Treatment and Outcome of Patients with Skull Base Chordoma: A Meta-analysis

A Prospective Phase I/II Clinical Trial of High-Dose Proton Therapy for Chordomas and Chondrosarcomas

Purpose

The purpose of this study was to evaluate the feasibility and safety of dose-escalated proton beam therapy for treating chordomas and chondrosarcomas of the skull base and spine. Methods: A prospective cohort of 54 patients (42 with chordomas and 12 with chondrosarcomas) was enrolled between 2010 and 2018. The primary endpoints were feasibility and <20% rate of acute grade ≥3 toxicity, and secondary endpoints included cancer-specific outcomes and toxicities. Patients were followed with magnetic resonance imaging or computed tomography at 3-month intervals. Proton beam therapy was delivered with doses up to 79.2 Gy using protons only, combination protons/intensity modulated radiation therapy (IMRT), or IMRT only.

Results

Feasibility endpoints were met, with only 2 out of 54 patient radiation therapy plans failing to meet dosimetric constraints with protons, and 4 out of 54 experiencing a delay or treatment break >5 days, none for toxicities related to treatment. There were no grade 4 acute toxicities and 1 grade 3 acute toxicity (sensory neuropathy). The only 2 grade 3 late toxicities recorded, osteoradionecrosis and intranasal carotid blowout (mild and not emergently treated), occurred in a single patient. We report overall survival as 83% at 5 years, with local failure-free survival and progression-free survival rates of 72% and 68%, respectively. Five patients developed distant disease, and among the 9/54 patients who died, 4 deaths were not attributed to treatment or recurrence.

Conclusions

Our findings suggest that high-dose proton therapy alone or in combination with IMRT is a safe and effective treatment option for chordomas and chondrosarcomas of the skull base and spine.

Proton Therapy in the Adolescent and Young Adult Population

BACKGROUND

Adolescent and young adult cancer patients are at high risk of developing radiation-associated side effects after treatment. Proton beam radiation therapy might reduce the risk of these side effects for this population without compromising treatment efficacy.

METHODS

We review the current literature describing the utility of proton beam radiation therapy in the treatment of central nervous system tumors, sarcomas, breast cancer and Hodgkin lymphoma for the adolescent and young adult cancer population.

RESULTS

Proton beam radiation therapy has utility for the treatment of certain cancers in the young adult population. Preliminary data suggest reduced radiation dose to normal tissues, which might reduce radiation-associated toxicities. Research is ongoing to further establish the role of proton therapy in this population.

CONCLUSION

This report highlights the potential utility of proton beam radiation for certain adolescent young adult cancers, especially with reducing radiation doses to organs at risk and thereby potentially lowering risks of certain treatment-associated toxicities.

Fractionated Radiotherapy After Gross Total Resection of Clival Chordoma: A Systematic Review of Survival Outcomes

BACKGROUND

Current treatment guidelines for clival chordomas recommend surgical resection followed by high-dose radiotherapy (RT). However, in patients in whom gross total resection (GTR) is achieved, the benefits of additional RT remain unclear.

OBJECTIVE

To investigate whether RT offers any benefit to progression-free survival (PFS) in patients undergoing GTR of clival chordoma by performing a systematic review of all currently published literature.

METHODS

A total of 5 databases were searched to include all studies providing data on GTR ± RT for clival chordomas (January 1990-June 2021). Qualitative assessment was performed with Newcastle-Ottawa Scale guidelines for assessing quality of nonrandomized studies. Statistical analysis using individualized patient data of PFS was performed.

RESULTS

The systematic search yielded 2979 studies, weaned to 22 full-text articles containing 108 patients. All patients underwent GTR of clival chordoma, with 46 (43%) patients receiving adjuvant RT. Mean PFS for RT patients was 31.09 months (IQR: 12.25-37.75) vs 54.92 months (IQR: 14.00-85.75) in non-RT patients. Overall, RT did not increase PFS (HR 0.320, P = .069) to a value that achieved statistical significance. Stratifying by photon therapy vs particle beam therapy yielded no statistically significant benefit for particle beam therapy for PFS ( P = .300). Of patients with age ≥65 years, RT did not improve outcomes to statistical significance for PFS (HR 0.450, P = .481). Patients age ≥65 years had lower PFS on both bivariate analysis (HR 3.708, P = .007) and multivariate analysis (HR 3.322, P = .018).

