F Unger

Medical University of Graz, Gratz, Styria, Austria

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Publications (40)55.63 Total impact

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    ABSTRACT: Stereotactic radiosurgery (SRS) is a neurosurgical field that has become increasingly important in the treatment of acoustic neuromas. Radiosurgical treatment modalities include the Gamma knife, the linear accelerator (LINAC), and the CyberKnife. Gamma knife radiosurgery (GKRS) is still unsurpassed in terms of the spatial accuracy of radiation delivery and has been used for decades in acoustic neuromas (>18000 patients). In contrast to surgical resection, the goal of SRS is long-term prevention of tumour growth with preservation of neurological function. Radiation-induced neuropathies rarely occur. However, there are essential differences between SRS and fractionated stereotactic radiotherapy (FSR) in terms of both their radiobiological effects and their modes of application. SRS can be performed in an outpatient setting. Neuromas of up to 3 cm in diameter represent potential candidates for SRS or FSR. For larger tumours, cystic lesions and neuromas with brain stem compression, microsurgical resection in experienced neurosurgical centres is still the preferred option. SRS (and FSR) are possible options for patients with tumour progression after subtotal surgery or tumour recurrence, or for patients unable or unwilling to undergo surgery.
    HNO 01/2011; 59(1):31-7. · 0.42 Impact Factor
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    ABSTRACT: Die stereotaktische Radiochirurgie (SRS) ist ein neurochirurgischer Arbeitsbereich, der zunehmend in der Behandlung von Akustikusneurinomen genutzt wird. Radiochirurgische Methoden sind das Gamma-Knife, die sog. LINAC-Technologie und das Cyberknife. Die Gamma-Knife-Radiochirurgie (GKRS) weist die größte Genauigkeit auf und wird seit Jahrzehnten bei Akustikusneurinomen eingesetzt (>18.000 Patienten). Im Unterschied zu chirurgischen Verfahren ist das Ziel der SRS eine Langzeitarretierung des Tumorwachstums bei Erhalt der neurologischen Funktion. Strahlenbedingte Neuropathien treten sehr selten auf. Die seit einigen Jahren verwendete fraktionierte stereotaktische Radiotherapie (FSR) weist wesentliche Unterschiede zur einzeitigen SRS bei radiobiologischer Wirksamkeit und Anwendung auf. Die SRS ist zumeist ambulant möglich. Neurinome bis zu 3cm Größe sind mögliche Indikationen für SRS oder FSR. Größere Tumoren, Zysten und Neurinome mit Hirnstammkompression sollten wie bisher in erfahrenen Zentren (HNO oder Neurochirurgie) mikrochirurgisch reseziert werden. SRS (und FSR) sind ggf. als Option bei Patienten mit Tumorwachstum nach subtotaler Resektion oder Rezidivtumoren zu erwägen oder bei Patienten, die nicht operationstauglich oder -willig sind. Stereotactic radiosurgery (SRS) is a neurosurgical field that has become increasingly important in the treatment of acoustic neuromas. Radiosurgical treatment modalities include the Gamma knife, the linear accelerator (LINAC), and the CyberKnife. Gamma knife radiosurgery (GKRS) is still unsurpassed in terms of the spatial accuracy of radiation delivery and has been used for decades in acoustic neuromas (>18000 patients). In contrast to surgical resection, the goal of SRS is long-term prevention of tumour growth with preservation of neurological function. Radiation-induced neuropathies rarely occur. However, there are essential differences between SRS and fractionated stereotactic radiotherapy (FSR) in terms of both their radiobiological effects and their modes of application. SRS can be performed in an outpatient setting. Neuromas of up to 3cm in diameter represent potential