Biomedical subjects

K Roessler

Publications and source records attributed to K Roessler.

15 recordsLinked to original sources

PubMed2001

Epidural metastasis of a glioblastoma after stereotactic biopsy: case report.

Tumor seeding along the biopsy tract is a rare complication in stereotactic biopsy. We present the unique case of a 42-year-old male with epidural tumor seeding along the needle tract after computer tomography-guided stereotactic biopsy of a glioblastoma in the right basal ganglia. Three months after the biopsy and one week following fractionated radiation therapy, the patient died of brain edema and cardiac dilatation. Besides further tumor growth at the primary site, autopsy revealed a right frontal epidural, nodular metastatic tumor at the site of dura incision of the stereotactic biopsy. Histological examination showed a glioblastoma that spread epidurally along the needle tract. This is the first report of an epidural intracranial implantation metastasis of a glioblastoma after stereotactic biopsy.

Adult↗

PubMed2001

Gamma knife radiosurgery of recurrent central neurocytomas: a preliminary report.

OBJECTIVES: A series of three recurrent central neurocytomas treated by gamma knife radiosurgery (GKRS), which were initially totally resected, are described. Up to now, no reports exist on this treatment modality for this rare tumour entity. METHODS: Three male patients, aged between 20 and 25 years, presented with large intraventricular tumours. Total tumour removal was achieved by a single surgical procedure (one patient) or two operations (two patients). Neuropathological investigation showed a central neurocytoma, immunohistochemically all three tumours expressed a neuronal antigenic profile typical for neurocytomas, and the MIB-1 proliferation index ranged from 2.4% to 8.7%. Each patient experienced a tumour recurrence after 5 to 6 years. The recurrence was multifocal in two and a singular tumour mass in one patient. Gamma knife radiosurgery was performed. The tumours were enclosed within the 30% to 60% isodoseline, and delivered a tumour marginal dose of 9.6 to 16 Gy. During the follow up period, the patients were tested clinically and the volume of the tumours was measured on MRI. RESULTS: Within follow up periods of 1 to 5 years, control MRI showed a significant decrease of the tumour mass in all cases. None of the patients developed new neurological symptoms after GKRS. Two patients returned to work in their previous employment, whereas one patient remained permanently disabled due to a pre-existing visual impairment and abducens palsy. CONCLUSION: GKRS proved to be a useful tool in the treatment of recurrent central neurocytomas. Tumour control and even tumour shrinkage can be achieved with a single procedure and a low risk of morbidity.

Adult↗

PubMed2000

Gamma knife radiosurgery of skull base meningiomas.

BACKGROUND: The standard surgical treatment of meningiomas is total resection of the tumour. The complete removal of skull base meningiomas can be difficult because of the proximity of cranial nerves. Stereotactic radiosurgery (SRS) is an effective therapy, either for adjuvant treatment in case of subtotal or partial tumour resection, or as solitary treatment in asymptomatic meningiomas. METHOD: Between September 1992 and October 1995. SRS using the Leksell Gamma Knife was performed on 46 patients (f:m 35:15), ranging in age from 35 to 81 years, with skull base meningiomas at the Neurosurgical Department of the University of Vienna. According to the indication of gamma knife radiosurgery (GKRS) the patients (n = 46) were divided into two subgroups. Group I (combined procedure: subtotal resection followed by GKRS as a planned procedure or because of a recurrent meningioma), group II (GKRS as the primary treatment). Histological examination of tumour tissue was available for 31 patients (67%) after surgery covering 25 benign (81%) and 6 malignant (19%) meningioma subtypes. FINDINGS: The overall tumour control rate after a mean follow-up period of 48 months (ranging from 36 to 76 months) was 96% (97.5% in benign and 83% in malignant meningiomas). Group I displayed a 96.7% tumour control rate, followed by group II with 93.3% respectively. Neurological follow-up showed an improvement in 33% stable clinical course in 58%) and a persistent deterioration of clinical symptoms in 9%. Remarkable neurological improvement after GKRS was observed in group II (47%), whereas in group I (26%) the amelioration of symptoms was less pronounced. INTERPRETATION: GKRS in meningiomas is a safe and effective treatment. A good tumour control and low morbidity rate was achieved in both groups (I, II) of our series, either as a primary or adjunctive therapeutic approach. The planned combination of microsurgery and GKRS extends the therapeutic spectrum in the treatment of meningiomas. Reduction of tumour volume, increasing the distance to the optical pathways and the knowledge of the actual growing tendency by histological evaluation of the tumour minimises the risk of morbidity and local regrowth. Small and sharply demarcated tumours are in general ideal candidates for single high dose-GKRS, even after failed surgery and radiation therapy, and in special cases also in larger tumour sizes with an adapted/reduced margin dose.

