Progress in neurological surgery最新文献

Stereotactic radiosurgery (SRS) is an effective treatment for patients with multiple brain metastases. Three decades of increasingly powerful scientific studies have shown that SRS improves outcomes and reduces toxicity when it replaces whole-brain radiation therapy (WBRT). Expert opinion surveys of clinicians have reported that the total intracranial tumor volume rather than the number of brain metastases is related to outcomes. As a result, an increasing number of treating and referring physicians have replaced the reflex use of WBRT with SRS, unless the patient has miliary disease or carcinomatous meningitis. In the current era of immunotherapy and targeted therapies with potentially increased systemic disease survival, 10 or more tumors are routinely treated with SRS alone at most academic medical centers. In a single SRS session we routinely treat patients with cumulative tumor volumes of 25 cm3 even if they have ≥10 metastases.

Glomus tumors of the head and neck typically compress adjacent blood vessels and cranial nerves and result in varied clinical presentations. Moreover, they are seldom encountered, even at large medical centers, and specialists in neurosurgery, otolaryngology, and radiation oncology have yet to reach a generalized consensus regarding the optimal management approach. In an effort to summarize the available data and better elucidate optimal treatment and management strategies for glomus tumors, we conducted a review of the published literature on this topic with emphasis on stereotactic radiosurgery.

Stereotactic radiosurgery (SRS) has become a standard management option for less common glial tumors. When imaging defines a recurrent or progressive ependymoma after initial resection in a child who has completed adjuvant fractionated radiation therapy, SRS may be used as a boost or salvage strategy. For patients with oligodendrogliomas diagnosed by biopsy or after cytoreductive surgery, SRS may be used as a primary option in smaller volume tumors, or as an adjuvant option for tumors that have progressed after initial surgery, chemotherapy, or fractionated radiation therapy. Currently the increasing use of molecular markers in both tumors helps to define the prognosis, risk of recurrence, and perhaps response to boost or salvage SRS. This report examines the role of SRS in these less common glial tumors.

The JLGK0901 study showed the non-inferiority of stereotactic radiosurgery (SRS) alone as the initial treatment for 5-10 as compared to 2-4 brain metastases (BM) in terms of overall survival and most secondary endpoints [Lancet Oncol 2014;15:387-395]. A trend for patients with 5-10 tumors to undergo SRS alone has since become apparent. The next step is to reappraise whether results of SRS treatment alone for tumor numbers ≥10 differ from those for 2-9 tumors. During the past 2 decades, several retrospective studies have demonstrated the SRS alone treatment strategy to have certain benefits for carefully selected patients with ≥10 BM, i.e., a sufficiently long survival period with lower incidences of neurological death, neurological deterioration, local recurrence, and SRS-related complications. Herein, we introduce our Mito experiences with SRS for ≥10 BM, employing a case-matched study on 934 patients, 467 each in groups with 2-9 BM and ≥10 BM. Post-SRS treatment results, i.e., median survival time, neurological death-free survival time and cumulative incidences of local recurrence, repeat SRS for new lesions, neurological deterioration, and SRS-related complications, were not inferior for patients with ≥10 BM as compared to those with 2-9 BM. We conclude that patients with ≥10 tumors are not unfavorable candidates for SRS alone.

The outcome of patients with malignant gliomas has not substantially improved, even with advances in imaging, neurosurgery, molecular subtyping, and radiation, and newer oncologic options. Maximal safe resection when feasible remains the initial treatment of choice for most malignant gliomas. These tumors often recur and require additional therapy to control the tumor growth. Leksell stereotactic radiosurgery (SRS) is offered as salvage therapy in patients with recurrent or residual malignant gliomas. SRS is well tolerated and is associated with a relatively low risk of adverse radiation effects in malignant glial tumor patients who otherwise have relatively few options. SRS allows the surgeon more flexibility in terms of surgical options and may enhance quality of life for patients postoperatively. Although randomized controlled studies are lacking in the use of salvage SRS after the failure of initial standard of care management, preliminary data suggest that radiosurgery improves tumor control and overall survival for patients with recurrent malignant gliomas.

