Chordoma and chondrosarcoma: Similar, but quite different, skull base tumors

A single-center experience of the upright proton therapy for skull-base chordomas and chondrosarcomas: Updated results

Aim

To access efficacy and safety of the upright proton therapy for the skull-base chordomas and chondrosarcomas.

Materials and methods

The study encompasses single-center experience of proton therapy in chordomas (CA) and chondrosarcomas (CSA) of skull-base localization. We evaluate overall survival, local control and toxicity. Tumor response was assessed in accordance with RANO criteria. Treatment-related toxicity was evaluated with the help of CTCAE v 5.0 scale.

Results

Proton therapy in the upright position was utilized for 51pts (patients) with CA-CSA (40 pts with chordoma and 11pts with chondrosarcoma) at the A. Tsyb Medical Radiological Research Center in 2016-2023. Median tumor volume constituted 30 cm3 (IQR (interquartile range) 15-41 cm3). Median total dose was 70 GyRBE. Median number of fractions was 35. Overall survival (OS) at 1-, 2- and 3-year rates reached 98.0 %, 88.6 % and 82.7 %, respectively. Median follow-up time was 36 months. The 1-, 2- and 3-year local control (LC) rates constituted, respectively, 98 %, 78.6 % and 66.3 %. Prior surgery showed statistically significant association with better prognosis (p = 0.023). Brainstem-to-tumor dose coverage compromise became the major pattern of LC failure (p = 0.03). The late radiation toxicity reactions included temporal lobe necrosis grade 2 in 2 pts, xerostomia grade 1 in 1pt, radiation cataract grade 2 in 1pt and persistent headache grade 2 in 4 pts. Severe late toxicity reactions were observed in 2 cases (4 %): 1 myelitis grade 3 and brainstem damage grade 5 in 1pt.

Conclusion

Local control was achieved in the majority of patients receiving the scanning-beam upright proton therapy for skull-base CA-CSA. The LC rates after a surgery-radiotherapy combination treatment were higher compared with irradiation alone. Pattern of failure is mostly brainstem-tumor dose compromise. The high OS and LC rates were accompanied by low toxicity incidence. Even in complex case of the skull base CA-CSA upright proton therapy shows promising clinical outcomes.

Controversies in neuro-oncology: Focal proton versus photon radiation therapy for adult brain tumors

Radiation therapy (RT) plays a fundamental role in the treatment of malignant and benign brain tumors. Current state-of-the-art photon- and proton-based RT combines more conformal dose distribution of target volumes and accurate dose delivery while limiting the adverse radiation effects. PubMed was systematically searched from from 2000 to October 2023 to identify studies reporting outcomes related to treatment of central nervous system (CNS)/skull base tumors with PT in adults. Several studies have demonstrated that proton therapy (PT) provides a reduced dose to healthy brain parenchyma compared with photon-based (xRT) radiation techniques. However, whether dosimetric advantages translate into superior clinical outcomes for different adult brain tumors remains an open question. This review aims at critically reviewing the recent studies on PT in adult patients with brain tumors, including glioma, meningiomas, and chordomas, to explore its potential benefits compared with xRT.

Surgical management of chondrosarcomas of the skull-base and temporal bone

OBJECTIVES

To analyze the overall long-term outcome of surgically treated skull base and temporal bone chondrosarcomas.

METHODS

The medical records of patients with surgically treated skull base and temporal bone chondrosarcomas between 1983 and 2024 were thoroughly evaluated.

RESULTS

Out of a total of over 5000 skull base surgeries performed at our center, only 29 patients had histopathologically confirmed chondrosarcomas of the skull base and temporal bone. The mean of patients age was 45.6, and the male-to-female ratio was 1.9:1. The most common symptoms included hearing loss (58.6%), tinnitus (41.4%), diplopia (31%), dysphonia (24.1%), dysphagia (20.7%), vertigo (10.3%), and dizziness (10.3%). The most frequent locations of lesions among the 29 patients are as follows: petroclival region (34.5%), jugular foramen (27.6%), petrous apex (17.2%), middle ear (13.8%), others (3.4%). TO, IFTA, IFTB, IFTC, POTS, and combined surgical approaches were commonly used. The rate of gross total removal and recurrence was 82.6% and 13.8% respectively. The follow-up duration of 6 patients was more than five years and less than ten years whereas ten patients had more than ten years of follow-up.

CONCLUSIONS

Chondrosarcoma of the skull base and temporal bone is a very rare pathology. Due to its multiple potential sites of origin and histological specificity, it presents us with significant challenges. Gross total removal is the primary treatment for chondrosarcoma of the skull base and temporal bone. Personalized decision-making should be considered based on the following aspects: tumor, patient, and surgeon's factors. Postoperative radiation therapy is complementary to surgical treatment in grades II and III lesions to achieve long-term survival.

Systematic Review and Meta-Analysis of Particle Beam Therapy versus Photon Radiotherapy for Skull Base Chordoma: TRP-Chordoma 2024

[Objective] The aim of this study was to compare the efficacy of particle beam therapy (PT) with photon radiotherapy (RT) for treatment of skull base chordoma. [Methods] A systematic review was conducted for skull base chordoma treated with PT or photon RT reported from 1990 to 2022. Data were extracted for overall survival (OS) and progression-free survival (PFS), late adverse events, age, gender, gross total resection (GTR) rates, tumor volume, total irradiation dose, and treatment modality. Random-effects meta-regression analysis with the treatment modality as an explanatory variable was performed for each outcome to compare the modalities. [Results] A meta-analysis of 30 selected articles found 3- and 5-year OS rates for PT vs. photon RT or combined photon RT/proton beam therapy (PBT) of 90.8% (95% CI: 87.4-93.3%) vs. 89.5% (95% CI: 83.0-93.6%), p = 0.6543; 80.0% (95% CI: 75.7-83.6%) vs. 89.5% (95% CI: 83.0-93.6%), p = 0.6787. The 5-year PFS rates for PT vs. photon RT or photon RT/PBT were 67.8% (95% CI: 56.5-76.7%) vs. 40.2% (95% CI: 31.6-48.7%), p = 0.0004. A random-effects model revealed that the treatment modality (PT vs. photon RT or photon RT/PBT) was not a significant factor for 3-year OS (p = 0.42) and 5-year OS (p = 0.11), but was a significant factor for 5-year PFS (p < 0.0001). The rates of brain necrosis were 8-50% after PT and 0-4% after photon RT or photon RT/PBT. [Conclusion] This study shows that PT results in higher PFS compared to photon RT for skull base chordoma, but that there is a tendency for a higher incidence of brain necrosis with PT. Publication and analysis of further studies is needed to validate these findings.

Evaluation of cranial nerve involvement in chordomas and chondrosarcomas: a retrospective imaging study

PURPOSE

Cranial nerve involvement (CNI) influences the treatment strategies and prognosis of head and neck tumors. However, its incidence in skull base chordomas and chondrosarcomas remains to be investigated. This study evaluated the imaging features of chordoma and chondrosarcoma, with a focus on the differences in CNI.

METHODS

Forty-two patients (26 and 16 patients with chordomas and chondrosarcomas, respectively) treated at our institution between January 2007 and January 2023 were included in this retrospective study. Imaging features, such as the maximum diameter, tumor location (midline or off-midline), calcification, signal intensity on T2-weighted image, mean apparent diffusion coefficient (ADC) values, contrast enhancement, and CNI, were evaluated and compared using Fisher's exact test or the Mann-Whitney U-test. The odds ratio (OR) was calculated to evaluate the association between the histological type and imaging features.

