Neurosurgery
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Radiation therapy (RT) plays a critical role in the overall management of many central nervous system (CNS) tumors. Advances in RT treatment planning, with techniques such as intensity modulated radiation therapy, volumetric modulated arc therapy, and stereotactic radiosurgery, now allow the delivery of highly conformal dose with great precision. These techniques rely on high-resolution 3-dimensional anatomical imaging modalities such as computed tomography or magnetic resonance imaging (MRI) scans to accurately and reliably define CNS targets and normal tissue avoidance structures. ⋯ In addition, advanced imaging modalities including diffusion, perfusion, and spectroscopic MRIs as well as positron emission tomography (PET) scans with novel tracers are being utilized to provide additional insight into tumor biology and behavior beyond anatomy. Together, these standard and advanced imaging modalities hold significant potential to improve future RT delivery and response assessment. In this review, we will discuss the current utilization of standard/advanced imaging for CNS tumors from a radiation oncology perspective as well as the implications of novel MRI and PET modalities currently under investigation.
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Review Case Reports
Myopericytoma at the Craniocervical Junction: Clinicopathological Report and Review of a Rare Perivascular Neoplasm.
Myopericytoma is an emerging class of neoplasm originating from the perivascular myoid cellular environment, previously classified as a variant of hemangiopericytoma. Most reported myopericytomas are found in soft tissues of the extremities; however, infrequent cases are described involving the central nervous system. Intracranial myopericytoma remains rare. Here, we describe the first report of myopericytoma occurring at the cervicomedullary junction in close proximity to the vertebral artery, mimicking a vascular lesion. ⋯ Tumors of perivascular origin include hemangiopericytoma, glomus tumor, myofibroma, and myopericytoma and are uncommon lesions intracranially. Consideration of and distinction among these perivascular tumors is critically important, as they each have distinct clinical behaviors and management. Myopericytoma can mimic other neoplastic and cerebrovascular pathologies, but it most commonly has a benign course and can be surgically cured if a gross total resection can be achieved. Rarer myopericytoma variants that adopt a more malignant course have been described, and ongoing molecular studies may identify mutations or activated signaling pathways that can be targeted to offer chemotherapeutic options in the future.
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Carotid revascularization has been recommended as the maximally beneficial treatment for stroke prevention in patients with recently symptomatic carotid stenosis (SCS). The appropriate timing for performing carotid endarterectomy (CEA) within the first 14 d after the occurrence of the index event remains controversial. We aim to provide a snapshot of the pertinent current literature related to the timing of CEA for patients with SCS. ⋯ The current literature suggests that patients who undergo urgent CEA (within 48 h) after nondisabling stroke as the index event have an increased periprocedural risk as compared to those who had transient ischemic attack (TIA) as the index event. Further prospective studies and clinical trials studying this question with separate groups classified as per the index event are required to shed more light on the subject. The current literature points to a changing paradigm towards early carotid surgery, specifically targeted within 48 h if the index event is TIA, and within 7 d if the index event is stroke.