bluuebunny/crossref_metadata_2025 huggingface dataset:
Interfraction and intrafraction performance of the Gamma Knife Extend system for patient positioning and immobilization
Authors: Schlesinger David , Xu Zhiyuan , Taylor Frances , Yen Chun-Po , Sheehan Jason
Published: November 2018

Object

The Extend system for the Gamma Knife Perfexion makes possible multifractional Gamma Knife treatments. The Extend system consists of a vacuum-monitored immobilization frame and a positioning measurement system used to determine the location of the patient's head within the frame at the time of simulation imaging and before each treatment fraction. The measurement system consists of a repositioning check tool (RCT), which attaches to the Extend frame, and associated digital measuring gauges. The purpose of this study is to evaluate the performance of the Extend system for patient repositioning before each treatment session (fraction) and patient immobilization between (interfraction) and during (intrafraction) each session in the first 10 patients (36 fractional treatments) treated at the University of Virginia.

Methods

The RCT was used to acquire a set of reference measurements for each patient position at the time of CT simulation. Repositioning measurements were acquired before each fraction, and the patient position was adjusted until the residual radial difference from the reference position measurements was less than 1 mm. After treatment, patient position measurements were acquired, and the difference between those measurements and the ones obtained for patient position before the fraction was calculated as a measure of immobilization capability.

Analysis of patient setup and immobilization performance included calculation of the group mean, standard deviation (SD), and distribution of systematic (components affecting all fractions) and random (per fraction) uncertainty components.

Results

Across all patients and fractions, the mean radial setup difference from the reference measurements was 0.64 mm, with an SD of 0.24 mm. The distribution of systematic uncertainty (Σ) was 0.17 mm, and the distribution of random uncertainty (σ) was 0.16 mm. The root mean square (RMS) differences for each plate of the RCT were as follows: right = 0.35 mm; left = 0.41 mm; superior = 0.28 mm; and anterior = 0.20 mm.

The mean intrafractional positional difference across all treatments was 0.47 mm, with an SD of 0.30 mm. The distribution of systematic uncertainty was 0.18 mm, and the distribution of random uncertainty was 0.22 mm. The RMS differences for each plate of the RCT were 0.24 mm for the right plate, 0.22 mm for the left plate, 0.24 mm for the superior plate, and 0.34 mm for the anterior plate. Data from 1 fraction were excluded from the analysis because the vacuum-monitoring interlock detected patient motion, which in turn required repositioning in the middle of the fraction.

Conclusions

The Extend system can be used to reposition and immobilize patients in a radiosurgical setting. However, care should be taken to acquire measurements that can implicitly account for rotations of the patient's head. Further work is required to determine the sensitivity of the vacuum interlock to detect patient motion.
Effectiveness of a 1-day aspiration plus Gamma Knife surgery procedure for metastatic brain tumor with a cystic component
Authors: Higuchi Fumi , Kawamoto Shunsuke , Abe Yoshihiro , Kim Phyo , Ueki Keisuke
Published: November 2018

Object

Gamma Knife surgery (GKS) has gained increasing relevance in the treatment of metastatic brain tumors, but many metastatic tumors contain a large cystic component and often exceed the size limit for GKS. For such lesions, the authors adopted a procedure in which stereotactic aspiration is first performed and followed immediately by GKS on the same day. In this paper, the authors describe this 1-day combined procedure and evaluate its efficacy.

Methods

Between 2005 and 2010, 25 cystic metastases in 25 patients were treated at Dokkyo Medical University. The patients first underwent MRI and stereotactic aspiration of the cyst while stationary in a Leksell stereotactic frame; immediately afterward, the patients underwent a second MR imaging session and Gamma Knife treatment. Tumor volume reduction, tumor control rate, and overall survival were examined.

Results

Tumor volume, including the cystic component, decreased from 8.0–64.2 cm3 (mean 20.3 cm3) to 3.0–36.2 cm3 (mean 10.3 cm3) following aspiration, and the volume of 24 of 25 lesions decreased to less than 16.6 cm3, which is equivalent to the volume of a 3.16-cm sphere. At least 20 Gy was delivered to the entire lesion in 24 of 25 cases. Good tumor control was obtained in 16 of 21 cases that could be evaluated during a median follow-up period of 11 months (range 1–27 months); however, reaccumulation of cyst contents was observed in 2 patients who required Ommaya reservoir placement.

Conclusions

The 1-day aspiration plus GKS procedure is an effective and time-efficient treatment for large cystic brain metastases.
High-precision volume-staged Gamma Knife surgery and equivalent hypofractionation dose schedules for treating large arteriovenous malformations
Authors: Fogh Shannon , Ma Lijun , Gupta Nalin , Sahgal Arjun , Nakamura Jean L. , Barani Igor , Sneed Penny K. , McDermott Michael , Larson David A.
Published: November 2018

Object

The goal of this study was to develop a technique for performing submillimeter high-precision volume-staged Gamma Knife surgery and investigate its potential benefits in comparison with hypofractionated stereotactic radiotherapy (SRT) for treating large arteriovenous malformations (AVMs).

Methods

The authors analyzed 7 pediatric AVM cases treated with volume-staged stereotactic radiosurgery (SRS) using the Gamma Knife Perfexion at the University of California, San Francisco. The target and normal tissue contours from each case were exported for hypofractionated treatment planning based on the Gamma Knife Extend system or the CyberKnife SRT. Both the Gamma Knife Extend and CyberKnife treatment plans were matched to yield the same level of target coverage (95%–98%) and conformity indices (1.24–1.46). Finally, hypofractionated treatment plans were compared with volume-staged treatment plans for sparing normal brain by using biologically equivalent 12-Gy normal brain volumes.

