The limited value of cytoreductive surgery in elderly patients with malignant gliomas.
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Aged↗
Biomedical subjects
C B Ostertag
Publications and source records attributed to C B Ostertag.
[Stereotaxic radiosurgery].
Radiosurgery aims at the precise destruction of small, defined volumes of tissue by employing ionizing radiation energy. Its methodologies may be subdivided into closed-skull, external focussed beam radiosurgery, and interstitial radiosurgery (brachytherapy). Focussed beam stereotactic radiosurgery has been used successfully for over two decades to treat cerebral arteriovenous malformations. Complete obliteration ranges from 30% to 50% after one year. After two years, obliteration is observed in up to 90% of patients. Outcome, however, is influenced by patient selection. In the treatment of acoustic neurinomas, follow-up data of larger series show that radiosurgery performed under local anesthesia on an out-patient basis is competitive with microsurgery data. Using multiple isocenters and magnetic resonance localization, tumor growth control is achieved in more than 90% of patients with preservation of hearing in approximately 50%. Pituitary tumors with Cushing's syndrome, acromegaly, Nelson's syndrome, prolactinomas and non-secreting adenomas have been treated. Only a small subgroup of patients with low-grade gliomas are candidates for interstitial radiosurgery, namely those with circumscribed tumors with limited spread of tumor cells into the periphery. For this subgroup, which usually comprises not more than 25% of all low-grade gliomas, interstitial radiosurgery competes with surgical resection. Local, single high-dose treatment remains controversial for highly malignant infiltrative tumors, and a significant treatment benefit remains to be demonstrated. Radiosurgery can be used to effectively treat solitary brain metastases (< or = 3 cm diameters) with less invasiveness, and dissection of normal tissue; it may be performed with lower morbidity and with less expense in comparison with open surgery.
Adenoma↗
Central nervous system injury from implanted isotopes.
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Animals↗
Impact of stereotactic interstitial radiation on brain capillary physiology.
rCBF, capillary permeability and vascular volume have been measured during the time course of interstitial stereotactic radiosurgery in normal and tumour-bearing dog brain. For rCBF measurement the stable Xenon-CT-technique with a modified Kety-Schmidt equation has been used, and for measurement of blood-to-brain transport of meglumine iothalamate the two-compartment CT-method as developed by Groothuis, which also reflects vascular volume. Anaplastic gliomas had been induced by intracerebral injection of avian sarcoma virus. Radiation sources have been 192-iridium and 198-gold. Both of the isotopes caused spherical blood-brain-barrier lesions with a more than 10-fold blood-to-brain transport increase. These effects occurred earlier and more pronounced with 192-iridium, but much longer lasting with 198-gold. Interstitial radiosurgery of the tumours led to a further increase of capillary permeability. Blood flow was significantly lowered not only within radionecrosis but also in the adjacent brain areas.
Anaplasia↗
Interstitial implant radiosurgery for cerebral metastases.
The effectiveness of interstitial implant radiosurgery (IRS) as an alternative or adjuvant treatment to radiotherapy (WBRT) or surgery of cerebral metastases remains unclear. In a retrospective study (1982-1991) we analysed four therapeutic regimes after stereotactic biopsy: IRS with a tumour dose of 60 Gy in combination with WBRT (40 Gy/5 x 2 Gy/week--38 patients), IRS only (tumour dose 60 Gy--22 patients), WBRT only (40 Gy/5 x 2 Gy/week--49 patients), and IRS only for recurrent cerebral metastases (tumour dose 60 Gy--21 patients). Low-activity iodine-125 seeds were used exclusively. IRS was performed in the case of circumscribed, mostly solitary metastases < or = 4 cm in diameter. Patients undergoing combined treatment had the best survival, with a median survival time of 17 months in comparison with 12 months after IRS alone and 7.7 months after WBRT. The median survival of patients with recurrent metastases after IRS was 6 months. A comparison of treatments in the multivariate analysis showed that IRS + WBRT was not superior to IRS alone. The metastases could be locally controlled in every case. There were no radionecroses requiring treatment. Most favourable determinants after IRS or IRS + WBRT were a solitary metastasis and a long time interval between diagnosis of the primary and diagnosis of the cerebral metastases. Our results demonstrate the effectiveness of IRS. For a single cerebral metastasis, IRS as a minimally invasive method offers major advantages.
Brain Neoplasms↗
Stereotactic management of congenital midline cysts.
