Chordomas and Chondrosarcomas of the Cranial Base: Results and Follow-up of 60 Patients

Management of Chordoma and Chondrosarcoma with Fractionated Stereotactic Radiotherapy

OBJECTIVE

To evaluate the efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) for chordoma and chondrosarcoma.

METHODS

Twenty consecutive patients with a histopathologic diagnosis of chordoma (n = 16) or chondrosarcoma (n = 4) treated between 2010 and 2016 were retrospectively identified. All patients underwent FSRT in five fractions to a median dose of 37.5 Gy (range: 25-40 Gy) and followed with serial magnetic resonance imaging. Overall survival (OS), local recurrence-free survival (LRFS), and event-free survival (EFS) were estimated using the Kaplan-Meier method.

RESULTS

With a median follow-up of 28 months after FSRT and 40 months after initial surgery, crude OS and LRFS were 90%. Nine patients (45%) reported grade 1-3 acute toxicity, and two patients (10%) experienced grade 4, 5 late toxicity. One patient previously treated with proton therapy died from radiation vasculopathy 9 months after FSRT. The use of FSRT for recurrent disease or in patients with prior radiation therapy was associated with significantly decreased EFS.

CONCLUSION

FSRT for chordoma and chondrosarcoma is associated with high rates of OS and local control. Although many patients experience acute toxicity, there is a low incidence of late toxicity or irreversible treatment related morbidity despite the frequency of prior radiotherapy in this population. FSRT is an effective adjuvant or salvage treatment for chordoma and chondrosarcoma.

Skull base chordomas: clinical outcome in a consecutive series of 45 patients with long-term follow-up and evaluation of clinical and biological prognostic factors

OBJECTIVE

Skull base chordomas (SBCs) are rare dysembryogenetic invasive tumors with a variable tendency for recurrence. According to previous studies, the recurrence rate seems to be affected by both clinical variables and tumor biological features. The authors present the results of treatment of SBCs in a large series of patients and investigate the role of 1p36 chromosomal region loss of heterozygosity (LOH) as a prognostic factor.

METHODS

Between 1990 and 2011, 45 patients were treated for SBCs. The mean follow-up was 76 months (range 1–240 months). An LOH analysis was performed in 27 cases. Survival analysis was performed to determine clinical and biological parameters correlating with clinical outcome.

RESULTS

The 5- and 10-year overall survival rates were 67% and 57%, respectively. Five- and 10-year progression-free survival rates were 58% and 44%, respectively. Multivariate analysis showed that extent of resection, adjuvant radiation therapy, and absence of rhinopharynx invasion were positive independent predictors of overall survival. The latter 2 variables and a younger patient age were positive independent predictors of progression-free survival. Twenty-one patients showed 1p36 LOH. All events of recurrence and death clustered in the group of patients with 1p36 LOH; however, this biological marker was not statistically significant on multivariate analysis.

CONCLUSIONS

Resection is the treatment of choice in primary and recurrent SBC. Patient age, rhinopharynx invasion at diagnosis, extent of tumor removal, and postoperative radiation therapy influence SBC prognosis. Genetic analysis, even while showing interesting results, did not reveal 1p36 LOH as an independent predictor of clinical outcome.

Intraoperative neurophysiological monitoring during endoscopic endonasal surgery for pediatric skull base tumors

OBJECT The aim of this study was to evaluate the value of intraoperative neurophysiological monitoring (IONM) using electromyography (EMG), brainstem auditory evoked potentials (BAEPs), and somatosensory evoked potentials (SSEPs) to predict and/or prevent postoperative neurological deficits in pediatric patients undergoing endoscopic endonasal surgery (EES) for skull base tumors. METHODS All consecutive pediatric patients with skull base tumors who underwent EES with at least 1 modality of IONM (BAEP, SSEP, and/or EMG) at our institution between 1999 and 2013 were retrospectively reviewed. Staged procedures and repeat procedures were identified and analyzed separately. To evaluate the diagnostic accuracy of significant free-run EMG activity, the prevalence of cranial nerve (CN) deficits and the sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS A total of 129 patients underwent 159 procedures; 6 patients had a total of 9 CN deficits. The incidences of CN deficits based on the total number of nerves monitored in the groups with and without significant free-run EMG activity were 9% and 1.5%, respectively. The incidences of CN deficits in the groups with 1 staged and more than 1 staged EES were 1.5% and 29%, respectively. The sensitivity, specificity, and negative predictive values (with 95% confidence intervals) of significant EMG to detect CN deficits in repeat procedures were 0.55 (0.22-0.84), 0.86 (0.79-0.9), and 0.97 (0.92-0.99), respectively. Two patients had significant changes in their BAEPs that were reversible with an increase in mean arterial pressure. CONCLUSIONS IONM can be applied effectively and reliably during EES in children. EMG monitoring is specific for detecting CN deficits and can be an effective guide for dissecting these procedures. Triggered EMG should be elicited intraoperatively to check the integrity of the CNs during and after tumor resection. Given the anatomical complexity of pediatric EES and the unique challenges encountered, multimodal IONM can be a valuable adjunct to these procedures.

