Multisession stereotactic radiosurgery for large vestibular schwannomas.

Object: Microsurgery is not the only option for larger vestibular schwannomas (VSs); recent reviews have confirmed the feasibility and efficacy of radiosurgery for larger VSs. This study illustrates the outcomes of a series of large VSs after multisession stereotactic radiosurgery (SRS).

Methods: A series of 33 VSs larger than 8 cm(3) (range 8-24 cm(3), mean 11 cm(3), median 9.

Early results of CyberKnife radiosurgery for arteriovenous malformations.

Object: The authors describe a method that utilizes an image-guided robotic radiosurgical apparatus (the CyberKnife) for treatment of cerebral arteriovenous malformations (AVMs). This procedure required the development of an original technique that allows a high degree of automation.

Methods: Angiographic images were imported into the treatment planning software by coregistering CT and 3D rotational angiography.

Cyberknife radiosurgery for benign meningiomas: short-term results in 199 patients.

Objective: To present initial, short-term results obtained with an image-guided radiosurgery apparatus (CyberKnife; Accuray, Inc., Sunnyvale, CA) in a series of 199 benign intracranial meningiomas.

Methods: Selection criteria included lesions unsuitable for surgery and/or remnants after partial surgical removal.

Three-dimensional angiography for radiosurgical treatment planning for arteriovenous malformations.

Object: Radiosurgical treatment of a cerebral arteriovenous malformation (AVM) requires the precise definition of the nidus of the lesion in stereotactic space. This cannot be accomplished using simple stereotactic angiography. but requires a combination of stereotactic biplanar angiographic images and stereotactic contrast-enhanced computerized tomography (CT) scans.

Employ of a new device for intra-operative radiotherapy of intracranial tumours.

Background: This paper presents the operating experience acquired during 18 months of use of the Photon Radiosurgery System manufactured by Photo-electron Corp. as an intra-operative radiation therapy device. The device is based on a miniature x-ray source that delivers low energy x-rays from the tip of a 3.

The role of decompressive craniectomy in the treatment of uncontrollable post-traumatic intracranial hypertension.

The benefit of decompressive craniectomy for the treatment of uncontrolled post-traumatic intracranial hypertension seems to be encouraging if medical management fails. We present our experience in 22 cases of cerebral edema due to head trauma. The edema alone was rarely the direct consequence of head trauma.

Gene stereotactic neurosurgery for recurrent malignant gliomas.

Four patients affected by glioblastoma recurrence were treated with a gene therapy-immunotherapy protocol consisting of intratumoral injections of culture cells producing a retroviral vector which expresses human interleukin-2 and the herpes simplex virus thymidine kinase genes. Seven to 14 days after implantation, the patients were treated with ganciclovir at standard doses. Anatomopathological and immunohistochemical data confirm the efficacy of transduction.

Linear accelerator radiosurgery of cerebral arteriovenous malformations: an update.

One hundred eighty patients affected by cerebral arteriovenous malformations (AVMs) underwent radiosurgical treatment in our department. One hundred fifty-three patients have been treated with complete irradiation of the entire AVM nidus. In 27 patients (with large and/or three-dimensional irregular target volumes), only part of the nidus was covered with a dose adequate for obliteration.

Risk factors for cerebral glioma in adults: a case-control study in an Italian population.

A case-control study on risk factors for cerebral tumors was conducted on an adult Italian population by the four Neurosurgical Departments of the Veneto Region, i.e. Padua, Treviso, Verona and Vicenza.

Linear accelerator radiosurgery of cerebral arteriovenous malformations: current status.

228 patients affected by cerebral arteriovenous malformations (AVMs) underwent linear accelerator radiosurgery. Follow-up ranges from 1 to 100 months (mean 42 months). Complete angiographic obliteration was achieved in 47% of treated patients at one year and 80% at 2 years.

Development of a second generation stereotactic apparatus for linear accelerator radiosurgery.

Linear accelerator radiosurgery technique is based on a multiple intersecting arc irradiations procedure. The coincidence of the axis of two rotation movements (of gantry and treatment couch) into the isocenter is critical for focusing irradiation. In October 1989, our linear accelerator was changed and the stereotactic apparatus had to be adapted to the new machine.

Combined radiosurgery and external radiotherapy of intracranial germinomas.