candidates for SRS or FSR. For larger tumours, cystic lesions and neuromas with brain stem compression, microsurgical resection in experienced neurosurgical centres is still the preferred option. SRS (and FSR) are possible options for patients with tumour progression after subtotal surgery or tumour recurrence, or for patients unable or unwilling to undergo surgery. SchlüsselwörterAkustikusneurinom–Vestibularisschwannom–Radiochirurgie–Gamma-Knife–Stereotaktische Radiotherapie KeywordsNeuroma, acoustic–Schwannoma, vestibular–Radiosurgery–Gamma knife–Stereotactic radiotherapy
    HNO 01/2011; 59(1):31-37. · 0.42 Impact Factor
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    ABSTRACT: This study investigated the efficacy of staged radiosurgical treatment for intracranial meningiomas exceeding 3 cm in diameter. Between April 1992 and May 2008, staged gamma knife radiosurgery was performed in 20 patients with large benign meningiomas. 14 patients had undergone surgery at least once. The patients' ages ranged between 26 and 73 years (median 60.5). Tumour volumes measured between 13.6 and 79.8 cm(3) (median 33.3) and treatment volumes between 5.4 and 42.9 cm(3) (median 19.0). Of 41 treatments, the prescription dose at the tumour margin was 12 Gy for 33 treatments, 10 Gy for one treatment, 14 Gy for four treatments, 15 Gy for one treatment and 25 Gy for a further two treatments (median 12 Gy to a marginal isodose of 45%). Median follow-up was 7.5 years. Tumour control was achieved in 90% of our series (25% tumour regression, 65% stable size). Two patients (10%) experienced tumour progression outlying the planning target volumes treated by an additional radiosurgical procedure. Thereafter tumour volume decreased in one patient and remained stable in the second one. Clinically, nine patients (45%) improved within the time of follow-up and 11 (55%) remained unchanged. As a result of excellent tumour control at a low concomitant morbidity, staged radiosurgical treatment for meningiomas represents a safe treatment modality that can be recommended for meningiomas in critical locations either after incomplete surgery or as primary treatment for patients with significant comorbidity.
    Journal of neurology, neurosurgery, and psychiatry 10/2009; 80(10):1172-5. · 4.87 Impact Factor
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    ABSTRACT: To date, the efficacy and safety of repeat radiosurgery (RS) for trigeminal neuralgia (TN) is based mainly on short term results. Between 1994 and 2006, 93 patients were treated by RS for TN at the Department of Neurosurgery, Graz, Austria. 22 patients underwent repeat gamma knife radiosurgery (GKRS) a mean of 18.8 months after the initial treatment. The mean dose for repeat treatment was 74.3 Gy. Pain outcome was rated using the Barrow Neurological Institute (BNI) Pain Intensity Scale and facial numbness according to the BNI Facial Numbness Scale. Mean follow-up after repeat RS was 5.4 years. Pain relief was noted in 72.7% (16/22) of patients; six patients had a second pain recurrence after a mean of 9.3 months and underwent medical, alternative and/or further RS. One patient was lost to follow-up. BNI pain scale evaluation for 21 patients indicated improvement in 76.2% (16/21) of cases without medication (BNI I and II). Facial numbness was recorded in 73.7% (14/19) but in only one was it classified as bothersome. Long term observation of repeat GKRS for TN showed good pain relief in more than two-thirds of patients. Despite a high percentage of facial numbness, most likely attributable to the higher delivered dose, repeat RS can still be regarded as safe. However, further studies are needed to determine an optimised treatment protocol.