Results

Hypofractionated Gamma Knife Extend and CyberKnife treatment plans exhibited practically identical sparing of normal brain for the studied cases. However, when matching such values with volume-staged treatments for the biological effective dose, only conservative dose fractionation schemes, such as 27.3 Gy in 5 fractions and 25 Gy in 4 fractions, were found to be comparable to the volume-staged treatments. On average, this represents a mean 18.7% ± 7.3% reduction in the single-fraction biologically equivalent dose for hypofractionated treatments versus the reference volume-staged treatments (p < 0.001).

Conclusions

Volume staging remains advantageous over hypofractionation in delivering a higher dose to the target and for better sparing of normal brain tissue in the treatment of large AVMs. More clinical data are needed, however, to justify the clinical superiority of this increased dose when compared with a hypofractionated treatment regimen.
Role of Gamma Knife surgery in the treatment of intracranial dural arteriovenous fistulas
Authors: Hanakita Shunya , Koga Tomoyuki , Shin Masahiro , Shojima Masaaki , Igaki Hiroshi , Saito Nobuhito
Published: November 2018

Object

The goal of this study was to assess the efficacy of Gamma Knife surgery (GKS) in the management of dural arteriovenous fistulas (dAVFs).

Methods

The authors performed a retrospective analysis of a group of 22 patients who underwent GKS for dAVFs at the University of Tokyo Hospital between 1991 and 2009. The patients underwent CT or MR imaging with contrast enhancement every 6 months after GKS; when obliteration of a dAVF was indicated by these images, patients also underwent angiography. Follow-up in these patients ranged from 12 months to 100 months (median 33 months) after GKS.

Results

Obliteration of the dAVF was confirmed by neuroimaging in 12 patients (55%). According to a Kaplan-Meier analysis, obliteration rates for the dAVFs were 51% at 3 years and 80% at 5 years. The obliteration rate for lesions without cortical venous drainage (CVD) was 86%, which was significantly higher than the rate for dAVFs with CVD (47%) (p = 0.007). Hemorrhage at presentation (p = 0.03), a target volume less than 1.5 cm3 (p = 0.009), and Cognard Type III or IV dAVF (p = 0.005) were factors associated with a higher obliteration rate. Among 10 patients whose dAVFs were not obliterated by the initial GKS, 5 patients underwent additional treatment and complete obliteration was achieved in all. Relief of tinnitus was obtained in 5 (83%) of 6 patients with transverse-sigmoid sinus dAVFs, and ophthalmic symptoms improved in 2 (67%) of 3 patients with cavernous sinus dAVFs. No patient experienced interval hemorrhage or radiation-induced complications after treatment.

Conclusions

Gamma Knife surgery is a safe and effective treatment for dAVF. It can be a first line of therapy in the multidisciplinary treatment strategy for dAVFs, especially when significant morbidity is anticipated with other therapeutic options. One should be very careful about recommending GKS for patients harboring dAVFs with CVD because of the expected natural history of such a lesion and the possibility of other therapeutic options.
Clinical results of Gamma Knife surgery for cavernous sinus hemangiomas
Authors: Li Peng , Ren Haibo , Zhang Shizhen , Wang Wei
Published: November 2018

Object

The purpose of this study was to gain an understanding of the efficacy and safety of Gamma Knife surgery (GKS) for the treatment of cavernous sinus hemangiomas (CSHs). The authors report on 16 patients who underwent GKS as a primary or adjuvant treatment for CSH.

Methods

Sixteen patients harboring CSHs (14 women and 2 men ranging in age from 21 to 65 years [mean 41.3 years]) underwent GKS at West China Hospital. In 4 patients the diagnosis was based on histological findings; in the other 12 patients it was based on findings on MR images. After patients were given a local anesthetic agent, the treatments were performed using a Leksell Gamma Knife model C. Gadolinium-enhanced MR images of T1-weighted, T2-weighted, and FLAIR sequences were obtained to determine the pretreatment location of the lesion. A mean peripheral dose of 13.3 Gy (range 11–14 Gy) was directed to the 40%–50% isodose line.

Results

The mean follow-up time in this study was 21.5 months (range 12–36 months). In 11 of 12 patients with symptoms, clinical improvement was reported at an average of 3.3 months (range 1–8 months) after GKS. Significant or partial tumor shrinkage was observed in 14 patients (87.5%) at the last follow-up. No new neurological impairments were reported after GKS.

Conclusions

Magnetic resonance imaging may play an important role in the preoperative diagnosis of CSHs. Gamma Knife surgery may be a safe and effective primary or adjuvant treatment option for CSHs; however, long-term follow-up with more cases is needed to verify the benefits of this treatment.
Standardization of terminology in stereotactic radiosurgery: Report from the Standardization Committee of the International Leksell Gamma Knife Society
Authors: Torrens Michael , Chung Caroline , Chung Hyun-Tai , Hanssens Patrick , Jaffray David , Kemeny Andras , Larson David , Levivier Marc , Lindquist Christer , Lippitz Bodo , Novotny Josef , Paddick Ian , Prasad Dheerendra , Yu Chung Ping
Published: November 2018

Object

This report has been prepared to ensure more uniform reporting of Gamma Knife radiosurgery treatment parameters by identifying areas of controversy, confusion, or imprecision in terminology and recommending standards.

Methods

Several working group discussions supplemented by clarification via email allowed the elaboration of a series of provisional recommendations. These were also discussed in open session at the 16th International Leksell Gamma Knife Society Meeting in Sydney, Australia, in March 2012 and approved subject to certain revisions and the performance of an Internet vote for approval from the whole Society. This ballot was undertaken in September 2012.

