Category: Oncology

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5-Aminolevulinic acid-induced protoporphyrin IX fluorescence as immediate intraoperative indicator to improve the safety of malignant or high-grade brain tumor diagnosis in frameless stereotactic biopsies

Acta Neurochir (2012) 154:585–588. DOI 10.1007/s00701-012-1290-8

Frameless stereotactic biopsies are replacing frame-based stereotaxy as a diagnostic approach to brain lesions. In order to avoid a sampling bias or negative histology, multiple specimens are often taken. This in turn increases the risk of hemorrhagic complications.

Objective We present the use of 5-aminolevulinic acid (5- ALA)-induced protoporphyrin IX fluorescence in frameless stereotaxy to improve the procedure duration and yield, and thereby reduce the risk of complications.

Methods Patients with suspected high-grade brain tumors are given 5-ALA 4 h prior to stereotactic biopsy. The biopsy needle is guided to the target using frameless stereotaxy based either on preoperative images or combined with intraoperative MRI sequences. The specimen is illuminated with blue light to look for fluorescence. In case of a positive fluorescence within the tissue sample, no frozen sections are obtained, and no further specimens are taken.

Results The samples of 13 patients revealed a positive fluorescence and were histologically confirmed as malignant or high-grade brain neoplasms. four cases were fluorescence-negative, requiring frozen section confirmation and/or multiple samples. In theses cases histology was either nonspecific gliotic changes or low-grade tumors. There were no complications related to the additional use of 5-ALA.

Conclusion 5-ALA fluorescence in stereotactic biopsies can increase the safety and accuracy of these procedures by reducing sampling errors and eliminating the need for multiple samples and/or frozen section verification, creating a more accurate, faster and safer procedure for cases of suspected malignant or high-grade brain tumors situated in deep or eloquent areas.

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Restorative neurosurgery of the cortex: resections of pathologies of the central area can improve preexisting motor deficits

Neurosurg Rev (2012) 35:277–286. DOI 10.1007/s10143-011-0361-2

Different pathologies such as tumors or focal dysplasias can be removed from eloquent areas without subsequent functional deficits. What has not yet been established is the removal of structural abnormalities in sensorimotor area associated with substantial neurological deficits performed in order to accomplish functional improvement. Neurosurgical resections in highly eloquent areas thus hold promise to open a new field achievement of functional restitution even in cases with long-standing deficits.

We present four exemplary cases where the removal of different structural abnormalities led to an impressive improvement of motor deficits. One patient had bilateral ischemic lesion resulting from perinatal hypoxia, one cavernoma, and two focal cortical dysplasias. All presented with motor or sensorimotor deficits and three had long-standing therapy refractory focal seizures. The extent of safe lesionectomy was determined using fMRI, fiber tracking, and PET studies and performed with intraoperative functional neuronavigation guidance and cortical stimulation. The achievement of the planned amount of resection was verified with an intraoperative MR examination.

New persisting neurological deficits after surgery were not registered. One patient had temporary worsening of the right hand weakness that rapidly resolved. One patient was completely seizure free, and in two patients, the seizures’ frequency, duration, and severity were significantly reduced. The preoperatively disturbed motor function improved in all four cases in the course of days or weeks.

In summary, pathological processes affecting the sensorimotor area may cause focal seizures and/or compromise sensorimotor functions. Lesionectomy may accomplish not only the amelioration of focal seizures but also substantial functional improvement.

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En Bloc Resection of Sacral Chordomas Aided by Frameless Stereotactic Image Guidance

Neurosurgery 70[ONS Suppl 1]:ons82–ons88, 2012 DOI: 10.1227/NEU.0b013e31822dd958 

The most important predictor of survival for patients with sacral chordomas is an initial en bloc resection with negative margins. However, obtaining negative margins can be technically challenging. Intraoperative navigation may be helpful in attempting an excision with negative margins.

OBJECTIVE: This is the first report of partial sacrectomy guided by frameless stereotactic navigation.

METHODS: Three patients with a mean age of 58.7 years underwent en bloc resection of sacral chordomas aided by image guidance. Intraoperatively, the reference arc was clamped to the spinous process of L5 and the bony landmarks of S1 were used for registration. Subsequently, the drill was registered, allowing the osteotomy trajectory to be visualized in real time with reference to the patients’ anatomy and tumor location.

