A multidisciplinary team approach to skull base chordomas

Spontaneous Shrinking and Growing Skull Base Chordoma

Background

Chordomas are rare slow-growing tumors occurring in the axial skeleton and can demonstrate local aggressive behavior, typically extending from the median axis, compressing surrounding tissue. Complete surgical resection and adjuvant radiotherapy are the preferred treatments. We present an unusual case of a spontaneously shrinking and growing off-midline petroclival chordoma.

Case Description

A 23-year-old woman presented with right abducens nerve palsy. Computed tomography and magnetic resonance imaging (MRI) revealed an off-midline petroclival lesion compressing the abducens nerve with characteristics of a chondrosarcoma. Preoperative MRI indicated spontaneous lesion regression, and the abducens nerve showed clinical improvement. Hence, the planned surgery was canceled. During the wait-and-scan period, abducens nerve palsy recurred. MRI confirmed lesion growth and showed an intratumoral linear structure indicative of blood. Even though preoperative MRI again demonstrated shrinkage, the lesion was surgically removed. Despite the unusual presentation, histopathological examination diagnosed a conventional chordoma. A second surgery was required to remove the residual tumor, after which the patient received high-dose photon beam therapy.

Conclusion

This article discusses the uncommon presentation and behavior of a petroclival chordoma, showing fluctuating cycles of off-midline growth and spontaneous regression. While intratumoral hemorrhage is hypothesized to explain this tumor behavior, the exact etiology needs further investigation. The case presented here emphasizes the importance of considering chordoma in the differential diagnosis despite an atypical disease course.

Proteogenomic characterization of skull-base chordoma

Skull-base chordoma is a rare, aggressive bone cancer with a high recurrence rate. Despite advances in genomic studies, its molecular characteristics and effective therapies remain unknown. Here, we conduct integrative genomics, transcriptomics, proteomics, and phosphoproteomics analyses of 187 skull-base chordoma tumors. In our study, chromosome instability is identified as a prognostic predictor and potential therapeutic target. Multi-omics data reveals downstream effects of chromosome instability, with RPRD1B as a putative target for radiotherapy-resistant patients. Chromosome 1q gain, associated with chromosome instability and upregulated mitochondrial functions, lead to poorer clinical outcomes. Immune subtyping identify an immune cold subtype linked to chromosome 9p/10q loss and immune evasion. Proteomics-based classification reveals subtypes (P-II and P-III) with high chromosome instability and immune cold features, with P-II tumors showing increased invasiveness. These findings, confirmed in 17 paired samples, provide insights into the biology and treatment of skull-base chordoma.

Assessing survival outcomes and complication profiles following surgical excision and radiotherapy as interventions for skull base chordoma: a systematic review of operative margins and surgical approaches

INTRODUCTION

Despite their precarious behavioral classification (benign and low grade on histopathology yet behaviorally malignant), great strides have been taken to improve prognostication and treatment paradigms for patients with skull base chordoma. With respect to surgical techniques, lateral transcranial (TC) approaches have traditionally been used, however endoscopic endonasal approaches (EEA) have been advocated for midline lesions. Nonetheless, due to the rarity of this pathology (0.2% of all intracranial neoplasms), investigations within the literature remain limited to small retrospective series. Furthermore, radiotherapeutic treatments investigated to date have proven largely ineffective.

METHODS

Accordingly, we performed a systematic review in order to profile surgical and survival outcomes for skull base chordoma. Fixed and random-effect meta-analyses were performed for categorical variables including GTR, STR, 5-year OS, 10-year OS, 5-year PFS, and 10-year PFS. Additionally, we pooled eligible studies for formal meta-analysis to compare outcomes by surgical approach (lateral versus midline). Statistical analyses were performed using R Studio 'metafor' package or Cochrane Review Manager. Furthermore, meta-analysis of pooled mortality rates and sub-analyses of operative margin and surgical complications were used to compare midline versus lateral approaches via the Mantel-Haenszel method. We considered all p-values < 0.05 to be statistically significant.

RESULTS

Following the systematic search and screen, 55 studies published between 1993 and 2022 reporting data for 2453 patients remained eligible for analysis. Sex distribution was comparable between males and females, with a slight predominance of male-identifying patients (0.5625 [95% CI: 0.5418; 0.3909]). Average age at diagnosis was 42.4 ± 12.5 years, while average age of treatment initiation was 43.0 ± 10.6 years. Overall, I2 value indicated notable heterogeneity across the 55 studies [I2 = 56.3% (95%CI: 44.0%; 65.9%)]. With respect to operative margins, the rate of GTR was 0.3323 [95% CI: 0.2824; 0.3909], I2 = 91.9% [95% CI: 90.2%; 93.4%], while the rate of STR was significantly higher at 0.5167 [95% CI: 0.4596; 0.5808], I2 = 93.1% [95% CI: 91.6%; 94.4%]. The most common complication was CSF leak (5.4%). In terms of survival outcomes, 5-year OS rate was 0.7113 [95% CI: 0.6685; 0.7568], I2 = 91.9% [95% CI: 90.0%; 93.5%]. 10-year OS rate was 0.4957 [95% CI: 0.4230; 0.5809], I2 = 92.3% [95% CI: 89.2%; 94.4%], which was comparable to the 5-year PFS rate of 0.5054 [95% CI: 0.4394; 0.5813], I2 = 84.2% [95% CI: 77.6%; 88.8%] and 10-yr PFS rate of 0.4949 [95% CI: 0.4075; 0.6010], I2 = 14.9% [95% CI: 0.0%; 87.0%]. There were 55 reported deaths for a perioperative mortality rate of 2.5%. The relative risk for mortality in the midline group versus the lateral approach group did not indicate any substantial difference in survival according to laterality of approach (-0.93 [95% CI: -1.03, -0.97], I2 = 95%, (p < 0.001).

CONCLUSION

Overall, these results indicate good 5-year survival outcomes for patients with skull base chordoma; however, 10-year prognosis for skull base chordoma remains poor due to its radiotherapeutic resistance and high recurrence rate. Furthermore, mortality rates among patients undergoing midline versus lateral skull base approaches appear to be equivocal.

Long-Term Outcomes after Multimodal Treatment for Clival Chordoma: Efficacy of the Endonasal Transclival Approach with Early Adjuvant Radiation Therapy

This study investigates the long-term outcomes of clival chordoma patients treated with the endonasal transclival approach (ETCA) and early adjuvant radiation therapy. A retrospective review of 17 patients (2002-2013) showed a 10-year progression-free survival (PFS) rate of 67.4%, with the ETCA group showing fewer progressions and cranial neuropathies than those treated with combined approaches. The ETCA, a minimally invasive technique, provided a similar extent of resection compared to conventional skull-base approaches and enabled safe delivery of high-dose adjuvant radiotherapy. The findings suggest that ETCA is an effective treatment for centrally located clival chordomas.

Clival Chordomas in the Endoscopic Endonasal Era: Clinical Management, Outcomes, and Complications

BACKGROUND

Surgical management of skull base chordomas has changed significantly in the past 2 decades, most notably with use of the endoscopic endonasal approach (EEA), although high quality outcome data using these modern approaches remain scarce.

OBJECTIVE

To evaluate outcomes in a large series of patients treated by a single surgeon, using primarily the EEA.

METHODS

Between 2006 and 2020, 68 patients with skull base chordoma underwent resection using mostly the EEA. Complications, outcomes, and potential contributing factors were evaluated using Kaplan-Meier survival analysis and univariable and multivariable Cox proportional hazards models.

RESULTS

Overall 5-year survival was 76.3% (95% CI 61.5%-86.0%), and 5-year progression-free survival was 55.9% (95% CI 40.0%-69.0%). In multivariable analysis, radical resection was associated with significant reduction in risk of death (hazard ratio [HR] 0.04, 95% CI 0.005-0.33, P = .003) and disease progression (HR 0.05, 95% CI 0.01-0.18, P < .001). Better preoperative function status reduced risk of death (HR 0.42 per 10-point increase in Karnofsky Performance Scale, 95% CI 0.28-0.63, P < .001) and progression (HR 0.60 per 10-point increase in Karnofsky Performance Scale, 95% CI 0.45-0.78, P < .001). Localization at the clivus reduced risk of death (HR 0.02, 95% CI 0.002-0.15, P < .001) and progression (HR 0.24, 95% CI 0.09-0.68, P = .007) compared with tumors at the craniovertebral junction.

CONCLUSION

In multivariable analysis, overall survival and progression-free survival of chordoma resection was most positively affected by radical resection, better preoperative functional status, and tumor location at the clivus rather than craniovertebral junction.