    Journal of neurology, neurosurgery, and psychiatry 05/2008; 79(12):1405-7. · 4.87 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 01/2008; 180. · 2.76 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 01/2008; 180. · 2.76 Impact Factor
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    ABSTRACT: Anterior callosotomy is a surgical option for the treatment of generalized tonic or atonic seizures associated with drop attacks. Besides open surgery, a radiosurgical callosal disconnection using the gamma knife (GK) also can be performed, but reliable data about tolerability and efficacy are sparse. Eight patients (three female, five male age range, 5 to 69 years) with severe generalized epilepsy associated with disabling drop attacks underwent GK callosotomy between 1993 and 2004. In six patients, the anterior third of the corpus callosum was radiosurgically disconnected. In one patient a second procedure with GK treatment of the middle third of the corpus callosum was added 17 months later. In two patients posterior GK callosotomy had followed partial hemispherotomy. Drop attacks (DAs) were completely abolished in three patients, and two patients had a marked DA seizure reduction of 60%. Two of four patients with additional generalized tonic-clonic seizures showed a reduction of 100%, and the remaining, a 50% and 60% decrease, respectively. Other seizure types responded less well to the radiosurgical treatment. In both patients with posterior GK callosotomy after hemispherotomy, partial seizures decreased. Beside transient headache in two patients, no immediate or long-term postradiosurgical side effects were observed. Palliative radiosurgical callosotomy is an efficient and safe noninvasive alternative to the open procedure with comparable results. No signs of postradiosurgical side effects were noted within an up to 12-year posttreatment period.
    Epilepsia 08/2006; 47(7):1184-91. · 3.91 Impact Factor
  • Clinical Neurophysiology 03/2006; 37(01). · 3.14 Impact Factor
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    ABSTRACT: Treatment of esthesioneuroblastoma (olfactory neuroblastoma) has been considerably improved by microsurgical techniques. Nevertheless, these rare tumours of the frontal skull base are still associated with high rates of tumour recurrence and mortality, thus remaining a challenge even for experienced surgeons. A novel therapeutic approach that combines endoscopic sinus surgery and Gamma Knife radiosurgery is presented here. Taking into account the rarity of the disease the present study comprises a relatively large series of patients treated in a similar manner. 14 patients (8 males, 6 females) aged 27-75 years (median 38) were treated between May 1993 and December 2003. This series comprises 12 newly diagnosed esthesioneuroblastomas. Two more patients had already previously undergone surgery (24/39 months earlier). Paranasal and nasal endoscopic sinus surgery was performed. Marginal irradiation doses ranging from 15-34 Gy were given to the residual tumours by means of radiosurgery (Gamma Knife) involving 1-7 isocentres within 3 months after surgery. Median follow-up is 58 months (range 13-128). There was no mortality. In all patients tumour control was achieved within the treated area. 4 patients underwent a second radiosurgical procedure 6-79 months (median 34 months) after initial radiosurgery. One patients had to undergo an additional craniotomy because of extensive neoplastic infiltration, 1 developed postoperative liquorrhea, 1 case was complicated by bilateral frontal sinusitis. All patients complained of nasal discharge and crusts. Karnovsky Index--preoperatively ranging from 80%-100%--remained stable in 12 patients, an improvement was observed in 2 cases. Based on the favourable results recorded so far, the combination of endoscopic sinus surgery and radiosurgery can be considered a promising treatment option for esthesioneuroblastoma that merits further consideration.
    Acta Neurochirurgica 07/2005; 147(6):595-601; discussion 601-2. · 1.55 Impact Factor
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    ABSTRACT: A cystic lesion adjacent to the dens with compression of the lower portion of the medulla oblongata was found on MRI in a 75-year-old male patient with a 2-month history of occipital pain and gait disturbance. Clinically, the patient showed mild tetraparesis, signs of spinal ataxia and symmetrical hyperreflexia. Following subtotal removal of the cyst via left-sided suboccipital craniotomy and left-sided hemilaminectomy of C1 the lesion was classified as synovial cyst on histopathological examination. Postoperatively, the quadriparesis almost completely subsided and the patient is currently doing well, 33 months after surgery. Synovial or ganglion cysts adjacent to the atlantoaxial articulation with ventral compression of the cervicomedullar cord represent rare surgical or radiological entities. Atlantoaxial synovial cysts have no typical radiographic appearance or specific neurological symptoms so that they are frequently misdiagnosed as intraspinal- or skull base tumour, rheumatoid lesion or ectatic vertebral artery. Since no ensuing complications or recurrences have been encountered in cases of incompletely removed cysts the less invasive operative approaches should be used to avoid destabilisation and subsequent additional surgical procedures.