Skull base chondrosarcoma radiosurgery: report of the North American Gamma Knife Consortium

OBJECT

Stereotactic radiosurgery (SRS) is a potentially important option for patients with skull base chondrosarcomas. The object of this study was to analyze the outcomes of SRS for chondrosarcoma patients who underwent this treatment as a part of multimodality management.

METHODS

Seven participating centers of the North American Gamma Knife Consortium (NAGKC) identified 46 patients who underwent SRS for skull base chondrosarcomas. Thirty-six patients had previously undergone tumor resections and 5 had been treated with fractionated radiation therapy (RT). The median tumor volume was 8.0 cm3 (range 0.9-28.2 cm3), and the median margin dose was 15 Gy (range 10.5-20 Gy). Kaplan-Meier analysis was used to calculate progression-free and overall survival rates.

RESULTS

At a median follow-up of 75 months after SRS, 8 patients were dead. The actuarial overall survival after SRS was 89% at 3 years, 86% at 5 years, and 76% at 10 years. Local tumor progression occurred in 10 patients. The rate of progression-free survival (PFS) after SRS was 88% at 3 years, 85% at 5 years, and 70% at 10 years. Prior RT was significantly associated with shorter PFS. Eight patients required salvage resection, and 3 patients (7%) developed adverse radiation effects. Cranial nerve deficits improved in 22 (56%) of the 39 patients who deficits before SRS. Clinical improvement after SRS was noted in patients with abducens nerve paralysis (61%), oculomotor nerve paralysis (50%), lower cranial nerve dysfunction (50%), optic neuropathy (43%), facial neuropathy (38%), trochlear nerve paralysis (33%), trigeminal neuropathy (12%), and hearing loss (10%).

CONCLUSIONS

Stereotactic radiosurgery for skull base chondrosarcomas is an important adjuvant option for the treatment of these rare tumors, as part of a team approach that includes initial surgical removal of symptomatic larger tumors.

Endoscopic endonasal resection of skull base chondrosarcomas: technique and early results

OBJECT

The authors of this study sought to report the technique and early clinical outcomes of a purely endonasal endoscopic approach for resection of petroclival chondrosarcomas.

METHODS

Between 2010 and 2014, 8 patients (4 men and 4 women) underwent endonasal endoscopic operations to resect petroclival chondrosarcomas at 2 institutions. The patients' mean age was 44.8 years (range 30-64 years). One of the patients had previously undergone radiation therapy and another a staged craniotomy. Using volumetric software, an independent neuroradiologist assessed the extent of the resections on MRI scans taken immediately after surgery and at the 3-month follow-up. Immediate complications and control of symptoms were also recorded. In addition, the authors reviewed the current literature on surgical treatment of chondrosarcoma.

RESULTS

The mean preoperative tumor diameter and volume were 3.4 cm and 9.8 cm(3), respectively. Six patients presented with cranial neuropathies. Endonasal endoscopic surgery achieved > 95% resection in 5 of the 8 patients and < 95% resection in the remaining 3 patients. One of the 6 neuropathies resolved, and the remaining 5 partially improved. One instance of postoperative CSF leakage required a reoperation for repair; no other complications associated with these operations were observed. All of the patients underwent adjuvant radiotherapy.

CONCLUSIONS

According to the authors' experience, the endoscopic endonasal route is a safe and effective approach for the resection of appropriately selected petroclival chondrosarcomas.