RESULTS

The incidence of CNI in chondrosarcomas was significantly higher than that in chordomas (63% vs. 8%, P < 0.001). An off-midline location was more common in chondrosarcomas than in chordomas (86% vs. 13%; P < 0.001). The mean ADC values of chondrosarcomas were significantly higher than those of chordomas (P < 0.001). Significant associations were identified between chondrosarcomas and CNI (OR = 20.00; P < 0.001), location (OR = 53.70; P < 0.001), and mean ADC values (OR = 1.01; P = 0.002).

CONCLUSION

The incidence of CNI and off-midline location in chondrosarcomas was significantly higher than that in chordomas. CNI, tumor location, and the mean ADC can help distinguish between these entities.

Chordoma cancer stem cell subpopulation characterization may guide targeted immunotherapy approaches to reduce disease recurrence

Introduction

Cancer stem cells (CSCs), a group of tumor-initiating and tumor-maintaining cells, may be major players in the treatment resistance and recurrence distinctive of chordoma. Characterizing CSCs is crucial to better targeting this subpopulation.

Methods

Using flow cytometry, six chordoma cell lines were evaluated for CSC composition. In vitro, cell lines were stained for B7H6, HER2, MICA-B, ULBP1, EGFR, and PD-L1 surface markers. Eighteen resected chordomas were stained using a multispectral immunofluorescence (mIF) antibody panel to identify CSCs in vivo. HALO software was used for quantitative CSC density and spatial analysis.

Results

In vitro, chordoma CSCs express more B7H6, MICA-B, and ULBP1, assessed by percent positivity and mean fluorescence intensity (MFI), as compared to non-CSCs in all cell lines. PD- L1 percent positivity is increased by >20% in CSCs compared to non-CSCs in all cell lines except CH22. In vivo, CSCs comprise 1.39% of chordoma cells and most are PD-L1+ (75.18%). A spatial analysis suggests that chordoma CSCs cluster at an average distance of 71.51 mm (SD 73.40 mm) from stroma.

Discussion

To our knowledge, this study is the first to identify individual chordoma CSCs and describe their surface phenotypes using in vitro and in vivo methods. PD-L1 is overexpressed on CSCs in chordoma human cell lines and operative tumor samples. Similarly, potential immunotherapeutic targets on CSCs, including B7H6, MICA-B, ULBP1, EGFR, and HER2 are overexpressed across cell lines. Targeting these markers may have a preferential role in combating CSCs, an aggressive subpopulation likely consequential to chordoma's high recurrence rate.

Incidence and centralization of chordoma in the Netherlands: A nationwide study between 1991 and 2020

INTRODUCTION

Chordomas are rare malignant bone tumors arising in the axial skeleton, with an incidence of 0.3-0.88 per million inhabitants. We studied the annual incidence rate and centralization of treatment for chordoma in the Netherlands.

METHODS

We retrieved pathology excerpts from the PALGA nationwide Dutch Pathology Registry between 1991 and 2019 for patients with a chordoma to calculate incidence rates. From pathology reports we extracted patient age at diagnosis, sex, year of diagnosis, localization of primary tumor, histologic chordoma subtype (conventional including chondroid, poorly differentiated or dedifferentiated), center of diagnosis (bone tumor referral center (BTC) or other hospital), and partial identification of the BTCs.

RESULTS

A total of 420 individual chordoma patients were identified in the given time period. The incidence of chordoma increased from 0.593 per million inhabitants between 1991-1995 to 1.111 from 2015-2019 (P = 0.001). Median age at diagnosis was 63 years (range 1-95), 252 patients (60%) were male. The proportion of samples analyzed in a BTC either primarily or secondary, as a consultation, revision or referral, increased significantly from 29.3% to 84.4% (P < 0.001). Most primary and secondary samples were analyzed at the Leiden University Medical Center (LUMC, 54.4% and 57% respectively).

CONCLUSIONS

This study shows an increase in the standardized incidence of pathology proven chordoma in the Netherlands. We observed an increase in samples being analysed in the specialized BTCs as well, which is in line with current guidelines and will hopefully lead to more accurate diagnoses and optimal treatment plans for chordoma patients in specialized treatment centers.

Treatment of Clival Giant Cell Tumor: A Case Report and Literature Review

Giant cell tumors (GCTs) are locally aggressive primary bone tumors of osteoclast-like cells. Most GCTs occur within the long bones, and primary GCTs involving the clivus are extremely rare. We present the case of an 18-year-old boy with binocular horizontal diplopia with an insidious onset who was found to have a hypointense enhancing mass involving the clivus and left side dorsum sellae on magnetic resonance images. The tumor was completely resected via an endoscopic endonasal transclival approach, and histopathologic examination via immunohistochemistry indicated a GCT. The patient's left abducens nerve palsy improved slightly after surgery. Because of the rarity of GCTs, there is no consensus about the definitive treatment protocol. However, we suggest that gross total resection is the treatment of choice, and denosumab plays a critical role in patients with subtotal resection.

A systematic review and meta-analysis of radiotherapy and particle beam therapy for skull base chondrosarcoma: TRP-chondrosarcoma 2024

Introduction

Chondrosarcoma is a rare malignant bone tumor. Particle beam therapy (PT) can concentrate doses to targets while reducing adverse events. A meta-analysis based on a literature review was performed to examine the efficacy of PT and photon radiotherapy for skull base chondrosarcoma.

Methods

The meta-analysis was conducted using 21 articles published from 1990 to 2022.

Results

After PT, the 3- and 5-year overall survival (OS) rates were 94.1% (95% confidence interval [CI]: 91.0-96.2%) and 93.9% (95% CI: 90.6-96.1%), respectively, and the 3- and 5-year local control rates were 95.4% (95% CI: 92.0-97.4%) and 90.1% (95% CI: 76.8-96.0%), respectively. Meta-regression analysis revealed a significant association of PT with a superior 5-year OS rate compared to three-dimensional conformal radiotherapy (p < 0.001). In the studies used in the meta-analysis, the major adverse event of grade 2 or higher was temporal lobe necrosis (incidence 1-18%, median 7%).

Conclusion

PT for skull base chondrosarcoma had a good outcome and may be a valuable option among radiotherapy modalities. However, high-dose postoperative irradiation of skull base chondrosarcoma can cause adverse events such as temporal lobe necrosis.

Integrated Molecular and Histological Insights for Targeted Therapies in Mesenchymal Sinonasal Tract Tumors

PURPOSE OF REVIEW

This review aims to provide a comprehensive overview of mesenchymal sinonasal tract tumors (STTs), a distinct subset of STTs. Despite their rarity, mesenchymal STTs represent a unique clinical challenge, characterized by their rarity, often slow progression, and frequently subtle or overlooked symptoms. The complex anatomy of the sinonasal area, which includes critical structures such as the orbit, brain, and cranial nerves, further complicates surgical treatment options. This underscores an urgent need for more advanced and specialized therapeutic approaches.