    Zentralblatt für Neurochirurgie 02/2003; 64(2):86-9. · 0.63 Impact Factor
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    ABSTRACT: The prevailing percutaneous treatment options for herniated non-contained lumbar discs have not reliably achieved the same good results as the conventional microsurgical techniques. In this study we evaluated clinical outcome and complication rate following endoscopic percutaneous transforaminal treatment of extruded or sequestrated herniated lumbar discs in 122 patients with a follow-up period of more than one year. Between October 1997 and December 2000, 86 male and 36 female patients with a median age of 55 years (range 18 to 89 years) underwent endoscopic treatment for non-contained herniated lumbar discs at our department. Neurological controls were conducted after 4 to 8 weeks routinely and the clinical result was reassessed at a follow-up of 15 to 53 months (median 35 months) according to the Macnab scale and Prolo outcome score. On follow-up examination, 96 patients were found with permanently ameliorated or normal clinical status following endoscopy alone. The remaining 26 cases with unchanged or only temporarily improved neurological disorders were submitted to conventional microsurgical interventions. Spinal nerve root injury during endoscopic treatment occurred in two patients but no additional neurological deficits or aggravation of pre-existing disorders were observed. Due to the minimal invasivity, the good functional outcome (78.7% clinical amelioration) and the low complication rate (1.6%), this procedure represents an attractive and efficient treatment alternative especially for foraminal and extraforaminal herniated lumbar discs and reduces the indications for open surgery in selected cases.
    Acta Neurochirurgica 11/2002; 144(10):997-1004; discussion 1003-4. · 1.55 Impact Factor
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    ABSTRACT: Aetiology and pathogenesis of eating disorders is a matter of controversy. In some cases they can occur in association with tumours involving the temporal cortex, in temporal lobe epilepsy or in the advanced state of degenerative diseases involving temporal structures. We report about three patients with right frontal intracerebral lesions, one oligo-astrocytoma and two vascular malformations, associated with partial seizures and anorexia nervosa. 3 patients, one female and two men with anorexia nervosa and right frontal intracerebral lesions were admitted to our wards due to focal seizures or loss of consciousness. They were treated either microsurgically or by endovascular embolization after neuro-imaging. In our retrospective analysis of the patients' reports and course we investigated the histopathology of the lesions, duration of the eating disorder and the clinical outcome. Two patients underwent craniotomy with extirpation of the lesion. In one case histology revealed an oligo-astrocytoma, in the other haemorrhagic infarction due to a venous malformation. The patient with the arteriovenous malformation (AVM) was embolized with microparticles. The patients with the oligoastrocytoma and AVM totally recovered. They gained weight and stayed seizure free. The patient with the infarction remained in a vegetative state. Right frontal intracerebral lesions with their close relationship to the limbic system could be causative for eating disorders. We therefore recommend performing a cranial MRI in all patients with suspected eating disorders, especially if they occur in combination with focal seizures.
    Acta Neurochirurgica 09/2002; 144(8):797-801; discussion 801. · 1.55 Impact Factor
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    ABSTRACT: Radiosurgery is either a primary or an adjunctive management approach used to treat patients with vestibular schwannomas. We sought to determine outcomes measuring the potential benefits against the neurological risks in patients who underwent radiosurgery after previous microsurgical subtotal resection or recurrence of the tumour after total resection. Gamma Knife radiosurgery was applied as an adjunctive treatment modality for 86 patients with vestibular schwannomas from April 1992 to August 2001. We evaluated the results of 50 patients who had a follow-up of at least 3.5 years (median 75 months, range 42-114 months). In 16 patients a recurrence of disease was observed after previous total resection. The median treatment volume was 3.4 ccm with a median dose to the tumour margin of 13 Gy. Tumour control rate was 96%. Two tumours progressed after adjunctive radiosurgery. Useful hearing (Gardner-Robertson II) (4 patients (8%)) and residual hearing (Gardner-Roberson III) (10 patients (20%)) remained unchanged in all patients, who presented with it before radiosurgery, respectively. Clinical neurological improvement was observed in 24 patients (46%). Adverse effects comprised transient neurological symptoms and signs (incomplete facial palsy, House-Brackman II/III) in five cases (recovered completely), mild trigeminal neuropathy in four cases, and morphological changes displaying rapid enlargement of a pre-existing macrocyst in one patient and tumour growth in another one. No permanent new cranial nerve deficit was observed. Radiosurgery appears to be an effective adjunctive method for growth control of vestibular schwannomas and is associated with both a low mortality rate and a good quality of life. Accordingly, radiosurgery is a rewarding therapeutic approach for the preservation of cranial nerve function in the management of patients with vestibular schwannoma in whom prior microsurgical resection failed.