RESULTS: None of the patients had any intraoperative or postoperative complications. Two patients with smaller tumors (5 cm) had negative margins, whereas the third patient with an 11.5 cm tumor had marginal margins. With an average follow-up of 44 months, none of the patients have had a recurrence of the tumor.

CONCLUSION: The use of frameless stereotaxy during the en bloc resection of sacral tumors is safe and feasible. Frameless stereotactic navigation was a useful adjunct to preoperative imaging and to the surgeon’s anatomic knowledge. Image guidance was used during the osteotomies to decrease the likelihood of injury to vital adjacent structures or violation of the tumor capsule and to increase the likelihood that the appropriate surrounding tissue was resected to attempt a wide or marginal resection.


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Electromagnetic Image-Guided Biopsy of Cerebral Lesions

Neurosurgery 70[ONS Suppl 1]:ons29–ons33, 2012 DOI: 10.1227/NEU.0b013e31822d75af

In recent years, frameless navigation techniques have been reported to be safe and effective for biopsy of cerebral lesions.

OBJECTIVE: To evaluate the safety and efficacy of a technique of frameless, pinless electromagnetic-guided biopsy for brain lesions with the Medtronic Stealth AxiEM.

METHODS: Prospective data were collected on consecutive brain biopsies performed by a single surgeon (P.L.G.) with this technology between October 2007 and May 2010. One trajectory was made per lesion with multiple specimens taken for analysis. Outcome measures included measures of accuracy, histological yield, and complication rate.

RESULTS: A total of 150 biopsies were performed in 149 patients (84 male and 65 female patients; age range, 19.8-83.8 years). The consultant performed 49 procedures, supervising a trainee in the others. In only 1 case (0.7%) was there nondiagnosis consequent of a registration error and inaccurate trajectory. In 4 other cases (2.7%), no specific diagnosis was established, but abnormal tissue was identified histologically, and postoperative imaging confirmed accurate targeting of these lesions. There were no instances of intracranial hemorrhage or significant morbidity and no deaths directly attributable to the procedure. Four patients (2.7%) died within 30 days of the procedure but not of complications of surgery. One patient suffered a transitory neurological deficit.

CONCLUSION: Electromagnetic navigation is proven to be a simple, safe, and effective innovation for frameless and pinless biopsy of cerebral lesions. This technique is time efficient, and elimination of frame placement enhances patient comfort and facilitates the use of local anesthetic technique.

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Natural history and surgical management of incidentally discovered low-grade gliomas

J Neurosurg 116:365–372, 2012. DOI: 10.3171/2011.9.JNS111068

Low-grade gliomas (LGGs) are rarely diagnosed as an incidental, asymptomatic finding, and it is not known how the early surgical management of these tumors might affect outcome. The purpose of this study was to compare the outcomes of patients with incidental and symptomatic LGGs and determine any prognostic factors associated with those outcomes.

Methods. All patients treated by the lead author for an LGG incidentally discovered between 1999 and 2010 were retrospectively reviewed. “Incidental” was defined as a finding on imaging that was obtained for a reason not attributable to the glioma, such as trauma or headache. Primary outcomes included overall survival, progression-free survival (PFS), and malignant PFS. Patients with incidental LGGs were compared with a previously reported cohort of patients with symptomatic gliomas.

Results. Thirty-five patients with incidental LGGs were identified. The most common reasons for head imaging were headache not associated with mass effect (31.4%) and trauma (20%). Patients with incidental lesions had significantly lower preoperative tumor volumes than those with symptomatic lesions (20.2 vs 53.9 cm3, p < 0.001), were less likely to have tumors in eloquent locations (14.3% vs 61.9%, p < 0.001), and had a higher prevalence of females (57.1% vs 36%, p = 0.02). In addition, patients with incidental lesions were also more likely to undergo gross-total resection (60% vs 31.5%, p = 0.001) and had improved overall survival on Kaplan-Meier analysis (p = 0.039, Mantel-Cox test). Progression and malignant progression rates did not differ between the 2 groups. Univariate analysis identified pre- and postoperative volumes as well as the use of motor or language mapping as significant prognostic factors for PFS.

