bluuebunny/crossref_metadata_2025 huggingface dataset:
Validity of stereotactic frame localization during radiosurgery after one fixation pin removal
Authors: MacKenzie James T. , Podgorsak Matthew B. , Moreland Douglas
Published: November 2018

Object. This study was designed to examine the effect on target localization of removing one fixation pin or post.

Methods. A stereotactic frame was applied to a head phantom by using four fixation pins. Contiguous axial computerized tomography (CT) slices (1 mm thick) were obtained through the head phantom. Using clinical treatment planning software, a marker was identified and its coordinates were determined. The imaging procedure and point localization were repeated independently seven times in the control configuration, after four-pin fixation, to study reproducibility.

Standard deviations in marker coordinates were 0.013, 0.046, and 0.039 mm along the x, y, and z axes, respectively, indicating excellent reproducibility. Each of the four pins was then removed separately, leaving three pins providing fixation to the skull. Imaging was repeated for each three-pin configuration. To simulate the forces at each pin-skull interface, a lever arm was connected to the head phantom allowing application of variable torque to the system. The CT scans were obtained for each torque strength and pin removal combination. Marker coordinates were compared with the control.

Conclusions. In most cases, it was found that accurate target positioning could be achieved after removal of a single pin and/or post. When high torque was used, however, removal of a pin resulted in up to a 1.2-mm error. The findings may be significant for clinical practice, depending on the condition being treated.
Acute symptoms after gamma knife radiosurgery
Authors: St. George E. J. , Kudhail J. , Perks J. , Plowman P. N.
Published: November 2018

Object. The purpose of this study was to examine the widely held assumption that early-onset symptoms after gamma knife radiosurgery (GKS) are uncommon. The study was designed to include all types of morbidity and not just those that lead to neurological dysfunction. It was hoped that the results of the study could lead to a more rational follow-up protocol.

Methods. Data regarding adverse events were collected prospectively (within 2–3 weeks post-GKS) by telephone interview from 47 of the first 65 patients who could be reached. Immediate adverse events were defined as any new or unexpected symptom developing within 2 weeks of treatment and were graded as mild, moderate, or severe.

Two thirds of all patients complained of new adverse symptoms; three patients required prolonged hospitalization, although in one case this was not related to the radiosurgery. The majority of symptomatic patients (91%) experienced mild or moderate complications. More than 50% of patients had headache. One third described pin site—related complications and one fifth suffered from nausea/vomiting or marked tiredness. Patients with moderate symptoms had a larger mean tumor volume and higher radiation dose than other patient groups. Prior radiation therapy, lesion type, or the posttreatment administration of steroid agents did not significantly influence the development of acute symptoms.

Conclusions. Acute adverse events following GKS are not uncommon if all types of morbidity are considered. An increased appreciation of these other complications may improve posttreatment care.
Skull base approaches and gamma knife radiosurgery for multimodality treatment of skull base tumors
Authors: Francel Paul C. , Bhattacharjee Sumon , Tompkins Paul
Published: November 2018

Object. The purpose of this study was to evaluate descriptive data obtained in patients who had received multimodality treatment with resection and gamma knife radiosurgery (GKS) for skull base tumors. Retrospective data were collected from 71 patients with skull base tumors who were treated from November 1996 to December 2000, all of whom underwent follow-up evaluation at 1 year or more.

Methods. Data were collected from hospital charts and office records, including patient age, tumor type and location, number of tumors, maximum radiation dose, estimated radiation dose to the periphery, tumor volume, and percentage of patients with tumors smaller or the same size at follow-up evaluation.

Conclusions. Of the 71 patients with 1 year or more of follow up, 93% had tumor either the same size or smaller and 34% of these patients had a smaller tumor size. It is concluded that: 1) GKS with multimodality treatment is effective for control of skull base tumors; 2) the radiosurgical team should consider the benefits of GKS for treatment of any skull base tumor to afford optimum patient management; and 3) neurosurgeons involved with the management of skull base tumors should either be trained and proficient in GKS or work closely with a colleague trained in the technique. This will ensure proper consideration of both options, resulting in overall improved patient treatment.
Staged radiosurgery for extra-large cerebral arteriovenous malformations: method, implementation, and results
Authors: Chung Wen-Yuh , Shiau Cheng-Ying , Wu Hsiu-Mei , Liu Kang-Du , Guo Wan-Yuo , Wang Ling-Wei , Pan David Hung-Chi
Published: November 2018

Object

The effectiveness and safety of radiosurgery for small- to medium-sized cerebral arteriovenous malformations (AVMs) have been well established. However, the management for large cerebral AVMs remains a great challenge to neurosurgeons. In the past 5 years the authors performed preplanned staged radiosurgery to treat extra-large cerebral AVMs.

Methods

An extra-large cerebral AVM is defined as one with nidus volume > 40 ml. The nidus volume of cerebral AVM is measured from the dose plan—that is, as being the volume contained within the best-fit prescription isodose. From January 2003 to December 2007, the authors treated 6 patients with extra-large AVMs by preplanned staged GKS. Staged radiosurgery is implemented by rigid transformation with translation and rotation of coordinates between 2 stages. The average radiation-targeted volume was 60 ml (range 47–72 ml). The presenting symptoms were seizure in 4 patients and a bleeding episode in 2. One patient had undergone a previous craniotomy and evacuation of hematoma. The mean interval between the 2 radiosurgical sessions was 6.9 months (range 4.5–9.1 months). The prescribed marginal dose given to the nidus volume in each stage ranged from 16 to 18.6 Gy. The expected marginal dose of total nidus was 17–19 Gy. Regular follow-up MR imaging was performed every 6 months. The mean follow-up period was 28 months (range 12–54 months).