    Acta Neurochirurgica 08/2002; 144(7):671-6; discussion 676-7. · 1.55 Impact Factor
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    ABSTRACT: Epilepsy surgery is a successful therapeutic approach in patients with medically intractable epilepsy. The presurgical evaluation aims to detect the epileptogenic brain area by use of different diagnostic techniques. In this review article the current diagnostic procedures applied for this purpose are described. The diagnostic armamentarium can be divided conceptually into three different groups: assessment of function/dysfunction, structural/morphologic imaging methods and functional neuroimaging techniques. Properties, diagnostic power and limits of all diagnostic tools used in the diagnostic evaluation are discussed. In addition, future perspectives and the diagnostic value of new technologies are mentioned. Some are increasingly gaining acceptance in the routine preoperative diagnostic procedure like MR volumetry or MR spectroscopy of the hippocampus in patients with temporal lobe epilepsy. Some, on the other hand, like MEG and 11C-flumazenil PET, still remain experimental diagnostic tools as they are technically demanding and cost intensive. Besides the refinement of established techniques, co-registration of different modalities like spike-triggered functional MRI will play an important role in the non-invasive detection of the epileptic seizure focus and may change the regimen of the preoperative diagnostic work up of epilepsy patients in the future.
    Acta neurochirurgica. Supplement 02/2002; 84:17-26.
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    ABSTRACT: Glomus jugular tumours are usually managed by microsurgical resection and/or radiotherapy with considerable risk for treatment-related morbidity. The role of Gamma Knife Radiosurgery (GKRS) in the management of these lesions remains to be defined. Between May 1992 and November 2000, 19 patients with glomus tumours underwent GKRS at our department. Nine patients received radiosurgery for residual or recurrent paragangliomas following microsurgical resection and in 10 cases GKRS was performed as primary treatment. The median tumour volume was 5.22 ccm (range: 0.38-33.5 ccm). Marginal doses of 12-20 Gy (median 14 Gy) were applied to enveloping isodose volume curves (Range: 30-55%, median 50%). Except for an 81-year-old patient who died 9 months after radiosurgery the observation time ranged from 1.5 to 10 years (median 7.2 yrs). The total tumour control rate was 94.7% (7 cases with decreased and 11 with stable tumour size). The only patient with tumour progression (5.3%) underwent repeated radiosurgical treatment 85 months after initial GKRS. A newly diagnosed second lesion in the cavernous sinus was treated radiosurgically as well 53 months after the first Gamma Knife procedure. On clinical examination 10 patients (52.6%) presented with improved and 8 patients (42.1%) with unchanged neurological status. Deterioration in one patient (5.3%) was not related to tumour or radiosurgery. As GKRS demonstrated to be a minimally invasive treatment alternative to microsurgery and radiotherapy with no acute or chronic toxicity it should be considered more frequently in the primary or adjuvant strategy for glomus jugular tumours.
    Acta neurochirurgica. Supplement 02/2002; 84:91-7.