Results

The recommendations in relation to volumes are that Gross Target Volume (GTV) should replace Target Volume (TV); Prescription Isodose Volume (PIV) should generally be used; the term Treated Target Volume (TTV) should replace TVPIV, GTV in PIV, and so forth; and the Volume of Accepted Tolerance Dose (VATD) should be used in place of irradiated volume. For dose prescription and measurement, the prescription dose should be supplemented by the Absorbed Dose, or DV% (for example, D95%), the maximum and minimum dose should be related to a specific tissue volume (for example, D2% or preferably D1 mm3), and the median dose (D50%) should be recorded routinely. The Integral Dose becomes the Total Absorbed Energy (TAE). In the assessment of planning quality, the use of the Target Coverage Ratio (TTV/ GTV), Paddick Conformity Index (PCI = TTV2/[GTV · PIV]), New Conformity Index (NCI = [GTV · PIV]/TTV2), Selectivity Index (TTV/PIV), Homogeneity Index (HI = [D2% –D98%]/D50%), and Gradient Index (GI = PIV0.5/PIV) are reemphasized. In relation to the dose to Organs at Risk (OARs), the emphasis is on dose volume recording of the VATD or the dose/volume limit (for example, V10) in most cases, with the additional use of a Maximum Dose to a small volume (such as 1 mm3) and/or a Point Dose and Mean Point Dose in certain circumstances, particularly when referring to serial organs. The recommendations were accepted by the International Leksell Gamma Knife Society by a vote of 92% to 8%.

Conclusions

An agreed-upon and uniform terminology and subsequent standardization of certain methods and procedures will advance the clinical science of stereotactic radiosurgery.
Gamma Knife surgery for treating brain metastases arising from hepatocellular carcinomas
Authors: Park Eun Suk , Kwon Do Hoon , Park Jun Bum , Lee Do Hee , Cho Young Hyun , Kim Jeong Hoon , Kim Chang Jin
Published: November 2018

Object

Brain metastases from hepatocellular carcinoma (HCC) are rare, and the evidence of the effectiveness of Gamma Knife surgery (GKS) in this disease is lacking. The authors report their institutional experience with GKS in patients with brain metastases from HCCs.

Methods

The authors retrospectively reviewed the medical records of 73 consecutive patients who had a combined total of 141 brain metastases arising from HCCs and were treated with GKS. Sixty-four (87.7%) patients were male, and the mean age of the patients was 52.5 years (range 30–79 years). The mean tumor volume was 7.35 cm3 (range 0.19–33.7 cm3). The median margin dose prescribed was 23 Gy (range 15–32 Gy). Univariate and multivariate survival analyses were performed to identify possible prognostic factors of outcomes.

Results

The estimated rate of local tumor control was 79.6% at 3 months after GKS. The median overall survival time after GKS was 16 weeks. The actuarial survival rates were 76.7%, 58.9%, and 26.0% at 4, 12, and 24 weeks after GKS, respectively. In the univariate analysis, an age of ≤ 65 years, Child-Pugh Class A (pertaining to liver function), high Karnofsky Performance Scale score (≥ 70), and low Radiation Therapy Oncology Group recursive partitioning analysis class (I or II) were positively associated with the survival times of patients. No statistically significant variable was identified in the multivariate analysis.

Conclusions

Although survival was extremely poor in patients with brain metastases from HCCs, GKS showed acceptable local tumor control at 3 months after the treatment. The authors suggest that GKS represents a noninvasive approach that may provide a valuable option for treating patients with brain metastases from HCCs.
Cost-effectiveness of stereotactic radiosurgery with and without whole-brain radiotherapy for the treatment of newly diagnosed brain metastases
Authors: Hall Matthew D. , McGee James L. , McGee Mackenzie C. , Hall Kevin A. , Neils David M. , Klopfenstein Jeffrey D. , Elwood Patrick W.
Published: November 2018

Object

Stereotactic radiosurgery (SRS) alone is increasingly used in patients with newly diagnosed brain metastases. Stereotactic radiosurgery used together with whole-brain radiotherapy (WBRT) reduces intracranial failure rates, but this combination also causes greater neurocognitive toxicity and does not improve survival. Critics of SRS alone contend that deferring WBRT results in an increased need for salvage therapy and in higher costs. The authors compared the cost-effectiveness of treatment with SRS alone, SRS and WBRT (SRS+WBRT), and surgery followed by SRS (S+SRS) at the authors' institution.

Methods

The authors retrospectively reviewed the medical records of 289 patients in whom brain metastases were newly diagnosed and who were treated between May 2001 and December 2007. Overall survival curves were plotted using the Kaplan-Meier method. Multivariate proportional hazards analysis (MVA) was used to identify factors associated with overall survival. Survival data were complete for 96.2% of patients, and comprehensive data on the resource use for imaging, hospitalizations, and salvage therapies were available from the medical records. Treatment costs included the cost of initial and all salvage therapies for brain metastases, hospitalizations, management of complications, and imaging. They were computed on the basis of the 2007 Medicare fee schedule from a payer perspective. Average treatment cost and average cost per month of median survival were compared. Sensitivity analysis was performed to examine the impact of variations in key cost variables.