Adjuvant stereotactic radiosurgery with or without postoperative fractionated radiation therapy in adults with skull base chordomas: a systematic review

OBJECTIVE

The objective of this retrospective study was to compare the survival of patients with biopsy-proven skull base chordoma who had undergone stereotactic radiosurgery (SRS) with versus without prior fractionated radiation therapy (RT).

METHODS

Relevant articles from database inception to September 2021 were retrieved from the PubMed, Scopus, Web of Science, and Cochrane databases for a systematic review of treatment protocols. Studies were included if they 1) involved adult patients (age ≥ 18 years) with histologically and radiologically confirmed chordomas located within the clival skull base region and treated with SRS; 2) reported data on clinical features, SRS protocols, and outcomes; and 3) were written in the English language. Studies were excluded if they 1) were literature reviews, case reports, technical notes, abstracts, or autopsy reports; 2) did not clearly differentiate the data of patients with chordomas from the data of patients with different tumors or the data of patients with chordomas in locations other than the skull base; or 3) lacked histological confirmation or treatment and outcome data. Extracted data included the following: study author and publication year, patient age and sex, symptoms, cranial nerve involvement, invaded structures, lesion size, treatment modality, surgical details, histopathological type, RT modality, SRS parameters, complications, postradiosurgery outcomes, complications, and survival outcomes.

RESULTS

After the selection process, 15 articles describing 130 patients met the study eligibility criteria, including 94 patients who had undergone postresection SRS (NoRT group) and 36 who had undergone postresection fractionated RT and subsequent SRS (RT group). The NoRT and RT groups were comparable in age (51.3 vs 47.4 years, respectively), sex (57.1% vs 58.3% male), tumor volume (9.5 vs 11.2 cm3), SRS treatment parameters (maximum dose: 35.4 vs 42.2 Gy, marginal dose: 19.6 vs 20.6 Gy, treatment isodose line: 60.2% vs 65.2%), and SRS adverse effects (10.9% vs 17.6%). For the entire cohort, the 3-, 5-, and 10-year progression-free survival (PFS) rates were 23%, 9%, and 3%, respectively, and the overall survival (OS) rates were 94%, 82%, and 76%, respectively. In the NoRT group, SRS was adjuvant treatment after resection in 38 patients (40.4%), salvage treatment for recurrent tumor treated with resection alone in 10 (10.6%), and not specified in 46 (48.9%). In the RT group, SRS was boost treatment in 9 patients (25.0%), salvage treatment after recurrence in 22 (61.1%), and not specified in 5 (13.9%). There was no difference between the two groups in terms of median PFS (24.0 months [Q1 34.0, Q3 15.0] vs 23.8 months [34.0, 18.0], respectively; p = 0.8) or median OS (293.0 months [not reached, 137.4] vs not reached [not reached, 48.0], respectively; p = 0.36). The adverse radiation effect rates were comparable between the groups (10.9% vs 17.6%, respectively; p = 0.4).

CONCLUSIONS

The role of SRS in the management of skull base chordomas is still evolving. This systematic literature review of biopsy-proven chordoma revealed that tumor control and survival rates for SRS alone after chordoma surgery were not inferior to those encountered after SRS plus fractionated RT.

Impact of Type of Treatment Center and Access to Care on Mortality and Survival for Skull Base Chordoma and Chondrosarcoma

Introduction In adults with skull base chordoma or chondrosarcoma, the impact of treatment center and access to care have not been well described in regard to perioperative mortality and survival.

Methods A query of the National Cancer Database (NCDB) and review of 1,102 adults—488 with chordomas and 614 with chondrosarcomas—was performed. The Kaplan–Meier's product limit method and chi-square analysis, respectively, assessed overall survival and 30-day (30D) and 90-day (90D) mortalities.

Results For 925 patients who had surgery and available mortality data, the 30D and 90D mortality rates were 0.9 and 1.5%. Lower education level (p = 0.0185) and treatment at a nonacademic facility (p = 0.016) were associated with increased risk of 90-day mortality. Median follow-up was 52 months and analysis was dichotomized by histology. For those with skull base chordoma, patients from a larger metro size (p = 0.002), age below the median 52 years (p ≤ 0.001), and private insurance (<0.001) were associated with prolonged survival, whereas for skull base chondrosarcoma, the factors were treatment at an academic medical center (p = 0.001), high-volume center (p = 0.007), age below the median 52 years (p ≤ 0.001), higher income (p = 0.043), higher education (p = 0.017), and private insurance (p ≤ 0.001). Comparing high-, medium-, and low-volume centers, high-volume centers were most likely to be academic, deliver radiotherapy, escalate doses >70 Gy, and utilize proton radiotherapy consistent across both disease subsets.

Conclusion Higher educational attainment and treatment at an academic facility were associated with decreased 90D mortality for patients with skull base chordoma and chondrosarcoma. For those with skull base chordoma, larger metro size, younger age, and private insurance were associated with prolonged survival; for those with chondrosarcoma, it was treatment at a high-volume or academic medical center, younger age, higher income or education, and private insurance.

Endoscope-assisted far-lateral transcondylar approach for craniocervical junction chordomas: a retrospective case series and cadaveric dissection

OBJECTIVE

Craniocervical junction (CCJ) chordomas are a neurosurgical challenge because of their deep localization, lateral extension, bone destruction, and tight relationship with the vertebral artery and lower cranial nerves. In this study, the authors present their surgical experience with the endoscope-assisted far-lateral transcondylar approach (EA-FLTA) for the treatment of CCJ chordomas, highlighting the advantages of this corridor and the integration of the endoscope to reach the anterior aspect and contralateral side of the CCJ and the possibility of performing occipitocervical fusion (OCF) during the same stage of surgery.

METHODS

Nine consecutive cases of CCJ chordomas treated with the EA-FLTA between 2013 and 2020 were retrospectively reviewed. Preoperative characteristics, surgical technique, postoperative results, and clinical outcome were analyzed. A cadaveric dissection was also performed to clarify the anatomical landmarks.

RESULTS

The male/female ratio was 1.25, and the median age was 36 years (range 14-53 years). In 6 patients (66.7%), the lesion showed a bilateral extension, and 7 patients (77.8%) had an intradural extension. The vertebral artery was encased in 5 patients. Gross-total resection was achieved in 5 patients (55.6%), near-total resection in 3 (33.3%), and subtotal resection 1 (11.1%). In 5 cases, the OCF was performed in the same stage after tumor removal. Neither approach-related complications nor complications related to tumor resection occurred. During follow-up (median 18 months, range 5-48 months), 1 patient, who had already undergone treatment and radiotherapy at another institution and had an aggressive tumor (Ki-67 index of 20%), showed tumor recurrence at 12 months.

CONCLUSIONS

The EA-FLTA provides a safe and effective corridor to resect extensive and complex CCJ chordomas, allowing the surgeon to reach the anterior, lateral, and posterior portions of the tumor, and to treat CCJ instability in a single stage.

Current Management and Image Review of Skull Base Chordoma: What the Radiologist Needs to Know

Chordomas of the skull-base are typically slow-growing, notochord-derived tumors that most commonly originate along the clivus. Skull base chordoma is treated with surgery and radiotherapy. Local recurrence approaches 50% at 10 years. Radiologists play a critical role in diagnosis, treatment planning, and follow-up. Surgeons and radiation oncologists rely on radiologists for pre-operative delineation of tumor and adjacent anatomy, identification of post-treatment changes and disease recurrence, and radiation treatment effects. This review provides an overview of clinical characteristics, surgical anatomy, indications for radiotherapy, identification of treatment complications, and patterns of disease recurrence for radiologists to provide value in the management of these lesions.

Revision surgery for incomplete resection or recurrence of cervical spine chordoma: a consecutive case series of 24 patients

PURPOSE

Chordomas are rare tumors with an annual incidence of approximately one per million. Chordomas rarely metastasize but show a high local recurrence rate. Therefore, these patients present a major clinical challenge, and there is a paucity of the literature regarding the outcome after revision surgery of cervical spine chordomas. Available studies suggest a significantly worse outcome in revision scenarios. The purpose of this study is to analyze the survival rate, and complications of patients that underwent revision surgery for local recurrence or incomplete resection of chordoma at the craniocervical junction or at the cervical spine.

METHODS

24 consecutive patients that underwent revision surgery for cervical spine chordoma remnants or recurrence at a single center were reviewed retrospectively. We analyzed patient-specific surgical treatment strategies, complications, and outcome. Kaplan-Meier estimator was used to analyze five-year overall survival.