CONCLUSION

After achieving GTR of clival chordoma, fractionated RT offers unclear benefit upon survival outcomes.

Outcomes of Endoscopic Resection in Pediatric Skull Base Chordoma: A Systematic Review

The endoscopic approach has been recommended as a primary option for treating chordomas, and it is associated with better resection rates and fewer surgical complications than transcranial surgery. This review aimed to assess the long-term consequences and evidence in the current literature regarding the endoscopic approach's efficacy in treating skull-base chordoma in children. A systematic review was conducted based on the PubMed, Web of Science, and EMBASE databases to examine the clinical outcomes of endoscopic endonasal surgery for pediatric skull base chordoma tumors. The review included studies published in English that employed specific research designs and reported on pediatric patients with skull base chordoma. Of the 268 studies initially considered, 25 met our eligibility criteria and were included in the final analysis. The average age of the patients was 11.5 years, with approximately equal number of males and females. The endoscopic endonasal approach (EEA) was the most commonly used modality. Gross total resection (GTR) was achieved in 62.7% of patients, while 18.09% had a subtotal resection (STR), and 13.83% had near-total resection only. Most patients showed significant to moderate improvement from their baseline condition and had no recurrence during their follow-up. Our findings further endorse that the endoscopic approach is a viable primary treatment option for pediatric skull base chordoma.

Malignant Brain and Spinal Tumors Originating from Bone or Cartilage

Malignant bone tumors affecting the brain and spine are a rare and exceedingly difficult-to-treat group of diseases. Most commonly consisting of chordoma and chondrosarcoma, these tumors also include giant-cell tumors and osteosarcomas. This chapter will cover the background, epidemiology, genetics, molecular biology, histopathology, radiographic features, clinical manifestations, therapeutic approaches, and clinical management of each entity.

Pure proton therapy for skull base chordomas and chondrosarcomas: A systematic review of clinical experience

Background

Skull base chordoma and chondrosarcoma are exceptionally rare bone tumors with high propensity for local recurrence. Different postoperative radiation modalities are often used to improve the clinical efficacy. Proton therapy (PT) might be among the most promising ones because of the unique ballistic characteristics of high-energy particles. However, previous meta-analysis often included studies with combined radiation techniques. No systematic review to date has directly analyzed the survival and toxicity of pure PT for these two types of malignancies.

Methods

By following the PRISMA guidelines, a systematic search of three databases was conducted. Articles were screened and data were extracted according to a prespecified scheme. R 4.2.0 software was used to conduct the meta-analysis. Normal distribution test was used for the incidence rate of each subgroup.

Results

A total of seven studies involving 478 patients were included in this analysis. The quality of included articles ranged from moderate to high quality. All patients were histopathologically diagnosed with chordoma or chondrosarcoma, and the follow-up time of the cohort ranged from 21 to 61.7 months. For PT planning, the median target volume ranged from 15 cc to 40 cc, and the administered median dose varied from 63 to 78.4 Gy_RBE at 1.8-2.0 Gy_RBE per fraction. The 1-, 2-, 3-, 5-, and 7-year local control and overall survival rates were 100%, 93%, 87%, 78%, and 68%, and 100%, 99%, 89%, 85%, and 68%, respectively. The late grade 3 or higher toxicities were reported in only two involved articles.

Conclusions

Until now, medical centers worldwide have exerted PT to improve outcomes of skull base chordomas and chondrosarcomas. PT not combined with other radiation modalities showed favorable local control and survival with a low incidence of severe radiation-induced toxicities, which manifests promising clinical benefits. However, high-quality evidence is still limited, requiring future clinical trials and prospective studies in selected patients.