Conclusions. In this retrospective cohort of surgically managed LGGs, incidentally discovered lesions were associated with improved patient survival as compared with symptomatic LGGs, with acceptable surgical risks.

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Results after treatment of craniopharyngiomas: further experiences with 73 patients since 1997

J Neurosurg 116:373–384, 2012. DOI: 10.3171/2011.6.JNS081451

The authors report surgical and endocrinological results of a series of 73 cases of craniopharyngioma that they treated surgically since 1997 to demonstrate their change in treatment strategy and its effect on outcome compared with a previous series and results reported in the literature.

Methods. A total of 73 patients underwent surgery for craniopharyngiomas between May 1997 and January 2005. In patients with poor clinical or neuropsychological condition, even following pretreatment, only stereotactic cyst aspiration took place (8 cases). In the remaining patients, gross-total resection (GTR) was intended and appeared to be possible. The most frequent approaches were subfrontal (27 cases) and transsphenoidal (26 cases); in some cases, a multistep approach was used. The rate of GTR, complications, and functional outcome (comparing pre- and postoperative endocrine and neuropsychological testing) were evaluated. The mean duration of follow-up was 25.2 months.

Results. Gross-total resection was achieved in 88.5% of cases in which a transsphenoidal approach was used and 79.5% of those in which a transcranial approach was used (85.2% of those in which a subfrontal approach was used and 72.7% of those in which a frontolateral approach was used). In the total series, GTR was achieved in 83.1% of cases (vs 49.3% in the authors’ former series). The complication rate was 13.8% without any mortality. New endocrine deficits were observed more frequently in patients treated with transcranial approaches over the years (16.3%– 66.7% vs 2.6%–50.0%) but were less frequent after transsphenoidal approaches (5.2%–19.2% vs 2.9%–45.7%).

Conclusions. Open surgery with intended total resection remains the treatment of choice in most patients. Initial stereotactic cyst aspiration or medical pretreatment to improve the patients’ condition and adequate choice of surgical approach(es) are essential to achieve that goal. Nevertheless, a moderate increase in endocrinological deficits has to be accepted. The authors recommend using radiotherapy only in cases in which there are tumor remnants or disease progression after surgery.

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Image-Guided Thoracoscopic Resection of Thoracic Dumbbell Nerve Sheath Tumors

Neurosurgery 70:461–468, 2012 DOI: 10.1227/NEU.0b013e318235ba96

Surgical removal of dumbbell nerve sheath tumors (NSTs) remains challenging because these neoplasms occupy ≥ 2 spinal and extraspinal spaces. The presence of intraspinal extension, tumor dimension, and/or its location within the thoracic cavity have previously made the resection of these types of neoplasms difficult.

OBJECTIVE: To describe the feasibility of performing minimally invasive thoracoscopic surgery, as facilitated by an image guidance system (IGS), to achieve gross total resection of select dumbbell NSTs located in the thoracic spine.

METHODS: The 3 cases presented here contained small intraspinal or foraminal components. Preoperative symptoms included Horner syndrome and back and chest wall pain. We used IGS to help guide the complete thoracoscopic resection of select dumbbell NSTs, consisting of extradural, intraforaminal, and paravertebral tumor components, which previously would have been challenging with only a thoracoscopic approach.

RESULTS: IGS provided continuous intraoperative anatomic orientation to achieve gross total resection in all 3 cases. All surgical and postsurgical outcomes were satisfactory; preoperative symptoms improved or resolved; and no adverse events were observed.

CONCLUSION: Thoracic dumbbell NSTs that have small intraspinal or foraminal components could be resected thoracoscopically when facilitated by IGS. Image-guided thoracoscopic resection of such dumbbell tumors may not only improve the precision of resection, reduce recurrence, and avoid the need for spinal reconstruction but also obviate the need for more invasive or simultaneous posterior procedures. The IGS enhances the accuracy and safety of 2-dimensional thoracoscopic surgery and may reduce its learning curve.