RESULTS

Gross total resection was achieved in 17 cases. Seven patients developed dehiscence of the pharyngeal wall, being the most common long-term complication. No instability was observed. Postoperatively, four patients received proton beam radiotherapy and 12 patients had combined photon and proton beam radiotherapy. The five-year overall survival rate was 72.6%.

CONCLUSION

With thorough preoperative planning, appropriate surgical techniques, and the addition of adjuvant radiotherapy, results similar to those in primary surgery can be achieved.

The management of clival chordomas: an Italian multicentric study

OBJECTIVE

In the last 2 decades, the endoscopic endonasal approach in the treatment of clival chordomas has evolved to be a viable strategy to achieve maximal safe resection of this tumor. Here, the authors present a multicentric national study, intending to analyze the evolution of this approach over a 20-year time frame and its contribution in the treatment of clival chordomas.

METHODS

Clival chordoma cases surgically treated between 1999 and 2018 at 10 Italian neurosurgical departments were included in this retrospective study. Clinical, radiological, and surgical findings, adjuvant therapy, and outcomes were evaluated and compared according to classification in the treatment eras from 1999 to 2008 and from 2009 to 2018.

RESULTS

One hundred eighty-two surgical procedures were reviewed, with an increase in case load since 2009. The endoscopic endonasal transclival approach (EETA) was performed in 151 of 182 cases (83.0%) and other approaches were performed in 31 cases (17%). There was an increment in the use of EETA, neuronavigation, and Doppler ultrasound after 2008. The overall postoperative complication rate was 14.3% (26 of 182 cases) consisting of 9 CSF leaks (4.9%), 7 intracranial hemorrhages (3.8%), 5 cases of meningitis (2.7%), and 5 cerebral ischemic injuries (2.7%). Gross-total resection (GTR) was achieved in 93 of 182 cases (51.1%). Extent of resection (EOR) improved in the second era of the study. Signs and/or symptoms at presentation worsened in 27 cases (14.8%), and the Katz Index worsened in 10 cases (5.5%). Previous treatment, dural involvement, EETA, and intraoperative Doppler ultrasound correlated with GTR. Patients received adjuvant proton beam radiation in 115 of 182 cases (63.2%), which was administered more in the latter era. Five-year progression-free survival (PFS) and overall survival (OS) were 62.3% and 73.5%, respectively. GTR, EETA, proton beam therapy, and the chondroid subtype correlated with a better survival rate. The mean follow-up was 62 months.

CONCLUSIONS

Through multicentric data collection, this study encompasses the largest series in the literature of clival chordomas surgically treated through an EETA. An increase in the use of this approach was found among Italian neurosurgical departments together with an improved extent of resection over time. The satisfactory rate of GTR was marked by low surgical morbidity and the preservation of patient quality of life. Surgical outcome was reinforced, in terms of PFS and OS, by the use of proton beam therapy, which was increasingly performed along the period of study.

Gamma Knife Stereotactic Radiosurgery for the treatment of chordomas and chondrosarcomas

INTRODUCTION

Primary chordomas and chondrosarcomas of the skull base are difficult tumours to treat successfully. Despite advances in surgical techniques, a gross total resection is often impossible to achieve. In addition, some patients may be deemed unsuitable or not wish to undergo extensive surgery for these conditions. This study examines the role of Gamma Knife Stereotactic Radiosurgery (GKRS) in the treatment of these difficult cases.

METHODS

All patients harbouring either a chordoma or chondrosarcoma treated at the National Centre for Stereotactic Radiosurgery, Royal Hallamshire Hospital, Sheffield, UK, between 1985 and 2018, were reviewed with regard to their clinical presentations, pre- and post-treatment imaging, GKRS prescriptions and outcomes.

RESULTS

In total, 24 patients with a mean tumour volume of 13 cm³ in the chordoma group (n=15) and 12 cm³ in the chondrosarcoma group (n=9) underwent GKRS. The 5- and 10-year overall survival rates for the chordoma group were 67% and 53% respectively, while for the chondrosarcoma group, they were 78% at both time points. The tumour control rates at 5 and 10 years in the chordoma group were 67% and 49% and for the chondrosarcoma group 78% at both time points. Patients with tumour volumes of less than 7 cm³ before GKRS treatment demonstrated a statistically significant longer overall survival rate (p=0.03).

CONCLUSIONS

GKRS offers a comparable option to proton beam therapy for the treatment of these tumours. Early intervention for tumour volumes of less than 7 cm³ gives the best long-term survival rates.

Apparent diffusion coefficient as a prognostic factor in clival chordoma

Clival chordoma is a rare disease with high recurrence rates even after a combination of surgical resection and radiotherapy. Apparent diffusion coefficient (ADC) has been used to evaluate aggressive features of chordoma, but its utility for clival chordoma has not been explored specifically. In this study, the utility of preoperative ADC values was analyzed for predicting tumor progression and recurrence in patients with clival chordoma. Between 2012 and 2019, a total of 30 operated cases were analyzed with available preoperative ADC data. Receiver operating characteristic (ROC) analysis was used to obtain ADC cutoff values for predicting tumor aggressiveness. The mean and minimum ADC values were significantly lower in the aggressive tumor group than in the stable tumor group (both P < 0.001). ROC analysis showed that a mean cutoff ADC value of 1198 × 10⁻⁶ mm²/s and minimum ADC value of 895.5 × 10^–6 mm²/s could be used to predict aggressive features of clival chordoma. Subtotal resection, partial resection, and mean and minimum ADC values that were lower than cutoff values were negative predictors of overall survival and progression-free survival. In conclusion, mean and minimum ADC values could be useful in predicting aggressiveness of clival chordoma.

Microsurgical versus endoscopic trans-sphenoidal approaches for clivus chordoma: a pooled and meta-analysis

Chordoma is a rare slow-growing neoplastic bone lesion. However, they show an invasive local growth and high recurrence rate, leading to an overall survival rate of 65% at 5 years and 35% at 10 years. We conducted a pooled and meta-analysis comparing recurrence rate, post-operative-complications, and survival in patients undergoing either microsurgical (MA) or endoscopic approaches (EA). Search of literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify surgical series of clivus chordomas published between January 1990 and March 2018 on Pubmed, Scopus, and Cochrane. Two different statistical analyses have been performed: a pooled analysis and a single-arm meta-analysis of overall recurrence rate and subgroup meta-analysis of complications in the subgroups open surgery and endoscopic surgery. After full-text screening, a total of 58 articles were included in the pooled analysis and 27 studies were included for the study-level meta-analysis. Pooled analysis-the extent of resection was the only association that remained significant (subtotal: HR = 2.18, p = 0.004; partial: HR = 4.40, p < 0.001). Recurrence was more prevalent among the surgical patients (45.5%) compared to endoscopic ones (23.7%). Meta-analysis-results of the cumulative meta-analysis showed an overall rate of recurrence of 25.6%. MA recurrence rate was 31.8% (99% CI 14-52.8), EA recurrence rate was 19.4% (5.4-39.2). CSF leak rate for the endoscopic group was 10.3% (99%CI 5-17.3) and 9.5% (99%CI 1.2-24.6) for the open surgery group. The partial removal versus total removal has an influence on recurrence rate (p < 0.001). MA recurrence rate was 31.8%; EA recurrence rate was 19.4%. The extent of resection is confirmed as a statistically significant factor affecting the risk for recurrence both with the pooled analysis and with the meta-analysis. Meta-analysis demonstrated that older patients tend to recur more than young patients, especially in surgical group.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Cranial Chordoma: A New Preoperative Grading System

BACKGROUND

Chordomas are rare but challenging neoplasms involving the skull base. A preoperative grading system will be useful to identify both areas for treatment and risk factors, and correlate to the degree of resection, complications, and recurrence.

OBJECTIVE

To propose a new grading system for cranial chordomas designed by the senior author. Its purpose is to enable comparison of different tumors with a similar pathology to clivus chordoma, and statistically correlate with postoperative outcomes.

METHODS

The numerical grading system included tumor size, site of the tumor, vascular encasement, intradural extension, brainstem invasion, and recurrence of the tumor either after surgery or radiotherapy with a range of 2 to 25 points; it was used in 42 patients with cranial chordoma. The grading system was correlated with number of operations for resection, degree of resection, number and type of complications, recurrence, and survival.

RESULTS

We found 3 groups: low-risk 0 to 7 points, intermediate-risk 8 to 12 points, and high-risk ≥13 points in the grading system. The 3 groups were correlated with the following: extent of resection (partial, subtotal, or complete; P < .002); number of operative stages to achieve removal (P < .014); tumor recurrence (P = .03); postoperative Karnofsky Performance Status (P < .001); and with successful outcome (P = .005). The grading system itself correlated with the outcome (P = .005).