A Review of Particle Therapy for Skull Base Tumors: Modern Considerations and Future Directions

Skull base tumors constitute one of the established indications for particle therapy, specifically proton therapy. However, a number of prognostic factors, practical clinical management issues, and the emerging role of carbon ion therapy remain subjects of active clinical investigation. This review summarizes these topics, assesses the present status, and reflects on future research directions focusing on the management of chordomas, one of the most aggressive skull base tumors. In addition, the role of particle therapy for benign tumors of the skull base, including pituitary adenoma and acoustic neuroma, is reviewed.

Proton and carbon ion radiotherapy in skull base chordomas: a prospective study based on a dual particle and a patient-customized treatment strategy

BACKGROUND

The aim of this study is to evaluate results in terms of local control (LC), overall survival (OS), and toxicity profile and to better identify factors influencing clinical outcome of skull base chordoma treated with proton therapy (PT) and carbon ion radiotherapy (CIRT).

METHODS

We prospectively collected and analyzed data of 135 patients treated between November 2011 and December 2018. Total prescription dose in the PT group (70 patients) and CIRT group (65 patients) was 74 Gy relative biological effectiveness (RBE) delivered in 37 fractions and 70.4 Gy(RBE) delivered in 16 fractions, respectively (CIRT in unfavorable patients). LC and OS were evaluated using the Kaplan-Meier method. Univariate and multivariate analyses were performed, to identify prognostic factors on clinical outcomes.

RESULTS

After a median follow-up of 44 (range, 6-87) months, 14 (21%) and 8 (11%) local failures were observed in CIRT and PT group, respectively. Five-year LC rate was 71% in CIRT cohort and 84% in PT cohort. The estimated 5-year OS rate in the CIRT and PT group was 82% and 83%, respectively. On multivariate analysis, gross tumor volume (GTV), optic pathways, and/or brainstem compression and dose coverage are independent prognostic factors of local failure risk. High rate toxicity grade ≥3 was reported in 11% of patients.

CONCLUSIONS

Particle radiotherapy is an effective treatment for skull base chordoma with acceptable late toxicity. GTV, optic pathways, and/or brainstem compression and target coverage were independent prognostic factors for LC.

KEY POINTS

• Proton and carbon ion therapy are effective and safe in skull base chordoma.• Prognostic factors are GTV, organs at risk compression, and dose coverage.• Dual particle therapy and customized strategy was adopted.

Clivus chordomas: Heterogeneous tumor extension requires adapted surgical approaches

OBJECTIVE

Clivus chordomas are semi-malignant, but infiltratively growing tumors. Currently, a widely-accepted treatment concept encompasses maximal, but safe, surgical resection and radiotherapy. Caused by the size and the tumor extension, different surgical approaches, especially in recurrent cases, might be necessary.

METHODS

Retrospective review of 50 patients on whom 70 surgeries were performed: 29 in primary and 41 in recurrent cases. Based on MRI images, all cases were asserted according to the size and the extension of the tumor. Used surgical approaches were evaluated. Postoperative complications, neurological function prior to and after the surgery, the extent of tumor resection on postoperative MR images were assessed and progression-free survival was calculated.

RESULTS

Tumor size was estimated as small (< 5 cm³) in 8, as medium (5-20 cm³) in 21, as large (20-100 cm³) in 17, and as giant (> 100 cm³) in 4 patients. Most frequently used surgical approaches in primary cases were the transsphenoidal one and midfacial degloving (51.7 % and 17.2 %, respectively). In recurrent cases, dependent on the tumor extension, transsphenoidal (21.9 %), retrosigmoidal (29.3 %), and pterional (19.5 %) approaches, as well as midfacial degloving (17.1 %) were used. Due to the vast tumor extension and infiltration, gross total or near total resection could be achieved in 12 patients (24 %), only. There was no mortality and no major complications in primary cases. In recurrences, however, postoperative hemorrhages and strokes emerged in 4.9 % and 7.1 %. Minor complications occurred in 17.1 % and were dominated by CSF leaks (12.2 %), both in primary in recurrent cases. While most cranial nerve impairments were caused by tumor infiltration of the cavernous sinus, and hence have not improved by treatment, the sixth nerve palsy as a consequence of tumor mass compression, could significantly be improved by surgery. Following surgery, patients were subjected to radiotherapy (68.9 % for primary cases, and 36.6 % for recurrences) mainly with carbon ions. Overall, 5-year progression-free survival was 44.7 %.