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Prognostic factors and survival in a prospective cohort of patients with high-grade glioma treated with carmustine wafers or temozolomide on an intention-to-treat basis

Acta Neurochir (2012) 154:211–222.DOI 10.1007/s00701-011-1199-7

Patients with high-grade glioma can be treated with carmustine wafers or following the Stupp protocol. As far as we are aware, no scientific evidence has been published comparing the two treatments. The primary objective of this study was to analyse the survival of groups of patients with each of these treatment modalities. The secondary objective was to assess the influence of the usual prognostic factors on the patients in our hospital.

Methods A prospective cohort of 110 patients with single, supratentorial high-grade glioma treated by craniotomy and tumour resection was retrospectively studied. Half of the patients had carmustine wafers placed during this operation while the others (55) did not, the latter group receiving firstline systemic chemotherapy on an intention-to-treat basis.

Findings Patients treated with carmustine wafers had a median survival of 13.414 months compared with 11.047 in the group without implants (p=0.856). For the overall cohort of patients, the following factors were found to influence survival: age (p<0.0001), postoperative KPS score (p=0.001), histological grade (p=0.004), RPA class (p=0.001), extent of resection (p=0.002) and salvage surgery (p=0.028).

Conclusions In this prospective cohort of patients, analysed on the basis of intention-to-treat at the time of the first surgery, no statistically significant differences in survival were found between the two treatment modalities (carmustine wafers vs. first-line systemic chemotherapy). On the other hand, age, preoperative KPS, histological grade, and RPA class were confirmed to be prognostic factors in this cohort. Finally, the extent of resection was also found to influence survival.

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Glioblastoma therapy in the elderly and the importance of the extent of resection regardless of age

J Neurosurg 116:357–364, 2012. DOI: 10.3171/2011.8.JNS102114

The objective of this study was to analyze whether age influences the outcome of patients with glioblastoma and whether elderly patients with glioblastoma can tolerate the same aggressive treatment as younger patients.

Methods. Data from 361 consecutive patients with newly diagnosed cerebral glioblastoma (2000–2006) who underwent regular follow-up evaluation from initial diagnosis until death were prospectively entered into a database. Patients underwent resection (complete, subtotal, or partial) or biopsy, depending on tumor size, location, and Karnofsky Performance Scale score. Following surgery, all patients underwent adjuvant treatment consisting of radiotherapy, chemotherapy, or combined treatment. Patients older than 65 years of age were defined as elderly (146 total).

Results. Two hundred thirty-four patients underwent tumor resection (complete 26%, subtotal 29%, and partial 45%). One hundred twenty-seven underwent biopsy. Mean patient age was 61 years, and overall survival was 11.6 ± 12.1 months. The overall survival of elderly patients (9.1 ± 11.6 months) was significantly lower than that of younger patients (14.9 ± 16.7 months; p = 0.0001). Stratifying between resection or biopsy, age was a negative prognostic factor in patients undergoing biopsy (4.0 ± 7.1 vs 7.9 ± 8.7 months; p = 0.007), but not in patients undergoing tumor resection (13.0 ± 8.5 vs 13.3 ± 14.5 months; p = 0.86). Survival of elderly patients undergoing complete tumor resection was 17.7 ± 8.1 months.

Conclusions. In this series of patients with glioblastoma, age was a prognostic factor in patients undergoing biopsy, but not in patients undergoing resection. Tumor location and patient clinical status may prohibit extensive resection, but resection should not be withheld from patients only on the basis of age. In elderly patients with glioblastoma, undergoing resection to the extent feasible, followed by adjuvant therapies, is warranted.

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Percutaneous biopsy of lesions in the cavernous sinus region through the foramen ovale: diagnostic accuracy and limits in 50 patients

J Neurosurg 116:390–398, 2012.DOI: 10.3171/2011.10.JNS11783

The cavernous sinus and surrounding regions—specifically the Meckel cave, posterior sector of the cavernous sinus itself, and the upper part of the petroclival region—are the location of a large variety of lesions that require individual consideration regarding treatment strategy. These regions may be reached for biopsy by a percutaneous needle inserted through the foramen ovale. The aim of this retrospective study was to evaluate the diagnostic accuracy of percutaneous biopsy in a consecutive series of 50 patients referred for surgery between 1991 and 2010.

