Malignant Skull Base Tumors Research Articles

Proton beam therapy for intracranial and skull base tumors

Radiotherapy is widely used for treating malignant and benign intracranial or skull base tumors because of the difficulty in performing wide or complete tumor resection due to the involvement of eloquent areas, vital vessels, or cranial nerves. Similarly, local radiotherapy with conventional methods may sometimes be inefficient for treating brain tumors because the tolerance doses for the optic nerves, eyes, and brainstem are strictly limited. Under the circumstances, particle radiotherapy with proton or carbon ion beams has excellent dose localization to the target volume owing to the sharp Bragg peak ionization in the human body. With this property, it is possible to deliver higher doses to tumors of various shapes while preserving the surrounding critical brain structures. Although the efficacy of proton beam therapy (PBT) has been suggested for skull base chordoma and unresectable meningioma, further clinical evidence is required for optimization and standardization of the therapy. In refractory tumors such as glioblastoma multiforme and anaplastic meningioma, it is necessary to deliver high doses to improve tumor control. Under these circumstances, protons or carbon ions have potential to deliver sufficient doses to the target while keeping the healthy brain intact. In this context, we focus on the current status of proton beam radiotherapy for treating intracranial and skull base tumors.

Pediatric bypasses for aneurysms and skull base tumors: short- and long-term outcomes

Object Cerebral bypass is a useful microsurgical technique for the treatment of unclippable aneurysms and invasive skull base tumors. The authors present the largest reported series of cerebrovascular bypasses in the pediatric population. They describe the short- and long-term clinical and radiographic outcomes of extracranial-intracranial and local bypasses performed for complex cerebral aneurysms and recurrent, invasive, and malignant skull base tumors in pediatric patients. Methods A consecutive series of 17 pediatric patients who underwent revascularization were analyzed retrospectively for indications, graft patency, and neurological outcomes. Results The mean age was 12 years (median 11 years, range 4–17 years), and there were 7 boys (41%) and 10 girls (59%). A total of 18 bypasses were performed in 17 patients and included 10 aneurysm cases (55.5%) and 8 tumor cases (45%). Of these 18 bypasses, there were 11 (61.1%) extracranial-intracranial bypasses (10 saphenous vein grafts [90%] and 1 radial artery graft [10%]), 1 side-to-side anastomosis (5.5%), 2 intracranial reimplants (11.1%), and 4 interposition bypass grafts (22.2%; 2 radial artery grafts, 1 saphenous vein graft, and 1 lingual artery graft). The mean clinical follow-up was 40.5 months (median 24 months, range 3–197 months). The mean radiographic follow-up was 40 months (median 15 months, range 9–197 months). Eighty-two percent of patients (14 of 17) achieved a modified Rankin Scale score between 0 and 2; however, 2 patients died of disease progression during long-term follow-up. The short-term (0- to 3-month) graft patency rate was 100%. Two patients had graft stenosis (11.7%) and underwent graft revisions. Two patients (11.1%) with giant middle cerebral artery aneurysms (> 25 mm) had strokes postoperatively but recovered without a persistent neurological deficit. One patient observed for 197 months showed a stable dysplastic change at the end of the graft. The long-term graft patency was 100% with a mean follow-up of 40 months. There were 2 deaths in the cohort during follow-up; both patients died of malignant tumors (osteogenic sarcoma and chondrosarcoma). Conclusions The authors conclude that in properly selected cases, bypasses can be safely performed in patients with aneurysms and skull base tumors. The bypasses remained patent over long periods of time despite the growth of the patients.

Transsphenoidal endoscopic skull base surgery: state of the art and future perspective

Abstract Given refinements in endoscopic image quality, instrumentation, surgical navigation, skull base closure techniques and anatomical understanding, the endonasal endoscopic approach is now a well-accepted and widely utilized technique for removal of many if not most midline ventral skull base tumors. Pituitary adenomas and Rathke’s cleft cysts (RCCs) constitute the majority of lesions removed via this route; however, craniopharyngiomas, clival chordomas, midline meningiomas and other benign and malignant skull base tumors are now increasingly removed by this approach. Herein we describe the evolution of the endonasal endoscopic technique, its current use for sellar and midline skull base tumors and potential for future innovation.

