bluuebunny/crossref_metadata_2025_split huggingface dataset:
A prospective cohort study of microvascular decompression and Gamma Knife surgery in patients with trigeminal neuralgia
Authors: Linskey Mark E. , Ratanatharathorn Vaneerat , Peñagaricano Jose 
Published: November 2018

Object
The aim of this study was to analyze 1 surgeon's 4-year experience with microvascular decompression ([MVD], 36 patients) and Gamma Knife surgery ([GKS], 44 patients) in 80 consecutive patients with trigeminal neuralgia (TN).

Methods
The authors conducted a prospective cohort study from March 1999 to December 2003 with an independent clinical assessment of the results and serial patient satisfaction surveys. All patients completed a 2004 patient satisfaction survey (0.5–5 years postoperative), and 70% of surviving patients completed the same survey in 2007 (3.9–8.5 years postoperative). Follow-up was undertaken in 100% of the patients (mean 3.4 ± 2.14 years, range 0.17–8.5 years).

Results
Respective initial and latest follow-up raw pain-free rates were 100 and 80.6% for MVD and 77.3 and 45.5% for GKS. The median time to the maximal benefit after GKS was 4 weeks (range 1 week–6 months). Respective initial, 2-, and 5-year actuarial pain-free rates were 100, 88, and 80% for MVD and 78, 50, and 33% for GKS (p = 0.0002). The relative risk of losing a pain-free status by 5 years posttreatment was 3.35 for patients in the GKS group compared with the MVD group. Initial and 5-year actuarial rates for ≥ 50% pain relief after GKS were 100 and 80%, respectively. The respective rates of permanent mild and severe sensory loss were 5.6 and 0% for patients in the MVD group, as opposed to 6.8 and 2.3% for patients in the GKS group. Anesthesia dolorosa did not occur during the study. Both procedures enjoyed a high degree of early patient satisfaction (95–100%). Microvascular decompression maintained the same rate of patient satisfaction, but satisfaction with GKS decreased to 75% as pain control waned. Twenty-three patients (29%) died of causes unrelated to the TN or the surgical intervention during the follow-up, and their pain status was known at the time of death. Statistically significant intergroup differences for the MVD versus GKS cohorts were age (median 54 years, range 36–70 years vs median 74 years, range 48–92 years, respectively), preoperative symptom duration (median 2.58 years, range 0.33–15 years vs median 7.5, range 0.6–40 years, respectively), and the presence of major comorbidities (2.8 vs 58.3%, respectively).

Conclusions
In this nonrandomized prospective cohort trial of selected patients with potentially relevant intergroup differences, MVD was significantly superior to GKS in achieving and maintaining a pain-free status in those with TN and provided similar early and superior longer-term patient satisfaction rates compared with those for GKS. The complications of wound cerebrospinal fluid leakage, hearing loss, and persistent diplopia (1 case each in the MVD group) were not seen after GKS.
Image registration accuracy of GammaPlan: a phantom study
Authors: Watanabe Yoichi , Han Eunyoung 
Published: November 2018

Object
The authors evaluated the accuracy of the automatic image coregistration function implemented in the Leksell GammaPlan treatment planning software (Version 4C with MultiView Extension and Version 8.0).

Methods
The authors used a phantom with 9 landmarks (tips of thin cylindrical acrylic rods) evenly distributed in the treatment space. Two sets of images of the phantom were taken with both CT and MR imaging systems. The first image was obtained with the phantom aligned with the scanner's axis and the second scan was made by intentionally shifting and rotating the phantom relative to the scanner's axis. The authors attempted image registration of 2 CT image sets, CT and MR image sets, and 2 MR image sets. The accuracy of image registration was evaluated by measuring the x, y, and z coordinate values of the landmarks on each image set after 2 image sets were coregistered. The authors calculated the differences of the x, y, and z values and the distance, d, between corresponding landmarks in 2 image sets. To minimize interobserver dependence of coordinate measurements, 2 physicists did measurements independently.

