Ultra-high Field (7 T) MRI and a Novel Robust Segmentation of Thalamic Nuclei on DWI for Gamma Knife Surgery Purposes: The Targeting of the Ventrointermediate Nucleus

Author(s):  
C. Tuleasca ◽  
E. Najdenovska ◽  
J. Ferreira Marques ◽  
J. Thiran ◽  
M. Bach Cuadra ◽  
...  
2021 ◽  
Author(s):  
Beverly Setzer ◽  
Nina E Fultz ◽  
Daniel E.P. Gomez ◽  
Stephanie D Williams ◽  
Giorgio Bonmassar ◽  
...  

The moment of awakening from sleep reflects a profound transformation in neural activity and behavior. The thalamus is a key controller of arousal state, but whether its diverse nuclei exhibit coordinated or distinct activity at transitions in behavioral arousal state is not known. Using fast fMRI at ultra-high field (7 Tesla), we measured sub-second activity across thalamocortical networks and within nine thalamic nuclei to delineate these dynamics during spontaneous transitions in behavioral arousal state. We discovered a stereotyped sequence of activity across thalamic nuclei that preceded behavioral arousal after a period of inactivity, followed by widespread cortical deactivation. These thalamic dynamics were linked to whether participants remained awake or fell back asleep, with unified thalamic activation reflecting subsequent maintenance of awake behavior. These results provide an outline of the complex interactions across thalamocortical circuits that orchestrate arousal state transitions, and additionally, demonstrate that fast fMRI can resolve sub-second subcortical dynamics in the human brain.


2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 21-27 ◽  
Author(s):  
Hyun Ho Jung ◽  
Jong Hee Chang ◽  
Kum Whang ◽  
Jin Soo Pyen ◽  
Jin Woo Chang ◽  
...  

Object The purpose of this study was to assess the efficacy of Gamma Knife surgery (GKS) for treating cavernous sinus dural arteriovenous fistulas (CSDAVFs). Methods Of the 4123 GKSs performed between May 1992 and March 2009, 890 procedures were undertaken to treat vascular lesions. In 24 cases, the vascular lesion that was treated was a dural arteriovenous fistula, and in 6 of these cases, the lesion involved the cavernous sinus. One of these 6 cases was lost to follow-up, leaving the other 5 cases (4 women and 1 man) to comprise the subjects of this study. All 5 patients had more than 1 ocular symptom, such as ptosis, chemosis, proptosis, and extraocular movement palsy. In all patients, CSDAVF was confirmed by conventional angiography. Three patients were treated by GKS alone and 2 patients were treated by GKS combined with transarterial embolization. The median follow-up period after GKS in these 5 cases was 30 months (range 9–59 months). Results All patients experienced clinical improvement, and their improvement in ocular symptoms was noticed at a mean of 17.6 weeks after GKS (range 4–24 weeks). Two patients received embolization prior to GKS but did not display improvement in ocular symptoms. An average of 20 weeks (range 12–24 weeks) was needed for complete improvement in clinical symptoms. There were no treatment-related complications during the follow-up period. Conclusions Gamma Knife surgery should be considered as a primary, combined, or additional treatment option for CSDAVF in selected cases, such as when the lesion is a low-flow shunt without cortical venous drainage. For those selected cases, GKS alone may suffice as the primary treatment method when combined with close monitoring of ocular symptoms and intraocular pressure.


2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 48-52 ◽  
Author(s):  
Toru Serizawa ◽  
Masaaki Yamamoto ◽  
Yasunori Sato ◽  
Yoshinori Higuchi ◽  
Osamu Nagano ◽  
...  