Results

Most of the patients exhibited clinical improvement: relief of headache and reduced frequency of seizure attack. All patients had significant regression of nidus observed on MR imaging follow-up. Two patients had angiogram-confirmed complete obliteration of the nidus 45 and 60 months after the second-stage radiosurgical session. One patient experienced minor bleeding 8 months after the second-stage radiosurgery with mild headache. She had satisfactory recovery without clinical neurological deficit after conservative treatment.

Conclusions

These preliminary results indicate that staged radiosurgery is a practical strategy to treat patients with extra-large cerebral AVMs. It takes longer to obliterate the AVMs. The observed high signal T2 changes after the radiosurgery appeared clinically insignificant in 6 patients followed up for an average of 28 months. Longer follow-up is necessary to confirm its long-term safety.
Gamma Knife surgery used as primary and repeated treatment for idiopathic trigeminal neuralgia
Authors: Huang Chuan-Fu , Tu Hsien-Tang , Liu Wen-Shan , Chiou Shyh-Ying , Lin Long-Yau
Published: November 2018

Object

The purpose of this study was to assess the outcome of idiopathic trigeminal neuralgia (TN) treated with Gamma Knife surgery (GKS) as a primary and repeated treatment modality with a mean follow-up of 5.7 years.

Methods

Between July 1999 and September 2005, a total of 89 patients with idiopathic TN underwent GKS as a primary treatment. The entry zone of the TN was targeted with a 4-mm collimator and treated with a maximal dose of 60–90 Gy (mean 79 Gy). The dose to the pontine margin was always kept < 15 Gy. Twenty patients received repeated GKS for recurrent or residual pain with a maximal dose of 40–76 Gy (mean 52 Gy). For the second procedure, the target was positioned at the same location as the first treatment.

Results

The mean follow-up period was 68 months (range 32–104 months). Sixty-nine (77.5%) of the 89 patients experienced a favorable response, as follows: 50 (56%) had excellent, 12 (13.5%) had good, and 7 (7.8%) had fair outcomes. The mean time to pain relief was 1.1 months (range 2 days–6 months). No significant correlation, but more likely a tendency, was found between the dose and pain relief (p = 0.08). Also, no correlation was noted for facial numbness (p = 0.77). The mean follow-up period after repeated GKS was 60 months (range 32–87 months). Outcomes after repeated GKS were excellent in 11 patients (55%) and good in 1 (5%). Seven patients experienced facial numbness. No correlation was found between the additive dose and pain relief (p = 0.24) or facial numbness (p = 0.15). Final outcomes of primary and repeated GKS were excellent in 61 (68.5%), good in 13 (14.6%), and fair in 7 (7.9%). In total, 91% of the patients were successfully treated with this method. There was no statistical significance for efficacy between primary and repeated GKS (p = 0.65), but there was a significant difference for facial numbness (p = 0.007).

Conclusions

Gamma Knife surgery established durable pain relief when used as a primary and repeated surgery. Treatment was successful for a total of 91% of patients at a mean follow-up of 5.7 years, but facial numbness was also relatively higher.
Use of hybrid shots in planning Perfexion Gamma Knife treatments for lesions close to critical structures
Authors: Petti Paula L. , Larson David A. , Kunwar Sandeep
Published: November 2018

Object

The authors investigated the use of different collimator values in different sectors (hybrid shots) when treating patients with lesions close to critical structures with the Perfexion model Gamma Knife.

Methods

Twelve patients with various tumors (6 with a pituitary tumor, 3 with vestibular schwannoma, 2 with meningioma, and 1 with metastatic lesion) that were within 4 mm of the brainstem, optic nerve, pituitary stalk, or cochlea were considered. All patients were treated at the authors' institution between June 2007 and March 2008. The patients' treatments were replanned in 2 different ways. In the first plan, hybrid shots were used such that the steepest dose gradient was aligned with the junction between the target and the critical structure(s). This was accomplished by placing low-value collimators in appropriate sectors. In the second plan, no hybrid shots were used. Sector blocking (either manual or dynamic) was required for all plans to reduce the critical structure doses to acceptable levels. Prescribed doses ranged from 12 to 30 Gy at the periphery of the target. The plans in each pair were designed to be equally conformal in terms of both target coverage (as measured by the Paddick conformity index) and critical structure sparing.

Results

The average number of shots required was roughly the same using either planning technique (16.7 vs 16.6 shots with and without hybrids). However, for all patients, the number of blocked sectors required to protect critical areas was larger when hybrid shots were not used. On average, nearly twice as many blocked sectors (14.8 vs 7.0) were required for the plans that did not use hybrid shots. The number of high-value collimators used in each plan was also evaluated. For small targets (≤ 1 cm3), for which 8 mm was considered a high value for the collimator, plans employing hybrids used an average of 2.3 times as many 8-mm sectors as did their nonhybrid counterparts (7.4 vs 3.2 sectors). For large targets (> 1 cm3), for which 16 mm was considered a high value for the collimator, hybrid plans used an average of 1.4 times as many 16-mm sectors as did the plans without hybrids (10.7 vs 7.7 sectors). Decreasing the number of blocked sectors and increasing the number of high-value collimator sectors led to use of shorter beam-on times. Beam-on times were 1–39% higher (average 17%) when hybrid shots were not allowed. The average beam-on time for plans with and without hybrid shots was 67.4 versus 78.4 minutes.