Results
The distances, d, averaged over the 9 landmarks, were 2.63 ± 1.64 and 0.95 ± 0.25 mm for CT–CT and MR–MR image registrations, respectively. When the CT images of the air-filled phantom and MR images were coregistered, however, the algorithm performed poorly: d = 13.8 ± 1.23 mm. To remedy this, the authors undertook a 2-step process by first performing landmark-based registration of the 2 image sets and subsequently applying the automatic registration. With this approach, the mean distance drastically improved: d = 0.74 ± 0.31 mm. When the water-filled phantom was used for CT scans, the registration accuracy of CT and MR image sets was acceptable without the 2-step registration process: d = 1.18 ± 0.36 mm.

Conclusions
The accuracy of automatic registration of image sets from the same modality was within the voxel size of the scanned images. The accuracy of CT–MR image registration strongly depended on whether the phantom for CT scans was filled with air or water. This indicates the significant effect of the amount of common data available for a mutual information-based algorithm on the accuracy.
The outcome of severe closed head injury
Authors: Marshall Lawrence F. , Gautille Theresa , Klauber Melville R. , Eisenberg Howard M. , Jane John A. , Luerssen Thomas G. , Marmarou Anthony , Foulkes Mary A. 
Published: November 2018

✓ The outcome of severe head injury was prospectively studied in patients enrolled in the Traumatic Coma Data Bank (TCDB) during the 45-month period from January 1, 1984, through September 30, 1987. Data were collected on 1030 consecutive patients admitted with severe head injury (defined as a Glasgow Coma Scale (GCS) score of 8 or less following nonsurgical resuscitation). Of these, 284 either were brain-dead on admission or had a gunshot wound to the brain. Patients in these two groups were excluded, leaving 746 patients available for this analysis.
The overall mortality rate for the 746 patients was 36%, determined at 6 months postinjury. As expected, the mortality rate progressively decreased from 76% in patients with a postresuscitation GCS score of 3 to approximately 18% for patients with a GCS score of 6, 7, or 8. Among the patients with nonsurgical lesions (overall mortality rate, 31%), the mortality rate was higher in those having an increased likelihood of elevated intracranial pressure as assessed by a new classification of head injury based on the computerized tomography findings. In the 276 patients undergoing craniotomy, the mortality rate was 39%. Half of the patients with acute subdural hematomas died — a substantial improvement over results in previous reports. Outcome differences between the four TCDB centers were small and were, in part, explicable by differences in patient age and the type and severity of injury.
This study describes head injury outcome in four selected head-injury centers. It indicates that a mortality rate of approximately 35% is to be expected in such patients admitted to experienced neurosurgical units.
A simple method for predicting imaging-based complications following gamma knife surgery for cerebral arteriovenous malformations
Authors: Ganz Jeremy C. , Reda Wael A. , Abdelkarim Khalid , Hafez Ayman 
Published: November 2018

Object. The authors studied the relationship between dose planning parameters and complications in the treatment of cerebral arteriovenous malformations (AVMs).
Methods. There were 41 continuous unselected patients. The mean follow-up period was 19 months; the mean age was 28 years; the male/female ratio was 2.2:1.0; the median prescription dose was 25 Gy (range 14–25 Gy); the median prescription isodose was 50%. The median lesion volume was 4.4 cm3. The median lesion coverage was 93%; and the mean conformity index was 1.22.
The authors found no relationship between lesion volume or integral dose and the development of the clinical effects based on the adverse radiation effects (AREs); however, there was a significant relationship between both target volume and integral dose with the development of AREs as well as the severity of the AREs.
Conclusions. The integral dose could be used as a guideline for the prescription dose. Arguments are made for maximizing the prescription dose for the long-term safety of the patient.
Gamma knife surgery for cavernous hemangiomas: an analysis of 125 patients
Authors: Liu Kang-Du , Chung Wen-Yuh , Wu Hsiu-Mei , Shiau Cheng-Ying , Wang Ling-Wei , Guo Wan-You , Hung-Chi Pan David 
Published: November 2018

