Stereotactic radiosurgery followed by whole ventricular irradiation for primary intracranial germinoma of the pineal region.

Intracranial germinomas can be cured by radiotherapy and/or chemotherapy. Three patients with pineal germinoma were treated with stereotactic radiosurgery using the gamma knife (10 - 12 Gy) to the tumors followed by whole ventricular irradiation (24 Gy). All patients had solitary pineal tumor measuring less than 3 cm, clinically compatible with germinoma, normal cerebrospinal fluid (CSF) and serum levels of alpha-fetoprotein and beta-human chorionic gonadotropin, no disseminated disease on spinal magnetic resonance (MR) imaging, and no abnormal CSF cytology. All patients showed complete response to the combined radiotherapy, and MR imaging has shown no recurrence of the tumor. Combined radiotherapy using gamma knife radiosurgery is effective for pineal germinoma, and reduced the cost of treatment with less need for hospitalization.

Routine clinical adoption of magnetic resonance imaging was associated with better outcome after surgery in elderly patients with a malignant astrocytic tumour: a retrospective review.

BACKGROUND: There is controversy about extensive surgical treatment for a malignant astrocytic tumour in more elderly patients who may have poorer outcomes and higher complication rates. This retrospective study investigated outcome in elderly patients with malignant astrocytic tumour before and after the adoption of routine clinical use of magnetic resonance (MR) imaging. METHODS: During 1982 through 1999, 88 patients with malignant astrocytic tumour aged 60 years or over were treated in our institute. Thirty-seven patients had an anaplastic astrocytoma and 51 had a glioblastoma. Thirty-seven patients treated from 1982 to 1988 did not have pre-operative evaluation by MR imaging (Group A), 26 patients treated from 1989 to 1995 had preoperative MR imaging evaluation (Group B), and 25 patients treated after 1996 underwent preoperative MR imaging with functional brain mapping and intra-operative navigation system monitoring (Group C). FINDINGS: The median survival time was 8.8 months in Group A, 12.7 months in Group B, and 17.6 months in Group C. Patients with glioblastoma in Group B (11.7 months, n = 15) and Group C (16.0 months, n = 19) had significantly longer median survival time than in Group A (6 months, n = 17) (P = 0.0054 between Groups A and B, P = 0.0024 between Groups A and C). Better preoperative performance status, more thorough surgical resection, and better performance status after the initial treatment was obtained after the introduction of MR imaging, and patients with the optimal indicators showed significantly longer survival time compared with the patients without these factors. INTERPRETATION: Pre-operative MR imaging may contribute to longer survival time by providing an earlier diagnosis in patients with better performance status, by allowing more thorough surgical resection, and resulting in better performance status after the treatment.

Stereotactic radiosurgery for nodular dissemination of anaplastic ependymoma.

Dissemination of primary intracranial ependymoma occurs in 10% of all cases and is difficult to treat, so this may be one of the major reasons for the poor prognosis. Two patients with nodular dissemination of anaplastic ependymoma were treated with repeated stereotactic radiosurgery using the gamma knife (GK), resulting in tumour control over 21 months. GK radiosurgery is a safe and effective treatment option for providing good local control in patients with nodular dissemination of ependymoma.

Usefulness of constructive interference in steady state (CISS) imaging for the diagnosis and treatment of a large extradural spinal arachnoid cyst.

We present a rare case of a symptomatic large extradural arachnoid cyst extending from the lower thoracic to sacral region in a 12-year-old boy, who presented with the signs and symptoms of spinal cord compression over 4 years. Since the pedicle of the cyst could not be delineated using conventional magnetic resonance imaging (MRI), cine-mode MRI, and computed tomography scan, partial resection of the cyst was initially performed, which significantly improved motor function. After the first operation, a single pedicle was clearly demonstrated by 3D constructive interference in steady state (CISS) MRI. Thus, additional surgery aimed at closing the dural defect was performed to prevent future enlargement of the cyst. The operative findings were consistent with those of 3D CISS imaging. Clinical and radiological features of this lesion are discussed, focusing on the usefulness of 3D CISS MRI for preoperative evaluation, and especially for delineating the pedicle in cases of large extradural spinal arachnoid cysts.

Pulsed liquid jet dissector using holmium:YAG laser--a novel neurosurgical device for brain incision without impairing vessels.