Adult↗

PubMed1999

Expression of BCL-2 oncoprotein on tumor cells and tumor-infiltrating lymphocytes (TIL) in meningiomas.

The Expression of the antiapoptotic oncoprotein BCL-2 and its correlation to tumor grade in 62 meningiomas (48 classic, 9 atypical, and 5 anaplastic) using single and double immunohistochemistry was investigated. BCL-2 expression was found in two different cell populations identified as lymphocytes (BCL-2+CD3+) and tumor cells (BCL+/CD3-). Tumor-infiltrating lymphocytes (TIL) (CD3+) were found within classic (9.5% of cells), atypical (2.4% of cells), and anaplastic (1.8% of cells) meningiomas. In classic meningiomas, 66.5% of TIL were BCL-2-positive, in atypical meningiomas 79.2%, and in anaplastic meningiomas 37.9%. In 33 (68.8%) of the classic meningiomas, medium to high counts of BCL-2+ tumor cells were detected. Atypical meningiomas showed nearly equal percentages of high (two patients), medium (five patients), and low (two patients) BCL-2+ tumor cell counts, whereas anaplastic meningiomas showed only medium (two patients) and low (three patients) BCL-2 tumor cell counts or were BCL-2-negative (one patient). In summary, a significant inverse correlation between the number of BCL-2-positive tumor cells and tumor grade in meningiomas was found. These findings support the hypothesis of cell survival prolongation by the antiapoptotic ability of BCL-2 proto-oncogenes and demonstrate the prognostic relevance of BCL-2 immunoreactivity in meningiomas.

CD3 Complex↗

PubMed1999

Multiple spinal "miliary" hemangioblastomas in von Hippel-Lindau (vHL) disease without cerebellar involvement. A case report and review of the literature.

We report on a 57-year-old male presenting with radicular pain in the nerve roots of L5 and S1 on the right side and dysuria. Magnetic resonance imaging (MRI) of the lumbar spine showed multiple (up to 20) small, intradural enhancing nodules attached to the cauda equina down to the sacrum, the largest 1 cm in diameter at the level Th12/L1 compressing the conus. Additionally, small nodules in the cervico-thoracal region adjacent to the cord, but no cerebellar or cerebral abnormalities, were detected in a consecutive MRI of the remaining neuroaxis. The histology of a resected lesion at Th12/L1 revealed hemangioblastoma of the reticular type. Together with a history of left eye enucleation performed 17 years ago for angiomatosis of the retina and the immunohistochemical detection of von Hippel-Lindau (vHL) protein within the removed spinal hemangioblastoma, a diagnosis of vHL disease was established. Family history and screening for visceral manifestations of vHL disease were negative. In contrast to cerebellar or solitary spinal hemangioblastomas, multiple spinal hemangioblastomas without cerebellar involvement in vHL represent unusual manifestations. Unlike the case for solitary lesions in non-syndromic patients, a surgical cure does not seem feasible in this case. The role of treatment modalities is discussed.

Biomarkers, Tumor↗

PubMed1998

Frameless stereotactic lesion contour-guided surgery using a computer-navigated microscope.