CONCLUSION

The proposed chordoma grading system can help surgeons to predict the difficulty of the case and know which areas of the skull base will need attention to plan further therapy.

Tumour Volume and Dose Influence Outcome after Surgery and High-dose Photon Radiotherapy for Chordoma and Chondrosarcoma of the Skull Base and Spine

AIMS

To evaluate the long-term outcomes of patients with chordoma and low-grade chondrosarcoma after surgery and high-dose radiotherapy.

MATERIALS AND METHODS

High-dose photon radiotherapy was delivered to 28 patients at the Neuro-oncology Unit at Addenbrooke's Hospital (Cambridge, UK) between 1996 and 2016. Twenty-four patients were treated with curative intent, 17 with chordoma, seven with low-grade chondrosarcoma, with a median dose of 65 Gy (range 65-70 Gy). Local control and survival rates were calculated using the Kaplan-Meier method.

RESULTS

The median follow-up was 83 months (range 7-205 months). The 5 year disease-specific survival for chordoma patients treated with radical intent was 85%; the local control rate was 74%. The 5 year disease-specific survival for chondrosarcoma patients treated with radical intent was 100%; the local control rate was 83%. The mean planning target volume (PTV) was 274.6 ml (median 124.7 ml). A PTV of 110 ml or less was a good predictor of local control, with 100% sensitivity and 63% specificity. For patients treated with radical intent, this threshold of 110 ml or less for the PTV revealed a statistically significant difference when comparing local control with disease recurrence (P = 0.019, Fisher's exact test). Our data also suggest that the probability of disease control may be partly related to both target volume and radiotherapy dose.

CONCLUSION

Our results show that refined high-dose photon radiotherapy, following tumour resection by a specialist surgical team, is effective in the long-term control of chordoma and low-grade chondrosarcoma, even in the presence of metal reconstruction. The results presented here will provide a useful source for comparison between high-dose photon therapy and proton beam therapy in a UK setting, in order to establish best practice for the management of chordoma and low-grade chondrosarcoma.

Endoscopic endonasal surgery for Clival Chordomas - a single institution experience and short term outcomes

Purpose: Clival Chordomas are locally aggressive tumours which pose a significant treatment challenge. Endoscopic endonasal approach for clival chordomas is correlated with higher resection rates and lower morbidity rates in comparison to open approaches. We present our initial single institution experience and short-term patient outcomes following endoscopic endonasal approach for resection of clival chordomas. Materials and methods: This is a retrospective analysis of ten patients undergoing endoscopic endonasal approach for clival chordomas in our neurosurgical unit over a 6 year period between August 2010 and September 2016. The procedures were performed using two surgeons, four hands, binostril endoscopic endonasal approach with a Karl Storz^® endoscope and intraoperative BrainLab^® image guidance. Results: Overall 15 endoscopic endonasal approach resections of clival chordoma were performed in 10 patients with median follow up period of 39.5 months (range 9-76). Gross total resection was achieved in 4 cases (40%), near total resection in 4 cases (40%) and subtotal resection in 2 cases (20%). 5 cases (50%) required revision resections. Cerebrospinal fluid leak occurred in 2 patients. 1 case of meningitis occurred in a patient with revision surgery. There were no new neurological deficits post operatively with 3 patients demonstrating resolution of diplopia post operatively. No recurrence occurred following gross total resection. 1 out of 4 cases of near total resection showed evidence of progression during the follow up period. Both cases of subtotal resection demonstrated evidence of progression with one dying of unrelated cause during the follow up period. Conclusion: Endoscopic endonasal approach represents a safe technique for debulking and resection of clival chordomas. Due to the rarity of clival chordomas, it is important that patients with this pathology are managed in high volume skull base centres where a multi-disciplinary team approach is available.

Gamma knife surgery efficacy in controlling postoperative residual clival chordoma growth

OBJECTIVE

This study primarily aims to evaluate the efficacy of gamma knife surgery in controlling growth progression rate of residual clival chordoma through retrospective outcome analysis of 12 consecutive patients.

PATIENTS AND METHODS

Data for 12 consecutive patients underwent GKS for post-operative residual histologically verified clival chordoma at our institution (IMC - Cairo- Egypt) from 2006 through end of 2017 were retrospectively reviewed and analyzed with mean follow-up period of 45 months (range12-120 months).

RESULTS

In the last follow up MR, tumor growth control was achieved in 33.3% of patients (mean treated tumors volume was 2.7cc with mean peripheral prescription dose of 16 Gy), and 66.7% of patients reported lost tumor growth control (mean treated tumor volume was 9.2 cc with mean peripheral dose was 13.5 Gy). The overall tumor free progression with mean follow up period of 45mos was 33.3%. The Actuarial 2, 3 and 5 year tumor control rates after initial GKS was 35%, 30% and 25% respectively.

CONCLUSION

Without satisfactory maximum tumor reduction and sufficient high peripheral prescription radiation tumor dose, it should not be expected that GKS could efficiently control the progression of residual clival chordoma, especially for long term.

Prognostic Implications of Gadolinium Enhancement of Skull Base Chordomas

BACKGROUND AND PURPOSE

Skull base chordomas often demonstrate variable MR imaging characteristics, and there has been limited prior research investigating the potential clinical relevance of this variability. The purpose of this retrospective study was to assess the prognostic implications of signal intensity on standard imaging techniques for the biologic behavior of skull base chordomas.

MATERIALS AND METHODS

Medical records were retrospectively reviewed for 22 patients with pathologically confirmed skull base chordomas. Clinical data were recorded, including the degree of surgical resection, the presence or absence of radiation therapy, and time to progression/recurrence of the tumor or time without progression/recurrence of the tumor following initial treatment. Pretreatment imaging was reviewed for the presence or absence of enhancement and the T2 signal characteristics. Tumor-to-brain stem signal intensity ratios on T2, precontrast T1, and postcontrast T1 spin-echo sequences were also calculated. Statistical analysis was then performed to assess correlations between imaging characteristics and tumor progression/recurrence.

RESULTS

Progression/recurrence of skull base chordomas was seen following surgical resection in 11 of 14 (78.6%) patients with enhancing tumors and in zero of 8 patients with nonenhancing tumors. There was a statistically significant correlation between skull base chordoma enhancement and subsequent tumor progression/recurrence (P < .001), which remained significant after controlling for differences in treatment strategy (P < .001). There was also a correlation between postcontrast T1 signal intensity (as measured by postcontrast T1 tumor-to-brain stem signal intensity ratios) and recurrence/progression (P = .02). While T2 signal intensity was higher in patients without tumor progression (median tumor-to-brain stem signal intensity ratios on T2 = 2.27) than in those with progression (median tumor-to-brain stem signal intensity ratios on T2 = 1.78), this association was not significant (P = .12).

CONCLUSIONS

Enhancement of skull base chordomas is a risk factor for tumor progression/recurrence following surgical resection.

Survival analysis of patients with spinal chordomas

This study was aimed to analyze the survival of patients with spinal chordomas. Patients' data in the Surveillance, Epidemiology, and End Results (SEER) database were retrieved and analyzed statistically. There were 765 patients with spinal chordomas between 1974 and 2013. The overall survival did not improve significantly over decades for patients receiving surgery and radiotherapy (SR) (P = 0.221). There were significant differences in overall survival among subgroups of patients receiving surgery (S), radiotherapy (R), and neither S nor R (NSR) (P = 0.031, 0.037, and 0.031, respectively). Cancer-specific survival did not change significantly among subgroups of patients receiving R (P = 0.411), while it increased steadily among subgroups of patients receiving S, SR, and NSR (P < 0.001, 0.001, and 0.049, respectively). In the multivariate Cox regression model, younger onset age (hazard ratio [HR] 1.052, P < 0.001), surgery (HR 0.291, P = 0.001), and tumor location of the sacrum (HR 0.401, P = 0.002) were associated with a better overall survival. Similarly, younger onset age (HR 1.036, P = 0.029), surgery (HR 0.221, P = 0.009), and tumor location of the sacrum (HR 0.287, P = 0.002) were also associated with a higher cancer-specific survival. The changes in overall and cancer-specific survival over time differ among different treatment groups. Younger onset age, surgical strategy, and tumor location of the sacrum may be correlated with a higher overall and cancer-specific survival.

