with an initial dose rate of 0.05 Gy/h with ¹²⁵I, delivering 100 Gy at 1 year and 103.68 Gy at infinity. Survival was evaluated using the Kaplan-Meier method for univariate analysis and the Cox regressional method for multivariate analysis. In addition to the implant, 34 patients received external radiation therapy (5,000–6,000 cGy) before the implant; 13 patients were implanted without additional external beam radiation, and 13 patients underwent external radiation therapy before implant placement. Results: With a mean follow-up of 77.6 months (range 3.5–164 months), 1-, 3-, 5- and 10-year survival were 86.7% (±0.05%), 60% (±0.07%), 50% (±0.07%) and 45.7% (±0.7%), respectively. The median survival time was 57 months. Second surgery was performed following the implant in 19 patients. Findings were tumor recurrence in 11 patients (22.5%), radiation necrosis in 7 patients (14.3%) and brain abscess in 1 patient (2%). Age, sex, tumor location, side of brain, tumor volume, Karnofsky score and neurological status were correlated with survival outcome. Favorable prognostic factors were age younger than 45 years, superficial tumor location and preoperative Karnofsky score greater than 70. RPA classification was used to define this group of patients. In RPA classes I and II (n = 43), 1-year survival was 93%, while 3-, 5- and 10-year survival was 67.4, 60.5 and 55.5%, respectively, and median survival time was 91 months. In RPA class III (n = 7), 1-year survival was 71.4%, while 3- and 5-year survival was 42.9 and 28.6%, respectively, and median survival time was 47 months. In RPA class IV (n = 10), 1-year survival was 60%, while 3-, 5- and 10-year survival was 50, 22.2 and 11.1%, respectively, and median survival time was 37 months. Conclusion: Brachytherapy with permanent implant of ¹²⁵I appears promising in the treatment of primary non-GBM malignant gliomas. It improved survival time and reduced the incidence of complications and provided good quality of life. In order to further confirm these results, multicenter randomized prospective studies are needed. RPA analysis is a valid tool to define prognostically distinct survival groups. In this study, 2-year survival and median survival time were improved in all prognostic classes. This would suggest that selection bias alone does not account for the survival benefit seen with ¹²⁵I implants. Further randomized studies with effective stratification are needed.

Object. The purpose of this study was to evaluate retrospectively the effectiveness of stereotactic radiosurgery for intracranial metastatic melanoma and to identify prognostic factors related to tumor control and survival that might be helpful in determining appropriate therapy. Methods. Twenty-four patients with intracranial metastases (115 lesions) metastatic from melanoma underwent radiosurgery. In 14 patients (58.3%) whole-brain radiotherapy (WBRT) was performed, and in 12 (50%) chemotherapy was conducted before radiosurgery. The median tumor volume was 4 cm3 (range 1–15 cm3). The mean dose was 16.4 Gy (range 13–20 Gy) prescribed to the 50% isodose at the tumor margin. All cases were categorized according to the Recursive Partitioning Analysis classification for brain metastases. Univariate and multivariate analyses of survival were performed to determine significant prognostic factors affecting survival. The mean survival was 5.5 months after radiosurgery. The analyses revealed no difference in terms of survival between patients who underwent WBRT or chemotherapy and those who did not. A significant difference (p < 0.05) in mean survival was observed between patients receiving immunotherapy or those with a Karnofsky Performance Scale (KPS) score of greater than 90. Conclusions. The treatment with systemic immunotherapy and a KPS score greater than 90 were factors associated with a better prognosis. Radiosurgery for melanoma-related brain metastases appears to be an effective treatment associated with few complications.

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