Methods. Seven biopsies (14%) were unproductive and 43 (86%) were productive, among which 28 lesions subsequently underwent histopathological examination during a second (open) surgery. To evaluate the diagnostic accuracy of the procedure, results from surgery were compared with those from the biopsy.

Results. Sensitivity of the percutaneous biopsy was 0.83 (95% CI 0.52–0.98), specificity was 1 (95% CI 0.79–1), and k coefficient was 0.81.

Conclusions. Because of its valuable diagnostic accuracy, percutaneous biopsy of the cavernous sinus and surrounding regions should be performed in patients with parasellar masses when neuroimaging does not provide sufficient information of a histopathological nature. This procedure would enable patients to obtain the most appropriate therapy, such as resective surgery, corticosteroids, chemotherapy, radiotherapy, or radiosurgery.

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A clinical trial of bevacizumab, temozolomide, and radiation for newly diagnosed glioblastoma

J Neurosurg 116:341–345, 2012.DOI: 10.3171/2011.9.JNS11656

The presence of angiogenesis is a hallmark of glioblastoma (GBM). Vascular endothelial growth factor (VEGF), which drives angiogenesis, provides an additional target for conventional therapy. The authors conducted a prospective clinical trial to test the effectiveness of bevacizumab, an inhibitor of VEGF, in newly diagnosed GBM.

Methods. From 2006 through 2010, 51 eligible patients with newly diagnosed GBM were treated with involvedfield radiation therapy and concomitant temozolomide (75 mg/m2 daily for 42 days) along with bevacizumab (10 mg/ kg every 2 weeks), starting 29 days after surgery. This was followed by 6 cycles of adjuvant temozolomide therapy (150 mg/m2 on Days 1–7 of a 28-day cycle) with bevacizumab administered at 10 mg/kg on Days 8 and 22 of each 28-day cycle.

Results. The 6- and 12-month progression-free survival (PFS) rates were 85.1% and 51%, respectively. The 12- and 24-month overall survival (OS) rates were 85.1% and 42.5%, respectively. Grade III/IV toxicities were noted in 10 patients (19.6%). No treatment-related deaths were observed. Asymptomatic intracranial bleeding was noted in 5 patients.

Conclusions. The addition of bevacizumab to conventional therapy in newly diagnosed GBM appears to improve both PFS and OS in patients with newly diagnosed GBM, with acceptable morbidity. A shift toward diffuse relapse was noted in a significant number of patients. Ongoing Phase III clinical trials will show the true benefit of this antiangiogenic approach.

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Accuracy of Diffusion Tensor Magnetic Resonance Imaging-Based Tractography for Surgery of Gliomas Near the Pyramidal Tract

Neurosurgery 70:283–294, 2012 DOI: 10.1227/NEU.0b013e31823020e6

Diffusion tensor (DT) imaging-based fiber tracking is a noninvasive magnetic resonance technique that can delineate the course of white matter fibers.

OBJECTIVE: To evaluate the accuracy and usefulness of this DT imaging-based fiber tracking for surgery in patients with gliomas near the pyramidal tract (PT).

METHODS: Subjects comprised 32 patients with gliomas near the PT. DT imagingbased fiber tracks of the PT were generated before and within 3 days after surgery in all patients. A tractography-integrated navigation system was used during the operation. Cortical and subcortical motor-evoked potentials (MEPs) were also monitored during resection to maximize the preservation of motor function. The threshold intensity for subcortical MEPs was examined by searching the stimulus points and changing the stimulus intensity. Minimum distance between the resection border and the illustrated PT was measured on postoperative tractography.

RESULTS: In all subjects, DT imaging-based tractography of the PT was successfully performed, preoperatively demonstrating the relationship between tumors and the PT. With the use of the tractography-integrated navigation system and intraoperative MEPs, motor function was preserved postoperatively in all patients. A significant correlation was seen between threshold intensity for subcortical MEPs and the distance between the resection border and PT on postoperative DT imaging.

CONCLUSION: DT imaging-based fiber tracking is a reliable and accurate method for mapping the course of subcortical PTs. Fiber tracking and intraoperative MEPs were useful for preserving motor function in patients with gliomas near the PT.