A panoramic view of the skull base: systematic review of open and endoscopic endonasal approaches to four tumors

Endoscopic endonasal surgery has been established as the safest approach to pituitary tumors, yet its role in other common skull base lesions has not been established. To answer this question, we carried out a systematic review of reported series of open and endoscopic endonasal approaches to four major skull base tumors: olfactory groove meningiomas (OGM), tuberculum sellae meningiomas (TSM), craniopharyngiomas (CRA), and clival chordomas (CHO). Data from 162 studies containing 5,701 patients were combined and compared for differences in perioperative mortality, gross total resection (GTR), cerebrospinal fluid (CSF) leak, neurological morbidity, post-operative visual function, post-operative anosmia, post-operative diabetes insipidus (DI), and post-operative obesity/hyperphagia. Weighted average rates for each outcome were calculated using relative study size. Our findings indicate similar rates of GTR and perioperative mortality between open and endoscopic approaches for all tumor types. CSF leak was increased after endoscopic surgery. Visual function symptoms were more likely to improve after endoscopic surgery for TSM, CRA, and CHO. Post-operative DI and obesity/hyperphagia were significantly increased after open resection in CRA. Recurrence rates per 1,000 patient-years of follow-up were higher in endoscopy for OGM, TSM, and CHO. Trends for open and endoscopic surgery suggested modest improvement in all outcomes over time. Our observations suggest that endonasal endoscopy is a safe alternative to craniotomy and may be preferred for certain tumor types. However, endoscopic surgery is associated with higher rates of CSF leak, and possibly increased recurrence rates. Prospective study with long-term follow-up is required to verify these preliminary observations.

Defining the “edge of the envelope”: patient selection in treating complex sellar-based neoplasms via transsphenoidal versus open craniotomy

Object

Endonasal approaches have become the gold standard intervention for many anterior and middle skull base tumors. The authors aimed to define some of the existing limitations of these approaches by reviewing their experience with complex sellar region tumors that were initially considered for both transsphenoidal and open skull base approaches and were thus deemed tumors at “the edge of the envelope.”

Methods

Between April 2008 and April 2010, 250 transsphenoidal operations were performed at Brigham and Women's Hospital. All cases were retrospectively reviewed to identify patients with complex sellar region tumors that were initially considered for, or soon thereafter required, an open craniotomy as the definitive treatment. The anatomical tumor characteristics that posed limitations to performing safe and effective endonasal skull base operations were reviewed.

Results

Thirteen cases exemplifying some of the existing limitations to achieving optimal surgical outcomes via transsphenoidal-based approaches are presented. The following 8 factors are separately discussed that repeatedly limited the extent of resection, increased the risk of the operation, and contributed to perioperative complications: significant suprasellar extension, lateral extension, retrosellar extension, brain invasion with edema, firm tumor consistency, involvement or vasospasm of the arteries of the circle of Willis, and encasement of the optic apparatus or invasion of the optic foramina.

Conclusions

Although the ability to approach and resect complex tumors using endonasal skull base techniques has evolved dramatically in recent years, several inherent tumor characteristics mandate extensive preoperative consideration. In selected cases these characteristics may lend support to selecting an open craniotomy as the initial operation.

Endoscopic endonasal transclival resection of chordomas: operative technique, clinical outcome, and review of the literature

OBJECT

Transcranial approaches to clival chordomas provide a circuitous route to the site of origin of the tumor often involving extensive bone drilling and brain retraction, which places critical neurovascular structures between the surgeon and pathology. For certain chordomas, the endonasal endoscopic transclival approach is a novel minimal access, but it is an equally aggressive alternative providing the most direct route to the tumor epicenter.

METHODS

The authors present a consecutive series of patients undergoing endonasal endoscopic resection of clival chordomas. Extent of resection was determined by postoperative volumetric MR imaging and divided into > 95% and < 95%.

RESULTS

Seven patients underwent 10 operations. Preoperative cranial neuropathies were present in 4. The mean patient age was 52.0 years. The mean tumor volume was 34.9 cm3. Intraoperative lumbar drainage was used in 1 patient, and the tumors extended intradurally in 3. One patient underwent 2 intentionally palliative procedures for subtotal debulking. Greater than 95% resection was achieved in 7 of 8 operations in which radical resection was the goal (87%). All tumors with volumes < 50 cm3 had > 95% resection (p = 0.05). The overall mean follow-up was 18.0 months. Cranial neuropathies resolved in all 3 patients with cranial nerve VI palsies. One patient with recurrent nasopharyngeal chordoma died of disease progression; another experienced 2 recurrences before receiving radiation therapy. All surviving patients remain progression free. There were no intraoperative complications; however, 1 patient developed a pulmonary embolus postoperatively. There were no postoperative CSF leaks.