BACKGROUND: The Zeiss MKM System is a recently developed computerized operating microscope for image-guided neurosurgery. The clinical advantages, reliability, accuracy, and limitations of this technique were investigated. METHODS: Since February 1995, 78 consecutive frameless stereotactic image-guided procedures were performed in 73 patients (30 males, 43 females; mean age, 46.9 years; range, 16-77 years) for tumor surgery (50/64.1%), cavernoma removal (16/20.5%), and functional procedures (12/15.4%). Skin markers (74 cases) or bone markers (4 cases) and a standard imaging protocol (2-mm cranial computed tomography (CCT) in 59 cases/1.5-mm magnetic resonance imaging (MRI) in 19 cases) were used. RESULTS: The main advantages were pre-operative skin incision, craniotomy and corticotomy planning, and determination of lesion boundaries. Useful registration and system reliability were noted in 97% (76/78) of the procedures. A significant improvement in registration accuracy was observed over the test period from a mean of 4.8 mm (SD = 3.36; Cases 1-25) to a mean of 2.2 mm (SD = 0.86; Cases 26-78). This resulted in an improvement in application accuracy from <5 mm in 71% (Cases 1-25) to <2 mm in 95% (Cases 26-78) of cases, and the accuracy led to successful localization of the lesion in every case. Accuracy was reliable at the beginning of every procedure, but degraded to values >5 mm by the end of the procedure in 29% (22/78) of cases. MRI cases achieved higher application accuracy values (2.1 mm mean) than CT cases (3.7 mm mean). CONCLUSIONS: The system offers a reliable alternative to frame-assisted stereotactic craniotomies in lesion targeting, but would need an intraoperative image update for resection guidance.

Adolescent↗

PubMed1998

Image-guided neurosurgery comparing a pointer device system with a navigating microscope: a retrospective analysis of 208 cases.

A retrospective analysis of neuronavigation procedures performed at the Vienna Neurosurgical Clinic was undertaken to elucidate the advantages of 2 technically different navigation systems in clinical use. In a 30-month period, 208 frameless stereotactic procedures were performed using a stereotactic microscope (MKM System, Zeiss; 92 procedures in 87 patients; 47 female, 40 male; mean age, 46 yrs) and a light emitting diode (LED) based pointer navigation device (Easy Guide Neuro (EGN), Philips; 116 procedures in 114 patients; 63 female, 51 male; mean age 46.4 yrs). The navigating microscope was exclusively used for cranial navigation, the pointer device system in 107 cases for cranial and in 9 cases for spinal navigation. Procedures were CCT-guided in 109 cases, MRI-guided in 95, and both CT/MRI guided in 4 cases. Skin fiducials were used in all these procedures. The MKM system provided coordinate-based navigation, similar to frame systems. This allowed surgical planning and performance using stereotactic coordinates for target calculation. Additionally, tumor volumes were defined by contours and projected into the ocular of the microscope, allowing guidance during targeting and resection of lesions. Both of these features proved beneficial in tumor surgery (60.8% MKM cases), cavernoma surgery (21.8% MKM cases), and epilepsy surgery (14.1% MKM cases). In contrast to the microscope, the pointer navigation system could be employed for intuitive correlation of image points with points of interest in the operating field by using a LED-equipped pointer device. This permitted image guidance during a wide spectrum of neurosurgical procedures, in tumor surgery (68.1% EGN cases), cavernoma surgery (5.1% EGN cases), epilepsy surgery (14.1% EGN cases), vascular surgery (3.4% EGN cases), spinal surgery (7.8% EGN cases), and guidance for burr holes and drainages (6.9% EGN cases), without calculating stereotactic coordinates. This analysis showed clear differences in the application of the two systems and may facilitate the decision as to which system best meets the individual demands of a neurosurgical department.

Adult↗

PubMed1998

Frameless stereotactic-directed tissue sampling during surgery of suspected low-grade gliomas to avoid histological undergrading.