Conclusions

The judicious use of hybrid shots in patients for whom the target is close to a critical structure is an efficient way to achieve conformal treatments while minimizing the beam-on time. The reduction in beam-on time with hybrid shots is attributed to a reduced use of blocked sectors and an increased number of high-value collimator sectors.
Mechanisms of edema after gamma knife surgery for meningiomas
Authors: Shehaby Amr El , Ganz Jeremy C. , Reda Wael A. , Hafez Ayman
Published: November 2018

✓ The authors describe two patients in whom tumor swelling and brain swelling (and possible tumor swelling), respectively, developed after undergoing gamma knife surgery. One had a skull defect with a palpable parasagittal tumor. One had neurofibromatosis Type 2 with multiple tumors, one of which was parasagittal.
Computational model for the estimation of the extracranial doses received during Leksell gamma knife model C treatment
Authors: Majali Mustafa , Novotny Josef , Novotny Josef
Published: November 2018

Object. Extracranial doses received by patients undergoing Leksell gamma knife surgery (GKS) can be of clinical concern. Therefore, the ability to preestimate peripheral doses received outside the treatment field during the GKS would be beneficial and could be used for the optimization of treatment planning by providing a reference for practitioners to calculate the extracranial dose burden to the body before the start of treatment.

Methods. A dose of 40 Gy was delivered to the Rando phantom in a single fraction to a midline hypothetical target close to the center of the skull. Treatment planning was performed for multiple isocenters with a prescription to the 50% isodose of each collimator. Treatment plans were produced for 1, 5, 10, 15, and 20 shots, keeping the same dose and dose distribution at different target volumes. An automatic positioning system was used for positioning the phantom during the treatment. The doses to different organs were measured during GKS using a thermoluminescent dosimeter. In vivo measurements were also made in 200 patients who underwent GKS with the model C unit for different diagnoses at Na Homolce Hospital.

Conclusions. The peripheral dose depended on the collimator size with a logarithmic dependence on collimator size and a linear dependence on the number of shots. This model can be used for the estimation of peripheral doses with a total error less than 20%. This information can help clinicians with treatment planning optimization, especially in patients with long survival expectancy.
Histopathological findings in a surgically resected thalamic cavernous hemangioma 1 year after 40-Gy irradiation
Authors: Nyáry István , Major Otto , Hanzély Zoltán , Szeifert György T.
Published: November 2018

✓ Stereotactic radiosurgery is a controversial treatment modality in the management of cerebral cavernous hemangiomas (CHs), and results vary from center to center. Even the interpretation of treatment failure is controversial. It is suggested that the systematic pathological investigation of irradiated specimens could help to resolve the controversy.

A hemorrhagic lesion in the posterior part of the thalamus had been diagnosed as a tumor and was treated with 40-Gy fractionated radiotherapy. One year after this treatment the case was reconsidered based on new imaging evidence, and the lesion was removed by conventional craniotomy. Histopathological examination revealed a CH with postirradiation changes. Compared with nonirradiated control CH tissue samples, there was endothelial cell destruction and marked fibrosis with scar tissue formation in the stroma of the treated lesion.

The histopathological findings in this specimen were similar to those described in arteriovenous malformations after gamma knife surgery. The results of light microscopic investigations suggest that the ionizing effect of radiation energy evokes vascular and connective tissue stroma changes in CHs as well.
Radiosurgery and the prevention of regrowth of incompletely removed nonfunctioning pituitary adenomas
Authors: Picozzi Piero , Losa Marco , Mortini Pietro , Valle Micol Angela , Franzin Alberto , Attuati Luca , da Passano Camillo Ferrari , Giovanelli Massimo
Published: November 2018

Object. The authors studied the efficacy of gamma knife radiosurgery (GKS) in the prevention of regrowth of nonfunctioning pituitary adenomas (NPA).

Methods. One hundred nineteen patients were included in this study and were divided into two groups. All patients had undergone surgery in our department and recurrent or residual adenoma was demonstrated on postoperative MR imaging. Group A consisted of 68 patients who were followed without additional treatment. Group B was composed of 51 patients who received GKS within 1 year after microsurgery. There was no significant demographic difference between the two groups. In Group B the mean margin dose was 16.5 ± 0.3 Gy (range 13–21 Gy). Fifty one and one tenth percent of patients in Group A were recurrence free at 5 years and 89.8% in Group B (p < 0.001). In Group B patients, tumor volume decreased from a baseline value of 2.4 ± 0.2 cm3 to 1.6 ± 0.2 cm3 at last follow up (p < 0.001).

Conclusions. The results of this study suggest that GKS is effective in controlling growth of residual NPA for at least 5 years following initial maximal surgical debulking compared with no radiation therapy. Thus, GKS is recommended after microsurgery when visible tumor can be detected on imaging studies.
Stereotactic noninvasive volume measurement compared with geometric measurement for indications and evaluation of gamma knife treatment
Authors: Del Valle Ramiro , Pérez Miguel , Ortiz Juan , Ruiz Salvador , de Anda Salvador , Jaramillo José , Martínez Manuel , Corona Roberto , Vivas Ingrid , Facha M.A. Teresa , Olmos Rosario , Arrieta Arturo , Estrada Josué
Published: November 2018

Object. Volume estimation is one of the most important criteria in the evaluation and follow up of radiosurgical treatments and outcomes; however, several limitations are involved in the calculation estimation of target volumes.

Methods. Retrospective and prospective studies were conducted to evaluate the efficacy of a new noninvasive stereotactic method when it is compared with geometric volume calculation of intracranial tumors for planning stereotactic radiosurgery treatment as well as for follow up and outcome evaluation.