CONCLUSIONS

The endonasal endoscopic transclival approach represents a less invasive and more direct approach than a transcranial approach to treat certain moderate-sized midline skull base chordomas. Longer follow-up is necessary to determine comparability to transcranial approaches for long-term control. Large tumors with significant extension lateral to the carotid artery may not be suitable for this approach.

Surgery for clival lesions: open resection versus the expanded endoscopic endonasal approach

OBJECT

Clival lesions pose significant challenges with regard to their surgical management. The expanded endoscopic endonasal (EEE) approach is a promising minimally invasive technique for lesions of the central skull base. The authors' aim in the current paper was to discuss the surgical treatment of clival lesions and to present the technical details, indications, and limitations of the EEE approach. Data from a recent endoscopically treated group will be compared with findings in a previous cohort of patients treated via classic open anterior and lateral approaches.

METHODS

Since June 2005, 17 patients with clival lesions underwent surgery via the EEE approach. Suitable candidates were chosen according to lesion characteristics, clinical parameters, and surgical goals. Neurological outcomes, Karnofsky Performance Scale scores, the extent of lesion resection, and complications were evaluated among these patients. Eighteen percent of the patients in the endoscopic group presented with recurrent disease. Another series of 43 patients, who had undergone resection of clival lesions via an anterior (rhinotomy, maxillectomy, microscopic transsphenoidal surgery, or transoral surgery) or lateral (pterional, frontoorbitozygomatic, or combined suprainfratentorial retrosigmoid) approach, was similarly reviewed. Twenty-three of these patients (53%) presented with recurrent disease and thus had undergone prior surgery.

RESULTS

Following the EEE approach, 11 (79%) of 14 patients who had presented with neurological symptoms experienced improvement, and gross-total resection was achieved in 59% of the patients and subtotal removal in 41%. Complications included CSF leakage (24%), tension pneumocephalus (6%), and intracranial hematoma (6%). The patient with the latter complication was the only one who experienced permanent neurological worsening. In the open resection group, neurological worsening occurred in 33% of the patients (14 of 43). Total and grosstotal removals were achieved in 84% of patients and subtotal removal in 14%.

CONCLUSIONS

The EEE approach has been shown to be a safe and effective technique for the resection of clival lesions with limited lateral extension. The choice of surgical approach must be tailored according to both patient and tumor characteristics. Although the 2 patient series featured in this paper are not comparable-because of a selection bias-higher rates of neurological morbidity and total and gross-total resections were observed in the open resection group. Given the long survival of some patients, the EEE approach should be favored whenever reasonable.

Impact of cytogenetic abnormalities on the management of skull base chordomas

Object

Cytogenetic studies of chordomas are scarce and show multiple changes involving different chromosomes. These abnormalities are implicated in the pathogenesis of chordoma, but the clinical significance of these changes is yet to be determined. In this study, the authors discuss the cytogenetic changes in a large series of skull base chordomas with long-term follow-up and focus on the impact of these changes on the prognosis, progression, and management of the disease.

Methods

The karyotypes of chordomas in 64 patients (36 men and 28 women) were studied in relation to survival and recurrence or progression over a mean follow-up period of 48 ± 37.5 months. The standard G-banding technique was used for karyotype analysis. Statistical analysis was performed with the Fisher exact test and ORs, and Kaplan-Meier curves were generated for survival and recurrence/progression of disease.

Results

Seventy-four percent of de novo chordomas had normal karyotypes and a 3% recurrence rate; there was a 45% recurrence rate in de novo tumors with abnormal karyotypes (p < 0.01). Recurrent tumors were associated with a high incidence of abnormal karyotype (75%). The OR for recurrence in lesions with an abnormal versus a normal karyotype was 12. Aberrations in chromosomes 3, 4, 12, 13, and 14 were associated with frequent recurrence and decreased survival time. Ninety-five percent of cases with progression involved chromosome 3 and/or 13. The median survival time was 4 months when both of these chromosomes had aberrations (p = 0.02).