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    ABSTRACT: Hypothalamic hamartomas are nonneoplastic lesions often characterized by central precocious puberty and gelastic epilepsy. Due to the delicate location surgery is often unsuccessful and associated with considerable risks. In the presented series, Gamma Knife radiosurgery was applied. Four cases (aged between 5-13 years) who presented with medically intractable gelastic epilepsy and increasing secondary generalization, abnormal behaviour and precocious puberty (3 cases) are reported. Hypothalamic hamartomas sized 11-17 mm had been diagnosed by MR imaging. Radiosurgical treatment was performed in general anaesthesia with margin doses of 12-14 Gy to the 50-90% isodoses covering volumes of 600-2300 mm3. After follow-up periods of 12 to 68 months, a continuing decrease both in seizure frequency and intensity was noted (outcome according to Engel: II a (3 cases) and III a (1 case)). All patients are socially reintegrated. MR imaging did not reveal significant changes concerning the size of the lesions. Gamma Knife radiosurgery can be an effective and safe alternative treatment modality for HH capable of achieving good seizure control and improving behavioural disorders in selected cases.
    Acta neurochirurgica. Supplement 02/2002; 84:57-63.
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    ABSTRACT: Radiosurgery is a management approach used to treat patients with vestibular schwannomas. The goals are long-term tumour growth control, maintenance of cranial nerve function and prevention of new deficiencies. We sought to determine long-term outcomes measuring the potential benefits against the neurological risks of primary radiosurgery. Gamma Knife radiosurgery was applied as a treatment modality for 289 patients with vestibular schwannomas from April 1992 to April 2002. The long-term results of 100 patients who underwent radiosurgery were evaluated. 60 patients received a primary treatment, 40 other cases presented with previously performed subtotal microsurgical resection or recurrence of disease (12-96 months, median 39). The median treatment volume was 3.4 ccm and the median dose to the tumour margin was 13 Gy. The median patient follow-up time was 76 months (range 60-120 months). Four tumours progressed after primary radiosurgery. Tumour control rate was 96%. Useful hearing (Gardner-Robertson I/II) was preserved in 16 patients (55%). Clinical neurological improvement occurred in 50%. Adverse effects comprised neurological symptoms (incomplete facial palsy) (House-Brackman II/III) in six cases (four recovered completely), mild transient trigeminal neuropathy in five cases, and morphological changes displaying rapid enlargement of preexisting macrocysts in two patients and tumour growth in two other patients. Microsurgical resection was performed in four cases (4%) and two patients underwent a shunting procedure because of hydrocephalus formation (2%). In patients who had undergone previous microsurgery, no new cranial nerve deficit was observed. Radiosurgery is an effective method for growth control of vestibular schwannomas and is associated with both a low mortality rate and a good quality of life. Accordingly, for the preservation of cranial nerve function radiosurgery is a useful method for the management of properly selected patients and is comparable to microsurgery.
    Acta neurochirurgica. Supplement 02/2002; 84:77-83.
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    ABSTRACT: Radiosurgery is either a primary or an adjunct management approach used to treat patients with vestibular schwannomas. The goals are long-term tumour growth control, maintenance of cranial nerve function and prevention of new neurologic deficiencies. We sought to determine long-term outcomes measuring the potential benefits against the neurological risks of radiosurgery. 278 patients with vestibular schwannomas underwent Gamma Knife radiosurgery as a treatment modality for from April 1992 to November 2001. The long-term results of 60 patients were evaluated who received radiosurgery as primary treatment. 12 cases presented with previously performed subtotal microsurgical resection or recurrence of disease (12-96 months, median 39). The median treatment volume was 3.8 ccm and the median dose to the tumour margin was 12 Gy. The median patient follow-up time was 88 months (range 72-114 months). Four tumours progressed after primary radiosurgery. Tumour control rate was 93%. Useful hearing (Gardner-Robertson I/II) was preserved in 16 patients (55%). Clinical neurological improvement occurred in 36 patients (60%). Adverse effects comprised neurological symptoms (incomplete facial palsy) (House-Brackman II/III) in five cases (three recovered completely), mild trigeminal neuropathy in three cases, and morphological changes displaying rapid enlargement of preexisting macrocysts in two patients and tumour growth in two other ones. Microsurgical resection was performed in three cases (5%) and one patient underwent a shunting procedure because of hydrocephalus formation. In patients who had undergone previous microsurgery, neither new cranial nerve deficit nor any tumour growth was observed. Radiosurgery performed with current techniques proved to be an effective method for growth control of vestibular schwannomas with both a low mortality rate and a good quality of life. An increasing percentage of patients will undergo radiosurgery as accessibility to this alternative increases, and more data regarding long-term follow-up are available. It is a post-operative complementary treatment for partially removed tumours. Accordingly, radiosurgery is a useful method for the management of properly selected patients.