Double flap technique for reconstruction of anterior skull base defects after craniofacial tumor resection: technical note

Successful reconstruction of large anterior skull base (ASB) defects after craniofacial resection of malignant skull base tumors is paramount for preventing cerebrospinal fluid (CSF) fistulas. The vascularized pedicled pericranial flap (PCF) has been the gold standard for repairing ASB defects after transbasal transcranial approaches. However, flap necrosis and delayed CSF leaks can occur after adjuvant radiation therapy. We describe a "double flap" reconstruction technique in which the PCF is augmented inferiorly by a secondary vascularized pedicled nasoseptal flap (NSF) that is harvested and rotated using an endoscopic endonasal approach. This technique is illustrated in 2 patients who underwent a combined cranionasal (transbasal and endoscopic endonasal) approach for large sinonasal malignancies with significant intracranial extension (1 esthesioneuroblastoma, 1 sinonasal teratocarcinosarcoma). After tumor removal via a combined cranionasal approach, primary repair of the ASB dural defect was performed with a free patch graft. The ASB defect was then repaired using the double flap technique with a vascularized PCF from above and augmented with a vascularized NSF from below. Postoperatively, there were no complications of CSF leakage, meningitis, or tension pneumocephalus in both patients. After subsequent radiation therapy, the double flap repair remained intact at 2 years postoperatively in both patients. The double flap skull base reconstruction technique provides an additional barrier of vascularized tissue to prevent CSF leakage, meningitis, tension pneumocephalus, and postradiation necrosis. This technique is a viable option if a combined transcranial and transnasal endoscopic tumor resection is performed and postoperative radiation is anticipated.

Double Flap Technique for Reconstruction of Anterior Skull Base Defects after Craniofacial Tumor Resection

Background: Successful reconstruction of large anterior skull base (ASB) defects after craniofacial resection of malignant skull base tumors is paramount for preventing cerebrospinal fluid (CSF) fistulas. The vascularized pedicled pericranial flap has been the gold standard for repair. However, flap necrosis and delayed CSF leaks can occur after adjuvant radiation therapy. We describe a double flap repair, where the pericranial flap is augmented inferiorly by a secondary vascularized nasoseptal flap (NSF) that is harvested and rotated using an endonasal endoscopic approach. This technique is illustrated in two patients who underwent resection of large sinonasal/anterior skull base malignancies with significant intracranial extension.

Craniofacial resection for malignant tumors involving the skull base in the elderly

In this study by the International Collaborative Group, the authors examined a large cohort of patients accumulated from multiple institutions that had experience in craniofacial surgery with the objective of reporting outcomes and complications for craniofacial resection (CFR) in the elderly. One hundred seventy patients aged ≥70 years were included in the study. The median age was 75 years (range, 70-98 years). One hundred four patients (61%) had received previous single-modality or combined treatment, which included surgery in 79 patients (46%), radiation in 47 patients (28%), and chemotherapy in 13 patients (8%). The most common histology was squamous cell carcinoma (67 patients; 39%). The margins of resection were close or microscopically positive in 56 patients (33%). Sixty-eight patients received adjuvant radiotherapy (40%), and 3 patients received chemotherapy (2%). Complications were classified into overall, local, central nervous system (CNS), systemic, and orbital. Overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were determined by using the Kaplan-Meier method. Outcomes were compared with patients aged <70 years. Statistical analyses for outcomes were performed in relation to patient characteristics, tumor characteristics (including histology and extent of disease), surgical resection margins, previous radiation, and previous chemotherapy to determine predictive factors. Postoperative mortality occurred in 16 patients (9%), and postoperative complications occurred in 72 patients (42%). Local wound complications occurred in 40 patients (24%), CNS complications occurred in 24 patients (14%), systemic complications occurred in 19 patients (11%), and orbital complications occurred in 4 patients (2%). Postoperative mortality and complications were significantly more frequent in elderly patients compared with patients aged <70 years (postoperative mortality: 9% vs 3%; P = .04; complications: 42% vs 32%; P = .0009). The 5-year OS, DSS, and RFS rates were significantly poorer than those for patients aged <70 years (OS: 42% vs 56%; P < .0001; DSS: 53% vs 61%; P = .04; RFS: 46% vs 54%; P = .03). Surgical margin status and primary tumor histology were independent predictors of OS, DSS, and RFS in multivariate analysis. CFR for malignant skull base tumors in elderly patients (aged ≥70 years) was associated with increased mortality, complications, and poorer outcomes compared with patients aged <70 years.

