Treatment of tumours of the pineal region and posterior part of the third ventricle

Endoscopic-assisted paramedian supracerebellar infratentorial approach to the posterior portion of the third ventricle: anatomical study and surgical cases

BACKGROUND

To date, morphometrical data providing a systematic quantification of accessibility and operability parameters to the boundaries of the posterior portion of the third ventricle (PTV) when applying an endoscopic-assisted paramedian supracerebellar infratentorial approach (EPSIA) are lacking. We performed an anatomical study and complemented our findings with surgical cases.

METHODS

Eight EPSIAs towards the PTV were performed in cadaveric specimens. Optimal approach angles (OA), surgical freedom (SF) and operability indexes (Oi) to the PTV boundaries were assessed. Additionally, a 54-year-old man and 33-year-old woman were operated on PTV tumors applying the EPSIA.

RESULTS

Sagittal OA to ventricle's roof and floor was 36±1.4° and 25.5±3.5° respectively, axial OA to the ipsilateral and contralateral ventricle's wall were 9.5±1.3° and 28.5±1.6°. SF was maximal on the contralateral wall (121.2±19.3mm2), followed by the roof (112.7±18.8mm2), floor (106.6±19.2mm2) and ipsilateral wall (94.1±15.7mm2). SF was significantly lower along the ipsilateral compared the contralateral wall (P<0.01) and roof (P<0.05). Facilitated surgical maneuvers with multiangled exposure were possible up to 8.5±1.07mm anterior to ventricle's entrance, whereas surgical maneuvers were possible but difficult up to 15.25±3.7mm. Visualization of more anterior was possible up to a distance of 27±2.9mm, but surgical maneuvers were barely feasible. EPSIA enabled successful resection of both PTV tumors and postoperative course was uneventful.

CONCLUSIONS

EPSIA can be effective for approaching the PTV, enabling surgery along all boundaries, but especially on its roof and contralateral wall. In the not-enlarged ventricle, surgical maneuvers are feasible up to the level of the Monro foramen, becoming more limited anteriorly.

The Minimally Invasive Lateral Occipital Infracortical Supra-/Transtentorial Approach in Surgery of Lesions of the Pineal Region: A Possible Alternative to the Standard Approaches

OBJECTIVE

The pineal region is an anatomical region that is difficult to access surgically, especially when it comes to removing neoplasms. Four main surgical approaches to this region are used as standards nowadays: infratentorial supracerebellar, occipital supra-/transtentorial, interhemispheric, and transventricular approaches. All methods have both advantages and disadvantages and are associated to any extent with intra- and postoperative risks. We have developed a lateral minimally invasive occipital infracortical supra-/transtentorial (OICST) approach, which retains the advantages of the standard occipital transtentorial approach while improving tumor exposure and minimizing its disadvantages.

METHODS

We describe 7 consecutive cases of successful complete removals of pineal tumor formations of various quality and size (3 pineal cysts, 2 pineocytomas, 1 meningioma, 1 medulloblastoma) using the OICST approach developed by us. Preoperative 3-dimensional and virtual reality-modeling and the use of a special retractor also contributed to reducing the size of the surgical approach.

RESULTS

All patients underwent surgery for removal of a lesion in the pineal region and suffered from no new and permanent neurological deficits postoperatively. The mean size of the craniotomies was 2.3 × 1.85 cm. The minimally invasive approach developed by us carries the advantages of the standard occipital transtentorial approach, but minimizes its disadvantages. The main disadvantage of the standard occipital approach is excessive retraction of the occipital lobe, which is frequently associated with visual neurological deficits. Also, with occipital approach, the Rosenthal vein lying along the surgical corridor is frequently not good visible since the tumor is approached from its tip rather than side which limits the overview of the surgical field and can pose a risk. Damage to this vein can cause infarction of the basal ganglia. By approaching the pineal region from more laterally the size of the craniotomy can significantly be reduced, excessive retraction of the occipital lobe can be avoided and the risk of damage to large deep veins can be minimized. The cosmetic outcome with a small skin incision of only about 3 cm is also a very good side effect of this minimally invasive technique.

CONCLUSIONS

The minimally invasive lateral OICST approach described by us can be successfully used in the surgery of pineal neoplasms. Reducing the size of the craniotomy does not limit the possibility of complete removal of tumors of various sizes and tissue consistency, and also minimizes the risks of both intra- and postoperative complications.

Evaluation of the Perioperative and Postoperative Course of Surgery for Pineal Germinoma in the SIOP CNS GCT 96 Trial

Background: CNS germinoma, being marker-negative, are mainly diagnosed by histological examination. These tumors predominantly appear in the suprasellar and/or pineal region. In contrast to the suprasellar region, where biopsy is the standard procedure in case of a suspected germ-cell tumor to avoid mutilation to the endocrine structures, pineal tumors are more accessible to primary resection. We evaluated the perioperative course of patients with pineal germinoma who were diagnosed by primary biopsy or resection in the SIOP CNS GCT 96 trial. Methods: Overall, 235 patients had germinoma, with pineal localization in 113. The relationship between initial symptoms, tumor size, and postoperative complications was analyzed. Results: Of 111 evaluable patients, initial symptoms were headache (n = 98), hydrocephalus (n = 93), double vision (n = 62), Parinaud syndrome (n = 57), and papilledema (n = 44). There was no significant relationship between tumor size and primary symptoms. A total of 57 patients underwent primary resection and 54 underwent biopsy. Postoperative complications were reported in 43.2% of patients after resection and in 11.4% after biopsy (p < 0.008). Biopsy was significantly more commonly performed on larger tumors (p= 0.002). Conclusions: These results support the practice of biopsy over resection for histological confirmation of pineal germinoma.

Two-stage endoscopic assisted approach for large pineal region and falcotentorial meningioma: first stage paramedian supracerebellar infratentorial approach, second stage interhemispheric occipital transtentorial approach: surgical cases and anatomical study

Resection of complex falcotentorial meningiomas, growing along the pineal region (PR), and posterior incisural space (PIS) represents a neurosurgical challenge. Here, we present our strategy for effective resection of large falcotentorial meningiomas applying a paramedian supracerebellar infratentorial and interhemispheric occipital transtentorial approach in staged surgeries. We further systematically compared the effectiveness of midline (MSIA) and paramedian (PSIA) supracerebellar infratentorial, as well as interhemispheric occipital transtentorial approaches (IOTA) to operate along the PR and PIS in 8 cadaveric specimens. The staged PSIA and IOTA enabled successful resection of both falcotentorial meningiomas with an uneventful postoperative course. In our anatomo-morphometrical study, superficial vermian veins at an average depth of 11.38 ± 1.5 mm and the superior vermian vein (SVV) at 54.13 ± 4.12 mm limited the access to the PIS during MSIA. MSIA required sacrifice of these veins and retraction of the vermian culmen of 20.88 ± 2.03 mm to obtain comparable operability indexes to PSIA and IOTA. Cerebellar and occipital lobe retraction averaged 14.31 ± 1.014 mm and 14.81 ± 1.17 mm during PSIA and IOTA respectively, which was significantly lower than during MSIA (p < 0.001). Only few minuscule veins were encountered along the access through PSIA and IOTA. The application of PSIA provided high operability scores around the pineal gland, ipsilateral colliculus and splenium, and acceptable scores on contralateral structures. The main advantage of IOTA was improving surgical maneuvers along the ipsilateral splenium. In summary, IOTA and PSIA may be advantageous in terms of brain retraction, vein sacrifice, and operability along the PR and PIS and can be effective for resection of complex falcotentorial meningiomas.