Results

No significant differences in overall survival were observed among patients treated with SRS alone, SRS+WBRT, or S+SRS with respective median survival of 9.8, 7.4, and 10.6 months. The MVA detected a significant association of overall survival with female sex, Karnofsky Performance Scale (KPS) score, primary tumor control, absence of extracranial metastases, and number of brain metastases. Salvage therapy was required in 43% of SRS-alone and 26% of SRS+WBRT patients (p < 0.009). Despite an increased need for salvage therapy, the average cost per month of median survival was $2412 per month for SRS alone, $3220 per month for SRS+WBRT, and $4360 per month for S+SRS (p < 0.03). Compared with SRS+WBRT, SRS alone had an average incremental cost savings of $110 per patient. Sensitivity analysis confirmed that the average treatment cost of SRS alone remained less than or was comparable to SRS+WBRT over a wide range of costs and treatment efficacies.

Conclusions

Despite an increased need for salvage therapy, patients with newly diagnosed brain metastases treated with SRS alone have similar overall survival and receive more cost-effective care than those treated with SRS+WBRT. Compared with SRS+WBRT, initial management with SRS alone does not result in a higher average cost.
Glossopharyngeal neuralgia and radiosurgery
Authors: Martínez-Álvarez Roberto , Martínez-Moreno Nuria , Kusak M. Elena , Rey-Portolés Germán
Published: November 2018

Object

Glossopharyngeal neuralgia is difficult to treat. On the basis of results obtained by using Gamma Knife surgery (GKS) to treat trigeminal neuralgia, the authors have used GKS to treat glossopharyngeal neuralgia in a series of patients since 2007. Their objectives with this study were to demonstrate the usefulness and safety of GKS for treating glossopharyngeal neuralgia and to describe a simple treatment method.

Methods

From 2007 through 2013, the authors treated glossopharyngeal neuralgia in 5 patients (4 women and 1 man), who ranged in age from 36 to 74 years. One patient had previously undergone treatment for trigeminal neuralgia at the Ruber International Hospital, Department of Functional Neurosurgery and Gamma Knife Radiosurgery. For all patients, before GKS, medical management did not control the pain. Three patients had previously undergone surgery (2 microvascular decompression and 1 rhizotomy) without improvement. For the GKS procedure, the nerve was localized by MRI and CT under stereotactic conditions and the target was located at the level of the glossopharyngeal meatus of the jugular foramen. For 1 patient, a maximum dose of 80 Gy was administrated with a 4-mm collimator, and for the others, the maximum dose was 90 Gy. The nerves located near the glossopharyngeal nerve received between 63 and 10 Gy, and the brainstem received less than 10 Gy. The mean follow-up time was 43 months (range 14–83 months).

Results

All patients improved within 3–6 months after undergoing GKS. All 5 are without pain; 3 patients take no medication, but the other 2 patients continue to take medication. No neurological deficits after GKS were observed.

Conclusions

GKS is useful and safe for treating glossopharyngeal neuralgia, even for patients who have previously undergone surgery. GKS should be considered as the initial therapy for glossopharyngeal neuralgia.
Microsurgery for vestibular schwannoma after Gamma Knife surgery: challenges and treatment strategies
Authors: Lee Cheng-Chia , Wu Hsiu-Mei , Chung Wen-Yuh , Chen Ching-Jen , Pan David Hung-Chi , Hsu Sanford P. C.
Published: November 2018

Object

Resection of vestibular schwannoma (VS) after Gamma Knife surgery (GKS) is infrequently performed. The goals of this study were to analyze and discuss the neurological outcomes and technical challenges of VS resection and to explore strategies for treating tumors that progress after GKS.

Methods

In total, 708 patients with VS underwent GKS between 1993 and 2012 at Taipei Veterans General Hospital. The post-GKS clinical courses, neurological presentations, and radiological changes in these patients were analyzed. Six hundred patients with imaging follow-up of at least 1 year after GKS treatment were included in this study.

Results

Thirteen patients (2.2%) underwent microsurgery on average 36.8 months (range 3–107 months) after GKS. The indications for the surgery included symptomatic adverse radiation effects (in 4 patients), tumor progression (in 6), and cyst development (in 3). No morbidity or death as a result of the surgery was observed. At the last follow-up evaluation, all patients, except 1 patient with a malignant tumor, had stable or near-normal facial function.

Conclusions

For the few VS cases that require resection after radiosurgery, maximal tumor resection can be achieved with modern skull-based techniques and refined neuromonitoring without affecting facial nerve function.
Clinical and pathological analysis of benign brain tumors resected after Gamma Knife surgery
Authors: Liu Ali , Wang Jun-Mei , Li Gui-Lin , Sun Yi-Lin , Sun Shi-Bin , Luo Bin , Wang Mei-Hua
Published: November 2018

Object

The goal of this study was to assess the clinical and pathological features of benign brain tumors that had been treated with Gamma Knife surgery (GKS) followed by resection.

Methods

In this retrospective chart review, the authors identified 61 patients with intracranial benign tumors who had undergone neurosurgical intervention after GKS. Of these 61 patients, 27 were male and 34 were female; mean age was 49.1 years (range 19–73 years). There were 24 meningiomas, 18 schwannomas, 14 pituitary adenomas, 3 hemangioblastomas, and 2 craniopharyngiomas. The interval between GKS and craniotomy was 2–168 months, with a median of 24 months; for 7 patients, the interval was 10 years or longer. For 21 patients, a craniotomy was performed before and after GKS; in 9 patients, pathological specimens were obtained before and after GKS. A total of 29 patients underwent GKS at the Beijing Tiantan Hospital. All specimens obtained by surgical intervention underwent histopathological examination.