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5-Aminolevulinic acid (5-ALA)-induced fluorescence in intracerebral metastases: a retrospective study

Acta Neurochir (2012) 154:223–228. DOI 10.1007/s00701-011-1200-5

Microsurgical, circumferential stripping of intracerebral metastases often proves to be insufficient to prevent local tumor recurrence.

Objective We were interested in the potential impact of 5- aminolevulinic acid (5-ALA)-induced-fluorescence (5-AIF) as a diagnostic tool for the resection of intracerebral metastases.

Methods A retrospective analysis was performed for 52 patients who underwent 5-AIF-guided resection for intracerebral mass lesions that histologically corresponded to metastases from tumors outside the central nervous system. The presence of ALA fluorescence in the tumor was determined in each patient. In 42 patients, fluorescence of the resection cavity after tumor removal was additionally recorded. Data were correlated with neuropathological findings in tissue specimens.

Results A total of 32 of the 52 metastases (62%) exhibited 5-AIF in tumor parts. All 5-AIF-positive metastases exhibited an inhomogeneous fluorescence pattern. 5-AIF was neither associated with the histological type nor with the site of origin of the metastases. Residual fluorescence of the resection cavity was detected after macroscopically complete white light resection in 24 patients with 5-AIF positive metastases. Residual tumor tissue was histologically confirmed in 6 of 18 patients with available tissue specimens from such 5-AIF positive areas (33%).

Conclusions The majority of metastases (62%) were 5-AIF positive, suggesting a potential impact of 5-AIF for improved visualization of metastatic tumor tissue within the brain. However, residual 5-AIF after macroscopically complete resection of a metastasis needs to be interpreted with caution because of the limited specificity for detection of residual tumor tissue.

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Dual-room 1.5-T intraoperative magnetic resonance imaging suite with a movable magnet: implementation and preliminary experience

Neurosurg Rev (2012) 35:95–110. DOI 10.1007/s10143-011-0336-3

We hereby report our initial clinical experience of a dual-room intraoperative magnetic resonance imaging (iMRI) suite with a movable 1.5-T magnet for both neurosurgical and independent diagnostic uses. The findings from the first 45 patients who underwent scheduled neurosurgical procedures with iMRI in this suite (mean age, 41.3±12.0 years; intracranial tumors, 39 patients; cerebral vascular lesions, 5 patients; epilepsy surgery, 1 patient) were reported. The extent of resection depicted at intraoperative imaging, the surgical consequences of iMRI, and the clinical practicability of the suite were analyzed.

Fourteen resections with a trans-sphenoidal/transoral approach and 31 craniotomies were performed. Eighty-two iMRI examinations were performed in the operating room, while during the same period of time, 430 diagnostic scans were finished in the diagnostic room. In 22 (48.9%) of 45 patients, iMRI revealed accessible residual tumors leading to further resection. No iMRI-related adverse event occurred. Complete lesion removal was achieved in 36 (80%) of all 45 cases.

It is concluded that the dual-room 1.5-T iMRI suite can be successfully integrated into standard neurosurgical workflow. The layout of the dual-room suite can enable the maximum use of the system and save costs by sharing use of the 1.5-T magnet between neurosurgical and diagnostic use. Intraoperative MR imaging may provide valuable information that allows intraoperative modification of the surgical strategy.

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Localization of Primary Language Areas by Arcuate Fascicle Fiber Tracking

Neurosurgery 70:56–65, 2012 DOI: 10.1227/NEU.0b013e31822cb882

To reduce the risk of disabling postoperative functional deficit in patients with lesions in the dominant hemisphere, information about the localization of eloquent language areas is mandatory.

OBJECTIVE: To demonstrate the feasibility of arcuate fascicle (AF) tractography for proper localization of eloquent language areas in the superior temporal (STG) and inferior frontal gyrus (IFG).

METHODS: Between January and June 2010, we performed surgery in 13 patients with highly eloquent lesions with close spatial relationship to the primary language areas. All of them received preoperative diffusion tensor imaging for AF tractography. The STG and IFG were delineated at the ends of the AF. Five patients underwent functional magnetic resonance imaging of the primary language areas. The results were compared with tractography.