Two equations were created that permit comparison of the calculated and measured volumes. These equations took linear and quadratic forms, respectively. Volume estimation using the stereotactic approach compared with traditional volume calculation gave more accurate results regardless of the shape and size of the lesion.

Conclusions. The use of stereotactic volume calculation is highly recommended in planning, follow up, and determination of the outcome in patients participating in radiosurgical treatment and should lead to more uniform reports of the response to treatment.
Evaluation of a new concept for the management of skull base chordomas and chondrosarcomas
Authors: Feigl Guenther Christian , Bundschuh Otto , Gharabaghi Alireza , Safavi-Abassi Sam , El Shawarby Amr , Samii Madjid , Horstmann Gerhard A.
Published: November 2018

Object. Chordomas and chondrosarcomas of the skull base are rare locally invasive tumors associated with high recurrence rates. The aim of this study was to evaluate the concept of microsurgical tumor volume reduction followed by early gamma knife surgery (GKS).

Methods. Thirteen patients with 15 tumors were treated between October 2000 and June 2003. There were three patients (23.1%) with chordomas and 10 (76.9%) with chondrosarcomas. There were nine men and four women who ranged in age between 19 and 69 years. All patients first underwent maximal tumor resection. Within 2 to 10 months after surgery they were treated with GKS. The mean postoperative tumor volume treated with GKS was 9.7 cm3 (range 1.4–20.3 cm3). Follow-up computerized tomography and magnetic resonance imaging examinations with volumetric tumor analysis were performed every 6 months after GKS.

The mean treatment dose was 17 Gy and the mean isodose was 52%. The mean follow-up duration was 17 months during which there was only one tumor recurrence at the margin of the radiation field. The mean volume reduction was 35.4%.

Conclusions. Results of this treatment strategy are encouraging but the efficacy of this multimodal treatment combining surgery and early GKS requires a longer follow up.
Does gamma knife surgery stimulate cellular immune response to metastatic brain tumors? A histopathological and immunohistochemical study
Authors: Szeifert György T. , Salmon Isabelle , Rorive Sandrine , Massager Nicolas , Devriendt Daniel , Simon Stephan , Brotchi Jacques , Levivier Marc
Published: November 2018

Object. The aim of this study was to analyze the cellular immune response and histopathological changes in secondary brain tumors after gamma knife surgery (GKS).

Methods. Two hundred ten patients with cerebral metastases underwent GKS. Seven patients underwent subsequent craniotomy for tumor removal between 1 and 33 months after GKS. Four of these patients had one tumor, two patients had two tumors, and one patient had three. Histological and immunohistochemical investigations were performed. In addition to routine H & E and Mallory trichrome staining, immunohistochemical reactions were conducted to characterize the phenotypic nature of the cell population contributing to the tissue immune response to neoplastic deposits after radiosurgery.

Light microscopy revealed an intensive lymphocytic infiltration in the parenchyma and stroma of tumor samples obtained in patients in whom surgery was performed over 6 months after GKS. Contrary to this, extensive areas of tissue necrosis with either an absent or scanty lymphoid population were observed in the poorly controlled neoplastic specimens obtained in cases in which surgery was undertaken in patients less than 6 months after GKS. Immunohistochemical characterization demonstrated the predominance of CD3-positive T cells in the lymphoid infiltration.

Conclusions. Histopathological findings of the present study are consistent with a cellular immune response of natural killer cells against metastatic brain tumors, presumably stimulated by the ionizing energy of focused radiation.
Diagnostic value of thallium-201 chloride single-photon emission computerized tomography in differentiating tumor recurrence from radiation injury after gamma knife surgery for metastatic brain tumors
Authors: Serizawa Toru , Saeki Naokatsu , Higuchi Yoshinori , Ono Junichi , Matsuda Shinji , Sato Makoto , Yanagisawa Masamichi , Iuchi Toshihiko , Nagano Osamu , Yamaura Akira
Published: November 2018

Object. The authors assessed the diagnostic value of 201Tl Cl single-photon emission computerized tomography (SPECT), performed after gamma knife surgery (GKS) for metastatic brain tumors in differentiating tumor recurrence from radiation injury.

Methods. Of 6503 metastatic brain tumors treated with GKS, 201Tl SPECT was required in 72 to differentiate between tumor recurrence and radiation injury. When the Tl index was greater than 5, the lesion was diagnosed as a tumor recurrence. When the index was < 3.0 it was called radiation injury. In cases with a Tl index between 3 and 5, 201Tl SPECT was repeated once per month until the Tl index was greater than 5 or less than 3. If the Tl index fluctuated between 3 and 5 for 2 months, the lesion was diagnosed as radiation injury. The final diagnosis was based on histological examination or clinical course.

The sensitivity of the method was 91%; thus 201Tl SPECT is effective for differentiating between tumor recurrence and radiation injury in metastatic brain tumors treated with GKS. Caution is necessary, however, for the following reasons: 1) simple interinstitutional comparisons of Tl indices are not possible because measurement methods are institute specific; 2) steroid administration decreases the Tl index to a variable degree; and 3) a severe radiation injury lesion, as is often seen after repeated GKS or very high dose GKS, may have a Tl index greater than 5.

Conclusions. Used with critical insight 201Tl Cl SPECT can be useful in distinguishing between tumor regrowth and radiation necrosis in patients with cerebral metastases.
Radiosurgery for trigeminal neuralgia: is sensory disturbance required for pain relief?
Authors: Pollock Bruce E.
Published: November 2018

Object

Over the past 15 years stereotactic radiosurgery has become an accepted surgical option for patients with medically unresponsive trigeminal neuralgia (TN). The mechanism whereby radiosurgery causes pain relief remains unclear.

