Brain shift and tissue deformation during surgery for intracranial lesions are the main actual limitations of neuro-navigation (NN), which currently relies mainly on preoperative imaging. Ultrasound ...(US), being a real-time imaging modality, is becoming progressively more widespread during neurosurgical procedures, but most neurosurgeons, trained on axial computed tomography (CT) and magnetic resonance imaging (MRI) slices, lack specific US training and have difficulties recognizing anatomic structures with the same confidence as in preoperative imaging. Therefore real-time intraoperative fusion imaging (FI) between preoperative imaging and intraoperative ultrasound (ioUS) for virtual navigation (VN) is highly desirable. We describe our procedure for real-time navigation during surgery for different cerebral lesions.
We performed fusion imaging with virtual navigation for patients undergoing surgery for brain lesion removal using an ultrasound-based real-time neuro-navigation system that fuses intraoperative cerebral ultrasound with preoperative MRI and simultaneously displays an MRI slice coplanar to an ioUS image.
58 patients underwent surgery at our institution for intracranial lesion removal with image guidance using a US system equipped with fusion imaging for neuro-navigation. In all cases the initial (external) registration error obtained by the corresponding anatomical landmark procedure was below 2 mm and the craniotomy was correctly placed. The transdural window gave satisfactory US image quality and the lesion was always detectable and measurable on both axes. Brain shift/deformation correction has been successfully employed in 42 cases to restore the co-registration during surgery. The accuracy of ioUS/MRI fusion/overlapping was confirmed intraoperatively under direct visualization of anatomic landmarks and the error was < 3 mm in all cases (100 %).
Neuro-navigation using intraoperative US integrated with preoperative MRI is reliable, accurate and user-friendly. Moreover, the adjustments are very helpful in correcting brain shift and tissue distortion. This integrated system allows true real-time feedback during surgery and is less expensive and time-consuming than other intraoperative imaging techniques, offering high precision and orientation.
Glioblastomas (GBMs) contain transformed, self-maintaining, multipotent, tumour-initiating cancer stem cells, whose identification has radically changed our perspective on the physiology of these ...tumours. Currently, it is unknown whether multiple types of transformed precursors, which display alternative sets of the complement of properties of true cancer stem cells, can be found in a GBM. If different subsets of such cancer stem-like cells (CSCs) do exist, they might represent distinct cell targets, with a differential therapeutic importance, also depending on their characteristics and lineage relationship. Here, we report the presence of two types of CSCs within different regions of the same human GBM. Cytogenetic and molecular analysis shows that the two types of CSCs bear quite diverse tumorigenic potential and distinct genetic anomalies, and, yet, derive from common ancestor cells. This provides critical information to unravel the development of CSCs and the key molecular/genetic components underpinning tumorigenicity in human GBMs.
Transformed, oncogenic precursors, possessing both defining neural-stem-cell properties and the ability to initiate intracerebral tumours, have been identified in human brain cancers. Here we report ...that bone morphogenetic proteins (BMPs), amongst which BMP4 elicits the strongest effect, trigger a significant reduction in the stem-like, tumour-initiating precursors of human glioblastomas (GBMs). Transient in vitro exposure to BMP4 abolishes the capacity of transplanted GBM cells to establish intracerebral GBMs. Most importantly, in vivo delivery of BMP4 effectively blocks the tumour growth and associated mortality that occur in 100% of mice after intracerebral grafting of human GBM cells. We demonstrate that BMPs activate their cognate receptors (BMPRs) and trigger the Smad signalling cascade in cells isolated from human glioblastomas (GBMs). This is followed by a reduction in proliferation, and increased expression of markers of neural differentiation, with no effect on cell viability. The concomitant reduction in clonogenic ability, in the size of the CD133+ population and in the growth kinetics of GBM cells indicates that BMP4 reduces the tumour-initiating cell pool of GBMs. These findings show that the BMP-BMPR signalling system-which controls the activity of normal brain stem cells-may also act as a key inhibitory regulator of tumour-initiating, stem-like cells from GBMs and the results also identify BMP4 as a novel, non-cytotoxic therapeutic effector, which may be used to prevent growth and recurrence of GBMs in humans.
Abstract Intramedullary spinal cavernoma is a rare vascular disease constituting 5–12% of all spinal vascular tumors. The clinical course is usually characterized either by an acute neurological ...deterioration, recurrent episodes of neurological deficits or by a slowly progressive neurological decline. Microsurgical removal is recommended when the symptoms become clinically relevant and the lesion appears accessible. In this article, we present a surgical technique to completely resect an intramedullary cavernoma with the aid of intraoperative electrophysiological monitoring and intraoperative real-time ultrasound guidance. A brief description of current management of this pathology is also presented.
BACKGROUND: Differentiating radionecrosis from local tumor recurrence is a major concern in the management of patients harbouring a cerebral tumor and treated with radiotherapy. In these cases, ...contrast-enhanced MRI usually shows ambiguous enhancement, while advanced imaging techniques (MRI spectroscopy, DWI, DTI, perfusion and PET) are still far from being validated as a reliable alternative to biopsy and histological assessment. CASE REPORT: We report the case of a patient who underwent cyberknife radiosurgery (21Gy) for a left rolandic brain metastasis from a lung carcinoma. Four months after radiotherapy, she started experiencing a progressive worsening of her upper right limb's strenght, with a neuroradiological evidence at serial MRIs of a progressive enhancing rolandic lesion. The patient underwent surgical removal of the lesion at our Neurosurgical Division: neurophysiological monitoring, standard B-mode UltraSonography and Contrast-Enhanced UltraSonography (CEUS) were performed intraoperatively to assist in tumor resection. Very interestingly, CEUS did not show any enhancement of the pathologic tissue, differently from what is expected for brain metastases, as reported in previous studies. Histopathological examination showed nervous tissue with post-treatment radiation effects (radionecrosis) with a few metastatic cells. DISCUSSION: Contrast-Enhanced UltraSound is progressively becoming a widespread tool in neurosurgery. Previous studies have described the contrastographic pattern of different cerebral lesions, including metastases. Surprisingly, despite a strong uptake of contrast agent at MRI, we observed that radionecrotic tissue did not show any enhancement at CEUS. For the first time we report the appearance of radionecrosis at CEUS; the lack of contrast enhancement could represent an important hallmark in differential diagnosis with neoplastic tissue. Moreover, in this report, the use of CEUS was confined to the intraoperative stage; however, new approaches to transcranial ultrasonography could extend the value of this technique to the bedside decision-making process. CONCLUSION: Of course, further investigation is required beyond this case report; nonetheless the findings here reported suggest that CEUS could become a promising tool in helping differentiating radionecrosis from tumor recurrence.
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