BACKGROUND: Neurosurgery has long required a method for dissecting brain tissue without damaging principal vessels and adjacent tissue, so as to prevent neurological complications after operation. In this study we constructed a prototype of such a device and used it in an attempt to resect beagle brain cortex. METHOD: The prototype device consisted of an optical fibre, a Y adaptor, and a nozzle whose internal exit diameter was 100 microm. Cold physiological saline (4 degrees C) was supplied to it at a rate of 40 ml/h. Pulsed liquid jets were ejected from the nozzle by a pulsed Holmium:YAG) (Ho:YAG) laser at an irradiation energy of 300 mJ/pulse. The profile of the liquid jet was observed with a high-speed camera while changing the distance between the optical fibre end and nozzle exit (equivalent to the standoff distance). With this device (3 Hz operation), brain dissection of anaesthetized beagles was attempted while measuring the local temperature of the target. A histological study of the incised parts was also performed. FINDINGS: When the standoff distance was 24 mm, the liquid jet was emitted straight from the nozzle at a maximum initial velocity of 50 m/s. The brain parenchyma was cut with this device while preserving vessels larger than 200 microm in diameter and keeping the operative field clear. The local temperature rose to no more than 41 degrees C, below the functional heat damage threshold of brain tissue. Histological findings showed no signs of thermal tissue damage around the dissected margin. INTERPRETATION: The Ho:YAG laser-induced liquid jet dissector can be applied to neurosurgery after incorporating some minor improvements.

Intraoperative direct neuroendoscopic observation of the aqueduct in Dandy-Walker malformation.

A 3-month-old female infant with Dandy-Walker malformation manifesting as hydrocephalus was treated successfully by only ventriculoperitoneal shunting. A flexible neuroendoscope was used intraoperatively to confirm the patency of the aqueduct, i.e. communication of the ventricular system and the cyst in the posterior fossa. Direct confirmation of the patency of the aqueduct and cyst communication is valuable to select the shunt procedure in the treatment of Dandy-Walker malformation.

Recurrent intracranial germinoma outside the initial radiation field with progressive malignant transformation.

A 19-year-old man with a pure germinoma in the pineal region was successfully treated with chemotherapy followed by 24 Gy local irradiation. Eight months later, magnetic resonance (MR) imaging detected ventricular wall dissemination outside the radiation field. Near complete response was achieved again after 28.8 Gy whole brain and 24 Gy whole spine irradiation. Two months later, MR imaging demonstrated recurrence of a mass at the corpus callosum. Gamma knife radiosurgery did not control this mass, so tumour resection was performed. Histological examination revealed immature teratoma. Enlargement of the recurrent mass at the trigone of the left lateral ventricle was found in spite of additional chemotherapy. Tumour extirpation was performed and histological examination revealed embryonal carcinoma. The patient died of tumour progression 34 months after the initial treatment. By a combination of chemotherapy regiments in use today, the initial radiation field to treat intracranial germinomas should not be confined to the tumour bed.

Aspergillus parasellar abscess mimicking radiation-induced neuropathy. Case report.

BACKGROUND: Transsphenoidal surgery is a safe procedure for treatment of pituitary adenomas. However, several complications, including post-surgical infection, are known. We describe a case of Aspergillus parasellar abscess that presented with cranial neuropathies following transsphenoidal surgery and radiosurgery. We initially diagnosed the case as radiation-induced neuropathies, which delayed the detection of Aspergillus. CASE DESCRIPTION: A 55-year-old man underwent transsphenoidal surgery for a pituitary adenoma that presented with pituitary apoplexy. Dexamethasone had been continuously administered for hypocortisolism probably caused by pituitary apoplexy. Four years later, radiosurgery was performed for a relapse in the right cavernous sinus. Another 4 years later, he developed painful right ophthalmoplegia, right ptosis, and bilateral visual impairment, successively. We initially suspected that the painful ophthalmoplegia and ptosis were because of radiation-induced cranial neuropathies; however, results of magnetic resonance (MR) imaging and his clinical course were not consistent with those of radiation-induced neuropathies. Therefore, we performed exploratory surgery that revealed a subdural abscess on the planum sphenoidale. Culture of a specimen grew Aspergillus fumigatus. CONCLUSION: Intracranial fungal abscess is a fatal complication unless it is treated early. It is thus important to consider the possibility of parasellar infection and differentiate it from radiation-induced cranial neuropathies when a patient presents with cranial neuropathies after transsphenoidal surgery and radiosurgery.

Surgical treatment of posterior fossa tumors via the occipital transtentorial approach: evaluation of operative safety and results in 14 patients with anterosuperior cerebellar tumors.