Detection of anaplastic tumor foci for precise grading of gliomas is crucial for prognostic assessment and appropriate postoperative treatment planning. To avoided undergrading in large suspected low-grade gliomas, we employed frameless sterotaxy during open surgery for tissue sampling of radiologically suspected anaplastic foci. In nine patients (mean age 44 years, range 10-67) with large supratentorial suspected low-grade gliomas (32.4 ccm mean vol, range 17.9-68.6 ccm) with small contrast enhancing areas (7.7% mean of total volume, range 0.7-15.3%), a neuronavigation system with a pointer device (Easy Guide System Philips) or a navigating microscope (MKM System Zeiss) was used to target small enhancing tumor parts for cytological investigation during open surgery. Consecutive cytological smears revealed anaplastic tumor foci in all patients, correlating with neuroradiologically demonstrated small contrast enhancing areas, although biopsies from all other tumor parts showed low-grade tumors. Final neuropathological diagnosis confirmed anaplasia within the neuroradiologically suspected low-grade gliomas in all patients (2 grade IV, 5 WHO grade III and 2 grade II-III tumors, WHO classification). In our experience frameless stereotactic-directed intraoperative tissue sampling during open surgery of large suspected low-grade gliomas helps to identify small anaplastic areas in mostly large low-grade tumors, and therefore, permits optimum planning of postoperative treatment.

Adolescent↗

PubMed1997

Frameless stereotactic guided neurosurgery: clinical experience with an infrared based pointer device navigation system.

An infrared based frameless stereotactic navigation device (Easy Guide Neuro) was investigated for its clinical applicability, registration/application accuracy and limitations in a standard operating room set-up. In a five-month period 40 frameless stereotactic procedures (23 female, 17 male, mean age 46.4, yrs range 10-83) including 36 craniotomies and 4 spinal surgery procedures were performed. Image registration, data transfer and operation planning using skin fixed fiducials (between 5-10, mean 6.6) and CCT in 12 patients/MRI in 28 patients, generally was done the day before surgery. Clinical applicability was proven in all procedures with an additional time for pre-operative imaging and system application in the OR of 50 min mean (35-120 range). A useful registration was achieved in 39/40 patients (97.5%) with a registration accuracy of 3.4 mm (range 1.8-6.7) for brain surgery cases and 14.4 mm (6.8-25) for spine cases. This resulted in intra-operative application accuracy values for brain surgery of 4.2 mm mean (range 1-12). Enhanced registration/application accuracy values over the test period from 4.2/3.8 mm mean (Cases 1-20) up to 3.2/2 mm mean (Cases 21-40) was observed. In spinal surgery an application accuracy of 11.3 mm mean (range 5-20) was found. An intra-operative re-calibration because of system-head drift was necessary in none of the patients, nevertheless, application accuracy degradation due to brain shift was detected in every case. In conclusion, the system allowed a time sufficient accurate frameless intra-operative localisation guidance in cavernoma, meningioma, glioma, and brain metastasis surgery. In spinal surgery, the application accuracy exceeded clinical usefulness due to high registration inaccuracy using skin markers.

Adolescent↗

PubMed1997

Contour-guided brain tumor surgery using a stereotactic navigating microscope.