CONCLUSION

Caused by the heterogenous pattern of growth of clivus chordomas, surgical approaches should be chosen individually. Vast and infiltrative tumor extension constitute major limitations of surgical resection, and hence result in poor progression-frees survival.

Application of endoscopic endonasal approach in skull base surgeries: summary of 1886 cases in a single center for 10 consecutive years

Background

Endonasal endoscopic skull base surgery has undergone rapid technological developments and is now widely performed, but its strengths and weaknesses deserve further investigation and deliberation. This study was performed to investigate the surgical indications, complications, and technical advantages and disadvantages of endonasal endoscopic skull base surgery.

Methods

The clinical data of 1886 endoscopic endonasal skull base surgeries performed in our ward at Beijing Tiantan Hospital from June 2006 to June 2016 were retrospectively analyzed.

Results

One thousand ninety-three (73.4%, 1490) pituitary adenomas, 54 (24.9%, 217) chordomas, 28 (80.0%, 35) craniopharyngiomas, and 15 (83.3%, 18) meningiomas underwent total resection. Two patients died postoperatively, both having pituitary adenomas. Other postoperative complications included olfactory disorders (n = 226, 11.9%), postoperative cerebrospinal fluid leakage (n = 78, 4.1%), hypopituitarism (n = 74, 3.9%), diabetes insipidus (n = 64, 3.4%), intracranial infection (n = 36, 1.9%), epistaxis (n = 24, 1.3%), vascular injury (n = 8, 0.4%), optic nerve injury (n = 8, 0.4%), and oculomotor movement impairment (n = 4, 0.2%). In total, 1517 (80.4%) patients were followed up for 6 to 126 months (average, 42.5 months) postoperatively. A total of 196 (13.2%) pituitary adenomas and 13 (37.1%) craniopharyngiomas recurred but no meningiomas recurred. Chordomas recurred in 97 (44.7%) patients, in whom 5-year survival rate was 65%.

Conclusion

Endoscopic surgery is an innovative surgical technique and the first choice for most midline extradural lesions such as chordomas, and an excellent choice for pituitary adenomas. It probably will be a good technique for many kinds of craniopharyngiomas and a common technique for most of skull base meningiomas, so the surgical indications of these cases should be chosen carefully to make good use of its respective advantages.

Radiation therapy strategies for skull-base malignancies

INTRODUCTION

The management of skull base malignancies continues to evolve with improvements in surgical technique, advances in radiation delivery and novel systemic agents.

METHODS

In this review, we aim to discuss in detail the management of common skull base pathologies which typically require multimodality therapy, focusing on the radiotherapeutic aspects of care.

RESULTS

Technological advances in the administration of radiation therapy have led to a wide variety of different treatment strategies for the treatment of skull base malignances, with outcomes summarized herein.

CONCLUSION

Radiation treatment plays a key and critical role in the management of patients with skull base tumors. Recent advancements continue to improve the risk/benefit ratio for radiotherapy in this setting.