“How Much Is Enough?” Endonasal Surgery for Olfactory Neuroblastoma

“How Much Is Enough?” Endonasal Surgery for Olfactory Neuroblastoma

Treatment of malignant tumors of the skull base with multi-session radiosurgery

ObjectiveMalignant tumors that involve the skull base pose significant challenges to the clinician because of the proximity of critical neurovascular structures and limited effectiveness of surgical resection without major morbidity. The purpose of this study was to evaluate the efficacy and safety of multi-session radiosurgery in patients with malignancies of the skull base.MethodsClinical and radiographic data for 37 patients treated with image-guided, multi-session radiosurgery between January 2002 and December 2007 were reviewed retrospectively. Lesions were classified according to involvement with the bones of the base of the skull and proximity to the cranial nerves.ResultsOur cohort consisted of 37 patients. Six patients with follow-up periods less than four weeks were eliminated from statistical consideration, thus leaving the data from 31 patients to be analyzed. The median follow-up was 37 weeks. Ten patients (32%) were alive at the end of the follow-up period. At last follow-up, or the time of death from systemic disease, tumor regression or stable local disease was observed in 23 lesions, representing an overall tumor control rate of 74%. For the remainder of lesions, the median time to progression was 24 weeks. The median progression-free survival was 230 weeks. The median overall survival was 39 weeks. In the absence of tumor progression, there were no cranial nerve, brainstem or vascular complications referable specifically to CyberKnife® radiosurgery.ConclusionOur experience suggests that multi-session radiosurgery for the treatment of malignant skull base tumors is comparable to other radiosurgical techniques in progression-free survival, local tumor control, and adverse effects.

First experience in 5-ALA fluorescence-guided and endoscopically assisted microsurgery of brain tumors

Abstract Background 5-Aminolevulinic acid (5-ALA) fluorescence-guided microsurgical resections have proved to be superior to conventional microsurgery of malignant brain tumors. New neuroendoscopes have recently become available which allow endoscopically assisted 5-ALA fluorescence-guided resections to be carried out during conventional microsurgery. A prospective randomized controlled phase I/II study was started in Burdenko Neurosurgical Institute at the end of 2007 in order to assess the feasibility and safety of this technique. The aim of this publication is to describe our first experience of applying this method. Materials and methods The primary tumor diagnosis included malignant glioma (WHO-grade IV), metastases (MTS) and malignant skull base tumors. A total of 17 patients were given 5-ALA prior to microsurgery of the brain tumor. Microsurgical resections were assisted by 5-ALA fluorescence-guided endoscopy using Karl Storz endoscopic equipment for the determination of tumor remnants in the resection cavity. Results The additional use of the endoscope was accepted by all surgeons as a feasible and straightforward procedure. In most cases surgeons acknowledged benefit from the possibility of controlling the “behind the border” regions of the resection cavity, i.e. thorough inspection of the entire surface of the resection cavity without any traction to brain tissue using the angled endoscope. Bright fluorescence was observed not only in gliomas grade IV, but also in three of four metastases, amongst them a single melanoma, a single case of pilocytic astrocytoma, and a single case of chordoma. Conclusions 5-ALA fluorescence-guided endoscopic assistance seems to be a feasible and beneficial technique. The use of 5-ALA fluorescence guidance may be extended to a number of brain tumors other than glioma grade IV. The technique is useful for distinguishing between normal brain and tumor tissue. No procedural or drug-related complications were observed.

Retrospective Study of Complications in Radical Surgery for Malignant Skull Base Tumors

Introduction: To evaluate the risk factors for postoperative complications among patients with malignant skull base tumors, a retrospective analysis of patients treated in Kobe University Graduate School of Medicine between January 2000 and January 2007 was conducted.

Standard Procedures for Malignant Skull Base Tumors: From Experience of 150 Patients

Introduction: Craniofacial en bloc resection and reconstruction has contributed to the improvement of long-term outcome of patients with malignant skull base tumors. In this presentation, we present our standard procedures for these malignant tumors.