Methods

A review of recent papers on the radiosurgical management of TN reveals a correlation between maximum prescription dose and facial pain outcomes (p = 0.03) and between maximum prescription dose and new-onset trigeminal dysfunction (p < 0.01). In five of six studies in which investigators specifically analyzed whether there is any relationship between postradiosurgical trigeminal dysfunction and facial pain outcomes, there was a statistically significant greater chance of patients being pain free without medications if new trigeminal dysfunction developed after radiosurgery. Likewise, combining the results of two small series on repeated radiosurgery for TN also showed a significant correlation between postradiosurgical trigeminal dysfunction and facial pain outcomes (p = 0.02).

Conclusions

Although the quality of data available does not permit a formal metaanalysis of radiosurgery for TN, the preponderance of information supports an association between the development of facial sensory loss and pain relief after radiosurgery. Consequently, radiosurgery should be considered a destructive technique in which the goal is similar to that in other percutaneous ablative techniques used to manage TN: create sufficient damage to the trigeminal system to achieve pain relief, but not so much injury that the patient is at risk for deafferentation pain syndromes.
Radiosurgery for glomus jugulare tumors: experience treating 16 patients in Iran
Authors: Bitaraf Mohammad Ali , Alikhani Mazdak , Tahsili-Fahadan Pouya , Motiei-Langroudi Rouzbeh , Zahiri Alireza , Allahverdi Mahmoud , Salmanian Soraya
Published: November 2018

Object

Glomus jugulare tumors (GJT) have traditionally been treated by surgery or fractionated external-beam radiotherapy. The aim of this retrospective study was to determine the tumor control rate, clinical outcome, and short-term complications of stereotactic radiosurgery in subsets of patients who are poor candidates for these procedures, based on age, medical problems, tumor size, or prior treatment failure.

Methods

The Leksell Gamma Knife was used to treat 16 patients harboring symptomatic, residual, recurrent, or unresectable GJTs. The age of the patients ranged from 12 to 77 years (median 46.5 years). Gamma Knife surgery (GKS) was performed as primary treatment in five patients (31.3%). Microsurgery preceded radiosurgery in 10 patients (62.5%) and fractionated radiotherapy in three patients (18.8%). The median tumor volume was 9.8 cm3 (range 1.7–20.6 cm3). The median marginal dose applied to a mean isodose volume of 50% (range 37–70%) was 18 Gy (range 14–20 Gy).

Neurological follow-up examinations revealed improved clinical status in 10 patients (62.5%), a stable neurological status in six (37.5%), and no complications. After radiosurgery, follow-up imaging was conducted in 14 patients; the median interval from GKS to the last follow up was 18.5 months (range 4–28 months). Tumor size had decreased in six patients (42.9%), and the volume remained unchanged in the remaining eight (57.1%). None of the tumors increased in volume during the observation period.

Conclusions

According to the authors' experience, GKS represents a useful therapeutic option to control symptoms and may be safely conducted in patients with primary or recurrent GJTs with no death and no acute morbidity. Because of the tumor's naturally slow growth rate, however, long-term follow-up data are needed to establish a cure rate after radiosurgery.
Calculation of isoeffective doses and the α /β value by comparing results following radiosurgery and radiotherapy for arteriovenous malformations of the brain
Authors: Karlsson Bengt , Lax Ingmar , Yamamoto Masaaki , Söderman Michael , Jokura Hidefumi , Rosen Charles , Bailes Julian
Published: November 2018

Object

The authors sought to assess the relationship between obliteration rate and different dose parameters following fractionated radiotherapy for arteriovenous malformations (AVMs). A comparison of the results of radiosurgery and radiotherapy for AVMs was made to calculate the best fit α/β value, which would then be used as a model for predicting the treatment outcome, independent of the number of fractions applied.

Methods

Data from 1453 patients were analyzed: 1154 treated with radiosurgery and 300 with fractionated radiotherapy. The relationships between dose and obliteration rate after 3 years were calculated, and the best fit curve to the empirical results was defined. The higher the dose per fraction, biologically effective dose, and the lower the total dose, the higher the obliteration rate. The isoeffective doses when comparing radiotherapy and radiosurgery independent of the α/β value could not be defined. The dose per fraction had the best predictive value, independent of the number of fractions.

Conclusions

Dose per fraction seems to be the decisive parameter for the treatment response following both radiotherapy and radiosurgery. A larger number of fractions did not increase the obliteration rate. The data indicate that higher doses per fraction should be used when irradiating AVMs.
Long-term results of Gamma Knife surgery for arteriovenous malformations: 10- to 15-year follow up in patients treated with lower doses
Authors: Inoue Hiroshi K.
Published: November 2018

Object

Several adverse effects such as brain edema, necrosis, arterial stenosis, hemorrhage after obliteration, and delayed cyst formation have been reported as early and late complications of Gamma Knife surgery (GKS) for arteriovenous malformations (AVMs). These adverse effects seem to be decreased in a lower-dose treatment regimen compared with the classic higher margin doses of 25 Gy because the radiation insult to the surrounding tissue is minimized. Long-term results of lower-dose GKS for AVMs are presented.

Methods

One hundred fourteen patients with AVMs were treated with lower-dose GKS (≤ 20-Gy margin dose). There were 68 male and 46 female patients, aged 10 to 68 years (mean 35.4 years). The evaluation of AVM nidi and dose planning were performed using both angiography and MR imaging in all cases to exclude the surrounding brain tissue. The mean margin dose was 19.5 Gy.