Conclusions

Chordomas with normal karyotypes were associated with a low rate of recurrence and a long patient survival, and recurrent chordomas were associated with an abnormal karyotype, disease progression, and poor survival. De novo chordomas with normal karyotypes may be amenable to radical resection and adjunctive proton beam therapy. Recurrent and de novo chordomas with abnormal karyotypes were associated with complex cytogenetic abnormalities and a poor prognosis, particularly in the presence of aberrations underlying tumor progression in chromosomes 3, 4, 12, 13, and 14.

Endoscopic endonasal surgery for clival chordoma and chondrosarcoma

BACKGROUND

Conventional microsurgical approaches are limited to exposing the lateral and bilateral regions because of surgical trauma. Total removal of clival chordoma and chondrosarcoma is very difficult. This study was undertaken to determine the potential role of an endoscopic endonasal approach in improved management of clival chordoma and chondrosarcoma.

METHODS

Seven patients with chordoma and 2 patients with chondrosarcoma treated by endoscopic endonasal surgery between November 2002 and February 2006 were studied prospectively. The mean age was 35 years. The follow-up periods ranged from 3 to 39 months.

RESULTS

Total removal was achieved in 6 cases of chordoma and 1 case of chondrosarcoma, with subtotal removal in 1 case of chordoma and of chondrosarcoma. At the last follow-up, 7 patients had no evidence of disease and 1 was alive with disease. The chordomas had recurred in 1 patient after 5 months with subtotal removal.

CONCLUSION

The use of nasoendoscopy to perform clival chordoma and chondrosarcoma surgery is not limited to merely the minimally invasive aspects. It provides better visualization of the deeper anatomical structures in the skull base and affords a means to 'look around corners'. This approach promises a simple and rapid access to the clivus. It is both a safe and efficient procedure.

Radiosurgery for chordomas and chondrosarcomas of the skull base

OBJECT

Chordomas and chondrosarcomas of the skull base are aggressive and locally destructive tumors with a high tendency for local progression despite treatment. The authors evaluated the effect of stereotactic radiosurgery (SRS) on local tumor control and survival.

METHODS

Twenty-eight patients with histologically confirmed chordomas (18) or chondrosarcomas (10) underwent Gamma Knife SRS either as primary or adjuvant treatment. Their ages ranged from 17 to 72 years (median 44 years). The most common presenting symptom was diplopia (26 patients, 93%). In two patients, SRS was the sole treatment. Twenty-six patients underwent between one and five additional surgical procedures. Two underwent an initial transsphenoidal biopsy. The average tumor volume was 9.8 cm3. The median dose to the tumor margin was 16 Gy.

RESULTS

No patient was lost to follow-up. Transient symptomatic adverse radiation effects developed in only one patient. The actuarial local tumor control for chondrosarcomas at 5 years was 80 +/- 10.1%. For chordomas both the actuarial tumor control and survival was 62.9 +/- 10.4%.

CONCLUSIONS

Stereotactic radiosurgery is an important option for skull base chordomas and chondrosarcomas either as primary or adjunctive treatment. Multimodal management appears crucial to improve tumor control in most patients.

Gamma Knife surgery for skull base chordomas and chondrosarcomas

Object

The purpose of this study was to evaluate radiosurgical outcomes in skull base chordomas and chondrosarcomas, and to determine which tumors are appropriate for stereotactic radiosurgery as adjuvant therapy following maximum tumor resection.

Methods

Thirty-seven patients (48 lesions) were treated using Gamma Knife surgery (GKS); 27 had chordomas, seven had chondrosarcomas, and three had radiologically diagnosed chordomas. The mean tumor volume was 20 ml, and the mean maximum and marginal doses were 28 and 14 Gy, respectively. The mean follow-up period was 97 months from diagnosis and 59 months from GKS.

Results

The actuarial 5- and 10-year survival rates after GKS were 80 and 53%, respectively. The actuarial 5- and 10-year local tumor control (LTC) rates after single or multiple GKS sessions were 76 and 67%, respectively. All patients with low-grade chondrosarcomas achieved good LTC. A tumor volume of less than 20 ml significantly affected the high rate of LTC (p = 0.0182). No patient had adverse radiation effects, other than one in whom facial numbness worsened despite successful tumor control.