Results

Most patients underwent craniotomy because of tumor recurrence and/or exacerbation of clinical signs and symptoms. Neuroimaging analyses indicated tumor growth in 42 patients, hydrocephalus in 10 patients with vestibular schwannoma, cystic formation with mass effect in 7 patients, and tumor hemorrhage in 13 patients, of whom 10 had pituitary adenoma. Pathological examination demonstrated that, regardless of the type of tumor, GKS mainly induced coagulative necrosis of tumor parenchyma and stroma with some apoptosis and, ultimately, scar formation. In addition, irradiation induced vasculature stenosis and occlusion and tumor degeneration as a result of reduced blood supply. GKS-induced vasculature reaction was rarely observed in patients with pituitary adenoma. Pathological analysis of tumor specimens obtained before and after GKS did not indicate increased tumor proliferation after GKS.

Conclusions

Radiosurgery is effective for intracranial benign tumors of small size and deep location and for tumor recurrence after surgical intervention; it is not effective for intracranial tumors with symptomatic mass effect. The radiobiological effects of stereotactic radiosurgery on the benign tumors are mainly caused by cellular and vascular mechanisms. Among the patients in this study, high-dose irradiation did not increase tumor proliferation. GKS can induce primary and secondary effects in tumors, which could last more than 10 years, thereby warranting long-term follow-up after GKS.
Gamma Knife radiosurgery for vestibular schwannoma: clinical results at long-term follow-up in a series of 379 patients
Authors: Boari Nicola , Bailo Michele , Gagliardi Filippo , Franzin Alberto , Gemma Marco , Vecchio Antonella del , Bolognesi Angelo , Picozzi Piero , Mortini Pietro
Published: November 2018

Object

Since the 1990s, Gamma Knife radiosurgery (GKRS) has become the first-line treatment option for small- to medium-size vestibular schwannomas (VSs), especially in patients without mass effect–related symptoms and with functional hearing. The aim of this study was to assess the safety and efficacy of GKRS, in terms of tumor control, hearing preservation, and complications, in a series of 379 consecutive patients treated for VS.

Methods

Of 523 patients treated at the authors' institution for VS between 2001 and 2010, the authors included 379 who underwent GKRS as the primary treatment. These patients were not affected by Type 2 neurofibromatosis and had clinical follow-up of at least 36 months. Clinical follow-up (mean and median 75.7 and 69.5 months, respectively) was performed for all patients, whereas audiometric and quantitative radiological follow-up examinations were obtained for only 153 and 219 patients, respectively. The patients' ages ranged from 23 to 85 years (mean 59 years). The mean tumor volume was 1.94 ± 2.2 cm3 (median 1.2 cm3, range 0.013–14.3 cm3), and the median margin dose was 13 Gy (range 11–15 Gy). Parameters considered as determinants of the clinical outcome were long-term tumor control, hearing preservation, and complications. A statistical analysis was performed to correlate clinical outcomes with the radiological features of the tumor, dose-planning parameters, and patient characteristics.

Results

Control of the tumor with GKRS was achieved in 97.1% of the patients. In 82.7% of the patients, the tumor volume had decreased at the last follow-up, with a mean relative reduction of 34.1%. The rate of complications was very low, with most consisting of a transient worsening of preexisting symptoms. Patients who had vertigo, balance disorders, or facial or trigeminal impairment usually experienced a complete or at least significant symptom relief after treatment. However, no significant improvement was observed in patients previously reporting tinnitus. The overall rate of preservation of functional hearing at the long-term follow-up was 49%; in patients with hearing classified as Gardner-Robertson (GR) Class I, this value was 71% and reached 93% among cases of GR Class I hearing in patients younger than 55 years.

Conclusions

Gamma Knife radiosurgery is a safe and effective treatment for VS, achieving tumor control in 97.1% of cases and resulting in a very low morbidity rate. Younger GR Class I patients had a significantly higher probability of retaining functional hearing even at the 10-year follow-up; for this reason, the time between symptom onset, diagnosis, and treatment should be shortened to achieve better outcomes in functional hearing preservation.
Race against the clock: Overcoming challenges in the management of anticoagulant-associated intracerebral hemorrhage
Authors: Le Roux Peter , Pollack Charles V. , Milan Melissa , Schaefer Alisa
Published: November 2018

Patients receiving anticoagulation therapy who present with any type of intracranial hemorrhage—including subdural hematoma, epidural hematoma, subarachnoid hemorrhage, and intracerebral hemorrhage (ICH)—require urgent correction of their coagulopathy to prevent hemorrhage expansion, limit tissue damage, and facilitate surgical intervention as necessary. The focus of this review is acute ICH, but the principles of management for anticoagulation-associated ICH (AAICH) apply to patients with all types of intracranial hemorrhage, whether acute or chronic.

A number of therapies—including fresh frozen plasma (FFP), intravenous vitamin K, activated and inactivated prothrombin complex concentrates (PCCs), and recombinant activated factor VII (rFVIIa)—have been used alone or in combination to treat AAICH to reverse anticoagulation, help achieve hemodynamic stability, limit hematoma expansion, and prepare the patient for possible surgical intervention. However, there is a paucity of high-quality data to direct such therapy. The use of 3-factor PCC (activated and inactivated) and rFVIIa to treat AAICH constitutes off-label use of these therapies in the United States. However, in April 2013, the US Food and Drug Administration (FDA) approved Kcentra (a 4-factor PCC) for the urgent reversal of vitamin K antagonist (VKA) anticoagulation in adults with acute major bleeding. Plasma is the only other product approved for this use in the United States.1 Inconsistent recommendations, significant barriers (e.g., clinician-, therapy-, or logistics-based barriers), and a lack of approved treatment pathways in some institutions can be potential impediments to timely and evidence-based management of AAICH with available therapies. Patient assessment, therapy selection, whether to use a reversal or factor repletion agent alone or in combination with other agents, determination of site-of-care management, eligibility for neurosurgery, and potential hematoma evacuation are the responsibilities of the neurosurgeon, but ultimate success requires a multidisciplinary approach with consultation from the emergency department (ED) physician, pharmacist, hematologist, intensivist, neurologist, and, in some cases, the trauma surgeon.
US regional variations in rates, outcomes, and costs of spinal arthrodesis for lumbar spinal stenosis in working adults aged 40–65 years
Authors: Raad Micheal , Reidler Jay S. , El Dafrawy Mostafa H. , Amin Raj M. , Jain Amit , Neuman Brian J. , Riley Lee H. , Sciubba Daniel M. , Kebaish Khaled M. , Skolasky Richard L.
Published: November 2018

