Factors predicting recurrence after resection of clival chordoma using variable surgical approaches and radiation modalities.

BACKGROUND

Clival chordomas frequently recur because of their location and invasiveness.

OBJECTIVE

To investigate clinical, operative, and anatomic factors associated with clival chordoma recurrence.

METHODS

Retrospective review of clival chordomas treated at our center from 1993 to 2013.

RESULTS

Fifty patients (56% male) with median age of 59 years (range, 8-76) were newly diagnosed with clival chordoma of mean diameter 3.3 cm (range, 1.5-6.7). Symptoms included headaches (38%), diplopia (36%), and dysphagia (14%). Procedures included transsphenoidal (n=34), transoral (n=4), craniotomy (n=5), and staged approaches (n=7). Gross total resection (GTR) rate was 52%, with 83% mean volumetric reduction, values that improved over time. While the lower third of the clivus was the least likely superoinferior zone to contain tumor (upper third=72%/middle third=82%/lower third=42%), it most frequently contained residual tumor (upper third=33%/middle third=38%/lower third=63%; P<.05). Symptom improvement rates were 61% (diplopia) and 53% (headache). Postoperative radiation included proton beam (n=19), cyberknife (n=7), intensity-modulated radiation therapy (n=6), external beam (n=10), and none (n=4). At last follow-up of 47 patients, 23 (49%) remain disease-free or have stable residual tumor. Lower third of clivus progressed most after GTR (upper/mid/lower third=32%/41%/75%). In a multivariate Cox proportional hazards model, male gender (hazard ratio [HR]=1.2/P=.03), subtotal resection (HR=5.0/P=.02), and the preoperative presence of tumor in the middle third (HR=1.2/P=.02) and lower third (HR=1.8/P=.02) of the clivus increased further growth or regrowth, while radiation modality did not.

CONCLUSION

Our findings underscore long-standing support for GTR as reducing chordoma recurrence. The lower third of the clivus frequently harbored residual or recurrent tumor, despite staged approaches providing mediolateral (transcranial+endonasal) or superoinferior (endonasal+transoral) breadth. There was no benefit of proton-based over photon-based radiation, contradicting conventional presumptions.