Interhemispheric Precuneus Retrosplenial Transfalcine Approach for Falcotentorial Meningiomas: Anatomic Study and Clinical Series

BACKGROUND

Falcotentorial meningiomas are surgically challenging. Currently accepted approaches include occipital interhemispheric and supracerebellar infratentorial approaches, which have documented drawbacks.

OBJECTIVE

To propose an alternative approach to the posterior tentorial incisural space, the interhemispheric precuneus retrosplenial transfalcine approach (IPRTA).

METHODS

A total of 6 colored-silicone-injected adult cadaveric heads were dissected. We measured the interval between bridging veins and studied computed tomography venography scans of 20 subjects to confirm the feasibility of the IPRTA. Bony landmarks, the region's bridging veins, and the anterior and posterior borders of the approach were identified. The surgical corridor widths (veins' interval) and lengths were compared between alternative midline approaches. We also reviewed 4 consecutive clinical cases using this approach.

RESULTS

The IPRTA provides the shortest distance to the anterior and posterior limits of the posterior tentorial incisura. Moreover, it is the only approach that provides direct visualization of the anterior and posterior limits of falcotentorial junction meningiomas. In all specimens and patients, a minimum 30-mm interval between the anterior and posterior parietal veins was found in at least one of the hemispheres. Tumor removal was successful in all 4 patients but resulted in mild paresthesia in the lower extremities of 2 patients and temporary foot drop in 1 patient.

CONCLUSION

The IPRTA offers the shortest and most direct corridor for falcotentorial meningiomas and provides excellent visualization of most of the critical structures in the region. Detailed preoperative evaluation of the deep and superficial venous structures is recommended.

The Inferior Colliculus in Alcoholism and Beyond

Post-mortem neuropathological and in vivo neuroimaging methods have demonstrated the vulnerability of the inferior colliculus to the sequelae of thiamine deficiency as occurs in Wernicke-Korsakoff Syndrome (WKS). A rich literature in animal models ranging from mice to monkeys-including our neuroimaging studies in rats-has shown involvement of the inferior colliculi in the neural response to thiamine depletion, frequently accomplished with pyrithiamine, an inhibitor of thiamine metabolism. In uncomplicated alcoholism (i.e., absent diagnosable neurological concomitants), the literature citing involvement of the inferior colliculus is scarce, has nearly all been accomplished in preclinical models, and is predominately discussed in the context of ethanol withdrawal. Our recent work using novel, voxel-based analysis of structural Magnetic Resonance Imaging (MRI) has demonstrated significant, persistent shrinkage of the inferior colliculus using acute and chronic ethanol exposure paradigms in two strains of rats. We speculate that these consistent findings should be considered from the perspective of the inferior colliculi having a relatively high CNS metabolic rate. As such, they are especially vulnerable to hypoxic injury and may be provide a common anatomical link among a variety of disparate insults. An argument will be made that the inferior colliculi have functions, possibly related to auditory gating, necessary for awareness of the external environment. Multimodal imaging including diffusion methods to provide more accurate in vivo visualization and quantification of the inferior colliculi may clarify the roles of brain stem nuclei such as the inferior colliculi in alcoholism and other neuropathologies marked by altered metabolism.

Long-term survival outcomes of pineal region gliomas

Purpose

Surgical series of pineal region gliomas are rarely available. Whereas it is a general assumption that the extent of surgical resection correlates with survival outcomes of intracranial gliomas; the impact of the microsurgical resection on the long-term outcomes of pineal gliomas has been questioned. We present a surgical series of pineal region gliomas with focus on the survival outcome analysis.

Methods

17 histologically confirmed pineal region glioma patients classified as diffuse and non-diffuse gliomas were retrospectively analyzed. A detailed description of the series was followed by regression models to identify predictors of clinical outcomes. Uni- a multivariate survival analysis was performed to determine independent predictors of mortality.

Results

Although the number of treated patients was small, only WHO grade histopathology remained significant (p = 0.02) after multivariate survival analysis with extent of resection, age, tumor volume, and preoperative functional status. The extent of the surgical resection did not correlate with the disease survival rates of non-diffuse (p = 1), diffuse (p = 0.2), nor all gliomas (p = 0.6). 15 of 17 patients underwent gross total (nine patients) or subtotal resection. The preoperative functional status of the patients showed overall improvement on the immediate (p < 0.001) and long-term (p = 0.03) follow-up after 106 (3 – 324) months.

Conclusion

The extent of the surgical resection does not seem to significantly impact on the survival outcomes of pineal region gliomas. Thus, genotype and molecular features may essentially affect the outcome. Further research on the field is required.

Electronic supplementary material

The online version of this article (10.1007/s11060-020-03571-z) contains supplementary material, which is available to authorized users.

An Alternative Route to the Posterior Half of the Third Ventricle: The Transoccipital Horn Approach. Technical Note

BACKGROUND

Lesions arising or abutting in the posterior half of the third ventricle are approached through established routes to avoid damage of essential brain structures. Occasionally, the features of the lesion require rethinking these traditional routes and tailoring the surgical approach to cause fewer debilitating sequelae to the patient. We introduce a modification of previously described transcortical approaches to lesions of the posterior third ventricle. The technique and possible indications are discussed.

METHODS

Two cases of posterior third ventricle tumors are presented. In both patients, a small posterior fossa and large tentorial veins located along the surgical route, as well as the position of the lesion underneath the internal cerebral veins, encouraged the concept of a novel transoccipital horn approach that was developed to access the tumor with less postoperative deficits.

RESULTS

Both lesions were removed with transitory postoperative visual deficits.

CONCLUSIONS

The transoccipital horn approach is a feasible alternative to other surgical routes to the posterior part of the third ventricle in cases of particularly challenging anatomy and tumor characteristics. It allows reaching the lesion along its major axis, fully exploiting the natural space created by the tumor in its growth and avoiding the internal cerebral veins.

Pineal Region Gliomas: A Single-Center Experience with 25 Cases

BACKGROUND

Pineal region glioma is a rare systematically reported tumor in the literatures, and little is known about its behavior, development, and best treatment strategies because of its complex anatomical relationship and rarity.

OBJECTIVE

We reviewed the outcomes of patients with pineal region gliomas in West China hospital in the past 5 years and searched the literature to add more information. As a result, key factors related to prognosis are identified.

METHODS

Twenty-five patients with pineal region gliomas were selected and information was collected about detailed medical history, imaging data, treatment methods, pathologic results, and latest neurosurgical radiologic progress during follow-up.