RESULTS: Tractography of the AF without prior knowledge of the localization of the STG and IFG was feasible in all cases. In the cases with functional magnetic resonance imaging, the activation maps matched the tractography results. In all but 1 patient, preservation of the primary language areas was possible, proven by the good neurological outcome. One patient suffered from a language dysfunction caused by a lesion in the medial and inferior temporal gyrus along the surgical pathway.

CONCLUSION: Tractography of the AF is a useful tool for identification of parts of the main primary language areas. Using tractography as a localization procedure to determine the primary language areas aids in the delineation of the STG and IFG and thus may help reduce the risk of postoperative permanent neurological deficit.

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Posterior petrous bone meningiomas: surgical experience in 53 patients and literature review

Neurosurg Rev (2012) 35:53–66. DOI 10.1007/s10143-011-0333-6

Meningiomas of the posterior fossa represent a heterogeneous group of tumors regarding difficulty of resection and functional outcome.

The aim of this review was to focus on tumors located mainly on the posterior surface of the petrous bone and threatening hearing and facial functions.

An anatomical classification was used to evaluate surgical outcome depending on the relationship of the tumor to the internal auditory meatus. The authors performed a retrospective chart review of 53 consecutive patients operated on for a posterior petrous bone meningioma in a tertiary referral center and a literature review. Tumors were classified in four groups according to the modified Desgeorges and Sterkers classification: posterior petrous (P; 17 tumors), meatus and internal auditory canal (M; 12 tumors), petrous apex without invasion of the internal auditory canal (A; 9 tumors), and cerebellopontine angle with invasion of the internal auditory canal (AMP; 15 tumors).

The facial function was preserved in 100% of P and A tumors, 75% of group M tumors, and 53% of AMP tumors. Hearing preservation was attempted only in P, A, and M groups where rates of serviceable hearing preservation were 82%, 80%, and 66%, respectively. The cumulative rate of hearing preservation for AMP tumors was 45% in our literature review. The increased facial morbidity associated with AMP tumors compared with other groups was also confirmed by the review of the literature.

In conclusion, this study shows that among posterior petrous bone meningiomas, tumors invading the internal auditory canal present with increased postoperative functional morbidity in spite of a tailored approach regarding dural insertion.

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Primary Vertebral Tumors: A Review of Epidemiologic, Histological and Imaging Findings, Part II: Locally Aggressive and Malignant Tumors

Neurosurgery 70:211–219, 2012 DOI: 10.1227/NEU.0b013e31822d5f17

This second part of a comprehensive review of primary vertebral tumors focuses on locally aggressive and malignant tumors. As discussed in the earlier part of the review, both benign and malignant types of these tumors affect the adult and the pediatric population, and an understanding of their subtleties may increase their effective resection. In this review, we discuss the epidemiologic, histological, and imaging features of the most common locally aggressive primary vertebral tumors (chordoma and giantcell tumor) and malignant tumors (chondrosarcoma, Ewing sarcoma, multiple myeloma or plasmacytoma, and osteosarcoma). The figures used for illustration are from operative patients of the senior authors (Z.L.G. and J.H.C.). Taken together, parts 1 and 2 of this article provide a thorough and illustrative review of primary vertebral tumors.

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Application of Novel Response/Progression Measures for Surgically Delivered Therapies for Gliomas: Response Assessment in Neuro-Oncology (RANO) Working Group

Neurosurgery 70:234–244, 2012 DOI: 10.1227/NEU.0b013e318223f5

The Response Assessment in Neuro-Oncology (RANO) Working Group is an international, multidisciplinary effort to develop new standardized response criteria for clinical trials in brain tumors. The RANO group identified knowledge gaps relating to the definitions of tumor response and progression after the use of surgical or surgically based treatments.

OBJECTIVE: To outline a proposal for new response and progression criteria for the assessment of the effects of surgery and surgically delivered therapies for patients with gliomas.

METHODS: The Surgery Working Group of RANO identified surgically related end-point evaluation problems that were not addressed in the original Macdonald criteria, performed an extensive literature review, and used a consensus-building process to develop recommendations for how to address these issues in the setting of clinical trials.