Clinical outcomes of an endoscopic transclival and transpetrosal approach for primary skull base malignancies involving the clivus

OBJECTIVE

The endoscopic endonasal approach for treating primary skull base malignancies involving the clivus is a formidable task. The authors hypothesized that tumor involvement of nearby critical anatomical structures creates hurdles to endoscopic gross-total resection (GTR). The aim of this study was to retrospectively review the clinical outcomes of patients who underwent an endoscopic endonasal approach to treat primary malignancies involving the clivus and to analyze prognostic factors for GTR.

METHODS

Between January 2009 and November 2015, 42 patients underwent the endoscopic endonasal approach for resection of primary skull base malignancies involving the clivus at 2 independent institutions. Clinical data; tumor locations within the clivus; and anatomical involvement of the cavernous or paraclival internal carotid artery, cisternal trigeminal nerve, hypoglossal canal, and dura mater were investigated to assess the extent of resection. Possible prognostic factors affecting GTR were also analyzed.

RESULTS

Of the 42 patients, 37 were diagnosed with chordomas and 5 were diagnosed with chondrosarcomas. The mean (± SD) preoperative tumor volume was 25.2 ± 30.5 cm3 (range 0.8–166.7 cm3). GTR was achieved in 28 patients (66.7%) and subtotal resection in 14 patients (33.3%). All tumors were classified as upper (n = 17), middle (n = 17), or lower (n = 8) clival tumors based on clival involvement, and as central (24 [57.1%]) or paramedian (18 [42.9%]) based on laterality of the tumor. Univariate analysis identified the tumor laterality (OR 6.25, 95% CI 1.51–25.86; p = 0.011) as significantly predictive of GTR. In addition, the laterality of the tumor was found to be a statistically significant predictor in multivariate analysis (OR 41.16, 95% CI 1.12–1512.65; p = 0.043).

CONCLUSIONS

An endoscopic endonasal approach can provide favorable clinical and surgical outcomes. However, the tumor laterality should be considered as a potential obstacle to total removal.

Surgical Resection and Adjuvant Radiation Therapy in the Treatment of Skull Base Chordomas

OBJECTIVE

Chordomas are rare tumors of notochordal origin that are known to be locally aggressive and are often treated with surgical resection followed by adjuvant radiation therapy (RT). The accepted standard of treatment for chordomas of the mobile spine, which includes en-bloc resection with wide margins, cannot be easily applied to the chordomas of the skull base because of their proximity to critical neurovascular structures. We describe our experience with the role of surgery and adjuvant RT in the treatment of chordomas over 16 years.

METHODS

We performed a retrospective chart review on patients with diagnoses of clival chordoma between the years 2000 and 2015 at Northwestern Memorial Hospital. We reviewed presenting symptoms, tumor location and size, extent of resection, complications, recurrence, adjuvant treatment, and follow-up duration.

RESULTS

A total of 20 patients underwent 32 surgeries. Of the 20 initial surgeries, 80% underwent gross total resection, and 20% had subtotal resection. The mean follow-up time was 60.75 months. Mean tumor volume was 23.07 cm³. Most common presenting signs and symptoms were headaches (70%), cranial nerve palsies (45%), and diplopia (55%). Diplopia was defined as complaints of double vision without any objective evidence of a cranial nerve palsy. Median time to progression was 57 months, and median overall survival was 136 months. Initial tumor volume and the need for a second dose of RT either as sole or as adjuvant treatment of a recurrence had a statistically significant effect on progression-free survival (P = 0.009, 0.009). None of the factors studied had a statistically significant effect on overall survival.

CONCLUSIONS

The treatment of chordomas remain challenging and requires multimodal treatment strategies spanning different specialties. Initial tumor size and need for second dose of RT for recurrence appear to play a significant role in progression-free survival. Adjuvant RT after gross total resection may play a role in improved progression-free and overall survival in patients with clival chordomas.

Circulating vascular endothelial growth factor (VEGF) as predictive factor of progression-free survival in patients with advanced chordoma receiving sorafenib: an analysis from a phase II trial of the french sarcoma group (GSF/GETO)

Background

Patients with advanced chordoma are often treated with tyrosine kinase inhibitors without any predictive factor to guide decision. We report herein an ancillary analysis of the the Angionext phase II trial (NCT 00874874).

Results

From May 2011 to January 2014, 26 were sampled. The 9-month PFS rate was 72.9% (95%-CI: 45.9-87.9). During sorafenib treatment, a significant increase in PlGF (18.4 vs 43.8 pg/mL, p<0.001) was noted along with a non-significant increase in VEGF (0.7 vs 1.0 ng/mL, p=0.07). VEGF at D1 >1.04 ng/mL (HR=12.5, 95%-CI: 1.37-114, p=0.025) and VEGF at D7 >1.36 ng/mL (HR=10.7, 95%-CI: 1.16-98, p=0.037) were associated with shorter PFS. The 9-month PFS rate was 92.3% (95%-CI: 56.6-98.9) when VEGF at D1 was ≤1.04 ng/mL versus 23.3% (95%-CI: 1.0-63.2) when >1.04 ng/mL.

Patients and Methods

Chordoma patients were treated with sorafenib 800 mg/day for 9 months, unless earlier occurrence of progression or toxicities. Six biomarkers (sE-Selectin, VEGF, VEGF-C, placental growth factor (PlGF), Thrombospondin, Stem Cell Factor (SCF)) were measured at baseline (day 1: D1) and day 7 (D7).

Conclusion

High levels of VEGF was associated with poor outcome.

Best practices for the management of local-regional recurrent chordoma: a position paper by the Chordoma Global Consensus Group

Chordomas are rare, malignant bone tumors of the skull-base and axial skeleton. Until recently, there was no consensus among experts regarding appropriate clinical management of chordoma, resulting in inconsistent care and suboptimal outcomes for many patients. To address this shortcoming, the European Society of Medical Oncology (ESMO) and the Chordoma Foundation, the global chordoma patient advocacy group, convened a multi-disciplinary group of chordoma specialists to define by consensus evidence-based best practices for the optimal approach to chordoma. In January 2015, the first recommendations of this group were published, covering the management of primary and metastatic chordomas. Additional evidence and further discussion were needed to develop recommendations about the management of local-regional failures. Thus, ESMO and CF convened a second consensus group meeting in November 2015 to address the treatment of locally relapsed chordoma. This meeting involved over 60 specialists from Europe, the United States and Japan with expertise in treatment of patients with chordoma. The consensus achieved during that meeting is the subject of the present publication and complements the recommendations of the first position paper.

Endonasal Endoscopic Resection and Radiotherapy in Skull Base Chordomas

OBJECTIVES

This study evaluates the impact combined endonasal endoscopic resection and radiotherapy for skull base chordomas.

METHODS

Thirty-two patients with skull base chordomas between July 2006 and June 2015 were divided into 2 groups: the surgery alone group and the surgery with radiation therapy group.

RESULTS

Gross total resection was achieved in 9 (28.1%) patients with skull base chordoma, subtotal resection was achieved in 16 (50.0%) patients, and partial resection was achieved in 7 (21.9%) patients. The progression-free survival (PFS) rate at 3 and 5 years was 44.0% and 16.5%, respectively. The overall survival (OS) rate at 3 and 5 years was 79.4% and 69.5%, respectively. Kadish staging predicted PFS and OS with statistical significance when the extent of resection was categorized into gross total resection, subtotal resection, and partial resection (P = 0.035 and P = 0.003, respectively). There was a significant OS advantage for the surgery plus radiation group compared with the surgery alone group (P = 0.035).

CONCLUSION

Gross total resection can achieve very good results for the treatment of skull base chordomas. Postoperative adjuvant radiation therapy is recommended for all skull base chordomas, as it offered a higher OS rate.