Total angiographically documented obliteration was achieved in 65 (85.5%) of 76 patients. Eleven patients underwent a second treatment, including staged treatment for large AVMs; total AVM obliteration has been achieved in six of them to date. Of 38 patients in whom no follow-up examination could be performed, 19 of them were healthy and 10 were lost from follow up. Nine patients experienced bleeding during the latency period, and four of them suffered lethal hemorrhage. Symptomatic early complications were extensive brain edema after repeated GKS in one patient and an adverse effect on the internal capsule in one. Delayed cyst formation was found in one patient as a late complication 10 years after treatment. No treatment-related death has been noted to date.

Conclusions

Lower-dose GKS is an effective and safe treatment for patients with AVMs and may decrease long-term adverse effects to the surrounding brain.
Les aspects et les enjeux du silence dans Jacques le fataliste de Diderot
Authors: Ben Sassi-Taktak Salwa
Published: November 2018

The novel presents a variety of writings of silence; but we limit ourselves, in the context of the present work, to the most relevant aspects, namely interruptions in narratives, narrative ellipses and point of suspension as the particular language of silence. These three modalities nevertheless serve a prolix discourse, and are innovate. Suddenly the novel exemplifies what contemporary literature calls the anti-novel.
Un silence éloquent : narration et fantastique dans Fragoletta (1829) de Latouche et La Vénus d’Ille (1837) et Lokis (1869) de Mérimée
Authors: Jeleva Alexandra
Published: November 2018

The paper analyses three works having employed a similar narrative strategy which triggers tension between the explicable and inexplicable and an interpretative crisis that allows a fantastic reading of the fictional text. This strategy is related to the paradoxical statute of the narrator due to which the reader is faced with an incomplete elliptic account because of the former’s reluctance (or impossibility) to offer a definite interpretation of the events.
Le silence en maux dans l’œuvre théâtrale de Samuel Beckett
Authors: Colin Marjorie
Published: November 2018

The silence in Beckett’s plays can be interpreted in many different ways. It often shows the anxiety of the characters faced with the vacuity in their lives. Left to themselves, they hardly manage to let go during these recurring silences (marked in an obsessional way in Beckett’s texts with the word "pause" as an absolute punctuation in the theatrical language). So they really feel the silence as the "arising of nothingness ", a sort of gateway to finitude. This silence is also the one appearing among Beckettian couples to reveal the aporia in language: inability to communicate, "doing" instead of (impossible) "saying". This Beckettian "doing" is shown in a conspicuous gestuality which conveys a certain materiality to this silence as well as it tries desperately to fill it. Thus Beckett’s characters act and give silence some substance, incarnating therefore a full-fledged character. Finally, silence can also embody the religious, at least the expectation (of the divine? in Godot particularly?). This silence grows solemn and reveals a suspension in the speech and characters in search of a follow-up. Silence then becomes the opening of an area where everything is possible since nothing has been said yet, implicitly expressing fantasies of joy and salvation.
La réception du témoignage à l’épreuve du silence. L’aîné des orphelins de Tierno Monénembo
Authors: Giguère Caroline
Published: November 2018

From the perspective of the reader-response criticism, this article underlines the ethical and esthetical tension between the duty of memory and the unspeakable in the context of the project « Rwanda : écrire par devoir de mémoire » and specificly in the novel L’aîné des orphelins by Tierno Monénembo. Although the « horizon » of expectations typical to the commitment toward the duty of memory is reinforced by the peritext (Genette, 1987), Monembo’s novel challenges the reader’s expectations by silencing and delaying the personnal story of young narrator-survivor Faustin.This stepback from direct violence allows the novel to focus on structual forms of violence (Galtung 2010) and urges the public to question his responsability in the testimonial reception.
Pemodelan UML Pada Sistem Pengajuan Dana Anggaran Untuk Peningkatan Produktivitas Perusahaaan
Authors: Liantoni Febri , Yusincha Amalia
Published: November 2018

Dunia teknologi informasi berkembang pesat dengan dukungan teknologi yang semakin canggih. Unified Modeling Languange salah satu sistem yang bisa digunakan untuk standar pembuatan sistem informasi. Dengan menggunakan Unified Modeling Languange perancangan dan pembuatan sistem dapat dikerjakan lebih cepat. Pada penelitian ini pemodelan Unified Modeling Languange digunakan untuk membuat sistem pengajuan dana anggaran. Pembuatan sistem ini bertujuan untuk meningkatkan produktivitas perusahaaan dalam menangani proyek yang dikerjakan. Berdasarkan analisa dan pengujian sistem diperoleh kesimpulan bahwa sistem yang dibuat dapat mempermudah para karyawan perusahaan dalam proses pengajuan dana anggaran dan pertanggungjawaban dana proyek. Sistem yang dibuat juga memberikan informasi mengenai pengajuan dana yang diterima atau ditolak suatu proyek, sehingga dapat membuat pekerjaan yang dikerjakan lebih efisien dan dapat mengurangi resiko kesalahan terhadap pengajuan dana proyek.