RECENT FINDINGS

Advancements in molecular diagnostics, particularly in next-generation sequencing, have significantly enhanced our understanding of STTs. Consequently, the World Health Organization has updated its tumor classification to better reflect the distinct histological and molecular profiles of these tumors, as well as to categorize mesenchymal STTs with greater accuracy. The growing understanding of the molecular characteristics of mesenchymal STTs opens new possibilities for targeted therapeutic interventions, marking a significant shift in treatment paradigms. This review article concentrates on mesenchymal STTs, specifically addressing sinonasal tract angiofibroma, sinonasal glomangiopericytoma, biphenotypic sinonasal sarcoma, and skull base chordoma. These entities are marked by unique histopathological and molecular features, which challenge conventional treatment approaches and simultaneously open avenues for novel targeted therapies. Our discussion is geared towards delineating the molecular underpinnings of mesenchymal STTs, with the objective of enhancing therapeutic strategies and addressing the existing shortcomings in the management of these intricate tumors.

Diagnostics of IDH1/2 Mutations in Intracranial Chondroid Tumors: Comparison of Molecular Genetic Methods and Immunohistochemistry

Intracranial chondroid tumors are a heterogeneous group of neoplasms characterized by the presence of a cartilage matrix. These tumors exhibit overlapping clinical and histological features. Mutations in IDH1/2 genes serve as important diagnostic markers of tumor type, particularly chondrosarcoma. To improve the accuracy of IDH1/2 diagnostics, we compared three methods: biochip assay, real-time PCR with DNA melting analysis using TaqMan probes and sequencing (qPCR-DMA-Sanger), and immunohistochemistry (IHC). Tumor samples from 96 patients were investigated. The IDH1 mutations were detected in 34/64 (53%) chondrosarcomas; IHC detected 27/56 (48.2%) mutations, the qPCR-DMA-Sanger method 27/59 (46%) mutations, and the biochip assay revealed 29/60 (48.3%) mutations. The detection of IDH1 mutations in chordoma (2/15) and osteosarcoma (2/7) suggested the need for a revised diagnosis. In benign tumors, IDH1 mutations were present in chondroma (4/6), but absent in chondromyxoid fibroma (0/4). The most frequent IDH1 mutations were R132C (60%), R132L, and R132G (13.5% each), R132H (8%), and R132S (5%). The concordance between the biochip assay and IHC was 90%, between IHC and PCR-DMA-Sanger 83%, and between biochip assay and qPCR-DMA-Sanger was 98%, respectively. No IDH2 mutations were found. The use of independent diagnostic methods may improve the detection of IDH-mutant specimens in chondroid tumors.

[Transoral approach in surgery for chordomas extending into craniovertebral junction: a systematic review of the literature]

To date, treatment of chordomas involves maximal tumor resection followed by proton therapy. Various approaches are used depending on location of tumor (transcranial and through natural anatomical openings (nose, mouth), as well as their combinations). Although transoral approach has been introduced into neurosurgical practice for a long time, it is routinely used in patients with chordoma only in certain hospitals in the world.

OBJECTIVE

To analyze postoperative outcomes in patients with chordomas of skull base and craniovertebral joint after transoral surgery.

MATERIAL AND METHODS

We analyzed literature data devoted to patients with chordomas of skull base and craniovertebral joint after transoral surgery or another approach combined with transoral access. Among 111 primary articles, we selected 38 manuscripts including description of 109 patients with skull base chordoma who underwent transoral surgery or combination of approaches including transoral one.

RESULTS

Gross total resection was achieved in 45.9% (n=50) of cases including 1 patient after en bloc resection. Subtotal resection was carried out in 28.4% of cases, partial - in 24.8%, biopsy - in 0.9% of cases. The complication rate in this group was 30%. The most common events were swelling of the tongue (10%) and diastasis of posterior pharyngeal wall sutures (8.2%) that required redo surgery. CSF leakage and meningitis were rare (1.8% and 3.6%, respectively).

CONCLUSION

Transoral access allows for gross total resection of midline tumors with low incidence of severe complications. Combination of transoral and transcranial approaches is advisable to increase extent of resection.

Radical resection of intracavernous chondrosarcoma using an intradural keyhole approach: how I do it

BACKGROUND

Skull base chondrosarcoma is rare, arising from the clivus or petroclival junction, and usually presents as ocular motility disorders. Endonasal transsphenoidal surgery may be performed in some cases of midline clivus chondrosarcoma. Chondrosarcoma is located within the cavernous sinus and presents a softer/gelatinous mass and can be removed with suctions and curettage. We have been using a simple intradural keyhole transcavernous approach, avoiding a complex extradural transcavernous dissection.

METHODS

The intracavernous chondrosarcoma was removed via a 5 mm keyhole opening over the Parkinson's triangle using a standard frontotemporal intradural approach.

CONCLUSION

Minimally invasive keyhole surgical resection can be performed to eradicate skull base chondrosarcomas, avoiding complex extradural cranial base approaches.

Adjuvant Stereotactic Radiosurgery With or Without Postresection Fractionated Radiation Therapy for the Management of Clival Chordomas in Adults: An International Multicenter Case Series

BACKGROUND

Clival chordomas are challenging because of their proximity to critical neurovascular structures. Stereotactic radiosurgery (SRS) has been proven effective with minimal adverse effects.

OBJECTIVE

To compare the outcomes of histologically confirmed primary clival chordomas in adults who underwent SRS alone (SRS group) vs SRS after fractionated radiotherapy (FRT+SRS group).

METHODS

We collected patient data from 10 institutions affiliated with the International Radiosurgery Research Foundation. We evaluated overall survival, tumor control, and freedom from additional treatment (FFAT).

RESULTS

Fifty-seven (77%) patients were included in the SRS group and 17 (23%) in the FRT+SRS group. The median radiological follow-up was 48 months (IQR, 24-85) in the SRS group and 36 months (IQR, 25-41) in the FRT+SRS group. During the follow-up, 8 SRS and 2 FRT+SRS patients died ( P = .80). The groups had comparable 10-year overall survival (SRS: 76% vs FRT+SRS: 80%; logrank test, P = .75) and tumor control rates (SRS: 34% vs FRT+SRS: 45%; logrank test, P = .29). The SRS group had a superior 10-year FFAT rate (40%) compared with FRT+SRS (23%; logrank test, P = .02). This finding persisted in the multivariate analysis of the Cox proportional hazards illustrating a 2.40-fold increase in the relative risk of requiring additional treatment among the FRT+SRS group ( P = .04).

CONCLUSION

Adjuvant FRT with subsequent boost SRS did not provide superior overall survival or tumor control compared with patients who underwent adjuvant SRS alone. Further studies are required to refine management guidelines among adults with clival chordomas.