Clinical features and surgical outcomes of patients with skull base chordoma: a retrospective analysis of 238 patients

OBJECTIVE Skull base chordoma is relatively rare, and a limited number of reports have been published regarding its clinical features. Moreover, the factors associated with extent of resection, as well as the value of marginal resection for long-term survival, are still in question for this disease. The objective of this study was to investigate these factors by evaluating their clinical features and surgical outcomes. METHODS A retrospective analysis of 238 patients with skull base chordomas, who met the inclusion criteria, was performed. This study summarized the clinical features, selection of approaches, degree of resection, and postoperative complications by statistical description analyses; proposed modified classifications of tumor location and bone invasion; studied the contributions of the clinical and radiological factors to the extent of resection by Pearson χ², ANOVA, rank test, and binary logistic regression analysis; and estimated the differences in overall survival and progression-free survival rates with respect to therapeutic history, classification of tumor location, extent of bone invasion, and extent of tumor resection by the Kaplan-Meier method. A p value < 0.05 was considered statistically significant. RESULTS The study included 140 male and 98 female patients with a mean age of 38.1 years. Headache and neck pain (33.2%) and diplopia (29%) were the most common initial symptoms. Sphenoclival type accounted for the largest proportion of tumor location (59.2%); endophytic chordoma was the more common type of bone invasion (81.5%). Lateral open approaches were performed in two-thirds of the study population (78.6%). The rate of marginal resection was 66%, composed of gross-total resection (11.8%) and near-total resection (54.2%). Meningitis (8%) and CSF leakage (3.8%) were the most frequent complications. The mean follow-up period was 43.7 months. The overall survival and progression-free survival rates at 5 years were 76% and 45%, respectively. Recurrent tumor and larger tumor volume (≥ 40 cm³) were identified as risk factors of marginal resection. Patients who presented with recurrent tumor and underwent intralesional resection had a worse long-term outcome. CONCLUSIONS The classifications of both tumor location and bone invasion demonstrated clinical value. Marginal resection was more likely to be achieved for primary lesions with smaller volumes (< 40 cm³). The rate of CSF leakage declined due to improved dura mater repair with free fat grafts. Marginal resection, or gross-total resection when possible, should be performed in patients with primary chordomas to achieve better long-term survival.

Factors for Overall Survival in Patients with Skull Base Chordoma: A Retrospective Analysis of 225 Patients

BACKGROUND

Although a controversial and complex issue, the prognostic factors of skull base chordomas are worth exploring.

METHODS

Prognostic factors associated with overall survival (OS) were retrospectively estimated in an individual cohort of skull base chordomas prospectively maintained for 10 years by a Kaplan-Meier method and univariate Cox proportional hazards model. Multivariate analysis by Cox regression analysis was performed to identify the independent prognostic factors. A nomogram was then formulated by R software based on the results.

RESULTS

A total of 180 primary patients and 45 recurrent cases were included, with a mean follow-up period of 43.7 months (range, 4-127 months). The OS of the primary group at 5 years and 7 years was 84% and 78%, and the mean OS was 103.8 months, which was significantly longer than the recurrent group, in which the mean postrecurrent OS was 68.4 months. In the primary group, preoperative Karnofsky Performance Status (KPS) score (P = 0.004) and a decline of perioperative KPS score (P = 0.015) were identified as independent predictors of OS. A nomogram was contracted to predict 5-year, and 7-year OS, which was well calibrated and had good discriminative ability (adjusted Harrell C statistic, 0.74). In the recurrent group, visual deficit was verified as an independent risk factor associated with postrecurrent OS (P = 0.014).

CONCLUSIONS

Both pathologic and perioperative KPS score evaluations are significant in OS prediction of both primary and recurrent cases. The nomogram for primary lesions, consisting of preoperative functional status and its perioperative changes, appears useful for risk stratification of long-term survival.

Differences in Dural Penetration of Clival Chordomas Are Associated with Different Prognosis and Expression of Platelet-Derived Growth Factor Receptor-β

OBJECTIVE

We sought to compare the prognosis of clival chordomas with different dural penetration and establish the relationship between dural penetration and platelet-derived growth factor receptor (PDGFR)-β signaling pathway.

METHODS

Tumors in Type I (33 cases) showed limited dural penetration, while those in Type II (34 cases) had more serious dural penetration. Cox multivariate regression analysis was used to analyze risk factors affecting survival. Kaplan-Meier analysis measured overall survival (OS) and progression-free survival (PFS). To determine the relationship between dural penetration and PDGFR-β signaling, expression of PDGFR-β, Akt, mammalian target of rapamycin (mTOR), and phosphatase and tensin homolog (PTEN) expression was compared using immunohistochemistry, quantitative reverse transcription polymerase chain reaction, and Western blotting.

RESULTS

Total resection was achieved in 9 cases in Type I and 11 in Type II. There were significant correlations between OS and dural penetration (P = 0.032) and age (P = 0.034). PFS correlated significantly with dural penetration (P = 0.022), gender (P = 0.001), and degree of resection (P = 0.001). Mean OS in Type I was significantly longer than in Type II (P = 0.046). Patients aged <55 years had longer OS than those aged ≥55 years (P = 0.004). Total resection was correlated with longer PFS (P = 0.011). Among patients with tumors totally resected, mean PFS in Type I was significantly longer than in Type II (P = 0.007). Expression of PDGFR-β in Type II was higher than in Type I.

CONCLUSIONS

Clival chordomas have different degrees of dural penetration. Patients with chordomas with serious dural penetration have poorer prognosis. Higher expression of PDGFR-β is related to more serious dural penetration of clival chordomas.

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.

Proton beam therapy in the management of skull base chordomas: systematic review of indications, outcomes, and implications for neurosurgeons

BACKGROUND

Chordomas are rare tumours affecting the skull base. There is currently no clear consensus on the post-surgical radiation treatments that should be used after maximal tumour resection. However, high-dose proton beam therapy is an accepted option for post-operative radiotherapy to maximise local control, and in the UK, National Health Service approval for funding abroad is granted for specific patient criteria.

OBJECTIVES

To review the indications and efficacy of proton beam therapy in the management of skull base chordomas. The primary outcome measure for review was the efficacy of proton beam therapy in the prevention of local occurrence.

METHODS

A systematic review of English and non-English articles using MEDLINE (1946-present) and EMBASE (1974-present) databases was performed. Additional studies were reviewed when referenced in other studies and not available on these databases. Search terms included chordoma or chordomas. The PRISMA guidelines were followed for reporting our findings as a systematic review.

RESULTS

A total of 76 articles met the inclusion and exclusion criteria for this review. Limitations included the lack of documentation of the extent of primary surgery, tumour size, and lack of standardised outcome measures. Level IIb/III evidence suggests proton beam therapy given post operatively for skull base chordomas results in better survival with less damage to surrounding tissue.

CONCLUSIONS

Proton beam therapy is a grade B/C recommended treatment modality for post-operative radiation therapy to skull base chordomas. In comparison to other treatment modalities long-term local control and survival is probably improved with proton beam therapy. Further, studies are required to directly compare proton beam therapy to other treatment modalities in selected patients.

Three-dimensional endoscopy in transnasal transsphenoidal approach to clival chordomas

BACKGROUND

The purpose of this prospective, observational study was to evaluate the management of skull base chordomas surgically resected via a 3D-endoscopic transnasal approach.

METHODS

Thirteen consecutive patients were observed and only 9 were surgically treated using a 3D-endoscopic transnasal approach assisted by a novel 3D visualization system.

RESULTS

Nine consecutive male patients (mean age, 57.4 years) underwent exclusive 3D-endoscopic transnasal transsphenoidal resection of clival chordomas; gross total resection was achieved in 66.6% of cases (6 of 9 patients), near-total resection in 11.2% (1 of 9 patients), and partial resection in 22.2% (2 of 9 patients). The complications observed were 2 cases of postoperative cerebrospinal fluid (CSF) leaks and 1 case of temporary VI cranial nerve palsy.

CONCLUSION

No discomfort was recorded; when a dura opening was required, 3D vision allowed an accurate intradural sharp dissection and a precise repair of the skull base. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1814-E1819, 2016.

Is there a role for conventional MRI and MR diffusion-weighted imaging for distinction of skull base chordoma and chondrosarcoma?

BACKGROUND

Chordoma and chondrosarcoma are locally invasive skull base tumors with similar clinical symptoms and anatomic imaging features as reported in the literature.

PURPOSE

To determine differentiation of chordoma and chondrosarcoma of the skull base with conventional magnetic resonance imaging (cMRI) and diffusion-weighted MR imaging (DWI) in comparison to histopathological diagnosis.

MATERIAL AND METHODS

This retrospective study comprised 96 (chordoma, n = 64; chondrosarcoma, n = 32) patients with skull base tumors referred to the Paul Scherrer Institute (PSI) for proton therapy. cMRI signal intensities of all tumors were investigated. In addition, median apparent diffusion coefficient (ADC) values were measured in a subgroup of 19 patients (chordoma, n = 11; chondrosarcoma, n = 8).

RESULTS

The majority 81.2% (26/32) of chondrosarcomas displayed an off-midline growth pattern, 18.8% (6/32) showed clival invasion, 18.8% (6/32) were located more centrally. Only 4.7% (3/64) of chordomas revealed a lateral clival origin. Using cMRI no significant differences in MR signal intensities were observed in contrast to significantly different ADC values (subgroup of 19/96 patients examined by DWI), with the highest mean value of 2017.2 × 10(-6 )mm(2)/s (SD, 139.9( )mm(2)/s) for chondrosarcoma and significantly lower value of 1263.5 × 10(-6 )mm(2)/s (SD, 100.2 × 10(-6 )mm(2)/s) for chordoma (P = 0.001/median test).