OBJECTIVE: The benefit of intraoperative radiological data integration in approach planning and resection of brain tumors using a computer navigating microscope (MKM Zeiss) was investigated. METHODS: Since February 1995, out of 86 MKM-guided surgical procedures, 53 contour-guided tumor cases (24 females, 29 males, mean age 51.6) including 16 metastasis, 14 glioblastomas, 10 low-grade gliomas, 6 anaplastic gliomas, 3 meningiomas and 4 others were performed. The preoperative planning was based on CT in 42 cases and Magnetic Resonance Tomography (MRT) in 11 cases using skin markers (4-9, mean 6). Neuroradiologically defined tumor contours were transferred into the ocular of the microscope and projected into the operating field during the procedure. RESULTS: The advantages of the system were: (1) preoperative approach planning; (2) minimal, accurate skin incision and craniotomy; (3) intraoperative detection of deep seated lesions or lesion components; (4) determination of lesion boundaries; (5) minimized traumatization in/near eloquent areas. Mean registration accuracy improved from 5.3 mm for the first 10 cases up to 2 mm for the last 18 cases. In glioma surgery, the system provided exact definition of radiologically planned resection borders. In meningioma surgery, it allowed a tailored craniotomy, dura opening and resection, lowering the risk of recurrence. In metastasis surgery, it provided a safe approach to deep and eloquent located lesions. CONCLUSION: Contour-guided operation planning and resection guidance using the investigated navigating microscope provides additional security to avoid some potential risks in brain tumor surgery.

Adult↗

PubMed1996

Histological heterogeneity of neuroradiologically suspected adult low grade gliomas detected by Xenon enhanced computerized tomography (CT).

Xenon-enhanced computerized tomography (XeCT) was performed on 14 consecutive adult patients presenting with seizures showing supratentorial non-enhancing radiologically uniform appearing low grade gliomas on CT/MR images. Pre-operative XeCT patterns were compared with postoperative histological diagnosis, grading and Ki67 proliferation indices (PI). After gross-total, subtotal resection or biopsy, 11 astrocytomas, 2 oligodendrogliomas and 1 oligo-astrocytoma were diagnosed and graded: Grade I: 2 patients (Ki67-PI = 0.5-0.8), Grade I-II: 4 patients (Ki67-PI = 0.3-1.5), Grade II: 3 patients (Ki67-PI = 0.5-3.5), Grade II-III: 4 patients (Ki67-PI = 3.8-6.8) and Grade III: 1 patient (Ki67-PI = 5.2), (Kernohan Classification). Xenon CT studies revealed different flow patterns, correlating with the postoperative histological diagnosis, grading and proliferation indices: A tumour group with well defined, delayed, only minimally enhancing tumour area (5 patients, Grade I, I-II or II), a second group with less well defined low-flow-area borders and inhomogenous, strong enhancement within the tumour (4 patients, Grade II-III, III) and a third group with fast enhancing tumours was identified. The third pattern was exclusively shown in the 2 oligodendrogliomas (Grade I and II-III) and 1 oligo-astrocytoma (Grade II). The preliminary report identifies the Xenon enhance CT as a beneficial pre-operative investigation for patients with radiologically uniform appearing suspected adult supratentorial low-grade gliomas, which may give information about the presence of anaplastic foci or oligodendroglial components.

Adolescent↗

PubMed1996

Endoscopic exploration of the IVth ventricle.

Regarding to the upcoming techniques in neuroendoscopy the IVth ventricle was examined. First in a series of 30 fresh and fixed anatomical specimens-the vessels injected with LATEX-the fourth ventricle was investigated endoscopically. There are three possibilities to reach the IVth ventricle: coming from the IIIrd ventricle via the aqueductus cerebri, using the basal cisterns through the apertura lateralis Luschkae and coming via the cerebellomedullar cistern through the foramen of Magendi. Using different kinds of endoscopes (rigid, flexible and steerable flexible)-diameter ranging from 5 to 9 french-with different optical systems (0 degree, 5 degrees, 30 degrees, 75 degrees) and different light sources (Halogen, Xenon) the anatomical details seen under the endoscope and the topographical landmarks of the approaches were investigated, presented and discussed. Based on the experience at the end of the cadaver work a short comment on which kind of equipment seems the best was given. A series of 14 clinical cases was presented as the second part of the study (7 cases with a tumor in the IVth ventricle-2 metastasis, 3 gliotic tumors, 1 ependymoma, 1 medulloblastoma, 3 patients with an occluded aqueduct because of meningo-ventriculitis and 4 patients with cystic malformations). The neuroendoscopic approaches, the neuroanatomical details relevant for surgery and the clinical data will be given and discussed. In general no intraoperative or postoperative complications were seen. In conclusion our experience from the theoretical neuroanatomical and the clinical part as well as the advantages and disadvantages from the different kind of endoscopes and approaches are discussed.