RESULTS

Pilocytic astrocytomas (20%) and glioblastomas (24%) were the most common pathologic subtypes. Twenty-three patients underwent open surgery, 3 Gamma Knife radiosurgery, and 4 whole-brain radiation therapy. Chemotherapy was applied to 3 patients. Low-grade gliomas tended to have a better prognosis than did high-grade. Karnofsky Performance Status at admission (≤60) was intimately associated with prognosis for low-grade gliomas. As for high-grade gliomas, patients whose age at admission was ≤30 years had a better prognosis than did older patients (＞30 years). However, whatever the grade, there was no overall survival difference as to gender, gross total resection versus not gross total resection, preoperative maximal tumor diameter (≤4 vs. ＞4 cm), and time since first symptoms (≤30 vs. ＞30 days), and radiation therapy versus no radiation therapy.

CONCLUSIONS

Open surgery is the first-line strategy for pineal region gliomas with tolerable mortality and disability rate. Radiosurgery and chemotherapy can be applied as adjuvant or alternative methods when surgery is contraindicated.

Quality of life following surgical treatment of lesions within the pineal region

OBJECTIVEPineal region tumors are a rare and heterogeneous group of lesions. The optimal therapeutic approach is currently a topic of controversy, particularly in light of the potential operative risks and complications. The potential beneficial effects of surgery have already been described, but information about neurological outcome and, in particular, health-related quality of life (HRQOL) is still lacking in the literature. The aim of this study was to assess the therapeutic effect of resection of pineal region lesions, emphasizing grade of tumor resection, neurological outcome, quality of life, and the necessity of additional shunt procedures.METHODSThe authors performed a prospective study of HRQOL in 32 patients who had undergone surgical treatment of lesions in the pineal region (20 tumors and 12 cysts) between 2008 and 2014. All patients had at least 6 months of follow-up, with reexamination including standardized neurological assessment, an evaluation of dependency using the modified Rankin Scale, and an evaluation of HRQOL. The authors retrospectively examined patient charts and collected information regarding imaging studies, neurological status prior to surgery, surgical strategies used, any complications, and histological diagnoses.RESULTSIn this study, there was no surgery-associated mortality or major morbidity. Permanent minor morbidity was reported for 4 patients (13%). Comparing pre- and postoperative neurological symptoms, 75% of tumor patients had either complete resolution or improvement of preoperative symptoms; symptoms were unchanged in 10% of tumor patients and deteriorated in 15%. In patients with pineal cysts, long-term follow-up showed that 42% of patients were free of any symptoms and 58% experienced improvement of their preoperative symptoms. These outcomes were also reflected in the modified Rankin Scale scores, which demonstrated significant improvement following resection of pineal region lesions. Furthermore, significant improvements in HRQOL scores occurred in global health status, in all functional scales, and in pain, nausea and vomiting, fatigue, and insomnia (p < 0.0001). Moreover, a significant reduction in the necessity for permanent shunt procedures was observed after gross-total tumor resection compared with subtotal resection (p = 0.035) of pineal cysts.CONCLUSIONSDespite potential risks, (radical) surgery is a highly effective and safe treatment option for pineal region lesions and should be considered for the majority of patients.

The Posterior Transcallosal Approach to the Pineal Region and Posterior Third Ventricle: Intervenous and Paravenous Variants

BACKGROUND: There are a number of surgical approaches to the posterior third ventricle and pineal region, each with its associated advantages and disadvantages.

OBJECTIVE: To present our experience with the posterior interhemispheric transcallosal approach and to analyze the indications, technique, and outcomes.

METHODS: A retrospective study was conducted to identify and analyze all children and young adults who underwent the posterior transcallosal approach from July 2010 to March 2015. Perioperative data included patient demographics, signs and symptoms on presentation, tumor characteristics (type, origin, and size), complications, and clinical and radiographic outcome at final follow-up.

RESULTS: Twenty-two patients (9 female, 13 male) were identified in 24 cases with a mean age of 10.5 years (range, 3-32 years). The most common tumor type was pineoblastoma (n = 6). Eleven patients underwent gross total resections; 11 underwent subtotal resections; and 2 tumors were biopsied. The intervenous operative corridor was used in 15 cases; the paravenous was used in 9. Of the 22 patients, 19 experienced 31 total postoperative events. There were 12 instances of contralateral weakness. Retraction-related hemiparesis was usually temporary; resection-related hemiparesis lasted longer. There were no complications related to occlusion of one or more bridging cortical veins or from thrombosis of 1 internal cerebral vein. Eight patients have died of tumor progression, and of the remaining 14 patients, only 1 patient to date has developed local progression.

CONCLUSION: The posterior interhemispheric transcallosal approach allows resection of tumors located within the pineal region, posterior third ventricle, and thalamus. New postoperative neurological deficits can occur; however, many will improve significantly or resolve completely over time.

Microsurgical resection of tumors of the lateral and third ventricles: operative corridors for difficult-to-reach lesions

Tumors of the lateral and third ventricles are cradled on all sides by vital vascular and eloquent neural structures. Microsurgical resection, which always requires attentive planning, plays a critical role in the contemporary management of these lesions. This article provides an overview of the open microsurgical approaches to the region highlighting key clinical perspectives.

Two cases of pineal-region meningiomas derived from arachnoid membrane over the vein of Galen without dural attachment

BACKGROUND

We present two rare cases of pineal-region meningiomas. These tumors are the first reported cases of dura-unrelated meningiomas originating from the arachnoid membrane over the vein of Galen (AMG).

CASE DESCRIPTION

In Case 1, a 37-year-old woman presented with a progressing headache. Magnetic resonance imaging (MRI) showed a large tumor in the pineal region, displacing the vein of Galen upward. Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the veins on the right medial surface of the occipital lobe to the superior sagittal sinus. In Case 2, a 67-year-old man presented with dizziness. MRI demonstrated a large mass in the pineal region, displacing the vein of Galen inferiorly. Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the collateral venous channel into the transverse sinus. Both tumors were totally excised (Simpson Grade III for Case 1, Grade I for Case 2) via a left occipital transtentorial approach. No dural attachment was recognized in either case, but the tumor in Case 1 was firmly adherent to the inferior portion of the AMG, while that in Case 2 was attached to the superior portion of the AMG, but remained dissectible.

CONCLUSIONS

We reported two cases of pineal-region meningiomas originating from the arachnoid membrane over the vein of Galen, resulting in meningioma without dural attachment. These tumors can be totally resected by careful dissection of the tumor from the arachnoid membrane surrounding the vein of Galen.

Arterial vascularization of the pineal gland

PURPOSE

The arterial vascularization of the pineal gland (PG) remains a debatable subject. This study aims to provide detailed information about the arterial vascularization of the PG.

METHODS

Thirty adult human brains were obtained from routine autopsies. Cerebral arteries were separately cannulated and injected with colored latex. The dissections were carried out using a surgical microscope. The diameters of the branches supplying the PG at their origin and vascularization areas of the branches of the arteries were investigated.