CONCLUSION

An off-midline growth pattern can differentiate chondrosarcoma from chordoma on cMRI in a majority of patients. Additional DWI is a promising tool for the differentiation of these skull base tumors.

Adjuvant Stereotactic Radiosurgery and Radiation Therapy for the Treatment of Intracranial Chordomas

Objective Chordomas are locally aggressive, highly recurrent tumors requiring adjuvant radiotherapy following resection for successful management. We retrospectively reviewed patients treated for intracranial chordomas with adjuvant stereotactic radiosurgery (SRS) and stereotactic radiation therapy (SRT). Methods A total of 57 patients underwent 83 treatments at the UCLA Medical Center between February 1990 and August 2011. Mean follow-up was 57.8 months. Mean tumor diameter was 3.36 cm. Overall, 8 and 34 patients received adjuvant SRS and SRT, and the mean maximal dose of radiation therapy was 1783.3 cGy and 6339 cGy, respectively. Results Overall rate of recurrence was 51.8%, and 1- and 5-year progression-free survival (PFS) was 88.2% and 35.2%, respectively. Gross total resection was achieved in 30.9% of patients. Adjuvant radiotherapy improved outcomes following subtotal resection (5-year PFS 62.5% versus 20.1%; p = 0.036). SRS and SRT produced comparable rates of tumor control (p = 0.28). Higher dose SRT (> 6,000 cGy) (p = 0.013) and younger age (< 45 years) (p = 0.03) was associated with improved rates of tumor control. Conclusion Adjuvant radiotherapy is critical following subtotal resection of intracranial chordomas. Adjuvant SRT and SRS were safe and improved PFS following subtotal resection. Higher total doses of SRT and younger patient age were associated with improved rates of tumor control.

Sorafenib in patients with locally advanced and metastatic chordomas: a phase II trial of the French Sarcoma Group (GSF/GETO)

BACKGROUND

There is no consensual treatment of locally advanced or metastatic chordomas.

PATIENTS AND METHODS

We conducted a multicenter, open-label, uncontrolled phase II trial of sorafenib (800 mg/day). The primary end point was the 9-month progression-free rate according to RECIST 1.1. All patients had documented progressive disease at the time of study entry.

RESULTS

Twenty-seven patients were enrolled between May 2011 and January 2014. The median age was 64 (range, 30-86) years. There were 17 men and 10 women. Twelve patients had been previously treated with chemotherapy and molecularly targeted agents. The maximum toxicity grade per patient was grade 3 in 21 cases (77.8%) and grade 4 in 4 cases (14.8%). Sorafenib provided an intent-to-treat best objective response of 1/27 [3.7%; 95% confidence interval (CI) 0.1% to 19.0%], a 9-month progression-free rate of 73.0% (95% CI 46.1-88.0) and a 12-month overall survival rate of 86.5% (95% CI 55.8-96.5). Survival curves were similar in pretreated and not pretreated patients.

DISCUSSION

Additional clinical trials further exploring sorafenib as a treatment of locally advanced or metastatic chordomas are warranted.

Endoscopic Endonasal Infrapetrous Transpterygoid Approach to the Petroclival Junction for Petrous Apex Chondrosarcoma: Technical Report

Chondrosarcomas of the skull base are rare tumors that present difficult management considerations due to the pathoanatomical relationships of the tumor to adjacent structures. We present the case of a 25-year-old female patient presenting with a chondrosarcoma of the right petrous apex extending inferiorly, medial to the cranial nerves. The tumor was resected via an endoscopic endonasal infrapetrous transpterygoid approach that achieved complete resection and an excellent long-term outcome with no complications. Technical nuances and potential pitfalls of the case are discussed in depth including measures to protect the carotid artery while performing the required drilling of the skull base to access the lesion.

Transoral vs. endoscopic endonasal approach for clival/upper cervical chordoma

The surgical results of 18 cases of clival/upper cervical chordoma treated in the last decade via the endoscopic endonasal approach (EEA, 9 cases) and the transoral-transpalatal approach (TO-TPA, 9 cases) were compared. Each group showed the same incidence of subdural invasion, with 5 cases each. The superior (frontal base) and lateral surgical fields were wider by EEA, but the inferior view lower than the cranio-vertebral junction (CVJ) was wider by TO-TPA. Gross total removal was achieved in 3 cases in the EEA group, but in only 1 case in the TO-TPA group. Differences in radicality might be due to the extent of the lateral and subdural overview. However for large tumors extending below the CVJ, TO-TPA was the only viable approach for surgical removal. Surgical complications were higher in the EEA (4 cases) than the TO-TPA group (1 case), and were mainly caused by aggressive management of subdural invasion in the EEA group. Post-operative oral intake was earlier and the operative time was shorter in the EEA group. The surgical results were more radical and less invasive in the EEA group than the TO-TPA group. However in tumors extending below the CVJ, the surgical field in EEA was limited, indicating the need to use the transoral route or a combination of routes. A higher complication rate following subdural management was a negative factor that requires improvement in the EEA group and two-staged EEA followed by a transcranial approach may be considered for the cases with subdural invasion.

Endoscopic transnasal surgery as a replacement for maxillotomy techniques to approach the central skull base: fewer complications and more acceptable to patients?

Objectives To compare the complication rates of endoscopic transnasal and open maxillotomy approaches for the central skull base. Design Retrospective review. Setting Single-center study, London, United Kingdom. Participants From 1992 to 2012, 81 patients underwent surgery for skull base lesions, 59 by maxillotomy and 22 by endoscopy. Main Outcome Measures Total time of surgical anesthesia, blood loss, complications, duration of tracheal intubation, duration of hospital stay, myelopathy score, and mortality rate. Results The surgical time, blood loss, and duration of the postoperative intubation period were significantly less with endoscopy (p < 0.001). Requirements for intensive care, ward stay, and total hospital stay were also significantly less in the endoscopic group (p = 0.01, p < 0.001, and p < 0.001, respectively). The complication rate was lower with transnasal endoscopic surgery. Conclusion In patients for whom open maxillotomy or endoscopic surgery are both feasible, the preference should be to perform endoscopic surgery, with better visualization and fewer complications.

Determinants of quality of life in patients with skull base chordoma

Object

Skull base chordomas can be managed by surgical intervention and adjuvant radiotherapy. As survival for this disease increases, identification of determinants of quality of life becomes an important focus for guiding comprehensive patient care. In this study the authors sought to measure functional outcome and quality of life in patients with skull base chordomas and to identify determinants of quality of life in these patients.

Methods

The authors carried out an internet-based cross-sectional survey, collecting detailed data for 83 individual patients. Demographic and clinical variables were evaluated. Functional outcomes were determined by Karnofsky Performance Scale (KPS) and Glasgow Outcome Scale Extended (GOSE), quality of life was measured using the 36-Item Short Form Health Survey (SF-36), and depression was assessed using Patient Health Questions–9 (PHQ-9) instrument. Caregiver burden was assessed using the Zarit Burden Interview (ZBI). Univariate and multivariate analysis was performed to identify determinants of the physical and mental components of the SF-36.

Results

Patients with skull base chordomas who have undergone surgery and/or radiation treatment had a median KPS score of 90 (range 10–100, IQR 10) and a median GOSE score of 8 (range 2–8, IQR 3). The mean SF-36 Physical Component Summary score (± SD) was 43.6 ± 11.8, the mean Mental Component Summary score was 44.2 ±12.6, and both were significantly lower than norms for the general US population (p < 0.001). The median PHQ-9 score was 5 (range 0–27, IQR 8). A PHQ-9 score of 10 or greater, indicating moderate to severe depression, was observed in 29% of patients. The median ZBI score was 12 (range 0–27, IQR 11), indicating a low burden. Neurological deficit, use of pain medication, and requirement for corticosteroids were found to be associated with worse SF-36 Physical Component Summary score, while higher levels of depression (higher PHQ-9 score) correlated with worse SF-36 Mental Component Summary score.

Conclusions

Patients with skull base chordomas have a lower quality of life than the general US population. The most significant determinants of quality of life in the posttreatment phase in this patient population were neurological deficits (sensory deficit and bowel/bladder dysfunction), pain medication use, corticosteroid use, and levels of depression as scored by PHQ-9.