Adult↗

PubMed1995

Intra-operative marking of neuroanatomical details--helpful for radiosurgery?

This report is a list of simple but effective techniques for marking important structures intra-operatively. During the last 2 years in 52 patients intra-operative marking techniques have been used. In 37 cases a small piece of fat has been taken. In 10 patients it was done by a radiopaque Barium impregnated silicon sphere and in 5 patients with a piece of a monofilament suture. Postoperative checks were done by conventional X-ray, computer tomography and Magnetic Resonance Imaging. The indication in all cases was to offer landmarks helpful for planning postoperative radiosurgery. In case of fat and radiopaque Barium impregnated silicone spheres the markings were always well defined and clear in contrast. In those cases where a piece of monofilament suture was used it was impossible to get clear postoperative information. In general there were no intra- or post-operative complications. All markers were well tolerated and no side effects have been observed so far. The advantages and disadvantages of each of these possibilities are described and discussed.

Adenoma↗

PubMed1995

Detection of tumor necrosis factor-alpha protein and messenger RNA in human glial brain tumors: comparison of immunohistochemistry with in situ hybridization using molecular probes.

Tumor necrosis factor-alpha (TNF alpha) protein and messenger (m)RNA distribution was studied in biopsy samples of glial brain tumors, using immunohistochemistry and in situ hybridization with molecular probes, to investigate the role of this cytokine in tumor proliferation and immunological host defense. Focal expression of TNF alpha was detected in four of four glioblastomas, one of two anaplastic astrocytomas, and four of five low-grade astrocytomas, regardless of their subtype or grade of malignancy, but in none of the normal peritumoral brain tissues used as controls. The TNF alpha protein and mRNA were present in reactive astrocytes and protoplasmic tumor cells, confined to areas of leukocyte or T-lymphocyte infiltrating, and less pronounced in tumor cells at the edge of necrosis. Additionally, TNF alpha reactivity was found in infiltrating macrophages and perivascular microglia. Immunohistochemistry and in situ hybridization for TNF alpha showed comparable reaction patterns and numbers of TNF alpha-positive cells, even though the sensitivity of in situ hybridization was significantly higher. Quantitative evaluation of TNF alpha protein, TNF alpha mRNA, and leukocyte infiltration revealed a significant positive correlation between the TNF alpha-positive reactive astrocytes and the number of lymphocytes present in corresponding areas. Together, these data lead to the conclusion that TNF alpha in reactive astrocytes and monocytic cells within tumor areas of high leukocyte infiltration and in tumor cells at the border of necrosis may represent one defense pathway of the immune system against tumor proliferation.

Adolescent↗

PubMed1986

Radiation stability of organic matter in liquid and frozen H2O, NH3 and water-ammonia mixtures.

The redox properties of irradiated liquid and frozen H2O, NH3 and H2O/NH3 mixtures at 298 K and 77 K, resp., towards some simple organic molecules have been checked by injecting carrierfree 11C atoms and analyzing their chemical state by means of radiochromatography. The reactions and the stability of organic products versus radiation dose (in this study by MeV protons) depend on temperature, phase state, mobility of radicals, their concentration and reactivity. Especially dangerous are the reactive OH and O2H radicals which oxidize organic material to inorganic CO2. Highest stability has been found at low temperatures (solid state, reduced mobility of radicals) and for systems containing H-donors (H2O/NH3 mixtures), which reduce the concentration of oxidizing radicals. The fact that many bodies in space consist of H2O-ice with NH3 and CH4 additives at temperatures between 10 and 150 K is promising in view of the survival of organic matter under high doses of radiation.

Ammonia↗