OBJECTIVE

It is important to identify differences in the treatment of common diseases over time and across geographic regions. Several studies have reported increased use of arthrodesis to treat lumbar spinal stenosis (LSS). The purpose of this study was to investigate geographic variations in the treatment of LSS by US region.

METHODS

The authors reviewed inpatient and outpatient medical claims from 2010 to 2014 using the MarketScan Commercial Claims and Encounters database (Truven Health Analytics), which includes data on commercially insured members younger than 65 years. ICD-9 code 724.02 was used to identify patients aged ≥ 40 and < 65 years who underwent surgery for “spinal stenosis of the lumbar region” and for whom LSS was the only principal diagnosis. The primary outcome was the performance of spinal arthrodesis as part of the procedure. Geographic regions were based on patient residence and defined according to the US Census Bureau as the Northeast, Midwest, South, and West.

RESULTS

Rates of arthrodesis, as opposed to decompression alone, varied significantly by region, from 48% in the South, to 42% in the Midwest, 36% in the Northeast, and 31% in the West. After controlling for patient age, sex, and Charlson Comorbidity Index values, the differences remained significant. Compared with patients in the Northeast, those in the South (OR 1.6, 95% CI 1.50–1.75) and Midwest (OR 1.3, 95% CI 1.18–1.41) were significantly more likely to undergo spinal arthrodesis. On multivariate analysis, patients in the West were significantly less likely to have a prolonged hospital stay (> 3 days) than those in the Northeast (OR 0.84, 95% CI 0.75–0.94). Compared with the rate in the Northeast, the rates of discharge to a skilled nursing facility were lower in the South (OR 0.41, 95% CI 0.31–0.55) and West (OR 0.72, 95% CI 0.53–0.98). The 30-day readmission rate was significantly lower in the West (OR 0.81, 95% CI 0.65–0.98) than in the Northeast and similar between the other regions. Mean payments were significantly higher in the Midwest (mean difference $5503, 95% CI $4279–$6762), South (mean difference $6187, 95% CI $5041–$7332), and West (mean difference $7732, 95% CI $6384–$9080) than in the Northeast.

CONCLUSIONS

The use of spinal arthrodesis, as well as surgical outcomes and payments for the treatment of LSS, varies significantly by US region. This highlights the importance of developing national recommendations for the treatment of LSS.
Location of correction within the lumbar spine impacts acute adjacent-segment kyphosis
Authors: Lafage Renaud , Obeid Ibrahim , Liabaud Barthelemy , Bess Shay , Burton Douglas , Smith Justin S. , Jalai Cyrus , Hostin Richard , Shaffrey Christopher I. , Ames Christopher , Kim Han Jo , Klineberg Eric , Schwab Frank , Lafage Virginie , _ _
Published: November 2018

OBJECTIVE

The surgical correction of adult spinal deformity (ASD) often involves modifying lumbar lordosis (LL) to restore ideal sagittal alignment. However, corrections that include large changes in LL increase the risk for development of proximal junctional kyphosis (PJK). Little is known about the impact of cranial versus caudal correction in the lumbar spine on the occurrence of PJK. The goal of this study was to investigate the impact of the location of the correction on acute PJK development.

METHODS

This study was a retrospective review of a prospective multicenter database. Surgically treated ASD patients with early follow-up evaluations (6 weeks) and fusions of the full lumbosacral spine were included. Radiographic parameters analyzed included the classic spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], PI−LL, and sagittal vertical axis [SVA]) and segmental correction. Using Glattes’ criteria, patients were stratified into PJK and noPJK groups and propensity matched by age and regional lumbar correction (ΔPI−LL). Radiographic parameters and segmental correction were compared between PJK and noPJK patients using independent t-tests.

RESULTS

After propensity matching, 312 of 483 patients were included in the analysis (mean age 64 years, 76% women, 40% with PJK). There were no significant differences between PJK and noPJK patients at baseline or postoperatively, or between changes in alignment, with the exception of thoracic kyphosis (TK) and ΔTK. PJK patients had a decrease in segmental lordosis at L4-L5-S1 (−0.6° vs 1.6°, p = 0.025), and larger increases in segmental correction at cranial levels L1-L2-L3 (9.9° vs 7.1°), T12-L1-L2 (7.3° vs 5.4°), and T11-T12-L1 (2.9° vs 0.7°) (all p < 0.05).

CONCLUSIONS

Although achievement of an optimal sagittal alignment is the goal of realignment surgery, dramatic lumbar corrections appear to increase the risk of PJK. This study was the first to demonstrate that patients who developed PJK underwent kyphotic changes in the L4–S1 segments while restoring LL at more cranial levels (T12–L3). These findings suggest that restoring lordosis at lower lumbar levels may result in a decreased risk of developing PJK.
Education level as a prognostic indicator at 12 months following decompression surgery for symptomatic lumbar spinal stenosis
Authors: Elsayed Galal A. , Dupépé Esther B. , Erwood Matthew S. , Davis Matthew C. , McClugage Samuel G. , Szerlip Paul , Walters Beverly C. , Hadley Mark N.
Published: November 2018

OBJECTIVE

The goal of this study was to analyze the effect of patient education level on functional outcomes following decompression surgery for symptomatic lumbar spinal stenosis.