The treatment of congenital midline cysts remains a controversial issue. The stereotactic management of 27 patients (6 symptomatic cavum septi pellucidi/cavum Vergae, 6 suprasellar cysts, 5 intraventricular cysts, 4 parasagittal cysts, and 6 supracollicular cysts) is reviewed. In 23 patients stereotactic ventriculo-cystostomy by catheter implantation (internal drainage) led to clinical recovery or improvement accompanied by decreased cyst size. In four patients the internal drainage was not sufficient and was therefore completed as a ventriculo-atrial shunt system. Three minor complications (bleeding, aseptic meningitis, catheter infection) led to no sequelae. The results suggest that stereotactic internal drainage of these benign lesions is a safe, minimally invasive and efficient procedure.
Adolescent↗
Titanium Riechert head ring for MR stereotaxy. Technical note.
Magnetic Resonance has become the preferred neuro-imaging modality. To fully take advantage of the high anatomical resolution the Riechert stereotactic system was adapted for use in Magnetic Resonance Stereotaxy. The head ring which until recently was made of an aluminum alloy has been replaced by an unsegmented head ring of pure titanium without changing the dimensions and fixation mode. No significant misregistration due to eddy currents has been noticed. Minor distortion induced by the titanium head ring can be corrected mathematically. Thus the geometric information is limited only by the pixel resolution of the MR image.
Artifacts↗
[Stereotactic procedure in pineal cysts].
Benign large pineal cysts are rare lesions and sometimes difficult to distinguish from neoplastic cysts of the pineal region. Seven patients with cysts of the pineal region (1.5-2 cm diameter), treated stereotactically were identified by retrospective chart review. In all patients the cyst wall and contents were subjected to histopathological examination. In 2 patients stereotactic operation showed that secondary (neoplastic) cysts were ruled out. In 5 patients with symptomatic pineal cysts the stereotactic evacuation led to clinical recovery or marked improvement (mean follow-up 20 months). The previous literature is reviewed, aetiology, diagnostic work up and therapy discussed. We prefer the stereotactic management of cysts of the pineal region because it allows histological distinction of benign cysts from secondary cysts and is a safe, minimal invasive procedure.
Adolescent↗
Surgical resection and radiation therapy versus biopsy and radiation therapy in the treatment of glioblastoma multiforme.
There has been considerable controversy over the concept of treating glioblastoma multiforme with cytoreductive surgery. Therefore, a retrospective study of cases treated between 1986 and 1991 was conducted to analyze and compare the results of stereotactic biopsy followed by radiation therapy performed in 58 patients with those of surgical resection plus radiation therapy in 57 patients. In both groups, conventionally fractionated radiation (1.7 to 2.0 Gy/day) was delivered, with a total dose of 50 to 60 Gy. Biopsy was performed only in patients with tumors judged to be inoperable. These patients carried a higher surgical risk and were in worse neurological condition than the patients in the resection group. The median survival time for the resection group was 39.5 weeks, as compared with 32 weeks for the biopsy group. This difference was not significant. The most important prognostic factor was the patient's age. The treatment variable biopsy versus resection did not reach prognostic relevance. In patients with midline shift who underwent biopsy, the Karnofsky Performance Scale score decreased in more patients during radiation therapy. The clinical status 6 weeks after surgery, however, showed no significant differences between the two groups. The comparable survival times for the two groups place doubt on the concept of treating glioblastoma multiforme with cytoreductive surgery. Presently, radiation therapy is the most effective treatment for patients with glioblastoma. There is no question that decompressive surgery followed by radiation therapy should be performed whenever necessary for sever space-occupying lesions and when it will not cause new neurological deficits.
Aged↗
Brachytherapy--interstitial implant radiosurgery.
With both surgery and radiosurgery a selective destruction and removal of a lesion is undertaken. Using interstitial irradiation a calculated volume of necrosis is induced, which is subsequently removed by macrophage activity. Interstitial irradiation is therefore considered a radiosurgical method. To better understand the side effects of radiosurgical lesions in the brain, we studied the effects of three physically distinct gamma emitters iridium-192, gold-198 and iodine-125 with respect to the morphological development of radionecroses and the consecutive vasogenic oedema using different dose rates and application times. Experimental dose effects on normal brain (beagle dogs) revealed that depending on the energy range, application time and dose rate, calcified or liquified necroses develop from the center around the seed into the periphery. These well-defined radionecroses are surrounded by reactive glia and, temporarily, by fibrinoid necrosis of endothelial cells. In contrast to permanent implants, effects of temporary implants on tissue are characterised in the early stages of oedema, in later stages by progressive resorption of necrotic tissue and less permanent damage. Dose rate and energy range determine the volume of the necroses and the magnitude of vasogenic oedema. It is the vasogenic oedema which primarily determines the extent of demyelination and reactive glioses in the vicinity of the radionecrosis. Toxic side effects of interstitial implant radiosurgery can be minimised by using temporary implants with moderate dose rates, in which case repair processes are free to take place after removal of the radioactive source from the brain. Based on experimental and clinical findings a biological dosimetry has evolved which favours temporary implants of iodine-125 with dose rates of 10 cGy/h.
