Proton and carbon ion therapy for skull base chordomas

Extent of Surgical Resection as a Predictor of Tumor Progression in Skull Base Chordomas: A Multicenter Volumetric Analysis

INTRODUCTION

Skull-base chordomas are aggressive tumors with a propensity for recurrence/progression. Even with standard of care (SoC), 5-year recurrence rates are variable (19%-54%). This high recurrence/progression rate correlates with increased morbidity and mortality. We sought to analyze a multicenter cohort of skull base chordomas to identify predictors of progression in patients receiving SoC.

METHODS

The [Blinded]-Neurosurgery data registry was queried for skull base chordomas treated from 2008-2020. Patients with the histopathologic diagnosis of chordoma were included. The cohort was composed of patients with preoperative and postoperative magnetic resonance imaging. Tumor volume and radiologic characteristics were obtained from axial T2 sequences using a Digital Imaging and Communications in Medicine viewer. Survival analysis was performed using Kaplan-Meier method, and time-to-event multivariate regression was performed to identify independent predictors of progression.

RESULTS

The cohort included 195 patients, of which 66 patients met inclusion criteria; median age was 44, and 28 (42%) were females. Fifty-four (82%) received SoC, 7 (11%) resection only, and 5 (8%) radiotherapy only. Median preoperative and postoperative tumor volumes were 11.55 cm3 (0.33-54.89) and 0.34 cm3 (0-42.52), respectively. Recurrence rate with SoC was 37%. Postoperative tumor volume (P = 0.010) correlated with progression. A postoperative volume of >4.9 cm3 (P = 0.044), ≤81.3% of tumor resection (P = 0.02), and lower-clivus location (P < 0.005) correlated with decreased time to progression.

CONCLUSIONS

Skull base chordomas can be challenging to resect. Even though maximal resection and radiotherapy improve rate of tumor progression, many of these lesions eventually recur. We have identified a postoperative tumor volume of ≥4.9 cm3 and extent of resection of ≤81.3% in this cohort as predictors of progression in patients receiving SoC.

Primary Skull Base Chordomas: A Clinicopathological Analysis of 94 Patients

OBJECTIVE

To investigate prognostic factors in patients with primary skull base chordoma (PSBC) to guide future therapeutic advances.

METHODS

This retrospective cohort study of 94 PSBC patients was conducted in 2 institutions from January 2006 to December 2013. Independent predictors for progression-free survival (PFS) and overall survival were established with multivariate Cox regression analysis.

RESULTS

Age (P = 0.006), extent of resection (P = 0.037), and radiotherapy (RT) (P = 0.027) were established as independent predictors for PFS in PSBC patients. Similarly, age (P = 0.002), extent of resection (P = 0.048), and RT (P = 0.015) were established as independent predictors for overall survival. Meta-analysis manifested that lower MIB-1 correlated with longer PFS in skull base chordoma patients (P < 0.001). RT doubled the 5-year PFS rate from 28.6 ± 12.1% to 61.6 ± 10.7% (P = 0.031) and increased the 5-year overall survival rate from 54.5 ± 13.8% to 84.2 ± 8.4% (P = 0.020) in the subtotal resection/partial resection and MIB-1 labeling index (STR/PR+MIB-1 LI) <2% subgroup. In contrast, in the STR/PR+MIB-1 LI ≥2% subgroup, the survival benefit of RT remained uncertain. Further analysis revealed no survival difference between different RT modalities in STR/PR PSBC patients.

CONCLUSIONS

In PSBC patients, age, extent of resection, and adjuvant RT all are independent predictors for PFS. Lower MIB-1 LI is associated with longer PFS in PSBC patients. Adjuvant RT is necessary for PSBC patients who undergo STR/PR with MIB-1 LI <2%. Patients who undergo GTR or STR/PR with MIB-1 LI ≥2% seem nonresponsive to RT.

Research hotspots and trends of chordoma: A bibliometric analysis

Background

Chordoma is a type of mesenchymal malignancy with a high recurrence rate and poor prognosis. Due to its rarity, the tumorigenic mechanism and optimal therapeutic strategy are not well known.

Methods

All relevant articles of chordoma research from 1 January 2000 to 26 April 2022 were obtained from Web of Science Core Collection database. Blibliometrix was used to acquire basic publication data. Visualization and data table of collaboration network, dynamic analysis, trend topics, thematic map, and factorial analysis were acquired using Blibliometrix package. VOSviewer was used to generate a visualization map of co-citation analysis and co-occurrence.

Results

A total of 2,285 articles related to chordoma were identified. The most influential and productive country/region was the United States, and Capital Medical University has published the most articles. Among all high-impact authors, Adrienne M. Flanagan had the highest average citation rate. Neurosurgery was the important periodical for chordoma research with the highest total/average citation rate. We focused on four hotspots in recent chordoma research. The research on surgical treatment and radiotherapy was relatively mature. The molecular signaling pathway, targeted therapy and immunotherapy for chordoma are not yet mature, which will be the future trends of chordoma research.

Conclusion

This study indicates that chordoma studies are increasing. Surgery and radiotherapy are well reported and always play fundamental roles in chordoma treatment. The molecular signaling pathway, targeted therapy, and immunotherapy of chordoma are the latest research hotspots.

Long-term outcomes of high dose carbon-ion radiation therapy for unresectable upper cervical (C1-2) chordoma

Background

Chordoma is a rare, locally invasive neoplasm of the axial skeleton. Complete resection is often difficult, especially for the upper‐cervical (C1‐2) spine. We evaluated the efficacy and safety of carbon‐ion radiotherapy (CIRT) for unresectable C1‐2 chordoma.

Methods

Patients with C1‐2 chordoma treated with definitive CIRT (60.8 Gy [RBE] in 16 fractions) were retrospectively analyzed. We evaluated OS, LC, PFS, and toxicity.

Results

Nineteen eligible patients all completed the planned course of CIRT. With the median follow‐up 68 months (range: 29–144), median OS was 126 months (range: 36‐NA). Five‐year OS, LC, and PFS were 68.4% (95% CI, 42.8%–84.4%), 75.2% (46.1%–90.0%), and 64.1% (36.3%–82.3%), respectively. Regarding acute toxicity of grade ≥3, there was only one grade 3 mucositis. Late toxicity included radiation‐induced myelitis (grade 3 in 1 patient; 5.3%), and compression fractures (n = 5; 26.3%).

Conclusions

High‐dose CIRT is a promising treatment option for unresectable upper cervical chordoma.