Conclusions

As an adjuvant treatment after resection, GKS is a reasonable option for selected patients harboring skull base chordomas or chondrosarcomas with a residual tumor volume of less than 20 ml. Dose planning with a generous treatment volume to avoid marginal treatment failure should be made at a marginal dose of at least 15 Gy to achieve long-term tumor control.

Chordomas of the skull base: surgical management and outcome

OBJECT

The goal of this study was to report on the surgical management of skull base chordomas and to evaluate both the short- and long-term treatment outcomes.

METHODS

The authors retrospectively studied data from 49 patients who had undergone consecutive surgeries at a single institution. They also analyzed patterns of chordoma extension. Complications and surgery-related morbidity were recorded. A Kaplan-Meier analysis was performed to determine survival rates in patients 5 and 10 years after their first surgery. Operative approaches were selected on the basis of the predominant tumor extension.

RESULTS

The approach used most frequently was the transethmoidal in 36.3%, followed by the pterional in 23.4% and the retrosigmoid in 23.4%. The tumor was totally removed in 49.4% and subtotally in 50.6%. The rate of total removal was highest at initial surgery (78%) and progressively declined thereafter. In 11.8% of cases a new neurological deficit developed, while the preoperative deficit remained unchanged. In 20% of cases the preoperative deficits improved, but new deficits also appeared. The 5- and 10-year survival rates are 65 and 39%, respectively.

CONCLUSIONS

With an individually tailored surgical approach, total tumor removal in 78% of the cases was achieved at the initial surgery. Radical surgery appears to increase slightly the surgical morbidity, but at the same time prolongs the recurrence-free interval. Chordomas cannot be regarded as surgically curable tumors given the 5- and 10-year survival rates in patients harboring such lesions.

Sarcomatous transformation of clival chordoma after charged-particle radiotherapy

✓ Skull base chordomas containing a sarcomatous component are extremely rare. Here the authors report two new cases in which a recurrent tumor with a sarcomatous component appeared after the patient had undergone charged-particle radiotherapy. Histological examinations performed in Case 1 revealed some retention of epithelial features in the sarcomatous component, whereas no such regions were observed in Case 2. Both patients had rapidly deteriorating clinical courses and died within 6 months after diagnosis of the recurrent tumor. The authors discuss the significance of the histological subtypes of these tumors for long-term prognosis and their pathogenetic mechanisms in relation to radiotherapy. Although these sarcomatous transformations are rare in conventional chordomas, a careful histological examination and thorough follow-up imaging studies are crucial when treating patients with such lesions.

Management of malignant tumors of the anterior skull base: experience with 76 patients

As the management of anterior cranial fossa malignancies has undergone significant evolution, decreases in morbidity and mortality rates have occurred. In this article, the authors discuss the clinical presentation, neuroimaging findings, and management options for common anterior skull base malignancies. Also discussed are surgery-related indications and principles.

Chordomas of the skull base: follow-up review and prognostic factors

OBJECT

Chordomas are rare tumors that arise from the remnants of the notochord. Because of their deep location, local infiltrative nature, and involvement of surrounding bone, treatment of chordoma is a challenge. The authors analyze the data and prognostic factors obtained during the follow-up period (range 1-150 months, median 38 months) in 53 patients with craniocervical junction chordoma and 10 patients with chondrosarcoma.

METHODS

Several surgical approaches were used, and some tumor excisions required staged procedures. Survival was calculated according the Kaplan-Meier method. Statistical analysis was performed using the Fisher exact and Kruskal-Wallis tests. Radical/subtotal resection was achieved in 77.8% of the patients. The mortality rate during the follow-up period was 14.3%. In patients harboring chondrosarcoma better 5-year recurrence-free survival (RFS) rates were demonstrated than in those with chordoma (100% and 50.7%, respectively). Histological patterns (typical or chondroid chordoma) and patient age at onset of symptoms had no effect on the RFS rates. Radical/subtotal resections were associated with better RFS rates than partial resection. Adjuvant proton-beam radiotherapy was shown to increase the RFS rates compared with conventional radiotherapy (90.9% and 19.4%, respectively at 4 years posttreatment). Karyotypically abnormal tumors were associated with worst RFS rates as compared with karyotypically normal lesions (44.5% and 90.3%, respectively at 3 years). Cases of cranial nerve palsy, followed by CSF leakages were the most frequent postoperative complication. Permanent postoperative neurological deficit was observed in 28.6% of the patients.