OBJECT: To determine the safety and usefulness of performing surgery via the occipital transtentorial approach to treat anterosuperior cerebellar tumors, evaluation of 14 patients was performed over a 5-year period. METHODS: The study was performed in 14 patients, aged 6 months to 71 years, who harbored anterosuperior cerebellar tumors of the posterior fossa including four hemangioblastomas, three cerebellar astrocytomas, three medulloblastomas, two metastatic tumors, one recurrent astrocytoma, and one rhabdoid cell tumor. All patients underwent surgical treatment by the same surgical team and via the same surgical approach. Endoscopy combined with neuronavigation was used for large, deep-seated tumors extending to the fourth ventricle. Of the 14 patients, total or gross-total removal was achieved in 12 patients and subtotal removal in two patients. There was no incidence of mortality or morbidity in the 14 patients, and all functional outcomes were good to excellent postoperatively. Postoperative magnetic resonance imaging revealed that none of the patients had suffered brain damage or infarction around the cerebellum, brainstem, or occipital lobe. CONCLUSIONS: Although this study was the first in which a specific examination of the efficacy of the occipital transtentorial approach in patients with anterosuperior cerebellar tumors was undertaken, our findings suggest that this surgical approach is very useful, safe, and accurate for removing the primary tumor and evaluating the surrounding anatomy, as well as for determining operative strategy.

Value of constructive interference in steady-state three-dimensional, Fourier transformation magnetic resonance imaging for the neuroendoscopic treatment of hydrocephalus and intracranial cysts.

OBJECTIVE: To assess the value of constructive interference in steady-state, three-dimensional, Fourier transformation (CISS) magnetic resonance imaging in the endoscopic management of hydrocephalus and intracranial cysts. METHODS: CISS imaging and T2-weighted imaging were performed for 14 consecutive patients before and after fenestration procedures, using a flexible endoscope, to treat loculated or multiloculated hydrocephalus (4 patients), aqueductal stenosis or obstruction (4 patients), arachnoid cysts (4 patients), a cyst of the velum interpositum (1 patient), or an ependymal cyst (1 patient). Fifteen fenestration procedures were performed, including one reoperation. RESULTS: Preoperative CISS imaging demonstrated intracystic intraventricular septa not observed with conventional T2-weighted imaging for 11 of 15 procedures and provided better brain tissue/cerebrospinal fluid contrast, allowing better understanding of the cause of hydrocephalus and the nature of the cysts. CISS imaging and T2-weighted imaging were equally useful for monitoring postoperative changes in the sizes of ventricles or cysts and the presence of flow voids after third ventriculostomies. However, only CISS imaging clearly demonstrated the site of fenestration for six of the nine patients who underwent fenestration procedures. CONCLUSION: CISS imaging provides excellent cerebrospinal fluid/brain tissue contrast, allowing detailed study of the anatomic features of the ventricular system and cystic lesions. CISS imaging is valuable for both preoperative decision-making and postoperative evaluation.

Recurrent germinoma in the optic nerve: report of two cases.

OBJECTIVE AND IMPORTANCE: Intracranial germinomas often disseminate via the ventricular and subarachnoid pathways, but seeding to the perioptic arachnoid space is extremely unusual. We report two cases of recurrent germinoma seeding in the optic nerve. CLINICAL PRESENTATION: Two men with pure germinoma were initially treated with three cycles of a three-drug regimen of bleomycin, etoposide, and cisplatin, and a complete response was achieved. Patient 1 experienced ventricle wall dissemination 10 months after undergoing the initial treatment and was successfully treated with three cycles of carboplatin and etoposide and then by 24-Gy whole-ventricle radiation. Twelve months later, he complained of progressive visual acuity loss, and magnetic resonance imaging demonstrated bilateral enhancement of the optic nerves. Patient 2 also experienced ventricle wall dissemination 3 months after undergoing the initial chemotherapy, but he exhibited a complete response after undergoing 24-Gy whole-ventricle radiation. Two years later, he complained of progressive visual acuity loss. Magnetic resonance imaging demonstrated bilateral enhancement of the optic nerves and cerebellar hemispheres. INTERVENTION: None of the locations of recurrence were included in the irradiation field, whereas there was no recurrence within the radiation field. Complete responses were obtained with three cycles of a three-drug regimen of ifosfamide, cisplatin, and etoposide and then by 24-Gy whole-brain radiation that included the bilateral optic nerves. The visual acuity of each patient improved slightly. CONCLUSION: Delayed seeding in the optic nerve may result from germinoma cells that remain dormant, so they cannot be destroyed by chemotherapy regimens alone.

[Treatment of symptomatic convexity arachnoid cyst in the elderly by neuroendoscope assisted-stereotactic surgery: a case report].