Object. The authors sought to determine the value of gamma knife surgery (GKS) in the treatment of cavernous hemangiomas (CHs).
Methods. Between 1993 and 2002, a total of 125 patients with symptomatic CHs were treated with GKS. Ninety-seven patients presented with bleeding and 45 of these had at least two bleeding episodes. Thirteen patients presented with seizures combined with hemorrhage, and 15 patients presented with seizures alone. The mean margin dose of radiation was 12.1 Gy and the mean follow-up time was 5.4 years.
In the 112 patients who had bled the number of rebleeds after GKS was 32. These rebleeds were defined both clinically and based on magnetic resonance imaging for an annual rebleeding rate of 32 episodes/492 patient-years or 6.5%. Twenty-three of the 32 rebleeding episodes occurred within 2 years after GKS. Nine episodes occurred after 2 years; thus, the annual rebleeding rate after GKS was 10.3% for the first 2 years and 3.3% thereafter (p = 0.0038). In the 45 patients with at least two bleeding episodes before GKS, the rebleeding rate dropped from 29.2% (55 episodes/188 patient-years) before treatment to 5% (10 episodes/197 patient-years) after treatment (p < 0.0001). Among the 28 patients who presented with seizures, 15 (53%) had good outcomes (Engel Grades I and II). In this study of 125 patients, symptomatic radiation-induced complications developed in only three patients.
Conclusions. Gamma knife surgery can effectively reduce the rebleeding rate after the first symptomatic hemorrhage in patients with CH. In addition, GKS may be useful in reducing the severity of seizures in patients with CH.
Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases
Authors: Chung Wen-Yuh , Liu Kang-Du , Shiau Cheng-Ying , Wu Hsiu-Mei , Wang Ling-Wei , Guo Wan-Yuo , Ming-Tak Ho Donald , Hung-Chi Pan David 
Published: November 2018

Object. The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation.
Methods. A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3 (range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months.
A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a median follow-up period of 31 months resection was avoided in 96.8% of cases. Uncontrolled tumor swelling was noted in five patients at 3.5, 17, 24, 33, and 62 months after GKS, respectively. Twelve of 20 patients retained serviceable hearing. Two patients experienced a temporary facial palsy. Two patients developed a new trigeminal neuralgia. There was no treatment-related death. Histopathological examination of specimens in three cases (one at 62 months after GKS) revealed a long-lasting radiation effect on vessels inside the tumor.
Conclusions. Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.
Gamma knife surgery for multiple hemangioblastomas
Authors: Park Yong Sook , Chang Jong Hee , Chang Jin Woo , Chung Sang Sup , Park Yong Gou 
Published: November 2018

Object. The authors describe their experience in treating patients with hemangioblastoma, especially multiple lesions, with gamma knife surgery (GKS).
Methods.Nine patients with 84 hemangioblastomas underwent GKS between July 1992 and May 2003. Three patients harbored a single lesion and six patients had multiple lesions. Of the six patients with multifocal tumors, a diagnosis of von Hippel—Lindau disease had been established in five. In the patients with multiple lesions, the mean radiation dose delivered to the tumor margin was 16.6 Gy (range 12.8–29.75 Gy). The mean margin isodose was 60% (range 40–95%).
Three of the 84 lesions failed to be controlled after a mean follow-up period of 4.3 years (range 8.6–141 months). One patient who had undergone two GKS treatments suffered delayed radiation-induced complications, and posterior fossa decompression and ventriculoperitoneal shunt insertion were required.
Conclusions. To achieve tumor control and avoid morbidity, the surgeon should keep in mind minimizing field overlapping by using a small-diameter collimator or applying a steep dose gradient, and by accurate dose prescription.
Gamma knife surgery for intracranial cavernous hemangioma
Authors: Kim Moo Seong , Pyo Se Young , Jeong Young Gyun , Lee Sun Il , Jung Yong Tae , Sim Jae Hong 
Published: November 2018

Object. The purpose of this study was to assess the benefits of radiosurgery for cavernous hemangioma.
Methods. Sixty-five cavernous hemangiomas were treated with gamma knife surgery (GKS) between October 1994 and December 2002. Forty-two patients attended follow up. The mean patient age was 37.6 years (range 7–60 years). The lesions were located in the frontal lobe in 12 cases, deep in the parietal lobe in five, in the basal ganglia in five, in the temporal in three, in the cerebellum in three, in the pons/midbrain in six, and in multiple locations in eight cases. The presenting symptoms were seizure in 12, hemorrhage in 11, and other in 19. The maximum dose was 26.78 Gy, and the mean margin dose was 14.55 Gy.
The mean follow-up period after radiosurgery was 29.6 months (range 5–93 months). The tumor decreased in size in 29 cases, was unchanged in 12, and increased in size in one. In the seizure group, seizures were controlled without anticonvulsant medication in nine cases (81.8%) after 31.3 months (range 12–80 months). After 93 months, one patient developed a cyst, which was resected. Rebleeding occurred in one case (2.3%). On T2-weighted imaging changes were seen in 11 cases (26.2%), in three (7.1%) of which neurological deterioration was correlated with imaging changes. In other cases these deficits were temporary.
Conclusions. The authors found that GKS was an effective treatment modality for cavernous hemangiomas, especially for those located within the brainstem, basal ganglia, or deep portions of the brain. It can reduce seizure frequency significantly although this takes time. In the group receiving a marginal dose below 15 Gy the patients fared better than when the dose exceeded 15 Gy.
Gamma knife surgery for hemangioblastomas
Authors: Tago Masao , Terahara Atsuro , Shin Masahiro , Maruyama Keisuke , Kurita Hiroki , Nakagawa Keiichi , Ohtomo Kuni 
Published: November 2018