LOC554202 contributes to chordoma progression by sponging miR-377-3p and up-regulating SMAD3

Chordoma is a rare malignant bone tumor originating from the remnants of the notochord. Here, the role of long noncoding LOC554202 in chordoma progression and its associated mechanism were explored. Cell proliferation was analyzed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide and colony formation assays. Flow cytometry was conducted to analyze cell apoptosis rate. The migration and invasion of chordoma cells were analyzed by transwell migration and invasion assays and wound healing assays. A xenograft tumor model was established in nude mice to explore the role of LOC554202 in regulating tumor growth in vivo . The interaction between microRNA-377-3p (miR-377-3p) and LOC554202 or sekelsky mothers against d PP (SMAD) family member 3 (SMAD3) was verified by dual-luciferase reporter and RNA immunoprecipitation assays. The glycolytic rate of chordoma cells was analyzed using glucose assay kit, lactic acid kit and ApoSENSOR ADP/ATP ratio assay kit. LOC554202 expression was upregulated in chordoma tissues and cell lines. LOC554202 silencing suppressed the proliferation, migration and invasion and induced the apoptosis of chordoma cells. LOC554202 knockdown restrained xenograft tumor growth in vivo . miR-377-3p was confirmed as a target of LOC554202, and miR-377-3p silencing largely overturned LOC554202 knockdown-mediated anti-tumor effects in chordoma cells. miR-377-3p interacted with the 3' untranslated region (3'UTR) of SMAD3 and miR-377-3p overexpression-mediated antitumor effects in chordoma cells were largely attenuated by SMAD3 overexpression. LOC554202 could positively regulate SMAD3 expression by sponging miR-377-3p in chordoma cells. LOC554202 contributed to the glycolysis of chordoma cells by targeting binding to miR-377-3p/SMAD3 axis. LOC554202 facilitated the proliferation, migration, invasion and glycolysis and inhibited the apoptosis of chordoma cells by mediating miR-377-3p/SMAD3 axis.

Clinical Characteristics and Prognostic Risk Factors of Parasellar Chondrosarcoma

Background: Parasellar chondrosarcomas are extremely rare. This study describes the characteristics of parasellar chondrosarcoma and analyzes the risk factors and prognosis based on the resection degree. Methods: Fifteen patients with pathologically diagnosed parasellar chondrosarcoma were retrospectively analyzed for the clinical data, surgical methods, and prognosis to identify relationships between the surgical resection degree, tumor recurrence, and imaging characteristics. Results: Twelve patients had eye dysfunction and ptosis. Differentiation from other parasellar tumors by imaging is difficult. The preoperative Karnofsky Performance Scale (KPS) score positively correlated with the tumor resection degree (p = 0.026) and negatively correlated with the maximum tumor diameter (p = 0.001). Tumor recurrence negatively correlated with the resection degree (p = 0.009). The postoperative KPS score positively correlated with the preoperative KPS score (p < 0.001) and tumor resection degree (p = 0.026), and negatively correlated with the maximum tumor diameter (p = 0.016) and age (p = 0.047). An improved KPS score positively correlated with the tumor resection degree (p = 0.039). Patients who underwent total resection of the chondrosarcoma had longer progression-free survival than those who underwent partial resection (p = 0.0322). Conclusion: Parasellar chondrosarcomas are difficult to resect completely. Preoperative KPS score is an important factor for the degree of resection. KPS score, age, maximum tumor diameter, and resection degree may be important prognostic factors.

Outcomes of Gamma Knife radiosurgery for skull base chondrosarcomas: a multi-institutional retrospective study

OBJECTIVE

Radiotherapy has an essential role in the management of skull base chondrosarcomas (SBCs) after resection. This multi-institutional study evaluated the outcomes of Gamma Knife radiosurgery (GKRS) for histopathologically proven SBCs.

METHODS

Data of patients who underwent GKRS for SBCs at Gamma Knife centers in Japan were retrospectively collected. Patients without a histopathological diagnosis and those who had intracranial metastases from extracranial chondrosarcomas were excluded. Histologically, grade III and some nonconventional variants were identified as aggressive types. The cumulative local control rates (LCRs) and disease-specific survival (DSS) rates were calculated using the Kaplan-Meier method. Factors potentially affecting the LCR were evaluated using the Cox proportional hazards model for bivariate and multivariate analyses. The incidence of radiation-induced adverse effects (RAEs) was calculated as crude rates, and factors associated with RAEs were examined using Fisher's exact test.

RESULTS

Fifty-one patients were enrolled, with a median age of 38 years. Thirty patients (59%) were treated with upfront GKRS for residual SBCs after resection (n = 27) or biopsy (n = 3), and 21 (41%) underwent GKRS as a salvage treatment for recurrence. The median tumor volume was 8 cm3. The overall LCRs were 87% at 3 years, 78% at 5 years, and 67% at 10 years after GKRS. A better LCR was associated with a higher prescription dose (p = 0.039) and no history of repeated recurrence before GKRS (p = 0.024). The LCRs among patients with the nonaggressive histological type and treatment with ≥ 16 Gy were 88% at 3 years, 83% at 5 years, and 83% at 10 years. The overall survival rates after GKRS were 96% at 5 years and 83% at 10 years. Although RAEs were observed in 3 patients (6%), no severe RAEs with Common Terminology Criteria for Adverse Events grade 3 or higher were identified. No significant factor was associated with RAEs.

CONCLUSIONS

GKRS for SBCs has a favorably low risk of RAEs and could be a reasonable therapeutic option for SBC in multimodality management. A sufficient GKRS prescription dose is necessary for higher LCRs. Histological grading and subtype evaluations are important for excluding exceptional SBCs. Patients with conventional SBCs have a long life expectancy and should be observed for life after treatment.

Differentiation of Skull Base Chondrosarcomas, Chordomas, and Metastases: Utility of DWI and Dynamic Contrast-Enhanced Perfusion MR Imaging

BACKGROUND AND PURPOSE

Differentiation of skull base tumors, including chondrosarcomas, chordomas, and metastases, on conventional imaging remains a challenge. We aimed to test the utility of DWI and dynamic contrast-enhanced MR imaging for skull base tumors.

MATERIALS AND METHODS

Fifty-nine patients with chondrosarcomas, chordomas, or metastases between January 2015 and October 2021 were included in this retrospective study. Pretreatment normalized mean ADC and dynamic contrast-enhanced MR imaging parameters were calculated. The Kruskal-Wallis H test for all tumor types and the Mann-Whitney U test for each pair of tumors were used.

RESULTS

Fifteen chondrosarcomas (9 men; median age, 62 years), 14 chordomas (6 men; median age, 47 years), and 30 metastases (11 men; median age, 61 years) were included in this study. Fractional plasma volume helped distinguish all 3 tumor types (P = .003, <.001, and <.001, respectively), whereas the normalized mean ADC was useful in distinguishing chondrosarcomas from chordomas and metastases (P < .001 and P < .001, respectively); fractional volume of extracellular space, in distinguishing chondrosarcomas from metastases (P = .02); and forward volume transfer constant, in distinguishing metastases from chondrosarcomas/chondroma (P = .002 and .002, respectively) using the Kruskal-Wallis H test. The diagnostic performances of fractional plasma volume for each pair of tumors showed areas under curve of 0.86-0.99 (95% CI, 0.70-1.0); the forward volume transfer constant differentiated metastases from chondrosarcomas/chordomas with areas under curve of 0.82 and 0.82 (95% CI, 0.67-0.98), respectively; and the normalized mean ADC distinguished chondrosarcomas from chordomas/metastases with areas under curve of 0.96 and 0.95 (95% CI, 0.88-1.0), respectively.

CONCLUSIONS

DWI and dynamic contrast-enhanced MR imaging sequences can be beneficial for differentiating the 3 common skull base tumors.

Surgical Strategies and Outcomes for Intracranial Chondromas: A Retrospective Study of 17 Cases and Systematic Review

Objective

To improve the diagnosis and treatment of intracranial chondromas (ICDs) by discussing the clinical manifestations and imaging characteristics of ICDs, as well as surgical methods and treatment strategies.

Methods

We retrospectively analyzed 17 patients diagnosed with ICDs who underwent microsurgery or endoscopic transsphenoidal surgery at the Tangdu Hospital of Air Force Military Medical University and the Mianyang Central Hospital from January 2010 to November 2021. Clinical manifestations, imaging examinations, surgical treatments, and prognosis of these patients were analyzed.