A 70-year-old female had Gerstman syndrome and a mild right side hemiparesis. She had no history of head injury. MRI revealed a large left convexity arachnoid cyst. Stereotactic cyst-ventricular shunting assisted by neuroendoscope was performed under local anesthesia. The postoperative course was uneventful. CT scan, performed one week after operation, showed a size reduction of the cyst. Her preoperative clinical signs progressively improved. Symptomatic arachnoid cyst in the elderly is rare. This paper discussed their findings in the previous published papers and the effectiveness of neuroendoscope assisted stereotactic fenestration of the cyst.

Transsphenoidal surgery and adjuvant gamma knife treatment for growth hormone-secreting pituitary adenoma.

OBJECT: The results of combined transsphenoidal surgery and adjuvant gamma knife surgery (GKS) for growth hormone (GH)-secreting adenoma were investigated using biochemical cure criteria for surgery and biological cure criteria for adjuvant GKS. METHODS: Ninety patients (42 male and 48 female patients), ranging from 11 to 75 years of age, underwent transsphenoidal surgery for GH-secreting pituitary adenoma. Preoperative and postoperative GH and insulin-like growth factor-I levels were measured, as was the postoperative GH level after the oral glucose tolerance test. Tumor size, cavernous sinus (CS) invasion, and residual tumor were evaluated using magnetic resonance (MR) imaging. Transsphenoidal microsurgery was performed, followed by adjuvant GKS when there was persistent biochemical evidence of GH hypersecretion with residual tumor detectable in the CS on MR imaging. Patients in whom GKS was contraindicated were treated with conventional radiotherapy or by medical means. CONCLUSIONS: The overall surgical cure rate was 57% based on recently accepted biochemical cure criteria. Patients with no CS invasion achieved a 100% cure rate, whereas patients with CS invasion achieved an 82% cure rate (14 of 17 patients) after adjuvant GKS. The combination of transsphenoidal microsurgery and adjuvant GKS is the optimal therapy for patients with GH-secreting adenoma.

Investigation of hydrocephalus with three-dimensional constructive interference in steady state MRI.

We report four patients with various types of hydrocephalus in whom constructive interference in steady state (CISS) MRI disclosed the cause of the hydrocephalus. The imaging clearly delineated an abnormal contour of the ventricular system and intraventricular septa, essential information for surgical planning, including endoscopic surgery. Postoperative CISS images were useful for showing not only regression of hydrocephalus but also the patency of small fenestrations.

Endovascular treatment of aneurysms associated with cerebral arteriovenous malformations: experiences after the introduction of Guglielmi detachable coils.

The authors have treated 172 patients with arteriovenous malformation (AVM) since 1993. Among them, 25 patients had aneurysms with a total number of 43. The aneurysms were divided into four groups; proper feeder aneurysm (4), flow-related distal aneurysm (beyond the circle of Willis or M1, 7), flow-related proximal aneurysm (26) and remote aneurysm (6). Guglielmi detachable coil (GDC) embolisation was performed in 12 patients with 15 aneurysms. Gamma knife radiosurgery for AVM was performed in 10 of those 12 patients. Two of the proper feeder aneurysms were embolised with liquid material, together with the corresponding part of the AVM. The other aneurysms were treated surgically (14) or observed (12). There was no bleeding from aneurysms after treatment. In conclusion, GDC embolisation is a useful treatment for aneurysms associated with AVM, especially if the AVM is treated by radiosurgery. Liquid embolisation of a proper feeder aneurysm is one of the treatment options. Ltd.

Serial follow-up MR imaging after gamma knife radiosurgery for vestibular schwannoma.

BACKGROUND AND PURPOSE: Gamma knife radiosurgery has become an important treatment option for vestibular schwannoma. The effect of treatment can be assessed only by neuroimaging. We analyzed the evolution of follow-up MR imaging findings after gamma knife radiosurgery to provide information for the clinical management of these tumors. METHODS: Changes in tumor volume and enhancement were assessed visually on 341 follow-up MR studies obtained in 78 of 86 consecutive patients with unilateral vestibular schwannoma who underwent gamma knife radiosurgery. RESULTS: Follow-up MR studies were obtained between 10 and 63 months (mean, 34 months) after treatment. Tumor control rate was 81%. Changes in tumor volume were classified as temporary enlargement (41%), no change or sustained regression (34%), alternating enlargement and regression (13%), or continuous enlargement (12%). Temporary enlargement occurred within 2 years after radiosurgery. Changes in tumor enhancement were classified as transient loss of enhancement (84%), continuous increase in enhancement (5%), or no change in enhancement (11%). There was no significant correlation between changes in tumor volume and tumor enhancement. Areas of T2 hyperintensity in adjacent brain tissue appeared in 31% of patients. CONCLUSION: Dynamic changes in vestibular schwannoma are seen on serial follow-up MR studies obtained after gamma knife radiosurgery. An increase in tumor size up to 2 years after radiosurgery is likely to be followed by regression. Changes in contrast enhancement are not predictive of clinical outcome. Neuroimaging follow-up is recommended.