    Zentralblatt für Neurochirurgie 02/2002; 63(2):52-8. · 0.63 Impact Factor
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    ABSTRACT: The efficacy of radiosurgery in cases of mesiotemporal tumours associated with long standing epilepsy has not clearly been documented up to now. The authors present a retrospective analysis of 19 cases treated by Gamma-Knife radiosurgery (GKRS) for mesiotemporal tumour epilepsy. Between 1992 and 1997 19 patients (12 male and 7 female) with a mean age of 31 years (5-72) and mesiotemporal tumour-induced epilepsy of a mean duration of 8.6 years (0.9-28) were treated by GKRS. All tumours were within the mesiotemporal structures and the pathohistology proven by biopsy or resective procedure revealed 15 (79%) low grade astrocytomas, 3 (16%) gangliogliomas and 1 (5%) cavernoma. Beside tumour control, the main aim of GKRS was alleviation of epilepsy by irradiating the presumed epileptic foci outside the tumour volume. The 50% isodose volumes surrounding the tumours measured a mean of 6.2 ccm (1.1-18 ccm). Doses given at marginal isodoses ranged from 12 to 30 Gy (mean 17.3 Gy). The outcome with respect to epileptic seizures was evaluated by the Engel classification. After a follow-up (FU) of 1.7 to 9.7 years (mean 6.5 years) 11 patients (57.9%) were significantly ameliorated (Engel I and Engel II), 7 patients (36.8%) worthwhile improved (Engel III) and 1 patient (5.3%) unchanged. In 11 patients (58%) radiosurgically induced image changes were seen on MRI. Although microsurgical approach guided by electrocorticography (EcoG) is the state of art for treatment of mesiotemporal tumour epilepsy, GKRS can be used as a non-invasive, safe and effective alternative to resective surgery for selected cases.
    Acta neurochirurgica. Supplement 02/2002; 84:49-55.
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    ABSTRACT: Stereotactic radiosurgery has proved to be an effective alternative to microsurgical resection in treatment of acoustic neuroma. Still, microsurgery is considered by many to be the therapy of choice. In case of recurrence microsurgical resection is much more difficult because of scarring and has a higher risk of complications. Therefore in cases of recurrence the role of radiosurgery needed to be evaluated. From April 1992 to July 1997 135 patients suffering from acoustic neuroma were treated at the Neurosurgical Department of the University Medical School of Graz by means of the gamma-Knife. 12 patients had recurrence after a single or several microsurgical resections. The age distribution was between 38 and 71 years with a mean of 57 years. The diameter of the tumors varied between 10.5 and 31.2 mm. In all 12 cases the tumors could be inactivated biologically in a mean follow-up period of 58.8 months by means of stereotactic radiosurgery. Tumor shrinkage was achieved in 3 cases (25%), central necrotic areas were observed in 8 cases (67%). No additional cranial nerve palsies occurred. Stereotactic radiosurgery has proven to be a safe and effective treatment option instead of repeated microsurgery. Stereotactic radiosurgery should be considered as the therapy of choice in cases of recurrent acoustic neuromas.
    Laryngo-Rhino-Otologie 08/2001; 80(7):385-8. · 0.82 Impact Factor