Object. The authors reviewed their 14-year experience using stereotactic radiosurgery for the treatment of hemangioblastomas and define the role and the proper strategy for radiosurgery of this condition.
Methods. This is a retrospective study of 38 hemangioblastomas in 13 patients. Seven patients had von Hippel—Lindau disease. All patients have undergone at least one follow-up visit. The median and mean tumor volumes were 0.23 cm3 and 0.72 cm3 respectively (range 0.004:4.84 cm3). Twenty-eight tumors received 20 Gy to the margin, and the remainder received 18 Gy. The median clinical follow-up period was 36 months (range 3–159 months).
No patient died. The survival rate was 84.6% (11 of 13 patients). The actuarial 5- and 10-year survival rates were both 80.8%. The median radiological follow-up period was 35 months (range 7–147 months). Only one tumor increased in volume 24 months after treatment in association with an intratumoral hemorrhage. The tumor control rate was 97.4% (37 of 38 tumors). Actuarial 5- and 10-year control rates were both 96.2%. New lesions and/or those increasing in size outside the irradiated area were discovered in five patients (38.5%). Nine tumors revealed peritumoral contrast enhancement which was seen more frequently in larger tumors with a volume greater than 0.5 cm3 (p = 0.0034).
Conclusions. Gamma knife surgery is a safe and effective method to control hemangioblastomas for as many as 10 years. Higher doses and smaller tumors probably contribute to good outcomes. Recurrence outside the original irradiated area is common. Peritumoral contrast enhancement may be seen in larger tumors. The authors recommend regular imaging follow up and early repeated treatment in the face of new or growing tumors.
Pineal tumors: analysis of treatment results in 20 patients
Authors: Amendola Beatriz E. , Wolf Aizik , Coy Sammie R. , Amendola Marco A. , Eber Daryl 
Published: November 2018

Object. The authors evaluate their results when using gamma knife surgery (GKS) in the management of patients with tumors in the pineal region.
Methods. This is a retrospective clinical evaluation of 20 patients with primary tumors of the pineal region treated with GKS from November 1994 through August 2003. There were 13 germ cell tumors, two pineoblastomas, two low-grade gliomas, one primitive neuroectodermal tumor, one teratoma, and one pineocytoma. There were 10 male and 10 female patients. Their median age was 15.5 years (range 5–71 years). The median margin dose was 11 Gy (range 8–20 Gy). The median target volume was 3.1 cm3 (range 0.1–49.9 cm3). Five patients received sequential systemic chemotherapy and four underwent adjuvant conventional radiation therapy. Seventeen (85%) of 20 patients are alive with a median survival of 30.4 months (range 0–-85.7 months). Two patients required retreatment. Three patients died: one of unrelated causes, one who presented with extensive local disease, and the other of meningeal carcinomatosis with local control of the primary tumor. No complications from GKS were noted.
Conclusions. This initial experience suggests that GKS is a valuable treatment modality for the management of pineal region tumors. This technique offers excellent local tumor control and minimal patient morbidity, allowing for immediate use of systemic chemotherapy and/or conventional radiation if indicated.
Increased preservation of functional hearing after gamma knife surgery for vestibular schwannoma
Authors: van Eck Albertus T. C. J. , Horstmann Gerhard A. 
Published: November 2018