RESULTS

The main artery of the PG was the lateral pineal artery, and it originated from the posterior circulation. The other arteries included the medial pineal artery from the posterior circulation and the rostral pineal artery mainly from the anterior circulation. Posteromedial choroidal artery was an important artery that branched to the PG. The arterial supply to the PG was studied comprehensively considering the debate and inadequacy of previously published studies on this issue available in the literature.

CONCLUSIONS

This anatomical knowledge may be helpful for surgical treatment of pathologies of the PG, especially in children who develop more pathology in this region than adults.

Tumors of the posterior third ventricular region in pediatric patients: The Indian perspective and a review of literature

Background:

Diverse tumors in the posterior third ventricular region (TPTVR) frequently occur in children. A decade's experience with pediatric TPTVR is presented, focusing on the Indian perspective.

Materials and Methods:

25 children (age range: 3-18 years; mean age: 13.32 years; presentation range: 7 days-2.5 years) had clinico-radiological assessment with contrast computed tomography (CT) and magnetic resonance imaging (MRI). The ventricular/lumbar cerebrospinal fluid (CSF) alpha feto protein (AFP)/beta human chorionic gonadotrophin (HCG) estimation was done when radiological suspicion of a germ cell tumor was present. Extent of resection was deemed partial when some tumor mass remained at the end of surgery, near total when <10% was retained over vital neurovascular structures, and total when complete resection was attained.

Results:

Operations included infratentorial supracerebellar approach (n = 12), occipito-transtentorial approach (n = 2), endoscopic biopsy and third ventriculostomy (n = 1), frontal parasagittal craniotomy, interhemispheric transcallosal subchoroidal approach (n = 2), middle temporal gyrus transcortical transventricular approach (n = 1), fronto-temporo-zygomatic combined transylvian and subtemporal approach (n = 1) and right ventriculoperitoneal shunt and stereotactic biopsy (n = 1). Only CSF diversion was performed for five patients with a small TPTVR. CSF diversion was required in 12 (48%) patients. Tumor pathology included pinealoblastoma (n = 4; one with pineocytic differentiation), nongerminomatous germ cell tumor (NGGCT; n = 3), germinoma (n = 3), pilocytic astrocytoma (n = 2), epidermoid (n = 3) and primitive neuroectodermal tumor (PNET), fibrillary astrocytoma, glioblastoma, teratoma, and meningioma (n = 1, respectively). A patient with neurocysticercosis was diagnosed solely on MRI (four did not undergo biopsy). Fractionated radiotherapy was administered in 13 patients with primary pineal tumors, PNET, NGGCT, fibrillary astrocytoma and glioblastoma. Extent of excision was total in 10 (40%), near total in 5 (20%), partial in 3 (12%) and a biopsy in 2 (8%) patients.

Conclusions:

Histopathologic characterization of TPTVR is essential prior to their further management. Benign lesions often have a good prognosis following gross total surgical resection. Pure germinomas are highly susceptible to radiotherapy. NGGCTs often have malignant components that require adjuvant therapy following surgery. The advancements in microsurgical techniques have led to gratifying perioperative results in these deep-seated lesions.

Limitations of the transcallosal transchoroidal approach to the third ventricle

Object

The aim of this study was to determine the anatomical limitations of the transcallosal transchoroidal approach to the third ventricle.

Methods

Twenty-six formalin-fixed specimens were studied. Sagittal dissections were used to determine the anatomical relationships of the foramen of Monro, the angle of approach to landmarks, and placement of a callosotomy. Lateral ventricular dissections were performed to quantitate the forniceal anatomy.

Results

The foramen of Monro was found 1.07 ± 0.11 cm superior and slightly anterior to the mammillary bodies, 1.48 ± 0.16 cm posterosuperior to the optic recess, and 2.26 ± 0.16 cm anterosuperior to the aqueduct. Relative to the genu, a callosal incision 2.64 ± 0.53 cm long and angled 37 ± 4.3° anterior was needed to access the aqueduct, and an incision 4.92 ± 0.71 cm long and angled 49 ± 7.4° posterior was needed to access the optic recess. The fornix progressively widened within the lateral ventricle, from 1.25 ± 0.63 mm at the foramen of Monro to > 7 mm at 2 cm behind the foramen. Three zones of exposure were identified, requiring unique craniotomies, callosotomies, and angles of approach. The major limiting factors in the approach included the columns of the fornix anteriorly, the width of the fornix posteriorly, and the draining veins of the parietal cortex. The choroidal fissure opening was limited to 1.5 cm posterior to the foramen of Monro; this limited opening created an aperture effect that required an anterior-to-posterior angle, an anterior craniotomy, and an anteriorly placed callosotomy to access the posterior landmarks. In contrast, a posterior-to-anterior angle, posteriorly placed craniotomy, and posteriorly placed callosotomy were required to access anterior landmarks.

Conclusions

The transcallosal transchoroidal approach was ideally suited to access the foramen of Monro and the middle and posterior thirds of the third ventricle. Exposure of the anterior third ventricle was limited by the columns of the fornix and by the presence of parietal cortical draining veins.

Meningiomas of the falcotentorial junction: selection of the surgical approach according to the tumor type

BACKGROUND

We retrospectively analyzed a series of patients harboring a FT meningioma with regard to clinical presentation, surgical technique, and follow-up results.

METHODS

Clinical data in a consecutive series of 13 patients treated for a meningioma of the FT junction were retrospectively reviewed. Tumors were classified into 4 types according to their dural origin and tumor extent as depicted from preoperative MRI.

RESULTS

Main presenting symptom in 9 women and 4 men (mean age, 56 years) was headache (69%) and gait disturbance (54%). Clinical examination revealed gait ataxia in 62% of the patients. The tumor displaced the vein of Galen inferiorly in 6 patients, superiorly in 2, and medially in 5 cases. The main surgical approach to the meningioma was via an occipital interhemispheric route (10 patients). Additional resection of the falx and/or incision of the tentorium was performed in 6 cases each. A complete resection (Simpson grade 1 and 2) was achieved in 85% of patients. Permanent surgical morbidity was 23%. One tumor recurrence in an atypical meningioma was observed after the mean follow-up period of 6.2 years (range, 1-14 years) with clinical and MRI examination and had to be reoperated. Eighty-five percent of the patients regained full daily activity on follow-up.

CONCLUSIONS

The surgical approach should be tailored to the dural origin and extent of the tumor as depicted from preoperative MRI. Preservation of the straight sinus and Galenic venous system is recommended.

Endoscopic options in management of posterior third ventricular tumors

OBJECTIVE

A spectrum of both radiosensitive and radio-resistant lesions occurs in the region of the posterior third ventricle (PTV). Most of these are associated with hydrocephalus requiring a cerebrospinal fluid diversion procedure. The present study aims to assess the effectiveness of endoscopic biopsy and third ventriculostomy (ETV) in these patients.