Blood-Brain Barrier↗
[Interstitial radiosurgery of low grade glioma].
In this retrospective study the outcome of 324 patients with low-grade gliomas (WHO-Grade II) is evaluated, who from 1979 to 1991 underwent stereotactic biopsy and interstitial radiosurgery (Iodine-125). The patients were selected for interstitial radiosurgery if the tumor was unifocal, well-circumscribed and in diameter < or = 4 cm. Of these patients 251 had astrocytomas, 29 had oligodendrogliomas, and 44 had oligoastrocytomas. All patients presented with progressive neurological deficit or showed evidence of CT/MRI confirmed tumor growth. The preoperative performance status was > or = 70%. Diffusely infiltrative, non-delineated gliomas and gliomas crossing the midline were excluded. Five-year survival rates were 65% for astrocytomas, 80% for oligoastrocytomas and 58% for oligodendrogliomas. In the multivariate analysis age was a significant factor predicting survival. Patients who received temporary implants had a significantly better outcome than those with permanent implants. Radiation toxicity (3.1%) was seen mostly among the permanent implants. No patients required reoperation due to radionecrosis. The findings in this subgroup of gliomas indicate that interstitial radiosurgery using Iodine-125 is effective in controlling tumor growth and is well tolerated. Patients with differentiated and circumscribed gliomas particularly benefit from the treatment.
Adolescent↗
[Stereotactic interstitial radiosurgery and percutaneous radiotherapy in treatment of cerebral metastases].
The efficacy of interstitial radiosurgery as an alternative or adjuvant to radiotherapy or surgery of cerebral metastases remains unclear. In a retrospective study (1982-1991) we compared 4 therapeutic regimes for cerebral metastases. The first group (n = 38) was treated with interstitial radiosurgery (Iodine-125) with a tumor dose of 60 Gy in combination with percutaneous radiotherapy with 40 Gy. The second group was treated by interstitial radiosurgery alone (n = 22) (tumor dose: 60 Gy). The third group was treated with percutaneous radiotherapy alone with a total dose of 40 Gy (n = 49). The fourth group (n = 21) consisted of recurrent cerebral metastases which were treated by interstitial radiosurgery alone (tumor dose: 60 Gy). Interstitial radiosurgery was performed in cases of circumscribed mostly solitary metastases < or = 5 cm in diameter. Medium survival was 17 months after interstitial radiosurgery in combination with radiotherapy, 12 months after radiosurgery alone and 7.7 months after percutaneous radiotherapy. The medium survival of recurrent metastases after interstitial radiosurgery was 6 months. Prognostically favourable for the outcome following radiosurgery were a Karnofsky Score > or = 70, a solitary metastasis, absence of disseminated disease and a longer time interval between diagnosis of the primary and diagnosis of the cerebral metastases. Interstitial radiosurgery + percutaneous radiotherapy was not superior to interstitial radiosurgery alone in the multivariate analysis. No patient died from a locally treated metastasis. Percutaneous radiotherapy was the treatment of choice for multiple or non-circumscribed cerebral metastases. Our results show that for solitary metastases stereotactic interstitial radiosurgery is a beneficial minimally invasive method.
Adult↗
Iodine-125 interstitial irradiation for cerebral gliomas.
In this retrospective review the outcome of 539 patients is evaluated, who from 1979 through 1991 underwent stereotactic biopsy and interstitial irradiation using iodine-125 implants. Permanent (lost) 125-I implants were used in 345 cases (64%) (1979-1985), temporary (removable) implants in 194 cases (36%) (1985-1991). The patients were selected for interstitial irradiation on the basis of histological classification, location and circumscription of their tumours (106 pilocytic astrocytomas, 251 astrocytomas WHO grade II, 29 oligodendrogliomas, 44 oligo-astrocytomas, 75 anaplastic astrocytomas and 34 glioblastomas). Diffusely infiltrative non-delineated gliomas and gliomas crossing the midline were excluded. Five-year survival rates were 77% for pilocytic astrocytomas, 65% for astrocytomas WHO II, 80% for oligo-astrocytomas, and 58% for oligodendrogliomas. The 2-year survival rates were 36% for anaplastic gliomas and 16% for glioblastomas. Operative morbidity due to stereotactic biopsy, implantation, and explantation of seeds was 3.9%. In the subgroups of patients with astrocytomas (WHO-II), pilocytic astrocytomas and malignant gliomas age was a significant factor predicting survival. Patients with astrocytomas WHO II who received temporary implants had a significantly better outcome than those with permanent implants. Radiation toxicity (3.1%) was seen mostly among the permanent (lost) implants. No patients required re-operation due to radionecrosis. The findings among this subgroup of gliomas indicate that interstitial implant irradiation using 125-I is effective in controlling tumour growth and is well tolerated. Patients with differentiated and circumscribed gliomas particularly benefit from the treatment.
