OBJECTIVEIntraoperative MRI (iMRI) is assumed to safely improve the extent of resection (EOR) in patients with gliomas. This study focuses on advantages of this imaging technology in elective low-grade glioma (LGG) surgery in pediatric patients.METHODSThe surgical results of conventional and 1.5-T iMRI-guided elective LGG surgery in pediatric patients were retrospectively compared. Tumor volumes, general clinical data, EOR according to reference radiology assessment, and progression-free survival (PFS) were analyzed.RESULTSSixty-five patients were included in the study, of whom 34 had undergone conventional surgery before the iMRI unit opened (pre-iMRI period) and 31 had undergone surgery with iMRI guidance (iMRI period). Perioperative data were comparable between the 2 cohorts, apart from larger preoperative tumor volumes in the pre-iMRI period, a difference without statistical significance, and (as expected) significantly longer surgeries in the iMRI group. According to 3-month postoperative MRI studies, an intended complete resection (CR) was achieved in 41% (12 of 29) of the patients in the pre-iMRI period and in 71% (17 of 24) of those in the iMRI period (p = 0.05). Of those cases in which the surgeon was postoperatively convinced that he had successfully achieved CR, this proved to be true in only 50% of cases in the pre-iMRI period but in 81% of cases in the iMRI period (p = 0.055). Residual tumor volumes on 3-month postoperative MRI were significantly smaller in the iMRI cohort (p < 0.03). By continuing the resection of residual tumor after the intraoperative scan (when the surgeon assumed that he had achieved CR), the rate of CR was increased from 30% at the time of the scan to 85% at the 3-month postoperative MRI.The mean follow-up for the entire study cohort was 36.9 months (3–79 months). Progression-free survival after surgery was noticeably better for the entire iMRI cohort and in iMRI patients with postoperatively assumed CR, but did not quite reach statistical significance. Moreover, PFS was highly significantly better in patients with CRs than in those with incomplete resections (p < 0.001).CONCLUSIONSSignificantly better surgical results (CR) and PFS were achieved after using iMRI in patients in whom total resections were intended. Therefore, the use of high-field iMRI is strongly recommended for electively planned LGG resections in pediatric patients.
A sAfe and gross-total tumor resection is the main goal of many neurosurgical procedures to successfully treat patients or to extend survival if the disease cannot be healed. Important advances have been made throughout the last few years in visualizing and maximizing the extent of resection by using intraoperative MRI (iMRI). 10,21 To date, iMRI is mainly used to intraoperatively depict the precise anatomical location of the tumor margins as well as the unintentionally remaining tumor tissue, and to provide updates through the neuronavigation system to reveal the amount of brain shift at the same time. The possibility for advanced iMRI like diffusion tensor imaging (DTI), MR spectroscopy, or MR perfusion has been described before, but not for functional MRI (fMRI). 11,18,20,22 For lesions located within highly eloquent areas like the central region, pyramidal abbreviatioNs fMRI = functional MRI; ICA = independent component analysis; iMRI = intraoperative MRI; IOM = intraoperative monitoring; iRS-fMRI = intraoperative resting-state fMRI; MEP = motor evoked potential; ROC = receiver operating characteristic; RS = resting state; RSN = RS network; SMA = supplementary motor area; SMN = sensorimotor network; SSEP = somatosensory evoked potential. obJective The authors' aim in this paper is to prove the feasibility of resting-state (RS) functional MRI (fMRI) in an intraoperative setting (iRS-fMRI) and to correlate findings with the clinical condition of patients pre- and postoperatively. methods Twelve patients underwent intraoperative MRI-guided resection of lesions in or directly adjacent to the central region and/or pyramidal tract. Intraoperative RS (iRS)-fMRI was performed pre- and intraoperatively and was correlated with patients' postoperative clinical condition, as well as with intraoperative monitoring results. Independent component analysis (ICA) was used to postprocess the RS-fMRI data concerning the sensorimotor networks, and the mean z-scores were statistically analyzed. results iRS-fMRI in anesthetized patients proved to be feasible and analysis revealed no significant differences in preoperative z-scores between the sensorimotor areas ipsi- and contralateral to the tumor. A significant decrease in z-score (p < 0.01) was seen in patients with new neurological deficits postoperatively. The intraoperative z-score in the hemisphere ipsilateral to the tumor had a significant negative correlation with the degree of paresis immediately after the operation (r = -0.67, p < 0.001) and on the day of discharge from the hospital (r = -0.65, p < 0.001). Receiver operating characteristic curve analysis demonstrated moderate prognostic value of the intraoperative z-score (area under the curve 0.84) for the paresis score at patient discharge. coNclusioNs The use of iRS-fMRI with ICA-based postprocessing and functional activity mapping is feasible and the results may correlate with clinical parameters, demonstrating a significant negative correlation between the intensity of the iRS-fMRI signal and the postoperative neur...
Esta revista, en su edición número 48, presenta seis estudios elaborados a partir de un llamado a investigaciones realizado junto al Instituto Interdisciplinario de Economía Política de Buenos Aires (IIEP) de la Facultad de Ciencias Económicas de la Universidad de Buenos Aires (UBA). Este conjunto de trabajos constituye un aporte relevante para la agenda de políticas de comercio e inversión de la región vinculada a los servicios basados en el conocimiento, segmento muy dinámico a nivel global y en el cual América Latina y el Caribe ha registrado importantes avances, y en el que dispone de un fuerte potencial para explotar de cara al futuro. Desde el Instituto para la Integración de América Latina y el Caribe (INTAL) del Sector de Integración y Comercio (INT) del Banco Interamericano de Desarrollo (BID), buscamos contribuir a potenciar a los SBC en la región. La publicación de esta revista es parte también de las iniciativas que impulsamos para incrementar el conocimiento, los datos y la evidencia sobre estos sectores de crucial relevancia para las economías latinoamericanas. Esperamos que su lectura sea fuente de inspiración y reflexión con el propósito de promover una transformación productiva, digital, sustentable y equitativa en nuestra querida región.
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