CONCLUSIONS

A better prognosis was observed in patients with chondrosarcoma compared with those harboring chordoma. Histological pattern and the patient's age at symptom onset were not factors that influenced prognosis in cases of chordoma. Extensive resection and possibly adjuvant proton-beam radiotherapy provided better prognosis for these patients.

Suboccipital and cervical chordomas: radical resection with vertebral artery control

Object

Radical resection of chordomas seems to improve a patient's long-term prognosis. At the suboccipital and cervical levels, the vertebral artery (VA) is often considered as a limit in surgical possibilities. The authors report on the management of the VA in a series of 36 patients with chordomas located in the cervical region.

Methods

Over an 11-year period, 36 patients with chordomas located at the suboccipital (28 patients) or cervical (eight patients) level were treated in the authors' neurosurgical department. In 30 patients, the tumors extended laterally toward the VA and required surgical control of the VA. Sixteen of these 30 patients harbored primary tumor, whereas 14 were treated for recurrent disease.

The VA was encased in the tumor in 23 patients, with stenosis in six cases. A balloon occlusion test was performed in seven patients and the VA was resected in four. Extensive resection, via a lateral approach on one (22 cases) or on both (eight cases) sides, did not cause any permanent postoperative deficits. In five patients a complementary approach was performed: posterolateral in one and transoral in four. Spinal fixation was performed via the lateral approach (eight cases) or via a complementary posterior approach (five cases). All but two patients underwent radiotherapy, including 10 who underwent proton-beam radiotherapy.

Conclusions

Chordomas extending laterally to the VA can be radically resected via a lateral approach without causing significant morbidity. A complementary approach is often necessary. The best results are achieved in patients with primary compared with recurrent tumor.

Skull base chordomas: overview of disease, management options, and outcome

Cranial base chordomas are locally invasive tumors that, from a midline, clival location, extend in different directions and display various patterns of skull base invasion. Although histologically benign, their invasive nature makes true “oncological” resection virtually impossible to achieve in most cases, despite modern skull base surgical techniques. Moreover, because of the tumor's location and proximity to critical neural and vascular structures, surgery-related morbidity can be significant when an aggressive resection is undertaken. Cytoreductive surgery assumes a critical role in the management of these lesions. The choice of surgical approach and the extent of resection are dependent on several factors: location and extension of the tumor, the surgeon's philosophy and familiarity with a specific approach, and the patient's preexisting clinical status. Proton-beam radiotherapy seems to be effective as an adjunct to surgery in achieving local tumor control. The timing of radiation therapy, however, remains controversial. Gamma knife surgery has been proposed as an adjunctive therapy, but the limited experience and short follow-up periods do not permit formulation of meaningful conclusions at this time. Recurrences are common, although in a subset of patients prolonged disease-free survival is demonstrated.

Surgical seeding of chordomas

Object

Chordomas have a high propensity for local recurrence and progression, as well as for systemic and cerebrospinal fluid metastasis. The authors identified and analyzed a series of patients with chordomas, focusing on an underrecognized entity—surgical seeding.

Methods

In a retrospective analysis of 82 patients with chordomas treated over a 10-year period (1990–2000) the authors found six patients (7.3%) in whom surgical seeding had occurred. In five (83%) of these patients the primary tumor was located at the clivus. In one (17%) the tumor was present in the cervical region. There were two male (33%) and four female patients (67%) with a mean age of 34 years. The seeding sites, which were separate from the primary tumor, were located along the operative route or in the abdomen where fat was removed. The seeding was diagnosed 5 to 15 months after surgery (mean 12 months). One seeding site was present in five patients and 17 seeding sites were present in one patient. The involved tissues included mucosa, bone, dura, muscle, and fat. After resection, all seedings were documented histologically.

Conclusions

Seeding of chordomas occurs along the operative route and at distant locations where fat is harvested. Early diagnosis and aggressive surgical treatment are recommended. Based on the results of this study, it is suggested that surgical techniques, postoperative irradiation, the neuroradiological follow-up protocol, and even research on chordomas should be reevaluated.