Object The authors retrospectively reviewed the results of Gamma Knife surgery (GKS) used as the sole treatment for brain metastases in patients who met the eligibility criteria for the ongoing JLGK0901 multi-institutional prospective trial. They also discuss the anticipated results of the JLGK0901 study. Methods Data from 1508 consecutive cases were analyzed. All of the patients were treated at the Gamma Knife House of Chiba Cardiovascular Center or the Mito Gamma House of Katsuta Hospital between 1998 and 2007 and met the following JLGK0901 inclusion criteria: 1) newly diagnosed brain metastases, 2) 1–10 brain lesions, 3) less than 10 cm3 volume of the largest tumor, 4) no more than 15 cm3 total tumor volume, 5) no findings of CSF dissemination, and 6) no impairment of activities of daily living (Karnofsky Performance Scale score < 70) due to extracranial disease. At the initial treatment, all visible lesions were irradiated with GKS without upfront whole-brain radiation therapy. Thereafter, gadolinium-enhanced MR imaging was performed every 2–3 months, and new distant lesions were appropriately retreated with GKS. Patients were divided into groups according to numbers of tumors: Group A, single lesions (565 cases); Group B, 2–4 tumors (577 cases); and Group C, 5–10 tumors (366 cases). The differences in overall survival (OS) were compared between groups. Results The median age of the patients was 66 years (range 19–96 years). There were 963 men and 545 women. The primary tumors were in the lung in 1114 patients, gastrointestinal tract in 179, breast in 105, urinary tract in 66, and other sites in 44. The overall mean survival time was 0.78 years (0.99 years for Group A, 0.68 years for Group B, and 0.62 years for Group C). The differences between Groups A and B (p < 0.0001) and between Groups B and C (p = 0.0312) were statistically significant. Multivariate analysis revealed significant prognostic factors for OS to be sex (poor prognostic factor: male, p < 0.0001), recursive partitioning analysis class (Class I vs Class II and Class II vs III, both p < 0.0001), primary site (lung vs breast, p = 0.0047), and number of tumors (Group A vs Group B, p < 0.0001). However, no statistically difference was detected between Groups B and C (p = 0.1027, hazard ratio 1.124, 95% CI 0.999–1.265). Conclusions The results of this retrospective analysis revealed an upper CI of 1.265 for the hazard ratio, which was lower than the 1.3 initially set by the JLGK0901 study. The JLGK0901 study is anticipated to show noninferiority of GKS as sole treatment for patients with 5–10 brain metastases compared with those with 2–4 in terms of OS.


2008 ◽  
Vol 109 (Supplement) ◽  
pp. 118-121 ◽  
Author(s):  
Toru Serizawa ◽  
Masaaki Yamamoto ◽  
Osamu Nagano ◽  
Yoshinori Higuchi ◽  
Shinji Matsuda ◽  
...  

Object The authors compared results of Gamma Knife surgery (GKS) for brain metastases obtained at 2 institutions in Japan. Methods They analyzed a consecutive series of 2390 patients with brain metastases who underwent GKS from 1998 through 2005 in 2 institutes (1181 patients in Chiba; 1209 in Mito). In the 2 facilities, 1 neurosurgeon each was responsible for diagnosis, patient selection, GKS procedures, and follow-up (T.S. in Chiba, M.Y. in Mito). Even if tumor numbers exceeded 4, all visible lesions were irradiated with a total skull integral dose (TSID) of ≤ 10–12 J. No prophylactic whole-brain radiotherapy (WBRT) was applied. If new distant lesions were detected, salvage GKS was appropriately performed. Results The distributions of patient and treatment factors did not differ between institutes. The most common primary tumors were lung cancer (1572 patients), followed by gastrointestinal tract (316), breast (211), kidney (113), and other cancers (159). The median survival periods were 7.7 months in Chiba and 7.0 months in Mito (p = 0.0635). The significant poor prognostic factors for overall survival were active extracranial disease status, male sex, and low initial Karnofsky Performance Scale score on multivariate analysis (all p < 0.0001). The neurological survival rates at 1 year were 86.6% in Chiba and 84.2% in Mito (p = 0.3310). Conclusions This 2-institute study demonstrated no significant institutional differences in any of the treatment result items. Gamma Knife surgery for brain metastases without prophylactic WBRT prevents neurological death and allows a patient to maintain good brain condition. However, there is 1 important patient selection criterion: regardless of how many tumors there are, all lesions can be irradiated with a TSID of ≤12 J.


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