MATERIALS AND METHODS

Twenty-four patients with PTV lesions with moderate to severe hydrocephalus were managed prospectively. All patients underwent ETV and biopsy of the lesion during the same procedure. The ETV could be performed in all patients, where as in 23, a successful biopsy could be obtained. The ETV was successful in 22 patients; it failed in 2 patients requiring shunt insertion. A positive biopsy was obtained in all the patients (pinealocytoma 4, pinealoblastoma 10, embryonal cell carcinoma 1, germinoma 2, oligodendroglioma 1, astrocytoma 2, tuberculoma 4). All patients were subsequently managed with further surgery, radiation, and chemotherapy either alone or in combination depending on the pathology. One patient with a tumor bed hematoma required clot evacuation. The follow-up period ranged from 12 to 36 months. Two patients died, one during hospital stay with a tumor bed hematoma and another at 6 months follow-up due to extensive leptomeningeal spread.

CONCLUSIONS

The high yield of endoscopic biopsy (100%) and success of ETV (91%) emphasizes its role in management of the diverse group of PTV lesions in arriving at the optimal definitive management.

Peri-operative quality of life assessment in endoscopically treated patients with pineal region tumours

BACKGROUND

Therapeutic modalities for pineal region tumours are still matter of debate. Endoscopic treatment is a minimally invasive approach. The aim of this study was to assess the quality of life of patients with pineal region tumours who underwent endoscopic procedures.

MATERIALS AND METHODS

Eight patients (male:3, female 5) were included in this study. Post-operative evaluation of surgical outcome in terms of quality of life (QoL) was performed using the Quality of Life Questionnaire (QLQ-C30). The patient's outcome scores were compared with normative outcome values of the German population. Pre-operative and post-operative global QoL and symptoms such as headache, visual disturbance, gait disturbance, cognitive function and unconsciousness were documented. Descriptive and explorative statistics were performed.

RESULTS

There were no significant differences between the normal German population and the endoscopically treated patients in different health domains and measures of QLQ-C30 (physical functioning 87.5%, emotional functioning 50%, cognitive functioning 50%, social functioning 62.5%; percentage represents regular functioning). Improved quality of life could be demonstrated in short-term (3-12 months, n = 3) and long-term (21-29 months, n = 5) follow-up. Global QoL improved significantly (p < 0.001; t-test) post-operatively. The following changes between pre-operative and post-operative clinical symptoms were found (headache 87.5%/62.5%, visual disturbance 50%/25%, gait disturbance 87.5%/25%, cognitive functioning 75%/37.5%, unconsciousness 25%/-).

CONCLUSION

Endoscopic treatment of patients with pineal region tumours produces improved post-operative quality of life in all health domains. Therefore, the endoscopic approach should be considered as an alternative treatment in patients with newly diagnosed pineal tumours and/or related hydrocephalus.

Posterior interhemispheric approach: surgical technique, application to vascular lesions, and benefits of gravity retraction

OBJECTIVE

To review an experience with the posterior interhemispheric approach applied to vascular lesions in the posterior midline, to examine the effects of patient position and gravity retraction of the occipital lobe, and to identify circumstances requiring increased exposure by sectioning the falx and tentorium.

METHODS

During a 6.5-year period, 46 posterior interhemispheric approaches were performed to treat 28 arteriovenous malformations, 10 dural arteriovenous fistulae, seven cavernous malformations, and one posterior cerebral artery aneurysm. Twenty-three patients were positioned prone and 23 patient were positioned laterally.

RESULTS

A standard posterior interhemispheric approach was used in 38 patients, and the occipital bitranstentorial/falcine approach was used in seven patients. A contralateral occipital transfalcine approach was used with one thalamic cavernous malformation. All lesions were resected completely and/or obliterated angiographically, with good neurological outcomes in 83% of patients and no operative mortality. Blood loss was lower, operative durations were shorter, postoperative cerebral edema was decreased, and visual outcomes were improved in patients positioned laterally.

CONCLUSION

The posterior interhemispheric approach, without additional dural cuts, is appropriate for most vascular lesions in the posterior midline. Gravity retracts the occipital lobes when patients are positioned laterally, enhancing operative exposure and reducing morbidity. Extension of the posterior interhemispheric approach to a transtentorial or transfalcine approach is required for falcotentorial dural arteriovenous fistulae and vein of Galen arteriovenous malformations, but is not usually necessary with cavernous malformations or other arteriovenous malformations.

Pure pineal germinomas: analysis of gender incidence

OBJECTIVE

Pure pineal germinomas have been rarely reported in girls. Gender incidence and differences of pure pineal germinomas are not well known. The authors report a series of pure pineal germinoma and its gender characteristic is reviewed.

METHODS AND RESULTS

Of a total of 50 germ cell tumors operated on between 1988 and 2004 we found 26 cases (median age at diagnosis, 12 years) of pineal germ cell tumors. Of these, 14 cases (male/female ratio: 13/1) were pure pineal germinomas, and 12 cases (male/female ratio: 12/0) were non-germinoma germ cell tumors. In pure pineal germinomas, the main clinical presentations were intracranial hypertension and cranial nerve dysfunction. Imaging studies disclosed a homogeneous type of tumor (n = 10) and associated hydrocephalus (n = 6). Cases were managed with biopsy and subsequent radiation therapy and chemotherapy. After a follow up of 10 years, pure germinoma cases have no neurological deficits and tumor recurrence. The literature on gender incidence of pure pineal germinomas is analyzed and possible causes are discussed.

CONCLUSIONS

Although rare, pure pineal germinoma can be found in female subjects. On the basis of the literature review, the male/female ratio in cases of pure pineal germinoma is between 5:1 and 22:1 (mean 14:1). In our series, the male/female ratio was 13:1.

"Benign" imaging abnormalities in children and adolescents with headache

OBJECTIVE

To study the frequency of "benign" abnormalities on brain imaging in children with headache, compare it with the frequency of imaging findings that dictate a change in patient management, and determine the association of benign findings with headache.

METHODS

A database of 681 headache patients from the pediatric outpatient neurology department over 2 years was reviewed. Patients with benign imaging abnormalities were compared to those with nonbenign findings. Benign abnormalities were defined as those that did not result in a change in patient management. Using literature review, we discuss the benign findings and their possible association with headache.

RESULTS

Two-hundred and forty-one patients (35.4%) had imaging at our facility. Two-hundred and eighteen had brain magnetic resonance imaging and 23 had brain computed tomography (CT) only. Twenty-two patients had CT of the sinuses in addition to brain imaging. Forty-six (19.1%) were found to have 50 benign abnormalities including 13 sinus disease, 11 Chiari I malformations, 7 nonspecific white matter abnormalities, 5 venous angiomas, 5 arachnoid cysts, 4 enlarged Virchow-Robin spaces, 2 pineal cysts, 1 mega cisterna magna, 1 fenestration of the proximal basilar artery, and 1 periventricular leukomalacia. Twenty-three patients (9.5%) had findings requiring a change in management. These included 5 sinus disease, 4 tumors, 4 old infarcts, 3 Chiari I, 2 moyamoya, 1 intracranial vascular stenosis, 1 internal jugular vein occlusion, 1 arteriovenous malformation, 1 demyelinating disease, and 1 intracerebral hemorrhage. When excluding sinusitis, which was evident clinically prior to imaging, 3 patients had absence of abnormal neurologic symptoms and signs and imaging findings that resulted in a change in management.