A decision to develop a stereotactic radiosurgery center and install the first 201 cobalt-60 Gamma Knife in Pittsburgh was made in 1981 after gathering regional and leadership support. This was part of a 7-year quest that required overcoming barriers to a new technology unfamiliar to US regulatory authorities and insurance companies. The first patient was treated in August 1987. Since that time our center has installed each succeeding Gamma Knife device developed. During an initial 30-year experience we performed more than 14,750 patient procedures. In addition to patient care our Center's goal was to develop a major teaching and clinical research program that eventually led to the training of more than 2,500 physicians and medical physicists, the publication of more than 600 peer-reviewed clinical outcome research studies, and 4 books. This report summarizes the rationale for acquisition, the challenges and the early years, and then the evolution of our center which installed the first US 201 source Gamma Knife.

The most common primary cancers that metastasize to the brain are lung cancer, breast cancer, and melanoma. The established management approaches for brain metastasis include stereotactic radiosurgery, fractionated radiation therapy, and surgical resection. In the past the role of medical therapies in brain metastases was limited. In the last decade, our understanding of molecular drivers of brain metastases and CNS penetration of drugs across the blood-brain barrier has improved. The molecular targeted tyrosine kinase inhibitors have shown effectiveness in brain metastases with activating mutations from non-small cell lung cancer, breast cancer, and melanoma. More recently, immunotherapies have also shown efficacy in the management of these patients. These agents can be effective for both intracranial as well as extracranial disease and are being actively employed in this patient population.

There is a growing body of studies regarding the effects of Gamma Knife radiosurgery on vestibular schwannomas. However, due to their rare presence and variability, our experience with the management of non-vestibular schwannomas is relatively limited. Management strategies include radiological monitoring, microsurgical resection, microsurgery combined with radiosurgery, or upfront radiosurgery. The lack of large series and heterogeneous data makes it difficult to suggest a definitive treatment strategy and management should be tailored for each patient's radiological and clinical characteristics. Available data suggest that stereotactic radiosurgery, alone or combined with microsurgery, led to good outcomes with relatively low complication rates and constitutes an efficient treatment modality for patients with non-vestibular schwannomas.

Cavernous malformations (CM) represent a distinct subgroup of brain vascular malformations that are characterized by small sinusoidal vascular channels with hyaline degeneration and old blood pigments. Because of the increasing availability of magnetic resonance imaging (MRI) they are detected much more frequently in the present era. CM may be solitary or found in the context of a familial variant that results in an increasing number of CM developing as the patient ages. Because of the variable risk of subacute bleeding, their management options have been controversial. The annual risk of an incidentally detected CM bleeding is <0.5% each year. Leksell radiosurgery is used for a subgroup of patients who have repeatedly bled. In general, CM best considered for stereotactic radiosurgery are deep seated and do not pre-sent to a pial or ependymal surface where microsurgical corridors for removal are feasible. When radiosurgery is used for patients at high risk for both re-bleeding as well as microsurgical resection, the risk of bleeding can be reduced from as high as 33% each year to <0.5% each year after a 2-year latency interval. The target lies within the hemosiderin rim detected during the MRI that is part of planning. Marginal doses are significantly less than those used for angiographically visible arteriovenous malformations.

Traditional outcome measures after stereotactic radiosurgery (SRS) for cerebral arteriovenous malformations (AVMs) have focused predominantly on angiographic obliteration and general neurologic complications. Several grading scales attempting to predict the outcome for specific patients have previously been proposed and validated, and are outlined here. These have largely been based on both AVM and patient characteristics and attempt to predict obliteration. However, the most practical and clinically oriented goal in the management of AVMs is the prospective avoidance of neurological sequelae manifesting in the form of stroke or death, regardless of AVM obliteration. Long-term outcomes following SRS have demonstrated stroke or death rates of 1.5-2.0% per year for the first 5 years after SRS, followed by 0.2-0.4% annual risk thereafter. This focus on the avoidance of stroke or death is additionally crucial for direct comparisons to non-interventional natural history data. Here, we discuss the history of outcomes data on radiosurgery for AVMs and propose a re-evaluation of clinical outcome that is of most utility to the patient.