Adolescent↗
[The value of stereotactic biopsy and percutaneous radiation in therapy of glioblastoma multiforme].
The concept of cytoreductive surgery in the treatment of glioblastoma multiforme is controversial. A retrospective study was carried out between 1986 and 1991 to analyze the results of stereotactic biopsy followed by supportive treatment (n = 49), incomplete radiation therapy (less than 40 Gy, n = 26), and complete radiation therapy (greater than or equal to 40 Gy, n = 58) and to compare with those of resection plus irradiation described in the literature. The patients treated with supportive care and an incomplete course of irradiation had a median survival of less than 8 weeks. For the patients who completed the radiation therapy the median survival was 32 weeks. In patients with midline shift the Karnofsky scores worsened more often during the course of radiation therapy, or therapy had to be terminated prematurely. The most important prognostic determinant was the patient's age. A comparison of survival rates in our series with those reported by other authors for patients who received tumor resection with subsequent irradiation yielded no significant difference. This would appear to cast doubt on the concept of cytoreductive surgery. The treatment of choice for patients with glioblastoma multiforme is at present radiation therapy. There is no question about the necessity of decompressive surgery whenever it is required to perform radiation therapy for severe space-occupying lesions and when it can be performed without causing new neurological deficits.
Biopsy, Needle↗
[Cystic abnormalities of the brain: stereotaxic diagnosis and therapy].
We present the stereotactic treatment and evaluation of 33 patients with congenital cysts of the brain (6 cavum septi pellucidi/cavum vergae cysts, 5 suprasellar cysts, 3 intraventricular cysts, 4 cysts of the interhemispheric fissure, 4 cysts of the cerebral convexity, 5 supracollicular cysts, 3 cysts in the cisterna ambiens, 2 temporomedial cysts and 1 cyst in the pontomesencephalic junction). The patients were seen during an 8-year period (1984-1992) and had a mean follow-up time of 27 months. In 23 patients with cysts in or near the cerebral midline or at the cerebral convexity, a stereotactic ventriculocystostomy resulted in clinical improvement with diminished cyst size. Another 8 patients with relatively small cysts profited from stereotactic aspiration of the cyst contents. Three complications (bleeding, aseptic meningitis, catheter infection) remained without sequelae. The stereotactic procedure is the treatment of choice for these lesions because of the low operative risk, its minimal invasiveness and the possibility of distinguishing primary congenital cysts from other pseudocystic lesions. In well-chosen cases the carefully planned stereotactic internal derivation of the cysts in the ventricular system led to a long-lasting beneficial effect. Open craniotomy or shunting procedures can be avoided for most cases of congenital intracranial cysts.
Adolescent↗
Combined stereotactic and microsurgical approach to cerebral lesions.
A description is given of the technique of a combined CT-stereotactic and microsurgical approach for removal of small cerebral lesions. Its usefulness in 21 cases is demonstrated.
Brain Neoplasms↗
Diagnostic potential of stereotactic biopsy of midline lesions.
The technique of CT-guided stereotactic biopsy is described and its reliability is discussed based on the experiences with a series of 1747 procedures. We could show that stereotactic biopsy has an overall diagnostic accuracy of 95% and therefore is a safe and reliable tool for planning the therapeutic strategy.
Biopsy↗
The Clinical Cooperative Trial. Guide to a critical approach.
The growing difference with regard to academic and professional accountability between neurosurgeons and neuroscience is alarming. Controlled clinical trials continue to be the most scientifically valid method of evaluating standard treatments against the risks and benefits of medical innovations. Clinical research becomes more rewarding as neurosurgeons gain familiarity with the particulars of the structure and relevance of expertly designed clinical cooperative trials. The basic principles and the significance of biometrical essentials (research hypothesis, comparability, randomized and non-randomized trials, phases of studies and planning steps) are briefly discussed. A guide to the pertinent literature is provided.
Clinical Protocols↗