METHODS

Patients with surgically decompressed symptomatic lumbar stenosis were collected in a prospective observational registry at a single institution between 2012 and 2014. Patient education level was compared to surgical outcomes to elucidate any relationships. Outcomes were defined using the Oswestry Disability Index score, back and leg pain visual analog scale (VAS) score, and the EuroQol–5 Dimensions questionnaire score.

RESULTS

Of 101 patients with symptomatic lumbar spinal stenosis, 27 had no college education and 74 had a college education (i.e., 2-year, 4-year, or postgraduate degree). Preoperatively, patients with no college education had statistically significantly greater back and leg pain VAS scores when compared to patients with a college education. However, there was no statistically significant difference in quality of life or disability between those with no college education and those with a college education. Postoperatively, patients in both cohorts improved in all 4 patient-reported outcomes at 3 and 12 months after treatment for symptomatic lumbar spinal stenosis.

CONCLUSIONS

Despite their education level, both cohorts showed improvement in their functional outcomes at 3 and 12 months after decompression surgery for symptomatic lumbar spinal stenosis.
Association between payer status and patient-reported outcomes in adult patients with lumbar spinal stenosis treated with decompression surgery
Authors: Elsayed Galal , McClugage Samuel G. , Erwood Matthew S. , Davis Matthew C. , Dupépé Esther B. , Szerlip Paul , Walters Beverly C. , Hadley Mark N.
Published: November 2018

OBJECTIVE

Insurance disparities can have relevant effects on outcomes after elective lumbar spinal surgery. The aim of this study was to evaluate the association between private/public payer status and patient-reported outcomes in adult patients who underwent decompression surgery for lumbar spinal stenosis.

METHODS

A sample of 100 patients who underwent surgery for lumbar spinal stenosis from 2012 to 2014 was evaluated as part of the prospectively collected Quality Outcomes Database at a single institution. Outcome measures were evaluated at 3 months and 12 months, analyzed in regard to payer status (private insurance vs Medicare/Veterans Affairs insurance), and adjusted for potential confounders.

RESULTS

At baseline, patients had similar visual analog scale back and leg pain, Oswestry Disability Index, and EQ-5D scores. At 3 months postintervention, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.11, p < 0.001) and more leg pain (mean difference 1.26, p = 0.05). At 12 months, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.14, p < 0.001). There were no significant differences at 3 months or 12 months between groups for back pain (p = 0.14 and 0.43) or disability (p = 0.19 and 0.15). Across time points, patients in both groups showed improvement at 3 months and 12 months in all 4 functional outcomes compared with baseline (p < 0.001).

CONCLUSIONS

Both private and public insurance patients had significant improvement after elective lumbar spinal surgery. Patients with public insurance had slightly less improvement in quality of life after surgery than those with private insurance but still benefited greatly from surgical intervention, particularly with respect to functional status.
Artificial disc replacement versus fusion in patients with cervical degenerative disc disease with radiculopathy: 5-year outcomes from the National Swedish Spine Register
Authors: MacDowall Anna , Skeppholm Martin , Lindhagen Lars , Robinson Yohan , Löfgren Håkan , Michaëlsson Karl , Olerud Claes
Published: November 2018

OBJECTIVE

The long-term efficacy of artificial disc replacement (ADR) surgery compared with fusion after decompression for the treatment of cervical degenerative disc disease and radiculopathy has not previously been investigated in a population-based setting.

METHODS

All patients with cervical degenerative disc disease and radiculopathy who were in the national Swedish Spine Registry (Swespine) beginning in January 1, 2006, were eligible for the study. Follow-up information was obtained up to November 15, 2017. The authors compared, using propensity score matching, patients treated with anterior decompression and insertion of an ADR with patients who underwent anterior decompression combined with fusion surgery. The primary outcome was the Neck Disability Index (NDI), a patient-reported function score ranging from 0% to 100%, with higher scores indicating greater disability and a minimum clinically important difference of > 15%.

RESULTS

A total of 3998 patients (2018:1980 women/men) met the inclusion criteria, of whom 204 had undergone arthroplasty and 3794 had undergone fusion. After propensity score matching, 185 patients with a mean age of 49.7 years remained in each group. Scores on the NDI were approximately halved in both groups after 5 years, but without a significant mean difference in NDI (3.0%; 95% CI −8.4 to 2.4; p = 0.28) between the groups. There were no differences between the groups in EuroQol–5 Dimensions or in pain scores for the neck and arm.

CONCLUSIONS

In patients with cervical degenerative disc disease and radiculopathy, decompression plus ADR surgery did not result in a clinically important difference in outcomes after 5 years, compared with decompression and fusion surgery.
Radiosurgery for residual or recurrent nonfunctioning pituitary adenoma
Authors: Sheehan Jason P. , Kondziolka Douglas , Flickinger John , Lunsford L. Dade
Published: November 2018

Object. Nonfunctioning pituitary adenomas comprise approximately 30% of all pituitary tumors. The purpose of this retrospective study is to evaluate the efficacy and role of gamma knife radiosurgery (GKS) in the management of residual or recurrent nonfunctioning pituitary adenomas.