Results

ICDs had often been misdiagnosed as craniopharyngioma, chordoma, schwannoma, cavernous hemangioma, pituitary adenoma, and meningioma before surgery. Of the 17 cases, gross total resection (GTR) was performed in 10 cases, subtotal resection (STR) in 5, and partial resection in 2. GTR of tumor was achieved in eight cases via the endoscopic endonasal transsphenoidal approach (EETA) or the extended endoscopic endonasal transsphenoidal approach (EEETA), and the remaining patients underwent craniotomies. Clinical symptoms were assessed 1 week after surgery, 10 cases were relieved at varying degrees, and four cases had no improvement. Postoperative complications included right-limb hemiparesis, diplopia, eyelid ptosis, pulmonary infection, subcutaneous hydrops, cerebrospinal-fluid leakage (CSFL), and intracranial infection (ICI). One patient received gamma knife treatment at 3 months after surgery, two patients died due to tumor progression, and the remaining patients had no tumor recurrence.

Conclusions

ICDs lack typical imaging features and are often misdiagnosed. The EETA or EEETA helps improve the surgical outcomes and GTR rates of ICDs at different sites.

Chondrosarcoma and Chordoma of the Skull Base and Spine: Implication of Tumor Location on Patient Survival

BACKGROUND

Chondrosarcoma and chordoma are often grouped together because of their similar anatomic locations, clinical presentations, histopathological and radiological findings, and growth patterns. In the present study, we investigated the clinical and prognostic differences of chondrosarcomas and chordomas of the skull base and spine.

METHODS

We accessed the Surveillance, Epidemiology, and End Results database to search for patients from 2000 to 2018 with chondrosarcomas and chordomas of the skull base and spine for inclusion in the present study.

RESULTS

We included 1346 and 1536 cases of chondrosarcoma and chordoma for analysis, respectively. Chondrosarcomas of the cranial base and spine were seen in younger patients and were associated with a larger tumor size compared with chordomas. Among the tumors of the skull base, chondrosarcomas were more common in women, with a male predominance found for chordomas. We also observed a male predilection for both spinal chondrosarcomas and chordomas. Distinct metastatic patterns were found for chondrosarcomas versus chordomas, and spinal chondrosarcomas showed a greater risk of distant metastases at presentation compared with spinal chordomas. Cranial base chondrosarcomas were associated with superior outcomes compared with chordomas. However, we demonstrated an opposite survival pattern for spinal chondrosarcomas and chordomas.

CONCLUSIONS

Chondrosarcomas and chordomas have divergent clinical manifestations and prognoses depending on the anatomic location.

Multimodal Intraoperative Image-Driven Surgery for Skull Base Chordomas and Chondrosarcomas

Given the difficulty and importance of achieving maximal resection in chordomas and chondrosarcomas, all available tools offered by modern neurosurgery are to be deployed for planning and resection of these complex lesions. As demonstrated by the review of our series of skull base chordoma and chondrosarcoma resections in the Advanced Multimodality Image-Guided Operating (AMIGO) suite, as well as by the recently published literature, we describe the use of advanced multimodality intraoperative imaging and neuronavigation as pivotal to successful radical resection of these skull base lesions while preventing and managing eventual complications.

Long-term outcome of adjunctive Gamma Knife radiosurgery in skull-base chordomas and chondrosarcomas: An Indian experience

Skull-base chordomas (CD) and chondrosarcomas (CS) are locally-invasive tumors, have similar clinical presentations, while differing in their nature of growth and outcomes. In this study, we compare the long-term outcomes of Gamma Knife Radiosurgery (GKRS) as an adjunctive treatment modality for residual skull-base CD and CS. A retrospective analysis of clinico-radiological, pathological, radiotherapeutic and outcome data was carried out in patients who underwent adjunctive GKRS for residual skull-base CD and CS at P D Hinduja Hospital, Mumbai, between 1997 and 2020. All 27 patients included had either histopathologically proven CD (20 patients) or CS (7 patients). Brachyury immunohistochemistry in CD specimens gave 70.6% positivity. Total sessions of GKRS in CD and CS groups were 22 and 7, respectively. Mean tumor volume and mean margin dose in CD group were 6.53 ± 4.18 cm3 and 15.95 ± 1.49 Gy respectively, while for CS group, they were 4.16 ± 2.79 cm3 and 18.29 ± 3.15 Gy. With mean follow-up periods of 5.25 ± 4.73 years and 6 ± 2.07 years respectively, the CD and CS groups showed 5-year progression free survival (PFS) of 56.8% and 57.1%, and a 5-year overall survival (OS) of 82.1% and 100%. Sub-group analysis in both CD and CS groups revealed a better 5-year PFS with the following factors - CS histopathology, patient age < 45 years, margin dose > 16 Gy, tumor volume < 7 cm3 (p-value < 0.05), gross total resection, and brachyury positivity. Adjunctive radiotherapy for skull-base CD and CS holds promise.

Intraoperative Magnetic Resonance Imaging Assisted Endoscopic Endonasal Resection of Clival Chordomas

BACKGROUND

Cranial base chordomas are typically indolent and usually appear as encapsulated tumors. They slowly grow by infiltrating the bone, along with the lines of least resistance. Due to its relationship with important neurovascular structures, skull base chordoma surgery is challenging.

OBJECTIVE

The usefulness of intraoperative magnetic resonance imaging (IO-MRI) in achieving the goal of surgery, is evaluated in this study.

METHODS

Between March 2018 and March 2020, 42 patients were operated on for resection of skull base chordomas in our institution. All of them were operated on under IO-MRI. Patients were analyzed retrospectively for identifying common residue locations, complications and early post-operative outcomes.

RESULTS

In 22 patients (52,4%) gross total resection was achieved according to the final IO-MRI. In 20 patients (47,6%) complete tumor removal was not possible because of extension to the petrous bone (8 patients), pontocerebellar angle (6 patients), prepontine cistern (4 patients), temporobasal (1 patient), cervical axis (1 patient). In 13 patients, the surgery was continued after the first IO-MRI control was performed, which showed a resectable residual tumor. 7 of these patients achieved total resection according to the second IO-MRI, in the other 6 patients all efforts were made to ensure maximal resection of the tumor as much as possible without morbidity. Repeated IO-MRI helped achieve gross total resection in 7 patients (53.8%).

CONCLUSIONS

Our study proves that the use of IO-MRI is a safe method that provides the opportunity to show the degree of resection in skull base chordomas and to evaluate the volume and location of the residual tumor intraoperatively. Hence IO-MRI can improve the life expectancy of patients because it provides an opportunity for both gross total resection and maximal safe resection in cases where total resection is not possible.

Imaging features of cartilaginous tumors of the head and neck

There is a wide spectrum of head and neck cartilaginous lesions which include both neoplastic and nonneoplastic processes. Cartilaginous tumors of the head and neck are uncommon, posing a diagnostic challenge. Benign cartilaginous tumors that may occur in the head and neck include chondroma, chondroblastoma, chondromyxoid fibroma, osteochondroma, and synovial chondromatosis. Chondromesenchymal hamartoma is a rare non-neoplastic cartilaginous lesion that is included for the 1first time in the new WHO classification and radiologically can mimic a tumor. Malignant cartilaginous tumors include chondrosarcoma and chondroid variant of chordoma. Characteristic tumor locations, internal chondroid matrix calcification, and typical T2 hyperintense signal secondary to high-water content within the extracellular matrix of the hyaline cartilage are useful imaging features that narrow the differential diagnosis and help in diagnosing these diseases. This article presents a narrative review of the anatomy of the head and neck cartilaginous structures, discusses the current knowledge and imaging spectrum of benign and malignant cartilaginous tumors and tumor-like lesions of the head and neck.