Major and minor salivary gland tumours

Salivary glands carcinomas are very rare epithelial malignant tumors. In 2013 in Europe, 7800 new diagnoses were estimated, 8.5 % of all head and neck cancer. The last WHO classification (2017) counts more than 20 malignant histotypes, this variety as well as the rarity of some of them needs a skilled pathologist for diagnosis. Surgery remains the mainstay of management followed by radiation in high-grade and high-risk pathological features cases. The intensity modulated radiotherapy (IMRT) should be preferred over conformational radiotherapy techniques as adjuvant and exclusive treatment in advanced cases. Particle radiotherapy (i.e. protons, carbon ions) can have a role in advanced/unresectable disease since it was proved to have better results over photons in loco-regional control both in adenoid cystic carcinoma and in other histotypes. Although chemotherapy is still the most frequent treatment for metastatic patients, several new compounds (i.e. anti-angiogenic agents, tailored agents, checkpoint inhibitors) are under investigation.

Chordomas: Histopathological Study in View of Anatomical Location

BACKGROUND

Chordomas are aggressive bone tumors that have a predilection for the axial skeleton including the skull base and spinal/sacral bones. However, the histopathological and clinical differences between skull base chordoma (SBC) and sacral/spinal chordoma (SC) are unclear as previous studies have been focused on patient prognosis and treatment outcome. This study aimed to evaluate the clinicopathologic features and prognosis of chordoma according to its location.

METHODS

Patients with chordomas were enrolled, and the histopathologic features were compared according to the tumor location.

RESULTS

A total of 52 patients were enrolled. SBCs had more abundant chondroid matrix and diffuse growth pattern, while SCs had non-chondroid, myxoid matrix and a lobulating pattern, typical of chordoma. Old age and residual tumors were risk factors for shorter overall survival in SBCs. The chondroid matrix was an independent risk factor for shorter disease-free survival in the overall population.

CONCLUSION

Chordomas have different histopathologic features depending on the anatomical location.

Endoscopic endonasal approaches for the management of cranial base malignancies: histologically guided treatment and clinical outcomes

Malignancies of the skull base represent a highly diverse and challenging set of pathologies which exhibit a wide array of oncologic behavior. In recent decades, a number of important advances in treatment technique have evolved to improve oncologic outcomes and reduce morbidity in the treatment of these aggressive cancers. Intensity modulated radiation therapy has become the gold standard in radiotherapy owing to its precision planning and reduced morbidity. However heavy ion particle radiation (proton therapy, carbon ion, etc.) are recently emerging with promising results at the skull base related to the reduced exit dose to adjacent structures. Novel systemic therapeutics such as targeted and immunotherapies may dramatically alter the treatment paradigm for many of these pathologies. Nevertheless, most skull base malignancies remain surgical diseases. The evolution of the expanded endonasal approach for a minimally invasive surgical resection has proven validity in treating many of these pathologies when properly selected, and have largely supplanted open approaches owing to the reduced morbidity profile. In spite of these important advances, the most critical aspect in comprehensive treatment is a detailed understanding of the oncologic behavior and outcomes data for each of the specific histopathologies encountered at the skull base. The nuances in management strategy, histologic profile, and surveillance planning can be stratified through the development of a comprehensive, multidisciplinary skull base team to maximize therapeutic effect and minimize morbidity for each patient. This review aims to summarize the key body of data and approaches for each of the histologies frequently encountered in the skull base, while highlighting the value and technique of endonasal approaches.

Immunophenotypic features of dedifferentiated skull base chordoma: An insight into the intratumoural heterogeneity

Chordomas are rare and low-grade malignant solid tumours, despite their histologically benign appearance, that arise in the bone from embryonic notochordal vestiges of the axial skeleton, a mesoderm-derived structure that is involved in the process of neurulation and embryonic development. Chordomas occurring in the skull base tend to arise in the basiocciput along the clivus. Three major morphological variants have been described (classical, chondroid, and atypical/dedifferentiated). The pathogenesis and molecular mechanisms involved in chordoma development remain uncertain. From a pathological standpoint, the microenvironment of a chordoma is heterogeneous, showing a dual epithelial-mesenchymal differentiation. These tumours are characterised by slow modality of biologic growth, local recurrence, low incidence of metastasis rates, and cancer stem cell (CSC) phenotype. The main molecular findings are connected with brachyury immunoexpression and activation of the downstream Akt and mTOR signalling pathways. The differentiation between typical and atypical chordomas is relevant because the tumoural microenvironment and prognosis are partially different. This review provides an insight into the recent and relevant concepts and histochemical markers expressed in chordomas, with special emphasis on dedifferentiated chordomas and their prognostic implications.