Transmandibular, circumglossal, retropharyngeal approach for chordomas of the clivus and upper cervical spine

Extensive clival tumors that involve both the midline and lateral skull base compartments, or those that extend inferiorly to the anterior cervical spine, are difficult to expose in a wide fashion using any of the transmaxillary, transoral, or transcervical routes. In the transmandibular, circumglossal, retropharyngeal (TCR) approach wide access of this region can be obtained, thus allowing for a more complete resection of tumor and infiltrated bone. It also provides for an improved ability to perform dural reconstruction, should it be necessary. Over the past 4 years four patients with extensive clival chordomas underwent resection via the TCR approach. Gross-total resection was achieved in two patients, a greater than 98% resection in one patient, and a greater than 95% resection in the fourth patient. The surgical technique, all approach-related complications and morbidity, and patient outcome are discussed. If an expanded exposure of the clivus is necessary, the TCR approach is a good choice as well as a useful surgical technique to have available.

Stereotactic radiosurgery and hypofractionated stereotactic radiotherapy for residual or recurrent cranial base and cervical chordomas

Object

In patients with chordomas the lesions often recur. Furthermore, the location of some chordomas within the base of the skull and the cervical spine can prevent complete resection from being achieved. Previous series have shown that stereotactic radiosurgery can be used as a treatment for residual chordomas with good overall results. The authors review their experience in using linear accelerator (LINAC) stereotactic radiosurgery to treat patients with recurrent and/or residual cranial base and cervical chordomas.

Methods

Ten patients with chordomas (eight with cranial base and two with cervical lesions [below C-2]) underwent LINAC stereotactic radiosurgery. The mean patient age was 49 years (range 30–73 years). There were seven men and three women. Three patients had undergone one prior surgery, five had undergone two previous surgeries, and two had undergone three prior operations. The mean radiation dose was 19.4 Gy (range 18–24 Gy), and the maximum intratumoral dose averaged 27 Gy (range 24.1–33.1 Gy). The mean secondary collimator size was 14.4 mm (range 7.5–20 mm). The volume of the tumor treated ranged from 1.1 to 21.5 ml. In five patients a standard frame-based LINAC radiosurgery system was used, whereas in the other five the CyberKnife, a frameless image-guided LINAC radiosurgical system, was used. All patients were available for follow-up review, which averaged 4 years (range 1–9 years). Over the course of follow up, one chordoma (10%) was smaller in size, seven were stable, and two chordomas progressed (one in a patient who underwent reoperation and a second course of stereotactic radiosurgery, and the second in a patient who underwent reoperation alone). There were no new neurological deficits noted following radiosurgery in the eight of 10 patients in whom there was no tumor progression, and no patient developed radiation-induced necrosis.

Conclusions

Stereotactic radiosurgery can be used to treat patients with recurrent or residual chordomas with excellent tumor control rates. Longer follow-up review in larger series is warranted to confirm these findings.

Surgical approaches and strategies for skull base chordomas

Object

The management of chordomas involving the skull base continues to present a number of treatment-related problems. Recently, both radical resection and charged-particle irradiation or stereotactic radiosurgery have reportedly been found effective for tumor control and for promoting a better quality of life in patients. In this article the authors analyzed the outcomes in 17 patients with skull base chordomas who were surgically treated at Kobe University Hospital between 1972 and 2000.

Methods

Preoperative radiological examinations included magnetic resonance imaging, computerized tomography, angiography, and balloon occlusion test of the internal carotid artery. Among the various surgical approaches used to remove the tumor were the frontoorbitozygomatic, transmaxillary, transcondylar, transsphenoidal, and the transbasal. Total removal was achieved in two (12%), near-total removal in three (18%), subtotal removal in nine (52%), and partial removal in three patients (18%). Since 1990, chordomas have been radically resected via various skull base approaches; the combined total or near-total removal rate has been 80% in this period. Radical removal of the tumors has not led to an increased risk. At the final follow-up review (mean 59.5 month), 75% of the patients were still alive, and 25% had died of chordoma recurrence. The overall recurrence-free survival rate was 82% at 3 years and 51% at 5 years. The 5-year recurrence-free survival rate in the five patients who underwent the operation during the past decade was 77% (mean follow up of 5.2 years). In two patients with recurrent tumors who underwent radiosurgery, no evidence of tumor regrowth was demonstrated at 3 years posttreatment.

Conclusions

The authors suggest that for the treatment of skull base chordomas radical resection is a key factor for longer survival and improved quality of life. Patients with sufficiently small tumors, which show a favorable configuration and location, can be suitable candidates for stereotactic radiosurgery.