Methods. A review was conducted of the data obtained in 42 patients who underwent adjuvant GKS at the University of Pittsburgh between 1987 and 2001. Prior treatments included transsphenoidal resection, craniotomy and resection, or conventional radiotherapy. Endocrinological, ophthalmological, and radiological responses were evaluated. The duration of follow-up review varied from 6 to 102 months (mean 31.2 months). Fifteen patients were observed for more than 40 months. The mean radiation dose to the tumor margin was 16 Gy. Conformal radiosurgery planning was used to restrict the dose to the optic nerve and chiasm.

Tumor control after GKS was achieved in 100% of patients with microadenomas and 97% of patients with macroadenomas. Gamma knife radiosurgery was equally effective in controlling adenomas with cavernous sinus invasion and suprasellar extension. No patient developed a new endocrinological deficiency following GKS. One patient's tumor enlarged with an associated decline in visual function. Another patient experienced a deterioration of visual fields despite a decrease in tumor size.

Conclusions. Gamma knife radiosurgery can achieve tumor control in virtually all residual or recurrent nonfunctioning pituitary adenomas. Dose sparing facilitates tumor management even when the adenoma is close to the optic apparatus or invades the cavernous sinus.
Hemorrhage risks and obliteration rates of arteriovenous malformations after gamma knife radiosurgery
Authors: Inoue Hiroshi K. , Ohye Chihiro
Published: November 2018

Object. The purpose of this study was to analyze the risk of hemorrhage and the obliteration rate after treatment of patients with arteriovenous malformations (AVMs).

Methods. Between 1991 and 1995, 115 patients were treated using gamma knife radiosurgery (GKS). Surgical planning was based on angiograms and three-dimensional images. The angiographic features of the AVMs and the risk factors for hemorrhage were then evaluated.

Hemorrhages occurred in eight patients (7%) 7 to 42 months after GKS. Based on AVM morphology, the rates of hemorrhage were five (7.6%) of 66 for AVMs with a single draining vein, seven (14%) of 66 for AVMs with deep drainage, four (26.7%) of 15 for AVMs with a varix, four (28.6%) of 14 for AVMs with venous obstruction, eight (17.0%) of 47 for high-flow (shunt- and mixed-type) AVMs, and five (35.7%) of 14 for large AVMs with a volume of more than 10 cm3. No hemorrhages were observed in association with low-flow (moyamoya-type) AVMs in this series. Total AVM obliteration was achieved in 81.3% of 80 patients who underwent angiography. The obliteration rate was 91.3% for moyamoya-type AVMs and 67.6% for shunt- and mixed-type AVMs. Early obliteration within 12 months was achieved in 63% of the moyamoya-type AVMs.

Conclusions. Moyamoya-type AVMs seem to be at risk for post-GKS hemorrhage. Intravascular embolization should be considered prior to GKS for mixed- and shunt-type AVMs in an attempt to reduce the hemodynamic stress and thereby decrease the risk of hemorrhage.
Stereotactic radiosurgery for dural arteriovenous fistula involving the superior sagittal sinus
Authors: Maruyama Keisuke , Shin Masahiro , Kurita Hiroki , Tago Masao , Kirino Takaaki
Published: November 2018

✓The authors present a case of ruptured dural arteriovenous fistula primarily draining into the superior sagittal sinus, which was successfully treated by gamma knife radiosurgery.
Survival and pattern of failure in brain metastasis treated with stereotactic gamma knife radiosurgery
Authors: Petrovich Zbigniew , Yu Cheng , Giannotta Steven L. , O'day Steven , Apuzzo Michael L. J.
Published: November 2018

Object. Gamma knife radiosurgery (GKS) has become a well-established treatment modality in the management of selected patients with brain metastasis. The authors review the management patients with these tumors treated at a single center.

Methods. Between 1994 and 2002, 458 consecutive patients with metastatic brain disease underwent GKS. There were 1305 lesions treated in 680 separate sessions. The histological diagnosis was melanoma in 231 (50%), lung cancer in 94 (20.5%), breast cancer in 38 (8.3%), renal cell carcinoma (RCC) in 29 (6.3%), colon carcinoma in 13 (2.8%), unknown primary site in 14 (3.1%), and other in 39 patients (8.5%). The median tumor volume was 0.9 cm3 and the median volume treated was 2.3 cm3. The median radiation dose was 18 Gy prescribed to a median isodose of 60%; the median dose was 20 Gy in melanoma, sarcoma, and RCC. Whole-brain radiotherapy (WBRT) either prior to or following GKS was performed in 114 patients (25%). Follow up ranged from 3 to 84 months with a median of 9 months.

The median survival for all patients was 9 months and depended on tumor histology. Survival ranged from 6 months for patients with colon carcinoma, unknown primary tumors, and other tumors to 17 months for those with breast cancer. Median survival in patients with melanoma was 8 months. In multivariate analysis Karnofsky Performance Scale score (< 70 vs > 70), status of systemic disease (yes vs no), histological diagnosis, and total intracranial tumor volume were the only significant factors influencing survival. The number of brain metastases (one–five), WBRT (yes vs no), and age were not significant. Pattern of failure was different in patients with melanoma compared with those with other diagnoses. Cause of death in patients with melanoma was in 50% of the cases due to systemic disease and in 42% due to central nervous system causes, whereas it was 70% for the former and 23% for the latter in patients with other diagnoses. The treatment was well tolerated with significant late toxicity requiring craniotomy for removal of a necrotic focus in only 20 patients (4.7%).

Conclusions. Gamma knife radiosurgery provided an excellent palliation with low incidence of toxicity. A Phase III prospective randomized trial is required to define the role of WBRT in combination with GKS.