Germinomas are successfully treated with radiation therapy; we have observed six cases that have been stereotactically irradiated by means of a linear accelerator (radiosurgery). In most cases a single dose of stereotactic irradiation effects the reduction of the tumor volume in a few days. External whole brain and, in two cases, spinal irradiation completed the treatment to avoid seeding of tumor cells.

Low-grade astrocytomas: treatment with unconventionally fractionated external beam stereotactic radiation therapy.

Fourteen patients with nonoperable low-grade astrocytomas were treated with unconventionally fractionated stereotactic radiation therapy. The target volume was defined with computed tomography (CT) performed under stereotactic conditions. The treatment was carried out with a technique producing multiple noncoplanar arc irradiation, with the center of the target volume placed at the isocenter of the linear accelerator.

Validity of stereotactic biopsy as a diagnostic tool.

254 patients affected by intracranial lesions underwent stereotactic biopsy in our department from 1978 to 1986. Target localization was achieved by CT. Multiple biopsy sampling was performed by cup microforceps or sliding cannula.

Linear accelerator radiosurgery of arteriovenous malformations.

Forty-five patients affected by cerebral arteriovenous malformations not suitable to open surgery have been treated by a radiosurgical technique employing a linear accelerator. One-year follow-up angiography is available for 10 cases. Therapeutic effect of focalized irradiation is presented.

Osteogenic osteosarcoma of the calvaria following radiotherapy for cerebellar astrocytoma: report of a case in childhood.

Sarcoma as a second malignant neoplasm following radiotherapy is a rare occurrence in childhood. A case of osteogenic osteosarcoma of temporoparietal bone that developed 56 months after irradiation for a cerebellar astrocytoma in a 10-year-old child is reported and the pertinent literature is briefly reviewed. The possibility of an association (in the same patient) between these two rather uncommon lesions is extremely unlikely.

Stereotactic radiosurgery of intracranial tumors in childhood.

The Authors have developed an original stereotactic technique by which the radiation dose erogated by a 4 MV linear accelerator is focused into the target volume with a steep dose gradient at its borders. The technique has been employed in a series of 30 patients affected by deep seated brain tumors and AVMs. The paper deals with the preliminary results obtained in a series of 10 patients in pediatric age.

Radical excision of a craniobasal tumor involving the middle cranial fossa. Technical note.

Craniobasal tumors affecting the middle cranial fossa are rarely treated radically; the main problem to solve is the presence of important nervous and vascular structures in this region. The Authors report a case of complete removal of a malignant tumor involving the temporal bone and the middle cranial fossa. Surgery was performed by the cooperation of the neurosurgical and the ENT teams.

The posterior approach to cervical rizopathy.

The posterior approach to cervical rizopathy is a widely acquired technique; however only recently it encountered more favorable consideration. After a brief review of the literature, the Authors present some details of surgical approach, discuss its value and its limits with a comment on their own series.

Stereotactic biopsy of low-grade giant-cell astrocytoma.

Stereotactic biopsy was used to sample a hypodense lesion of the left temporo-occipital lobes in a 32-year-old female with a history of grand mal seizures. Although the intraoperative cytologic examination showed a picture suggestive of malignancy, including giant cells and atypical mitotic figures, the clinical and radiologic history militated against a malignant nature for the lesion, which was thus classified as a low-grade giant-cell astrocytoma. This case emphasizes both the utility of intraoperative cytologic examination of stereotactic biopsy specimens and the need to consider the cytologic and histologic evidence in light of the clinical and radiologic findings.

[Biopsy and stereotaxic radiotherapy of cerebral gliomas].

The Authors report their experience on a series of 125 patients that underwent stereotactic biopsy. The procedure has proved reliable and almost risk -free. The diagnosis obtained from the bioptic specimen by smear technique-cytological examination and by paraffin embedding-histological examination are compared.

A new dynamometric technique to measure and locate endocranial structures. Preliminary report.

An apparatus for measuring and recording the resistance to penetration of endocranial tissue has been planned and built. The probe carrier, driven by a constant-speed electric motor, is fitted onto a stereotactic head frame which is used to guide the tool to the intended target. The displacement and resistance encountered when the tool penetrates intracranial structures are measured and recorded on an x-y recorder.

Multiple meningiomas.

The authors discuss the criteria of differential diagnosis for a correct use of the term "multiple meningiomas". Reviewing a series of 934 meningiomas, of which 834 were intracranial and 100 were spinal, they found 14 cases of multiple meningiomas, i.e.