Sellar, suprasellar, and parasellar masses: Imaging features and neurosurgical approaches

The sellar, suprasellar, and parasellar space contain a vast array of pathologies, including neoplastic, congenital, vascular, inflammatory, and infectious etiologies. Symptoms, if present, include a combination of headache, eye pain, ophthalmoplegia, visual field deficits, cranial neuropathy, and endocrine manifestations. A special focus is paid to key features on CT and MRI that can help in differentiating different pathologies. While most lesions ultimately require histopathologic evaluation, expert knowledge of skull base anatomy in combination with awareness of key imaging features can be useful in limiting the differential diagnosis and guiding management. Surgical techniques, including endoscopic endonasal and transcranial neurosurgical approaches are described in detail.

Chondrosarcoma of the spine: a narrative review

Chondrosarcoma is an uncommon primary bone tumor with an estimated incidence of 0.5 per 100,000 patient-years. Primary chondrosarcoma of the mobile spine and sacrum cumulatively account for less than 20% of all cases, most .commonly causing patients to present with focal pain with or without radiculopathy, or myelopathy secondary to neural element compression. Because of the rarity, patients benefit from multidisciplinary care at academic tertiary-care centers. Current standard-of-care consists of en bloc surgical resection with negative margins; for high grade lesions adjuvant focused radiation with ≥60 gray equivalents is taking an increased role in improving local control. Prognosis is dictated by lesion grade at the time of resection. Several groups have put forth survival calculators and epidemiological evidence suggests prognosis is quite good for lesions receiving R0 resection. Future efforts will be focused on identifying potential chemotherapeutic adjuvants and refining radiation treatments as a means of improving local control.

Giant Ossified Clival Chondrosarcoma Resection: 2-Dimensional Operative Video

Chondrosarcomas are a spectrum of tumors with variable clinical behavior, histologically classified as grades I, II, and III.1 Maximal surgical resection with adjuvant radiation is the gold standard for grade III malignant tumors.2,3 Lower-grade skull base chondrosarcomas have a slow progressive local growth pattern with an overall benign profile.1,4 In these grade I and II tumors, radical resection can be sufficient in achieving long-term control of the disease without the need for adjuvant therapy, thus avoiding the long-term side effects of irradiation in relatively young patients.4,5 As a slow-growing tumor, skull base chondrosarcoma might reach a giant size with progressive neurological deficits prior to diagnosis. In these cases, to achieve maximal resection, skull base approaches tailored to the patient's anatomy are essential.4,6 Cranial approach is frequently needed due to the calcified nature of part of the tumor that is not amenable to resection through the endonasal approach. The endoscope is extremely helpful combined with the microscopic resection. We demonstrate these techniques through in the surgery of a 39-yr-old female who presented with progressive neurological deficits from a giant ossified chondrosarcoma and underwent a combined petrosal approach for the resection of her tumor. A postoperative small enhancement remained stable on the 4-yr follow-up exam. The pathology confirmed grade II chondrosarcoma, with the patient recovering from her neurological deficit except the third nerve. The patient consented to the surgery and publication of images.  Image at 1:36 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, ©LWW, 1998.

Intracranial chordoma: radiosurgery, hypofractionated stereotactic radiotherapy and treatment outcomes

Background

The aim of the study was to assess the results of stereotactic radiosurgery and hypofractionated stereotactic radiotherapy (SRS/SRT) for skull base chordomas.

Materials and methods

Twenty-three patients aged 12-75 were treated with SRS/SRT due to skull base chordoma. In 19 patients SRS/SRT was a part of the primary therapy, while in 4, a part of the treatment of recurrence. In 4 patients SRS/SRT was used as a boost after conventional radiotherapy and in 19 cases it was the only irradiation method applied. Patients were irradiated to total dose of 6-35 Gy and median total equivalent dose of 52 Gy.

Results

During median follow-up of 39 months, 4 patients died. One-, two- and five-year OS was 95%, 89% and 69%, respectively. In nine patients, progression of the disease was diagnosed during study period. One-, two- and five-year progression free survival (PFS) from the end of radiotherapy was 81%, 59% and 43%, respectively. Radiotherapy was well tolerated and only two patients in our group experienced moderate treatment-related toxicity.

Conclusion

SRS/SRT alone or in combination with surgery is a safe and effective method of irradiation of patients with skull base chordomas. High EQD₂ is necessary to achieve satisfactory treatment results.

Mid-term follow-up surgical results in 284 cases of clival chordomas: the risk factors for outcome and tumor recurrence

Objective

Skull base chordoma (SBC) is rare and one of the most challenging diseases to treat. We aimed to assess the optimal timing of adjuvant radiation therapy (RT) and to evaluate the factors that influence resection and long-term outcomes.

Methods

In total, 284 patients with 382 surgeries were enrolled in this retrospective study. Postsurgically, 64 patients underwent RT before recurrence (pre-recurrence RT), and 47 patients underwent RT after recurrence. During the first attempt to achieve gross-total resection (GTR), when the entire tumor was resected, 268 patients were treated with an endoscopic midline approach, and 16 patients were treated with microscopic lateral approaches. Factors associated with the success of GTR were identified using χ² and logistic regression analyses. Risk factors associated with chordoma-specific survival (CSS) and progression-free survival (PFS) were evaluated with the Cox proportional hazards model.

Results

In total, 74.6% of tumors were marginally resected [GTR (40.1%), near-total resection (34.5%)]. History of surgery, large tumor volumes, and tumor locations in the lower clivus were associated with a lower GTR rate. The mean follow-up period was 43.9 months. At the last follow-up, 181 (63.7%) patients were alive. RT history, histologic subtype (dedifferentiated and sarcomatoid), non-GTR, no postsurgical RT, and the presence of metastasis were associated with poorer CSS. Patients with pre-recurrence RT had the longest PFS and CSS, while patients without postsurgical RT had the worst outcome.

Conclusion

GTR is the goal of initial surgical treatment. Pre-recurrence RT would improve outcome regardless of GTR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10143-021-01576-4.

Transcavernous Resection of an Upper Clival Chondrosarcoma: "Cavernous Sinus as a Route": 2-Dimensional Operative Video

Complete resection of skull base chondrosarcomas offers the potential for a durable, or even lifelong, cure and is best achieved at the first surgery.1,2 When a skull base chondrosarcoma is located at the upper clivus and in the interpeduncular cistern and invading laterally toward the petrous apex and cavernous sinus, the traditional approaches, ie, endonasal endoscopic or middle fossa approaches, are not adequate for the exposure and resection. The transcavernous sinus approach has been utilized to remove tumor from the cavernous sinus and as a corridor to the interpeduncular cistern and upper clivus, originally described for the clipping of basilar apex aneurysms. We present a case of a chondrosarcoma centered in the upper clivus and eroding the right posterior clinoid, analogous to the location of a giant basilar apex aneurysm. Detailed study of the tumor extension, bony invasion, and relationship with neuroanatomy dictated the most effective surgical approach.3,4 Neuronavigation and intraoperative magnetic resonance imaging (MRI) facilitated the gross total resection of the tumor in the Advanced Multimodality Image-Guided Operating (AMIGO) suite. Achieving a gross total tumor removal of this World Health Organization (WHO) grade I chondrosarcoma, adjuvant irradiation can be withheld1 and the patient monitored with serial imaging. The patient did well after the surgery. The patient consented for surgery and the use of photography.