 

Kata kunci: Teknologi Informasi, Unified Modeling Languange, Sistem, Dana Anggaran

 

Abstract

 The world of information technology is growing rapidly with the support of increasingly sophisticated technology. Unified Modeling Language one of the systems that can be used for the standard of making information systems. Using Unified Modeling Language the design and manufacture of the system can be done faster. In this study Unified Modeling Language modeling is used to create a system for submitting budget funds. The creation of this system aims to improve the productivity of companies in handling the projects being worked on. Based on the analysis and testing of the system, it can be concluded that the system created can make it easier for company employees in the process of submitting budget funds and accountability for project funds. The system created also provides information about the submission of funds received or rejected by a project, so as to make the work done more efficiently and can reduce the risk of errors in the submission of project funds.

  Keywords: Information Technology, Unified Modeling Languages, Systems, Budget Funds
Dynamics of hindered CF3-rotor in 2,5-bis (trifl uoromethyl )-nitroben zene radical -anion in anhydro us DMF. A temperature - activation theory of reversible HFS transformations of EPR spectrum
Authors: Polenov E. A. , Melnikov P. V.
Published: November 2018

The temperature dependence of EPR spectrum of 2,5-bis(trifluoromethyl)nitrobenzene radical anion in anhydrous DMF was investigated. Internal dynamics of hindered rotation of the CF3-group in ortho-position to NO2-group causes HFS modulation. The spectrum changes are reversible and temperature-dependent. An original temperature-activation representation of complex spectral density was proposed instead of the traditional spectral-kinetics representation to explain the observed transformation. The change resulted in a new convenient phenomenological reconstruction model, which allowed simulating the spectra in the whole temperature range. Splitting constants and contributions to the spectral widths of the spectral lines were found. The activation energy of the CF3-group hindered rotation is significant and amounts to 37 kJ/mol.
The multivariate calculation of material balances of flowsheets for separating ternary mixtures of different physical-chemical nature
Authors: Frolkova A. V. , Ablizin M. A. , Mayevskiy M. A. , Frolkova A. K.
Published: November 2018

An approach to the determination of free variables required for calculating the material balance of the flowsheet of ternary mixtures separation is presented. Phase diagrams of the considered ternary systems are characterized by the presence of a two-phase splitting area and by the presence of different amounts of azeotropes (classes 3.1.0, 3.1.1, 3.2.1 and 3.3.1). For all the systems flowsheets containing three rectification columns and a florentine vessel for separation were suggested. The multivariance of the solution of the balance problem was shown. The approach was illustrated by the example of real ternary systems characterized by different phase diagrams (methanol - chloroform - water, butyl alcohol - water - toluene, nitromethane - hexane - water). The parameters of the rectification columns were presented.
STUDY OF MECHANISMS OF LIGHT ABSORPTION IN TITANIUM DIOXIDE FILMS
Authors: Novopashin V. V. , Skvortsov L. A. , Skvortsova M. I.
Published: November 2018

This work is devoted to comparison of optical absorption value of titanium dioxide coatings obtained by means of reactive thermal evaporation (RTE) and its activated species (ARTE), as well as to study on the dependence of the absorption coefficient of the coatings on the process parameters. Special attention is paid to the study of the influence of the films nonstoichiometry on absorption in the visible and near-infrared ranges of the spectrum. The results allow concluding that the dominant mechanism responsible for absorption in titanium dioxide films in the near-infrared range of the spectrum is the deviation from the stoichiometric composition. This deviation is caused by the presence of defects in the coating structure such as oxygen vacancies (ions Ti3+), which are seen as electron traps. As oxygen pressure and ionic current increase, the absorption of titanium dioxide films is reduced, and films with a composition closer to stoichiometric are obtained. In turn, the absorption of titanium dioxide in the visible spectrum (at wavelengths of 532 nm and 670 nm) has less to do with defects in stoichiometry, in contrast to contaminating impurities contained in the starting material, in the vacuum chamber and in the jet gas.
THE PROGNOSTIC MODEL OF ANTITUMOR EFFECT OF TARGETED DRUGS IN IMMUNOTHERAPY
Authors: Burlyaev V. V. , Davydenko А. А. , Nikolaeva O. M. , Russu L. I. , Suetina I. A. , Mezentseva M. V.
Published: November 2018

A prognostic model for constructing hypotheses about the relationship of combinations of cytokines with the proliferative activity of cancer cells is proposed. The model is based on the use of inductive inference methods. The methodology takes into account the synergistic interaction of cytokines and uses sequential construction of logical formulas for selecting groups of cytokines, a statistical analysis of contingency tables and logical integration of the obtained estimates. Implementation of the proposed method in the information system of forecasting the effect of targeted anticancer drugs in immunotherapy will greatly accelerate research in this area.
With some friends, you don't need enemies.
Authors: Redaktion Prokla
Published: November 2018

Das Prokla-Editorial zum USA-Heft ist, wie in der letzten Ausgabe teilweise dokumentiert, auf heftige Kritik gestoßen. Das war vielleicht nicht anders zu erwarten, denn erstens war das Editorial eine Provokation und zweitens enthält es die These, daß als Anti-Amerikaner gilt, wer die USA und denAmerican way oflife kritisiert. Allerdings wird in den Antworten auf das Editorial dieser Anti-Amerikanismus-Vorwurf mit Selbstauslöser nicht an der bloßen Tatsache der Kritik festgemacht, sondern an deren Form und Inhalt: So soll die Sprache vor Erbitterung, Zynismus und Wut »triefen<<, angeblich wird volkweise pauschalisiert, die US-amerikanische Opposition soll »irgendwie entmündigt« werden (wenn das von hier aus durch ein Editorial geschehen könnte, wäre es im übrigen nicht schade um sie) usw. usf.
Editorial
Authors: Redaktion PROKLA
Published: November 2018