The Evolving Role of Stereotactic Radiosurgery for Patients with Skull Base Tumors

Tumors located at the base of the skull are among the most difficult problems that neurosurgeons encounter. Management of patients with skull base tumors must take into account that complete tumor removal is not possible with acceptable morbidity in many patients. Therefore, radiation therapy and stereotactic radiosurgery are commonly performed. The use of radiosurgery for patients with skull base tumors has increased significantly over the past three decades and we now possess a better understanding of the expectations of skull base radiosurgery. For properly selected patients with benign tumors (meningiomas, schwannomas, glomus tumors), tumor control rates between 90 and 100% have been reported. Local control rates for chordomas and chondrosarcomas have ranged from 50 to 70%, but tumor growth adjacent to the treated area (marginal failure) remains a significant problem. Radiosurgery is also commonly performed for patients with malignant skull base tumors as a palliative treatment and symptom relief is common, especially for patients with facial pain related to their tumor. Follow-up beyond 10 years is still needed to better define long-term results of radiosurgery and the incidence of radiation-induced neoplasms after radiosurgery.

Craniofacial surgery for malignant skull base tumors: report of an international collaborative study.

Malignant tumors of the skull base are rare. Therefore, no single center treats enough patients to accumulate significant numbers for meaningful analysis of outcomes after craniofacial surgery (CFS). The current report was based on a large cohort that was analyzed retrospectively by an International Collaborative Study Group. One thousand three hundred seven patients who underwent CFS in 17 institutions were analyzable for outcome. The median age was 54 years (range, 1-98 years). Definitive treatment prior to CFS had been administered in 59% of patients and included radiotherapy in 367 patients (28%), chemotherapy in 151 patients (12%), and surgery in 523 patients (40%). The majority of tumors (87%) involved the anterior cranial fossa. Squamous cell carcinoma (29%) and adenocarcinoma (16%) were the most common histologic types. The margins of surgical resection were reported close/positive in 412 patients (32%). Adjuvant postoperative radiotherapy was received by 510 patients (39%), and chemotherapy was received by 57 patients (4%). Postoperative complications were reported in 433 patients (33%), with local wound complications the most common (18%). The postoperative mortality rate was 4%. With a median follow-up of 25 months, the 5-year overall, disease-specific, and recurrence-free survival rates were 54%, 60%, and 53%, respectively. The histology of the primary tumor, its intracranial extent, and the status of surgical margins were independent predictors of overall, disease-specific, and recurrence-free survival on multivariate analysis. CFS is a safe and effective treatment option for patients with malignant tumors of the skull base. The histology of the primary tumor, its intracranial extent, and the status of surgical margins are independent determinants of outcome.

Reconstruction of the skull base after tumor resection: an overview of methods

Successful surgical management of malignant skull base tumors depends on both tumor resection and reconstruction of the cranial base defect. The primary goals of skull base reconstruction are to repair dural defects, to prevent the development of cerebrospinal fluid fistulas, and to provide a protective barrier that isolates the intracranial contents from the nasopharynx and paranasal sinuses. Failure to do so can result in potentially life-threatening infectious complications. With modern skull base and reconstructive techniques, malignant tumors in this region, which were once deemed inoperable, can now be safely removed. The authors review the different modalities available for skull base reconstruction following tumor resection.

Complication avoidance in the treatment of malignant tumors of the skull base

The treatment of malignant skull base tumors has improved with the development of skull base surgical approaches that allow en bloc resection of a lesion and increase the efficacy of adjuvant therapies. The anatomical complexity of these lesions and their surroundings has led to a relatively high complication rate. Infection and cerebrospinal fluid fistulas are the most common serious procedure-related complications. They result from the frequent necessity of working in a contaminated space such as the paranasal sinuses as well as from the creation of large dural and skull base defects. The authors have reviewed the literature regarding complications of surgery for malignant skull base lesions and present several techniques and strategies for minimizing their incidence by performing the craniofacial approach to anterior skull base lesions.

The role of stereotactic radiosurgery in the treatment of malignant skull base tumors

To determine the efficacy and toxicity of stereotactic radiosurgery in the treatment of malignant skull base tumors. Thirty-two patients with 35 newly diagnosed or recurrent malignant skull base tumors < or = 33.5 cm3 were treated using the Leksell Gamma unit. Tumor histologies included: adenoid cystic carcinoma [12], basal cell carcinoma [1], chondrosarcoma [1], chordoma [8], nasopharyngeal carcinoma [3], osteogenic sarcoma [2], and squamous cell carcinoma [8]. After a median follow-up of 2.3 years, 83% +/- 15% (+/-95% confidence interval) of patients experienced a symptomatic response to treatment. Local control at the skull base was 95 +/- 9% at 2 years and 78 +/- 23% at 3 years. Local-regional control above the clavicles was 75 +/- 15% at 1 year and 51 +/- 20% at 2 years. Overall and cause specific survival were identical, 82 +/- 13% at 1 year, 76 +/- 14% at 2 years, and 72 +/- 16% at 3 years. One patient developed a radiation-induced optic neuropathy 12 months after radiosurgery. Stereotactic radiosurgery using the Leksell Gamma Unit can provide durable tumor control and symptomatic relief with acceptable toxicity in the majority of patients with malignant tumors 4 cm or less in size involving the skull base. Further evaluation of more patients with longer follow-up is warranted.