RESULTS: Recommendations were formulated for surgically related issues, including imaging changes associated with surgical resection or surgically mediated adjuvant local therapies, the determination of progression in the setting where all enhancing tumor has been removed, and how new enhancement should be interpreted in the setting where local therapies that are known to produce nonspecific enhancement have been used. Additionally, the terminology used to describe the completeness of surgical resections has been recognized to be inconsistently applied to enhancing vs nonenhancing tumors, and a new set of descriptors is proposed.

CONCLUSION: The RANO process is intended to produce end-point criteria for clinical trials that take into account the effects of prior and ongoing therapies. The RANO criteria will continue to evolve as new therapies and technologies are introduced into clinical trial and/or practice.

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Long-term Follow-up of Pediatric Benign Cerebellar Astrocytomas

Neurosurgery 70:40–48, 2012 DOI: 10.1227/NEU.0b013e31822ff0ed

The long-term prognosis of cerebellar astrocytomas needs to be reviewed.

OBJECTIVE: To elucidate the factors influencing tumor recurrence or progression and to determine how long these patient with cerebellar astrocytomas require surveillance with neuroimaging.

METHODS: A retrospective review of 101 children surgically treated for a cerebellar astrocytoma and followed up for >10 years was performed.

RESULTS: Mean follow-up was 18.4 years. Total resection confirmed by postoperative imaging was performed in 51 patients (50.5%; group A). Twenty-three patients (22.8%) had surgical total resection; however, equivocal residual tumor was found on postoperative imaging (group B). Subtotal resection leaving a portion of brainstem or cerebellar peduncle was performed in 27 patients (26.7; group C). Of these 50 residual tumors, 16 (32%) showed spontaneous regression and 8 (16%) showed arrested growth. Radiographic recurrence or progression was noted in 29 patients (28.7%). Only 3 of 51 patients (5.9%) of group A with total resection had recurrence, whereas 26 of 50 residual tumors (52%; groups B and C) progressed. The only factor affecting recurrence or progression by multivariate analysis was the extent of surgical resection. All tumor recurrence or progression except for 1 (96.6%) occurred within 8 years from the original surgery (range, 2-132 months).

CONCLUSIONS: Overall prognosis of cerebellar astrocytomas is good; the 10-year survival rate was 100% and recurrence- or progression-free rate was 71.3% in our cohort. Almost half of residual tumors showed spontaneous regression or arrested growth in the long term. Eight to 10 years is considered to be a reasonable follow-up period by neuroimaging.

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Neurocognitive function before and after surgery for insular gliomas

J Neurosurg 115:1115–1125, 2011. DOI: 10.3171/2011.8.JNS11488

Insular gliomas can be resected with acceptable rates of neurological morbidity, but little is known with regard to impairment of higher-order neurocognitive functions. The frequency and functional impact of neurocognitive deficits in patients with gliomas has until recently been underappreciated. The authors therefore examined neurocognitive function in patients with insular gliomas and compared the findings in this group to those in a matched control group of patients with gliomas in nearby brain regions.

Methods. Thirty-three patients with WHO Grade II or III insular gliomas participated in neuropsychological evaluations before and after resection. To establish whether the pattern of neurocognitive performance was different from that of other patients with tumors in neighboring areas, patients with insular tumors were matched with control patients for age, educational level, preoperative Karnofsky Performance Scale score, tumor side, grade, and volume. The control group comprised patients in whom gliomas had been resected from frontal, temporal, and parietal areas near the insula. Baseline pre- and postoperative neurocognitive test results were compared between and within groups.

Results. Preoperative neurocognitive impairment was common in both insular and control groups. Patients with insular tumors had significantly worse preoperative performance on naming tests. In both groups, postoperative decline occurred in most neurocognitive domains. There were no statistically significant differences between patients in the insular and control groups with regard to rates of postoperative decline on any test. However, there were trends suggesting differential cognitive performance postoperatively, because patients with insular tumors were more likely to experience greater decline in learning and memory. Neurological morbidity was similar to prior rates reported in the literature.

Conclusions. Few statistically significant differences in cognitive function were observed between patients in the insular and control groups at either the pre- or postoperative evaluation, although there was a trend for patients with insular tumors to exhibit greater postoperative decline in learning and memory. Although technically more challenging, surgery for insular region glioma appears feasible without profound neurological or cognitive morbidity for many patients.

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