Editorial: Probleme des Klassenkampfes
Klassenkämpfe in Indien
Authors: Armanski Gerhard , Pohlmann Jörg
Published: November 2018

Klassenkämpfe in Indien
Bundeswehr - Waffe des Kapitals
Authors: Armanski Gerhard , Hoffmann Werner , Kaiser Wolfgang , Tempel Karl , Wabnitz Thomas
Published: November 2018

Die vorliegende Arbeit ist als politisches Produkt einer bestimmten Phase der Studentenbewegung zu begreifen (1): 1m Sommer 1968 schlossen sich Hunderte von Bundeswehrreservisten, die an den Westberliner Universitäten studierten, zu einer Anti-Bundeswehr-Kampagne im Rahmen des Kampfes gegen die Verabschiedung der Notstandsgesetze zusammen. Die Kampagne kam über eine Resolution (2), einen Brief an das Bundesverteidigungsministerium und intensive Diskussionen iiber Fragen antimilitaristischer Taktik nicht hinaus. Ihre politische Unklarheit, mangelnde theoretische Grundlagen und die Abgehobenheit von der Praxis antimilitaristischer Arbeit in Westdeutschland lieben sie auf eine kleine Gruppe zusammenschrumpfen. Diese Gruppe unternahm es in der Folgezeit, die historischen, sozioökonomischen und politischen Aspekte der Rolle der Bundeswehr im Gesellschaftssystem der BRD herauszuarbeiten. Die unterschiedliche politische Zusammensetzung der Gruppe sowie der langwierige Erstellungsprozeß der Arbeit (vor allem dadurch bedingt, daß die Schwerpunkte des politischen Engagements der Beteiligten sich meist bald in andere Bereiche bewegten) erlaubte nur ansatzweise die Entwicklung einer durchgehenden, einheitlichen politischen und wissenschaftlichen Fragestellung und in ihrer Folge einer kollektiven Arbeitsweise. So stehen die einzelnen Teile der vorliegenden Arbeit oft relativ unverbunden nebeneinander. Vor allem konnten die neueren Fortschritte marxistischer Methode und Analyse nur teilweise aufgenommen werden
Zu einer modernen Ökonomie der DDR
Authors: Marz Lutz
Published: November 2018

Die DDR befindet sich in einem »Teufelskreis« von ökonomischen, ökologischen, ideologischen, theoretischen und machtpolitischen Zwängen. Weder der von vielen für einzig möglich erachtete Pfad eines nationalistischen Kapitalismus der freien Konkurrenz noch die sichere Sackgasse des real existierenden Sozialismus weisen einen Ausweg aus dem Teufelskreis. Denn weder lokal noch global läßt sich die Ökonomie einer modernen Gesellschaft über eine Universalisierung der bekannten Marktmechanismen und/oder der tradierten Machtdispositive gestalten. Einzig durch eine öffentliche Förderung dezentraler Kooperationsinitiativen, die die Subjekte und Kollektive zu eigenverantwortlicher Steuerung der Innovationsprozesse in den Alltagswelten und in der Gesamtgesellschaft motivieren, könnte sich die DDR-Gesellschaft zu einer wahrhaft modernen Gesellschaft transf armieren. Konkrete Kooperationsprojekte auf allen gesellschaftlichen Ebenen (und darin eingeschlossen solche der wirtschaftlichen Ost-West-Kooperation) müßten, so Marz, strategisch, eng und demokratisch, nicht aber kurzfristig, locker und elitär konzipiert und realisiert werden. Vor allem aber müßten sie aiif dem Prinzip der Reziprozität aufbauen - d.h. auf einer wechselseitigen Nutzung der Stärken eines jeden Kooperationspartners.
Geld im Sozialismus
Authors: Riese Hajo
Published: November 2018

Das realgeschichtliche Dilemma des Sozialismus, in Systemkonkurrenz mit dem Kapitalismus bestehen zu müssen, zwingt die sozialistischen Länder in die Alternative zwischen kapitalistischer Dynamik oder- im Rahmen einer Planungsökonomie - in den Status eines Entwicklungslandes. Weltmarktbedingungen erschweren dabei die Durchsetzung der ersten Alternative. Im Fall der DDR kommt hinzu, daß die Abwanderungsmöglichkeiten der Arbeitskräfte eine eigenständige Entwicklung erschweren.
Die Schriftsteller und der politische Umbruch in der DDR
Authors: Erbe Günter
Published: November 2018

Bis zum politischen Umbruch im Herbst 1989 wurden nicht wenige bedeutende Schriftsteller in der DDR als moralische Instanz, als Sand im Getriebe des realen Sozialismus wahrgenommen. Sie betrachteten sich selbst als Gewissen der Gesellschaft, die Literatur als Medium abweichender Meinungen im Kontrast zur offiziell vorgeschriebenen Einheitsmeinung. Ausgangspunkt der vorliegenden Untersuchung ist die Beobachtung, daß die kritischen Schriftsteller in der DDR die ihnen nach Beginn des politischen Umbruchs an der Seite der oppositionellen Gruppen zugewachsene Rolle als Wortführer der demonstrierenden Massen binnen kürzester Zeit einbüßten. Dies gibt Anlaß zu der Frage nach der politischen Rolle der Schriftsteller im realen Sozialismus, ihrem Politik- und Gesellschaftsverständnis, ihrer Wahrnehmung und Reflexion des Umbruchs. In den unterschiedlichen Stellungnahmen und Lagebeurteilungen werden spezifische Bewertungsmuster erkennbar, denen nicht zuletzt unterschiedliche Generationserfahrungen zugrundeliegen.