Management strategies in clival and craniovertebral junction chordomas: a 29-year experience

OBJECTIVE Chordomas represent one of the most challenging subsets of skull base and craniovertebral junction (CVJ) tumors to treat. Despite extensive resection followed by proton-beam radiation therapy, the recurrence rate remains high, highlighting the importance of developing efficient treatment strategies. In this study, the authors present their experience in treating clival and CVJ chordomas over a 29-year period. METHODS The authors conducted a retrospective study of clival and CVJ chordomas that were surgically treated at their institution from 1991 to 2020. This study focuses on three aspects of the management of these tumors: the factors influencing the extent of resection (EOR), the predictors of survival, and the outcomes of the endoscopic endonasal approaches (EEAs) compared with open approaches (OAs). RESULTS A total of 265 surgical procedures were performed in 210 patients, including 123 OAs (46.4%) and 142 EEAs (53.6%). Tumors that had an intradural extension (p = 0.03), brainstem contact (p = 0.005), cavernous sinus extension (p = 0.004), major artery encasement (p = 0.01), petrous apex extension (p = 0.003), or high volume (p = 0.0003) were significantly associated with a lower EOR. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 52.1% and 75.1%, respectively. Gross-total resection and Ki-67 labeling index < 6% were considered to be independent prognostic factors of longer PFS (p = 0.0005 and p = 0.003, respectively) and OS (p = 0.02 and p = 0.03, respectively). Postoperative radiation therapy correlated independently with a longer PFS (p = 0.006). Previous surgical treatment was associated with a lower EOR (p = 0.01) and a higher rate of CSF leakage after EEAs (p = 0.02) but did not have significantly lower PFS and OS compared with primary surgery. Previously radiation therapy correlated with a worse outcome, with lower PFS and OS (p = 0.001 and p = 0.007, respectively). EEAs were more frequently used in patients with upper and middle clival tumors (p = 0.002 and p < 0.0001, respectively), had a better rate of EOR (p = 0.003), and had a lower risk of de novo neurological deficit (p < 0.0001) compared with OAs. The overall rate of postoperative CSF leakage after EEAs was 14.8%. CONCLUSIONS This large study showed that gross-total resection should be attempted in a multidisciplinary skull base center before providing radiation therapy. EEAs should be considered as the gold-standard approach for upper/middle clival lesions based on the satisfactory surgical outcome, but OAs remain important tools for large complex chordomas.