CONCLUSIONS

Approximately 20% of pediatric headache patients with brain imaging have benign abnormalities that do not result in a change in headache management. Imaging findings that require a change in management are rare in patients with an absence of abnormal neurologic symptoms and signs, occurring in 1.2% of patients imaged in this study.

Endoscope-assisted infratentorial–supracerebellar approach to the third ventricle: an anatomical study

OBJECT

The authors studied the microsurgical anatomy and endoscopic features of the pineal region and third ventricle to describe a combined microsurgical-endoscopic infratentorial-supracerebellar approach to the posterior third ventricle. Such an approach exposes the pineal gland and its complex neurovascular structures so that the third ventricle can be reached through a minimally invasive parapineal incision.

METHODS

The approach was studied in 10 adult cadaveric heads, six fresh and four formalin fixed, by using an operative microscope with a magnification level of 6 to 40 and the assistance of an endoscope. The endoscope-assisted infratentorial-supracerebellar approach affords a complete view of the third ventricle from a posterior perspective. The third ventricle is entered through a parapineal incision using the natural space between the internal cerebral vein and the vein of Rosenthal located above the superior colliculi.

CONCLUSIONS

The infratentorial-supracerebellar approach to the third ventricle follows a natural corridor and requires minimal retraction and resection of critical neural structures. With the use of the endoscope, an unsurpassed view into the third ventricle from a posterior perspective is obtained.

The role of Gamma Knife radiosurgery in the treatment of pineal parenchymal tumours

OBJECT

The aim of this study was to document the possible role of Gamma Knife radiosurgery, suitable for the treatment of deep and well limited tumors, in the management of pineal parenchymal tumors (PPT).

POPULATION AND METHODS

We reviewed retrospectively a series of 13 patients with PPT treated by Gamma Knife radiosurgery during 16 procedures. Mean age was 31 (range 10 to 74). Eight patients had pineocytomas (61.5%), and 5 had pineoblastomas (38.5%). Radiosurgery was performed alone in 6 cases, after partial microsurgical resection in 3 cases, in association with chemotherapy in 3 cases and following conventional fractionated radiotherapy in 1 case. The marginal dose to these tumors ranged from 11 to 20 Gy (mean 15 Gy).

RESULTS

With a mean follow-up of 34 months (range 6 to 88), all tumors responded to treatment and disappeared or ceased growing. Two patients with pineoblastoma had tumor size progression out of the initial target requiring several radiosurgery procedures. At the end of the follow-up period, 10 out of 12 patients were alive. Two patients with pineoblastoma died because of carcinomatous meningitis or tumor size progression. We observed no mortality or major morbidity related to radiosurgery.

CONCLUSION

This study confirms that radiosurgery can be an effective and safe primary treatment modality for patients with pineocytomas. It should have a role in multimodality therapy which includes microsurgical resection, fractionated radiotherapy and chemotherapy for the management of malignant pineal tumors.

Far lateral supracerebellar infratentorial approach for the treatment of upper brainstem gliomas: clinical experience with pediatric patients

OBJECTIVE

Surgical exposure of intrinsic lesions located lateral to the brainstem still represents a challenging task. The aim of this study was to assess the feasibility of the extracerebral far lateral supracerebellar infratentorial (FLSI) approach for the treatment of gliomas located in the upper brainstem in the pediatric population.

METHODS AND RESULTS

Between 1992 and 2002, seven patients (mean age 8.7 years) with tumors of glial origin (WHO I-IV) located mainly in the pontomesencephalic region were operated with the FLSI approach in a sitting position. Satisfactory extent of resection without additional morbidity was achieved.

CONCLUSION

In a carefully selected pediatric patient population, the FLSI approach proved to be a feasible and effective surgical route for the treatment of upper brainstem gliomas.

The galenic venous system: surgical anatomy and its angiographic and magnetic resonance venographic correlations

OBJECTIVE

This study aims at evaluating the adequacy of digital subtraction angiography and magnetic resonance venography in imaging of the galenic venous system for surgical planning of approaches to the pineal region. Anatomical dissections were carried out in 10 cadavers of several age groups and these were compared to imaging findings in 10 living subjects.

METHODS

The presence or absence of 10 predetermined veins or vein groupings belonging to the galenic venous system were prospectively analyzed in 10 cadaver dissections and imaging findings of 10 age matched human subjects. The studied vessels were the vein of galen, the internal cerebral veins, both basal vein of Rosenthals, internal occipital vein, occipitotemporal veins, precentral cerebellar veins, tectal veins, pineal veins, superior vermian veins (including superior cerebellar veins (SCVs)) and posterior pericallosal veins. Each of the subjects had both digital subtraction angiography and magnetic resonance venography studies performed. Diagnostic digital subtraction angiography was performed using the transfemoral route and the venous phase was used for the study. Magnetic resonance venography was performed in 1.5 T MRI equipment using the 2D-TOF sequence. All studies were reported to be normal.

RESULTS

There was wide variation in the anatomy of the galenic venous system. There were interpersonal, intrapersonal and age related variations. Both the digital subtraction angiography and the magnetic resonance venography were efficient at demonstrating large veins. However, smaller veins were less readily demonstrated in either study. The general sensitivities of the digital subtraction angiography and the magnetic resonance venography for the galenic venous system were 45.5% and 32.5%, respectively. Surgically important veins were missed in most studies.

CONCLUSIONS

Anatomically, the galenic venous system is highly variable. This variability is caused by interpersonal, intrapersonal and age related differences and causes each individual galenic venous system to be unique. Therefore, modern neurosurgical procedures require anatomical information on individual differences. Current radiological methods of digital subtraction angiography and magnetic resonance venography fail short of providing the necessary information. New and more sophisticated MRI technology may fulfill this need.

Surgical strategies for treating patients with pineal region tumors

Optimal management of pineal region tumors depends on securing an accurate histologic diagnosis to facilitate management customized to the nuances of specific pathologies. As an initial step, surgical intervention by either stereotactic biopsy or open surgery is necessary to obtain tissue for pathologic examination. Stereotactic biopsy has the benefit of relative ease and minimal morbidity but is associated with greater likelihood of diagnostic inaccuracy compared to open surgery where more extensive tissue sampling is possible. The role of surgical debulking in the management of pineal tumors is clearly defined for some tumors but is less evident for others. Among the one third of pineal tumors that are benign or low grade, complete surgical resection is achievable and constitutes optimal management with excellent long-term recurrence-free survival. The benefits of aggressive surgical resection among malignant tumors are less clear but several studies have correlated degree of tumor removal with improved outcome. Advances in technology, surgical technique, and post-operative care have minimized surgical complications, however all surgical procedures in the pineal region, including both stereotactic biopsy and open surgery, are potentially hazardous. Advanced judgment, experience, and expertise are necessary to achieve rates of success sufficient to justify aggressive management. Management strategies using stereotactic biopsy, endoscopy, and radiosurgery can also provide favorable outcomes in some cases. Selective incorporation of these innovations can be expected to improve the already highly favorable outcome for all pineal region tumors.