[A case of TSH-secreting pituitary adenoma associated with an unruptured aneurysm: successful treatment by two-stage operation and gamma-knife].

We report a successfully treated case of invasive TSH-secreting pituitary adenoma associated with an unruptured internal carotid artery aneurysm by two-stage operation and gamma-knife radiosurgery. A 64-year-old woman was admitted to our department with a 3-year history of general fatigue and 1-year history of anxiety, palpitation and hyperhydrosis. Endocrinological examination revealed hyperthyroidism with elevated TSH, GH and somatomedin C. Magnetic resonance images demonstrated a tumor in the sella turcica which extended into the left cavernous sinus, furthermore, indicated aneurysm-like flow void at the ventral part of the left internal carotid artery. The aneurysm was confirmed by conventional angiography. Neck clipping of the aneurysm was performed through pterional approach as the first operation. One month later, at the second operation, the pituitary adenoma except for cavernous sinus portion was resected via the transsphenoidal approach. Immunohistological examination revealed positive for TSH and GH. Gamma-knife radiosurgery with a central dose of 33.3 Gy and peripheral dose of 17 Gy was carried out for residual tumor at the cavernous sinus under both MRI and CT guidance. Posttreatment course was uneventful with normalization of thyroid function at 16 months after gamma-knife. Two-stage operation and gamma-knife radiosurgery is effective for TSH-secreting adenoma extending into the cavernous sinus associated with an unruptured aneurysm.

Surgical treatment of pineal region tumours through the occipital transtentorial approach: evaluation of the effectiveness of intra-operative micro-endoscopy combined with neuronavigation.

OBJECT: To determine the efficacy and accuracy of surgically-assisted systems including endoscopy combined with neuronavigation in the treatment of pineal region tumours through the occipital transtentorial approach, an evaluation of thirty-one patients undergoing surgery was performed over a 10-year period. METHOD: The study was performed in 2 parts. The surgical approach to the pineal region was the same in the two parts, but in part 2 a smaller craniotomy window was used. Part 1 (from March 1989 to March 1997) included 15 patients who underwent surgical removal of pineal region tumours without using assisted systems; four out of the fifteen patients had surgery-related complications, including seizure and hemianopsia. Part 2 (from April 1997 to February 1999) included 16 patients who underwent surgical treatment by the same surgical team and with assisted systems; all 16 patients had excellent outcomes, with no complications. CONCLUSIONS: Although this study was the first specifically to examine the efficacy of endoscopy combined with neuronavigation in the treatment of pineal region tumours, our findings suggest that these systems are very useful, safe, and accurate in evaluating the primary tumour and surrounding anatomy as well as in determining operative strategy, such as the location and size of the scalp incision, craniotomy, and the extent of surgical removal. Therefore, we conclude that the addition of endoscopy combined with neuronavigation to standard surgical procedures can improve the outcome of surgical treatment of pineal region tumours.

A multi-institutional analysis of complication outcomes after arteriovenous malformation radiosurgery.

PURPOSE: To better understand radiation complications of arteriovenous malformation (AVM) radiosurgery and factors affecting their resolution. METHODS AND MATERIALS: AVM patients (102/1255) who developed neurological sequelae after radiosurgery were studied. The median AVM marginal dose (Dmin) was 19 Gy (range: 10-35). The median volume was 5.7 cc (range: 0.26-143). Median follow-up was 34 months (range: 9-140). RESULTS: Complications consisted of 80/102 patients with evidence of radiation injury to the brain parenchyma (7 also with cranial nerve deficits, 12 also with seizures, 5 with cyst formation), 12/102 patients with isolated cranial neuropathies, and 10/102 patients with only new or worsened seizures. Severity was classified as minimal in 39 patients, mild in 40, disabling in 21, and fatal in 2 patients. Symptoms resolved completely in 42 patients for an actuarial resolution rate of 54% +/- 7% at 3 years post-onset. Multivariate analysis identified significantly greater symptom resolution in patients with no prior history of hemorrhage (p = 0.01, 66% vs. 41%), and in patients with symptoms of minimal severity: headache or seizure as the only sequelae of radiosurgery (p < 0.0001, 88% vs. 34%). CONCLUSION: Late sequelae of radiosurgery manifest in varied ways. Further long-term studies of these problems are needed that take into account symptom severity and prior hemorrhage history.