Recurrent Chordoma Resection in the Advanced Multimodality Image Guided Operating Suite: 2-Dimensional Operative Video

Recurrent skull base chordomas are challenging lesions. They already had maximum radiation, and in the absence of any effective medical treatment, surgical resection is the only treatment.1,2 Surgery on recurrent previously radiated chordomas, however, carries much higher risk and the likelihood of subtotal resection. Maximizing tumor resection allows longer tumor control.3-5 The Advanced Multimodality Image Guided Operating Suite developed at the Brigham and Women's Hospital, Harvard Medical School, with the support of the National Institutes of Health, provides an optimal environment to manage these tumors. It offers the capability to obtain and integrate multiple modalities during surgery, including magnetic resonance imaging (MRI), positron emission tomography-computed tomography (PET-CT), endoscopy, ultrasound, fluoroscopy, and the ability to perform emergent endovascular procedures.5-7 The patient is a 39-yr-old male, presenting after 19 yr follow-up of a surgical resection and proton beam treatment for a skull base chordoma. He developed progressive ophthalmoplegia due to recurrence of his chordoma at the right petrous apex and cavernous sinus. Preoperative angiography demonstrated narrowing of the petrous segment of the right carotid artery suspect of radiation-induced angiopathy. The presence of radiation-induced angiopathy increases the risk of intraoperative carotid rupture, and the availability of endovascular intervention in the operative suite added favorable preparedness to deal with such complications if they happen. Given the clinical and radiological progression, surgical intervention was carried out through the prior zygomatic approach with the goal of performing maximum resection.8 The patient had an uneventful postoperative course and remained stable until he had a second recurrence 4 yr later. The patient consented to the procedure.

A clinical approach to parasellar lesions in the transition age

Many reviews have summarised the pathology and management of the parasellar region in adult patients, although an analysis of these aspects in the transition years, from puberty onset to the age of peak bone mass, has been lacking. A comprehensive search of English-language original articles, published from 2000 to 2020, was conducted in the MEDLINE database (December 2019 to March 2020). We selected all studies regarding epidemiology, diagnosis and management of the following parasellar lesions: germinoma, craniopharyngioma, Langerhans cell histiocytosis, optic glioma, hypothalamic hamartoma, tuber cinereum hamartoma, cranial chordoma, Rathke cleft cyst, hypophysitis and hypothalamitis during the transition age from childhood to adulthood. In the present review, we provide an overview of the principal parasellar lesions occurring in the transition age. Symptoms are usually a result of the mass effect of the lesions on nearby structures, as well as anterior pituitary deficits. Diabetes insipidus occurs frequently in these patients. In this age group, pubertal developmental disorders may be more evident compared to other stages of life. Parasellar lesions in the transition age mostly include neoplastic lesions such as germinomas, hamartomas, optic gliomas, craniopharyngiomas Langerhans cell histiocytosis and chordomas, and rarely inflammatory lesions (hypophysitis, hypothalamitis). There are limited data on the management of parasellar lesions in the transition age. Endocrine evaluation is crucial for identifying conditions that require hormonal treatment so that they can be treated early to improve the quality of life of the individual patient in this complex age range. The clinical approach to parasellar lesions involves a multidisciplinary effort.

Skull base chondrosarcoma presenting with parenchymal hemorrhage: A case report

Chondrosarcoma (CS) is a locally invasive, slow growing malignant neoplasm. Intracranial chondrosarcoma are extradural osseous lesions and intradural location with intratumoral hemorrhage is very rare. We report a rare case of 65-year-old male presenting with a small mass in left posterior skull base and later, suddenly deteriorating due to large cerebellar hemorrhage. A brief review of literature of such cases is also presented.

Long-term outcomes of grade I/II skull base chondrosarcoma: an insight into the role of surgery and upfront radiotherapy

PURPOSE

To clarify the need for post-operative radiation treatment in skull base chondrosarcomas (SBCs).

METHODS

A retrospective analysis of patients with grade I or II SBC. Patients were divided according to post-surgical treatment strategies: (A) planned upfront radiotherapy and (B) watchful waiting. Tumor control and survival were compared between the treatment groups. The median follow-up after resection was 105 months (range, 9-376).

RESULTS

Thirty-two patients (Grade 1, n = 16; Grade 2, n = 16) were included. The most frequent location was petroclival (21, 64%). A gross total resection (GTR) was achieved in 11 patients (34%). Fourteen (44%) underwent upfront radiotherapy (group A) whereas 18 (56%) were followed with serial MRI alone (group B). The tumor control rate for the entire group was 77% and 69% at 10- and 15-year, respectively. Upfront radiotherapy (P = 0.25), extent of resection (P = 0.11) or tumor grade (P = 0.83) did not affect tumor control. The majority of Group B patients with recurrent tumors (5/7) obtained tumor control with repeat resection (n = 2), salvage radiotherapy (n = 2), or a combination of both (n = 1). The 10-year disease-specific survival was 95% with no difference between the group A and B (P = 0.50).

CONCLUSION

For patients with grade I/II SBC, a reasonable strategy is deferral of radiotherapy after maximum safe resection until tumor progression or recurrence. At that time, most patients can be successfully managed with salvage radiotherapy or surgery. Late recurrences may occur, and life-long follow-up is advisable.

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.

Chordomas and chondrosarcomas of the skull base: treatment and outcome analysis in a consecutive case series of 24 patients

Background

We present our 9-year consecutive case series of skull base chordomas and chondrosarcomas from a UK tertiary referral centre, discussing treatments offered and outcomes. This was carried out to improve understanding around current treatment and to better inform the management of future patients.

Methods

Consecutive case series over a 9-year period (2007–2016). Retrospective data analysis from the electronic skull base multidisciplinary team database and the digital patient records at a UK tertiary referral centre

Results

Twenty-four patients were identified (11 chordomas, 13 chondrosarcomas, mean age 52). Nineteen had proton beam therapy (PBT) postoperatively; two had intensity-modulated radiotherapy; two had no further treatment. One patient was lost to follow-up. All chordomas were resected via a transnasal endoscopic approach. Of the 19 patients undergoing resection with PBT, 13 were disease free at latest follow-up, and six patients had local recurrence, of which two died (mean follow up 7.4 years). Of the three patients treated with surgery then IMRT/TomoTherapy, one died 4 years post-treatment, and the other two are alive after 4 and 5 years of follow-up respectively. Of the two patients treated with surgery alone, one was lost to follow-up, and the other is alive after more than 8 years. Chondrosarcoma 5-year survival was 91.6%, and chordoma 4-year survival was 75%.

Conclusion

Skull base chordomas and chondrosarcomas can be challenging to resect, and most cases require adjuvant therapy to achieve control. Where complete resection is not possible, it is critical to undertake sufficient resection to permit high-dose radiation.

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.