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.

Proton beam therapy for skull base chordomas in 106 patients: A dose adaptive radiation protocol

BACKGROUND AND PURPOSE

To evaluate clinical results and safety of a dose adaptive protocol based on tumor volume coverage and critical structure constraints, for the treatment of skull base chordomas.

MATERIAL AND METHODS

Between May 2006 and October 2012, 106 patients with skull base chordoma were treated by combined photon and proton irradiation. Prescribed dose levels were 68.4, 70.2, 72 and 73.8 Gy(RBE) in once daily fractionation of 1.8 Gy(RBE). Dose level and dosimetric constraints to organs at risk depended on postoperative residual Gross Tumor Volume (GTV) coverage. Local control (LC) and overall survival (OS) were evaluated using the Kaplan-Meier method.

RESULTS

With a median follow-up of 61 months, the 2-year, 4-year, and 5-year LC rates were 88.6%, 78.3%, and 75.1%, respectively. GTV > 25 mL (p = 0.034, HR = 2.22; 95%CI 1.06-4.62) was an independent unfavorable prognostic factor of LC. The 2-year, 4-year, and 5-year OS rates were 99%, 90.2%, and 88.3%, respectively. Grade 3-5 late toxicity was observed in 7 patients, resulting in 93% 5-year freedom from high-grade toxicity.

CONCLUSIONS

This study suggests that the probability of LC of skull base chordomas depends on postoperative GTV. The dose adaptive protocol achieves acceptable local control. Future studies should investigate whether further dose escalation to doses in excess of 74 Gy(RBE) would achieve better results.

Endoscopic Endonasal Management of Skull Base Chordomas: Surgical Technique, Nuances, and Pitfalls

Chordoma is a rare primary bone tumor derived from transformed notochord remnants. It has a local aggressive behavior and high recurrence rates. Treatment of skull base chordomas is complex and challenging. Control of the disease relies mainly on surgical excision of the tumor, sometimes followed by high-dose radiation therapy. The main surgical goal is to achieve maximal tumor removal with minimal morbidity. Development of the expanded endoscopic endonasal approach has improved surgical and prognostic results of skull base chordomas. This article highlights important aspects of approach selection, technique, and nuances of surgical management of this tumor.

The expanding role of the endonasal endoscopic approach in pituitary and skull base surgery: A 2014 perspective

BACKGROUND

The past two decades have been the setting for remarkable advancement in endonasal endoscopic neurosurgery. Refinements in camera definition, surgical instrumentation, navigation, and surgical technique, including the dual surgeon team, have facilitated purely endonasal endoscopic approaches to the majority of the midline skull base that were previously difficult to access through the transsphenoidal microscopic approach.

METHODS

This review article looks at many of the articles from 2011 to 2014 citing endonasal endoscopic surgery with regard to approaches and reconstructive techniques, pathologies treated and outcomes, and new technologies under consideration.

RESULTS

Refinements in approach and closure techniques have reduced the risk of cerebrospinal fluid leak and infection. This has allowed surgeons to more aggressively treat a variety of pathologies. Four main pathologies with outcomes after treatment were identified for discussion: pituitary adenomas, craniopharyngiomas, anterior skull base meningiomas, and chordomas. Within all four of these tumor types, articles have demonstrated the efficacy, and in certain cases, the advantages over more traditional microscope-based techniques, of the endonasal endoscopic technique.

CONCLUSIONS

The endonasal endoscopic approach is a necessary tool in the modern skull base surgeon's armamentarium. Its efficacy for treatment of a wide variety of skull base pathologies has been repeatedly demonstrated. In the experienced surgeon's hands, this technique may offer the advantage of greater tumor removal with reduced overall complications over traditional craniotomies for select tumor pathologies centered near the midline skull base.