P-5-646 - Treatment of malignant skull base tumors

P-5-646 - Treatment of malignant skull base tumors

Cranial base surgery: Results in 183 patients

To learn about the effects of cranial base surgery. Cohort study with a mean follow-up of 30 months. Population-based. A consecutive sample of 183 patients who underwent cranial base surgery; 118 patients had malignant skull base tumors, the majority of which were previously treated; 50 had benign tumors; 9 had congenital malformations of the skull base; 3 had inflammatory lesions, and 3 had traumatic defects of the skull base. Disease-free interval, overall survival, and rate of complications and functional status. Cranial base surgery was followed by radiotherapy (in previously untreated patients). After completion of follow-up (mean, 30 months), 30 (25.4%) patients had died of their malignant tumors and 8 (6.8%) had died of other causes. One patient (0.84%) was lost to follow-up. The overall cancer survival rate without regard to histologic type was 67% (63% with no evidence of disease). Among the patients who were treated for benign neoplasm, 72% had no evidence of disease at a mean follow-up of 39 months. The group of patients with congenital malformations and inflammatory and traumatic lesions demonstrated successful correction of their presurgical problem with skull base surgery. One patient (who had invasive aspergillosis) died of disease. The overall surgical-medical mortality rate was 2%; the complication rate was 33%, and the Karnofsky performance score was improved or unchanged after surgery in 83% of patients. The average duration of surgery, number of blood transfusions used, and length of the hospital stay were 10 hours, 3 units, and 15 days, respectively. Cranial base surgery is a valid surgical technique for treatment of cranial base afflictions. In this study it was found to be beneficial in controlling benign and malignant disease and to be the treatment of choice for selected congenital malformations, trauma, and inflammatory lesions.

Cranial base surgery. Results in 183 patients

To learn about the effects of cranial base surgery. Cohort study with a mean follow-up of 30 months. Population-based. A consecutive sample of 183 patients who underwent cranial base surgery; 118 patients had malignant skull base tumors, majority were previously treated; 50 had benign tumors, 9 patients had congenital malformations of the skull base; 3 patients had inflammatory lesions, and 3 had traumatic defects of the skull base. Disease-free interval and overall survival as well as rate of complications and functional status Cranial base surgery was followed by radiotherapy (in previously untreated patients). After completion of follow-up (30 months, mean), 30 (25.4%) patients had died of their malignant tumors and 8 (6.8%) had died of other causes. One patient (0.84%) was lost to follow-up. The overall cancer survival without regard to histologic type was 67% (63% with no evidence of disease). Among the patients who were treated for benign neoplasm 72% were NED at a mean 39 months of follow-up. The group of patients with congenital malformations, inflammatory, and traumatic lesions demonstrated successful correction of their pre-surgical problem with skull base surgery. One patient (invasive aspergillosis) died of disease. The overall surgical/medical mortality was 2%, complication rate was 33% and Karnofsky performance scale was improved or unchanged postoperatively in 83% of patients. The average duration of surgery, number of blood transfusions used and the length of the hospital stay was 10 hours, 3 units, and 15 days respectively. Cranial base surgery is a valid surgical technique for cranial base afflictions. In this study it was found to be beneficial in controlling benign as well as malignant disease and be the treatment of choice in selected congenital malformations, trauma, and inflammatory lesions.

Pediatric Skull, Skull Base, and Meningeal Tumors

Calvarial neoplastic and non-neoplastic tumors are routinely encountered by all neurosurgeons. Benign and malignant skull base and meningeal tumors are relatively rare lesions in children. Interdisciplinary approaches to those tumors more frequently encountered in the pediatric population in these locations are discussed. Unique aspects of the diagnosis, treatment, and prognosis for infants and children are discussed.