bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

ObjectThis 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.MethodsSeveral 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.ResultsThe 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%.ConclusionsAn 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

ObjectBrain 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.MethodsThe 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.ResultsThe 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.ConclusionsAlthough 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

ObjectStereotactic 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.MethodsThe 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.ResultsNo 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.ConclusionsDespite 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

ObjectGlossopharyngeal 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.MethodsFrom 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).ResultsAll 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.ConclusionsGKS 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

ObjectResection 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.MethodsIn 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.ResultsThirteen 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.ConclusionsFor 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

ObjectThe 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.MethodsIn 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.ResultsMost 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.ConclusionsRadiosurgery 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.