Chemotherapy of skull base chordoma tailored on responsiveness of patient-derived tumor cells to rapamycin

Skull base chordomas are challenging tumors due to their deep surgical location and resistance to conventional radiotherapy. Chemotherapy plays a marginal role in the treatment of chordoma resulting from lack of preclinical models due to the difficulty in establishing tumor cell lines and valuable in vivo models. Here, we established a cell line from a recurrent clival chordoma. Cells were cultured for more than 30 passages and the expression of the chordoma cell marker brachyury was monitored using both immunohistochemistry and Western blot. Sensitivity of chordoma cells to the inhibition of specific signaling pathways was assessed through testing of a commercially available small molecule kinase inhibitor library. In vivo tumorigenicity was evaluated by grafting chordoma cells onto immunocompromised mice and established tumor xenografts were treated with rapamycin. Rapamycin was administered to the donor patient and its efficacy was assessed on follow-up neuroimaging. Chordoma cells maintained brachyury expression at late passages and generated xenografts closely mimicking the histology and phenotype of the parental tumor. Rapamycin was identified as an inhibitor of chordoma cell proliferation. Molecular analyses on tumor cells showed activation of the mammalian target of rapamycin signaling pathway and mutation of KRAS gene. Rapamycin was also effective in reducing the growth of chordoma xenografts. On the basis of these results, our patient received rapamycin therapy with about six-fold reduction of the tumor growth rate upon 10-month follow-up neuroimaging. This is the first case of chordoma in whom chemotherapy was tailored on the basis of the sensitivity of patient-derived tumor cells.

Endoscopic endonasal approach in the management of skull base chordomas--clinical experience on a large series, technique, outcome, and pitfalls

Skull base chordomas represent very interesting neoplasms, due to their rarity, biological behavior, and resistance to treatment. Their management is very challenging. Recently, the use of a natural corridor, through the nose and the sphenoid sinus, improved morbidity and mortality allowing also for excellent removal rates. Prospective analysis of 54 patients harboring a skull base chordoma that were managed by extended endonasal endoscopic approach (EEA). Among the 54 patients treated (during a 72 months period), 21 were women and 33 men, undergoing 58 procedures. Twenty-two cases (40%) were recurrent and 32 (60%) newly diagnosed chordomas. Among the 32 newly diagnosed chordomas, a gross total resection was achieved in 28 cases (88%), a near total (>95% of tumor) in 2 cases (6%), a partial (>50% of tumor) in 2 cases (6%). Among the 22 recurrent chordomas, resection was complete in 7 cases (30%), near total in 7 (30%), and partial in 8 (40%). The global gross total resection rate was 65% (35/54 cases). Four patients (11%) recurred and 4 (11%) progressed within a mean follow-up of 34 months (range 12-84 months). Four patients (11%) were re-operated; one patient (1.8%) died due to disease progression, one patient (1.8%) died 2 weeks after surgery due to a massive bleeding from an ICA pseudo aneurysm. CSF leakage occurred in four patients (8%), and meningitis in eight cases (14%). No new permanent neurological deficit occurred. The EEA management of skull base chordomas requires a long and gradual learning curve that once acquired offers the possibility of either similar or better resection rates as compared to traditional approaches while morbidity is improved.

Recurrent upper cervical chordomas after radiotherapy: surgical outcomes and surgical approach selection based on complications

STUDY DESIGN

Retrospective review of a case series.

OBJECTIVE

To present and analyze our surgical results of recurrent chordomas in the upper cervical spine after radiotherapy and compare 2 surgical strategies.

SUMMARY OF BACKGROUND DATA

Surgical treatment of recurrent chordomas in the upper cervical spine after radiotherapy is clinically rare but extremely challenging. No reports are found in the literatures focusing on the surgical results and strategies of such recurrent chordomas.

METHODS

Clinical data of 8 patients with recurrent chordomas in the upper cervical spine after radiotherapy were retrospectively reviewed.

RESULTS

Preoperative symptoms were relieved after our surgical procedures in 7 of the 8 patients. Total tumor removal was achieved in 6 of the 8 patients. Surgical complications mainly including cerebrospinal fluid leak and incision disunion were observed in 6 of the 8, and all the 3 patients after transoral operation had those complicated surgical complications, whereas the other 3 of the 5 patients after anterior retropharyngeal operation had relatively slighter complications. The disease free survival rates 1 year and 2 years after the surgery in this series were 50% and 12.5%, respectively, comparing with the general survival rates 1 year and 2 years after the surgery 87.5% and 37.5%.

CONCLUSION

Revised surgery is effective for improving quality of life of patients with recurrent upper cervical chordomas after radiotherapy before further tumor recurrence. However, the prognosis of those patients is usually poor and surgical complications mainly including incision disunion and cerebrospinal fluid leak are common. To reduce the risk of surgical complications, anterior retropharyngeal approach may be superior to the transoral approach.

LEVEL OF EVIDENCE

N/A.

Evolution of Transoral Surgery

BACKGROUND:

Transoral surgery may be used to approach pathologies at the craniocervical junction. However, the need for this approach has decreased over the past few decades.

OBJECTIVE:

To assess the outcome and complications of transoral surgery and extended transoral approaches at a single UK center between 1980 and 2011.

METHODS:

A retrospective review was performed of 495 ventral midline operations (between1980 and 2004) and prospective review of 38 operations (2004-2011) in a total of 479 patients. Trends in surgery and factors associated with good or bad outcome were assessed over this 30-year period.

RESULTS:

Of 533 operations, the most frequently performed surgeries were simple transoral surgery (321 operations), transoral surgery with splitting of the palate (107 operations), open-door maxillotomy (58 operations), and mandibulotomy (11 operations). Since the 1990s, there has been a steady decrease in the number of operations performed, mainly due to the decrease in the number of patients with rheumatoid arthritis presenting for surgery. The incidence of craniocervical junction tumors remained constant. The number of complications was significantly associated with the preoperative neurological status, and more complications were seen in myelopathic rheumatoid patients as well as a greater trend in congenital basilar invagination. The rates of pharyngeal infection (0.6%) and cerebrospinal fluid leak (0.3%) for standard transoral surgery were extremely low.

CONCLUSION:

The number of transoral and associated operations has decreased over time. Transoral surgery is now mainly indicated for ventral midline tumors such as chordomas. Transnasal endoscopic techniques show promise, but a major advantage of standard transoral surgery is the low cerebrospinal fluid leak and infection rates.

Endoscopic endonasal approach for resection of cranial base chordomas: outcomes and learning curve

BACKGROUND

Gross total resection (GTR) of cranial base chordomas represents a surgical challenge because of the location, invasiveness, and tumor extension. In the past decade, the endoscopic endonasal approach (EEA) has been used with notable outcomes.

OBJECTIVE

To present the endoscopic endonasal experience in the treatment of cranial base chordomas at our institution.

METHODS

From April 2003 to March 2011, 60 patients underwent an EEA for primary (n = 35) or previously treated (n = 25) cranial base chordomas. We evaluated the degree of GTR and complications. We studied the factors that influenced outcomes and compared our surgical results in the early and late years of our experience.

RESULTS

The overall rate of GTR of cranial base chordomas was 66.7% (82.9% in primary and 44% in previously treated patients). The most important limitations for GTR were tumor volume greater than 20 cm (P = .042), tumor location in the lower clivus with lateral extension (P = .022), and previously treated disease (P = .002). The learning curve had a significant impact on GTR, increasing the success rate to 88.9% (92.6% in primary patients and 63.6% in previously treated patients) during recent years (P < .0001). The most frequent complication was cerebrospinal fluid leak (20%) resulting in meningitis in 3.3%. Carotid injuries occurred in 2 patients without any resulting deficit. Neurological complications included new cranial neuropathies (6.7%) and long tract deficits (1.7%). There was no operative mortality in our series.

CONCLUSION

For the treatment of cranial base chordomas, the EEA is a competitive alternative to transcranial approaches with minimal morbidity and high success rates of GTR when performed by experienced cranial base surgeons.

Skull base chordomas: clinical features, prognostic factors, and therapeutics

Chordomas of the skull base are one of the rarest intracranial malignancies that arise from ectopic remnants of embryonal notochod. The proximity of many chordomas to neurovascular structures makes gross total resection difficult, and the tendency for recurrence leads to the routine use of adjuvant postoperative radiation. Several surgical approaches are used ranging from extensive craniotomies to minimally invasive endonasal endoscopic approaches. In this review, the histopathology and epidemiology, imaging characteristics, surgical approaches, adjuvant therapies, prognostic factors, and molecular biology of chordomas are described.