Neuroendoscopic surgery of intracranial cysts in adults

OBJECTS

The purpose of this study was to describe the indications, surgical techniques and postoperative outcome of neuroendoscopic interventions in a heterogeneous group of intracranial cystic pathologies.

PATIENTS AND METHODS

Between 1992 and 2003, 127 patients with symptomatic intracranial cysts and cystic tumours underwent neuroendoscopic treatment in our department. In 22 patients indication for surgery was colloid cysts, in 9 patients pineal cysts and in 3 patients cavum vergae cysts. Twelve arachnoid cysts, 10 cystic craniopharyngiomas, 2 Rathke's cleft cysts and 69 malignant cystic tumours were operated on. The patients' mean age was 45 years and their clinical presentations varied from typical signs of increased intracranial pressure to focal neurological deficits.

RESULTS

One hundred and twenty-seven patients with intracerebral cystic space-occupying lesions were operated on using stereotactic frameless or frame-based endoscopic techniques. There was no operative mortality. The operative morbidity was 3.1% including 1 memory deficit due to fornix injury, 1 hemiparesis due to postoperative haematoma after lesion biopsy, 1 aseptic meningitis and 1 subdural fluid collection.

CONCLUSIONS

Endoscopic interventions enable neurosurgeons to manage intracranial cystic lesions. Via the same approach, the obstructed CSF pathways may be restored and consequently the increased intracranial pressure diminishes. With the aid of stereotactic guidance or a neuronavigation system, access to the lesion can be gained rapidly and with high accuracy.

Diagnosis and Management of Pineocytomas

OBJECTIVE:

Pineocytomas are associated with the most favorable prognosis of all pineal tumors. However, a subset of pineocytomas may have a predilection for recurrence and therefore behave aggressively.

PATIENTS AND METHODS:

Records of nine patients (five men, four women; mean age, 44 yr; range, 24–63 yr) with histologically diagnosed pineocytomas consecutively treated between 1990 and 2003 were reviewed retrospectively to identify factors predictive of aggressiveness. Eight patients presented with hydrocephalus and four with tectal compression. Three patients underwent gross total resection, and six underwent subtotal resection or biopsy.

RESULTS:

Three local recurrences necessitated reoperation. One recurrence involved the obex of the fourth ventricle. The mean time to recurrence was 3.5 years (range, 1–7 yr). There was no correlation between histological features and tumor recurrence. Patients undergoing radiosurgery showed stable or attenuated local disease (mean follow-up, 19.3 mo; range, 6–36 mo). Mean radiographic follow-up was 34 months (range, 6 mo to 10 yr). Mean clinical follow-up was 36 months (range, 1 mo to 10 yr).

CONCLUSION:

A subset of pineocytomas demonstrates the potential for symptomatic recurrence. We advocate an attempt at gross total tumor resection for all symptomatic patients with tectal plate compression, reserving radiosurgery for small, subtotally resected, or recurrent lesions. Patients must be followed closely for recurrence. Radiosurgery seems to be beneficial for local tumor control. Further investigation is needed to identify histological markers for pineocytomas that behave aggressively.

Comparison of posterior approaches to the posterior incisural space: microsurgical anatomy and proposal of a new method, the occipital bi-transtentorial/falcine approach

OBJECTIVE

Direct surgical approaches to the posterior incisural space, including the pineal region, remain as challenges for neurosurgeons. The purposes of this study were 1) to compare the surgical views in the various posterior approaches to the posterior incisural space and 2) to propose a new approach, which is a modification of the occipital transtentorial approach.

METHODS

Ten adult cadaveric specimens (20 sides) were studied, using x3 to x40 magnification, after perfusion of the arteries and veins with colored silicone. Intraoperative views in the posterior approaches to lesions were examined in stepwise dissections. In addition, the efficacy of the occipital bi-transtentorial/falcine approach was studied.

RESULTS

The posterior incisural space has a roof, a floor, and anterior and lateral walls and extends backward to the level of the tentorial apex. The operative views defined by each approach differ in the extent to which they allow observation of the anatomic structures in the posterior incisural space. The occipital bi-transtentorial/falcine approach permits better observation of the contralateral half of the quadrigeminal cistern.

CONCLUSION

Precise surgical anatomic knowledge of each approach is required for the treatment of lesions in the posterior incisural space, because the operative fields obtained with different approaches differ significantly. The occipital bi-transtentorial/falcine approach provides greater contralateral exposure of the posterior incisural space than does the occipital transtentorial approach.

Surgical approaches to pineal region tumors

Direct surgical resection of pineal region tumors has become safer, more effective, and now plays an essential role in their management. Tissue diagnosis allows for the initiation of appropriate therapies and resection can be curative or improve the efficacy of adjuvant therapies. Several approaches have been reported. Based on our operative experience with 57 patients over a 20-year period, we conclude that the Infratentorial Supracerebellar and Parieto-Occipital Paramedian Transtentorial approaches provide excellent exposure while allowing minimally invasive, relatively low risk access to the majority of pineal region tumors. Indications, positioning, techniques, advantages, and disadvantages are discussed. A review of other approaches, pertinent historical remarks, and a discussion of the role of surgery in the contemporary management of pineal region tumors are presented.

Combined supra/infratentorial-transsinus approach to large pineal region tumors

OBJECT

The authors sought to confirm that the combined supra/infratentorial-transsinus approach offers a safer means of resecting large pineal region tumors than other approaches currently being used. The aforementioned method provides a wider exposure of the pineal region with less brain retraction than the infratentorial-supracerebellar or the occipital-transtentorial approach alone and is applicable to some large and giant tumors of this area. This combined approach was used in six patients to remove large pineal region tumors including four tentorial meningiomas, one pineocytoma, and one epidermoid cyst.

METHODS

The transverse sinus and tentorium were sectioned after review of preoperative angiographic studies, after taking intraoperative measurements of the venous pressure in the nondominant transverse sinus before and after clipping and while monitoring the somatosensory evoked potentials. The occipital lobe cortex and cerebellum were retracted slightly along the tentorium. Deep veins of the galenic system, the quadrigeminal area, and the tumor were well exposed. Before it was used for tumor resection the approach was studied in five cadaveric head specimens, and the projection of different approaches was compared radiologically. The tumors were removed in a gross-total manner in all patients, and none of the major veins of the galenic system was injured. Resuturing of the nondominant transverse sinus was performed postoperatively in one patient. One of the six patients experienced transient visual loss, and another suffered mild right sixth cranial nerve paresis; however, both recovered in 3 weeks. The wide exposure of the combined approach was also confirmed on radiological and anatomical studies.