Object. Gamma knife surgery (GKS) for vestibular schwannoma is still associated with an additional hearing loss of approximately 30%. The purpose of this study was to record the effect on hearing preservation of maintaining a margin dose of 13 Gy while reducing the maximum dose to 20 Gy.
Methods. Seventy-eight of 95 patients who entered a prospective protocol with a follow up of at least 12 months (mean 22 months) were evaluated. The mean tumor volume was 2.28 cm3. After a mean follow-up duration of 22 months, the magnetic resonance imaging—based tumor control rate was 87%. In two cases a second procedure (surgery) was necessary. Thus, the clinical control rate was 97.5%. In two cases there was an increase in trigeminal dysesthesia. One patient suffered transient facial nerve impairment. Functional hearing was preserved in 83.4% of the patients with functional hearing preoperatively.
Conclusions. Reducing the maximum dose to 20 Gy seems to be an effective treatment, which probably increases preservation of functional hearing without sacrificing the high tumor control rates achieved in radiosurgery. Post-radiosurgery tumor swelling occurred in 25% of the cases and was not correlated with hearing deterioration.
Gamma knife surgery of superficially located meningioma
Authors: Kim Dong Gyu , Kim Chi Heon , Chung Hyun-Tai , Paek Sun Ha , Jeong Sang Soon , Han Dae Hee , Jung Hee-Won 
Published: November 2018

Object. The authors analyzed tumor control rates and complications in patients with superficially located meningiomas after gamma knife surgery (GKS).
Methods. Between 1998 and 2003, GKS was performed in 23 patients with 26 lesions in whom follow-up imaging for 1 year or more was available. The male/female ratio was 1:22. The mean age was 59 years. The median tumor volume was 4.7 cm3, and the mean margin dose was 16 Gy at the 50% isodose line. Peritumoral edema was revealed on magnetic resonance (MR) imaging in four patients before GKS. Magnetic resonance imaging and clinical examinations were performed every 6 months after GKS. The mean follow-up duration was 32 months.
The tumor shrank in eight cases, was stable in 17, and enlarged in one; thus 25 (95%) of 26 tumors were controlled. A peritumoral high signal on T2-weighted MR images was found in eight lesions and preexisting edema was aggravated in three lesions after GKS. Ten of these 11 patients complained of severe headache, and three patients experienced neurological deficits at the same time after a mean latency of 3 months; however, high signal was not demonstrated on imaging before 6 months on average. Steroid agents, when required, gave relief to all patients. The complication rate was 43% (10 of 23 cases). High signal disappeared in nine patients and decreased in the remaining two. High signal was associated with a high integral dose and a large tumor volume. Tumor shrinkage at the last follow-up examination was more prominent in the patients with symptomatic high signal (p = 0.03).
Conclusions. There was a good tumor control rate with a high complication rate. Longer follow up of more patients is needed. Adjusting the dose—volume relationship should be considered to reduce complications.
Microvascular decompression after gamma knife surgery for trigeminal neuralgia: intraoperative findings and treatment outcomes
Authors: Shetter Andrew G. , Zabramski Joseph M. , Speiser Burton L. 
Published: November 2018

Object. The authors sought to determine whether the results of trigeminal microvascular decompression (MVD) are influenced by prior gamma knife surgery (GKS).
Methods. Gamma knife surgery is an established procedure for treating medically intractable trigeminal neuralgia but failures do occur. The authors assessed six patients (two men and four women; mean age 52 years) who experienced pain recurrence after GKS and elected to undergo trigeminal MVD via retrosigmoid craniotomy. Three patients underwent a single GKS to a maximal dose of 80 Gy, whereas three others underwent a second GKS to total of 120 to 135 Gy.
At surgery, none of the six patients demonstrated excess arachnoid thickening, grossly apparent changes in the nerve itself, or any other tissue alterations that made successful mobilization of a blood vessel from the trigeminal root entry zone technically more difficult. A single individual had a small atherosclerotic plaque in the superior cerebellar artery near its contact point with the trigeminal nerve. Follow up at a mean of 25.4 months (range 7.5–42 months) indicated that five patients were pain free. One patient had improved but still relied on medications for pain control.
Conclusions. In the authors' experience, trigeminal MVD can be performed without added difficulty in patients who have previously undergone GKS. The success rates seem similar to those normally associated with MVD. Patients who elect the less invasive option of GKS can be assured that trigeminal MVD remains a viable alternative at a later date if further surgery is required.