Intra-cranial Chondroma: A Case Report and Problematic Diagnosis

Introduction:

Chondroma is a benign cartilaginous tumor. It is found very rarely in the head and neck.

Case presentation:

This report describes a 25-year-old woman who presented with generalized headache from 4 months ago. The patient underwent excisional surgery. The histological examinations revealed benign cartilage forming tumor, compatible with chondroma. The radiologic and histologic correlation confirmed the diagnosis. Based on the diagnosis, the patient received no more treatment.

Conclusion:

We concluded that intracranial chondroma should be included in the differential diagnosis of a calcified mass on skull imaging. Proper diagnosis is necessary for further patient management.

Vertebrobasilar Artery Encasement by Skull Base Chordomas: Surgical Outcome and Management Strategies

BACKGROUND

Vascular encasement by skull base chordomas can increase surgical risk and hinder completeness of resection. However, the evidence behind this remains anecdotic.

OBJECTIVE

To give a better portrayal of chordomas encasing vertebrobasilar arteries mainly in regard of surgical vascular risk and its impact on extent of resection.

METHODS

A retrospective cohort study comparing skull base chordomas with encasement (≥180o encirclement) of the vertebrobasilar arteries to a control group of skull base chordomas with intradural extension. Data gathered involved pre- and postoperative volumetric analysis of the tumor, degree of encasement of involved vessel, occurrence of complication, and survival data including progression-free survival (PFS) and overall survival (OS).

RESULTS

A total of 24 patients with vertebrobasilar encasement were included in the study and an equal number of control cases were randomly selected from the same time period, totalizing 48 patients. Lower clival tumors with condyle involvement were more likely to have encasement. Gross total resection (GTR) rate was significantly lower in the encasement group (13% vs 42%, P = .023). Rates of postoperative new neurological deficit, CFS leak and 30 d postoperative mortality were not statistically different between groups. There was no statistically significant difference in mean PFS (P = .608) and OS (P = .958).

CONCLUSION

Skull base chordomas encasing vertebrobasilar arteries are highly challenging tumors. This study demonstrates that although safe resection is possible, GTR is hindered by the presence of encasement. We advocate letting the tumor's adherence to vessels lead the resection, leaving a small piece of tumor behind if adherent to the vessels.

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.

Translational Windows in Chordoma: A Target Appraisal

Chordomas are rare tumors that are notoriously refractory to chemotherapy and radiotherapy when radical surgical resection is not achieved or upon recurrence after maximally aggressive treatment. The study of chordomas has been complicated by small patient cohorts and few available model systems due to the rarity of these tumors. Emerging next-generation sequencing technologies have broadened understanding of this disease by implicating novel pathways for possible targeted therapy. Mutations in cell-cycle regulation and chromatin remodeling genes have been identified in chordomas, but their significance remains unknown. Investigation of the immune microenvironment of these tumors suggests that checkpoint protein expression may influence prognosis, and adjuvant immunotherapy may improve patient outcome. Finally, growing evidence supports aberrant growth factor signaling as potential pathogenic mechanisms in chordoma. In this review, we characterize the impact on treatment opportunities offered by the genomic and immunologic landscape of this tumor.

LncRNA XIST Promotes Growth of Human Chordoma Cells by Regulating miR-124-3p/iASPP Pathway

Introduction

Chordoma is a malignant primary bone tumor that is found in the spine and skull. X-inactive specific transcript (XIST) is a long non-coding RNA (lncRNA) is known to be involved in the development of various cancers, but its precise function and mechanism in human chordoma have not been elucidated. Here, we investigated the role of lncRNA XIST in chordoma progression.

Methods

Quantitative real time-polymerase chain reaction (qRT-PCR) was performed to determine lncRNA XIST expression in human chordoma tissues and matched-noncancerous tissues. Western blot was used to determine protein expression. Silencing and overexpression of lncRNA XIST were carried out by RNA interference (RNAi) and lentiviral transduction, respectively. Cell Counting Kit-8 (CCK-8) assay and flow cytometry were employed to examine the effects of lncRNA XIST on growth of human chordoma cells. Lastly, the role of lncRNA XIST in vivo was explored using a xenograft model.

Results

We found that lncRNA XIST expression was upregulated in chordoma and strongly correlated with poor patient prognosis. Moreover, lncRNA XIST promoted proliferation and inhibited apoptosis of chordoma cells. Mechanistically, upregulation of lncRNA XIST led to a decrease in miR-124-3p expression, thereby promoting the expression of the miR-124-3p target gene, inhibitor of apoptosis-stimulating protein of p53 (iASPP). Addition of miR-124-3p inhibitor or mimic reversed the effects induced by lncRNA XIST silencing or overexpression on chordoma cell proliferation. Lastly, using a xenograft mouse model, we found that silencing of lncRNA XIST decreased tumorigenicity in vivo, as shown by increased tumor cell apoptosis.

Conclusion

Our findings demonstrate a key role for lncRNA XIST in chordoma progression by regulating miR124-3p/iAPSS pathway.

Suprasellar Benign Chondroma: A Case Report and Literature Review

Intracranial chondroma is a rare benign tumor comprising only 0.2% of all intracranial tumors. A 27-year-old woman presented with visual dysfunction and headache. Brain computed tomography and magnetic resonance imaging revealed a suprasellar mass lesion with a calcified component. Gross total removal was achieved via a basal interhemispheric approach. Postoperatively, visual function improved to the normal range, and no recurrence was evident 4 years later. Histopathological examination confirmed the diagnosis of benign chondroma. Preoperative differentiation of chondromas from chordomas is clinically important, because of the different treatment and prognostic implications. The only effective treatment for chondroma is total surgical removal. We present a case of gross total resection of a suprasellar chondroma with reference to the literature.

Carbon ion radiotherapy for skull base chordomas and chondrosarcomas: a systematic review and meta-analysis of local control, survival, and toxicity outcomes

BACKGROUND

Carbon ion radiotherapy (CIRT) is an emerging radiation therapy to treat skull base chordomas and chondrosarcomas. To date, its use is limited to a few centers around the world, and there has been no attempt to systematically evaluate survival and toxicity outcomes reported in the literature. Correspondingly, the aim of this study was to qualitatively and quantitatively assess these outcomes.

METHODS

A systematic search of seven electronic databases from inception to November 2019 was conducted following PRISMA guidelines. Articles were screened against pre-specified criteria. Outcomes were then pooled by random-effects meta-analyses of proportions.

RESULTS

A total of nine studies provided unique metadata for assessment, with six originating from Heidelberg, Germany. The surveyed cohort size was 632 patients, with 389 (62%) chordomas and 243 (38%) chondrosarcomas of the skull base. Across all studies, median cohort age at therapy and female proportion were 46 years and 51% respectively. Estimates of local control incidence at 1-, 5-, and 10-years in chordoma-only studies were 99%, 80%, and 56%, and in chondrosarcoma-only studies were 99%, 89%, and 88%. Estimates of overall survival probability at 1-, 5-, and 10-years in chordoma-only studies were 100%, 94%, and 78%, and in chondrosarcoma-only studies were 99%, 95%, and 79%. The incidence of early and late toxicity (Grade ≥ 3) ranged from 0 to 4% across all study groups.

CONCLUSIONS

The emerging use of CIRT to treat skull base chordomas and chondrosarcomas appear promising with regard to tumor control, overall survival, and risk profile of early and late toxicity. The current literature suffers from the fact only a few centers in the world currently employ this technology.