CONCLUSIONS

The combined supra/infratentorial-transsinus approach is preferred for the resection of certain large pineal region tumors.

Combined supra/infratentorial-transsinus approach to large pineal region tumors

Object

The authors sought to confirm that the combined supra/infratentorial-transsinus approach offers a safer means of resecting large pineal region tumors than other approaches currently being used. The aforementioned method provides a wider exposure of the pineal region with less brain retraction than the infratentorial-supracerebellar or the occipital-transtentorial approach alone and is applicable to some large and giant tumors of this area. This combined approach was used in six patients to remove large pineal region tumors including four tentorial meningiomas, one pineocytoma, and one epidermoid cyst.

Methods

The transverse sinus and tentorium were sectioned after review of preoperative angiographic studies, after taking intraoperative measurements of the venous pressure in the nondominant transverse sinus before and after clipping and while monitoring the somatosensory evoked potentials. The occipital lobe cortex and cerebellum were retracted slightly along the tentorium. Deep veins of the galenic system, the quadrigeminal area, and the tumor were well exposed. Before it was used for tumor resection the approach was studied in five cadaveric head specimens, and the projection of different approaches was compared radiologically.

The tumors were removed in a gross-total manner in all patients, and none of the major veins of the galenic system was injured. Resuturing of the nondominant transverse sinus was performed postoperatively in one patient. One of the six patients experienced transient visual loss, and another suffered mild right sixth cranial nerve paresis; however, both recovered in 3 weeks. The wide exposure of the combined approach was also confirmed on radiological and anatomical studies.

Conclusions

The combined supra/infratentorial-transsinus approach is preferred for the resection of certain large pineal region tumors.

Pineal region tumors and the role of stereotactic biopsy: review of the mortality, morbidity, and diagnostic rates in 370 cases

OBJECTIVE

It is classically considered that the morbidity and mortality rates are greater for stereotactic biopsies of pineal region tumors, compared with tumors in other regions. However, to date, the number of cases studied in the literature has been insufficient to evaluate these parameters and compare them with the morbidity and mortality rates for stereotactic biopsies of tumors located elsewhere.

METHODS

With the aim of evaluating these parameters, we reviewed 370 stereotactic biopsies of pineal region tumors, from 15 French neurosurgical centers. We statistically verified the absence of heterogeneity of the different French centers with regard to diagnostic, mortality, and morbidity rates. In contrast, statistical heterogeneity was clearly seen for the large stereotactic biopsy series (for all tumor locations) in the literature.

RESULTS

The mortality rate was 1.3% (5 patients of 370), and 3 patients suffered severe neurological complications. This study is the first to clearly demonstrate that the mortality, morbidity, and diagnostic rates for stereotactic biopsies are not different in the pineal region.

CONCLUSION

Our conclusion is that stereotactic biopsy must remain a main diagnostic modality for tumors of the pineal region.

Stereotactic management of lesions of the pineal region

OBJECTIVE

The relevance of the computed tomography-guided stereotactic approach for the management of lesions of the pineal region is analyzed.

METHODS

In a retrospective analysis conducted between 1985 and 1993, the risk profile, the diagnostic accuracy, and the therapeutic relevance of the stereotactic approach in 106 patients was studied. Survival analysis was used to assess the reliability of the stereotactically obtained diagnosis in terms of follow-up observation.

RESULTS

A histological diagnosis was obtained in 103 of the 106 patients. In three patients, a conclusive diagnosis could not be established because of intraoperative complications. One lesion was misdiagnosed as a pineocytoma instead of a pineoblastoma. Two of the 106 patients died; 9 patients experienced perioperative morbidity. In 38 patients, the stereotactic approach was also useful for therapy. Cyst aspiration and/or internal drainage was performed in 18 patients with symptomatic cystic lesions, and radiosurgical treatment with use of interstitial 125iodine was performed in 16 patients with low-grade tumors and in 4 patients with solitary metastases. In 12 patients, the obtained tissue diagnosis was the basis for deferring additional therapy. In 43 patients with germ-cell tumors, pineoblastomas, or malignant gliomas, a stereotactic biopsy was the starting point for additional radiotherapy/chemotherapy. Open tumor resection played a minor role (five patients).

CONCLUSION

The stereotactic approach to the pineal region is a relatively safe procedure in experienced hands. The diagnosis obtained by computed tomography-guided stereotactic biopsy is a valid basis for treatment decisions. Long-term follow-up observation of the benign lesions is necessary for a definite confirmation of diagnostic accuracy.

Intracranial germ-cell tumours--treatment results and residuals

There is only sparse information about the development of children after successful treatment for intracranial germ-cell tumours. Between January 1981 and June 1992, 26 children with intracranial germ-cell tumours were treated in the University Hospital Hamburg-Eppendorf. We report on treatment results, long standing residuals and the "quality of life" of these patients. The long-term event-free survival was 88% for the germinomas and 43% for the malignant teratomas. Of the patients 58% had no relevant functional neurological deficits and 37% had mild impairment. Only 1 patient with metastatic disease was severely handicapped. Six patients showed neuro-endocrine dysfunction. All of them had suprasellar/hypothalamic lesions and all received successful substitution therapy. As to neuropsychological functions, 53% of the patients had no or only mild disturbances. The most affected function was speed of information processing. Of the children 69% were able to proceed with their education at the same level as before therapy. The overall self-assessment revealed good results in 75% of the patients.

CONCLUSION

After surgical removal and radiation therapy long-term survival of intracranial germinomas amounts to 88%. Despite craniospinal axis radiation severe residuals are rare and a good quality of life is common. In malignant teratomas treatment regimens including chemotherapy are much less successful.

Treatment of nongerminomatous germ-cell tumors of the pineal region

Germ-cell tumors can be subdivided into germinoma, embryonal carcinoma, choriocarcinoma, endodermal sinus tumor (yolk-sac tumor), and teratoma. They are also distinguished by their production of secreted markers such as alpha-fetoprotein produced in endodermal sinus tumors and embryonal carcinoma or beta-human chorionic gonadotropin, produced by choriocarcinoma and embryonal carcinoma. Germinoma and teratoma produce none of the markers. Because it has been proposed that teratomas may differentiate from multipotent stem cells contained in embryonal carcinoma and are thus lineage related, the presence of markers indicates the presence of a nongerminomatous germ-cell tumor. Nongerminomatous germ-cell tumors are an invariably fatal subgroup within the pediatric pineal region germ-cell tumors. There is no effective, established therapeutic regimen. We report the treatment regimen for three children diagnosed with this highly aggressive tumor entity. The children were first given a course of chemotherapy with bleomycin, etoposide, and cisplatin. This resulted in the normalization of markers and the shrinkage of tumors. These were then removed by the infratentorial supracerebellar approach. Removal was followed by a second course of chemotherapy with vinblastine, ifosfamide, and cisplatin; after which the children underwent radiotherapy. All three children are well and without evidence of residual or recurrent disease 20, 30, and 32 months after surgery, respectively. We propose this therapy regimen for children in whom the markers are positive.