Stereotactic Radiosurgery for Chordoma: A Report From the North American Gamma Knife Consortium
ABSTRACT Although considered slow-growing, low-grade malignancies, chordomas are locally aggressive and destructive tumors with high recurrence rates.
To assess patient survival, tumor control, complications, and selected variables that predict outcome in patients who underwent Gamma Knife stereotactic radiosurgery (SRS) as primary, adjuvant, or salvage management for chordomas of the skull base.
Six participating centers of the North American Gamma Knife Consortium identified 71 patients who underwent SRS for chordoma. The median patient age was 45 years (range, 7-80 years). The median SRS target volume was 7.1 cm³ (range, 0.9-109 cm³), and median margin dose was 15.0 Gy (range, 9-25 Gy).
At a median follow-up of 5 years (range, 0.6-14 years) after SRS, 23 patients died of tumor progression. The 5-year actuarial overall survival after SRS was 80% for the entire group, 93% for the no prior fractionated radiation therapy (RT) group (n = 50), and 43% for the prior RT group (n = 21). Younger age, longer interval between initial diagnosis and SRS, no prior RT, < 2 cranial nerve deficits, and smaller total tumor volume were significantly associated with longer patient survival. The 5-year treated tumor control rate after SRS was 66% for the entire group, 69% for the no prior RT group, and 62% for the prior RT group. Older age, recurrent group, prior RT, and larger tumor volume were significantly associated with worse tumor control.
Stereotactic radiosurgery is a potent treatment option for small sized chordomas, especially in younger patients and as part of a multipronged attack that includes surgical resection when possible.
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ABSTRACT: OBJECTIVE: Chordomas and chondrosarcomas are rare skull base tumors, with similar radiographic and clinical presentations. We investigated factors influencing long-term survival in these 2 tumors using the Surveillance Epidemiology and End Results (SEER) database. METHODS: Patients with chordoma (n = 416) and chondrosarcoma (n = 269) within the skull base from 1983 to 2009 were identified within the SEER database. Kaplan-Meier curves and Cox proportional hazards models were used to test associations with survival. t tests and chi(2) tests were used to compare groups. RESULTS: Chordoma and chondrosarcoma patients were similar demographically. Survival at 5 years was 65% for chordomas and 81.8% (P < 0.0001) for chondrosarcomas and at 10 years was 32.3% and 49.5% (P = 0.004). Multivariate analysis demonstrated chordomas had a worse prognosis even when we controlled for age and tumor size (hazard ratio 3.0, 95% confidence interval 1.9-4.7, P < 0.0001). For chordomas, multivariate analysis demonstrated increasing age and tumor size were significantly associated with reduced survival. For chondrosarcomas, multivariate analysis demonstrated older age, earlier decade of diagnosis, and mesenchymal subtype were significantly associated with reduced survival. Postoperative radiation was given to 42% and 41% of patients with chordomas and chondrosarcomas, respectively. The addition of radiation did not improve survival. CONCLUSION: Consistent with previous case series, skull base chordomas have significantly worse prognosis than chondrosarcomas. Patients in the SEER database had worse survival overall compared with existing case series for both chordomas and chondrosarcomas, suggesting selection bias in the existing literature.World Neurosurgery 07/2014; 82(5). DOI:10.1016/j.wneu.2014.07.005 · 2.42 Impact Factor
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ABSTRACT: Clival chordomas frequently recur because of their location and invasiveness. To investigate clinical, operative, and anatomic factors associated with clival chordoma recurrence. Retrospective review of clival chordomas treated at our center from 1993 to 2013. 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. 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. GTR, gross total resectionIMRT, intensity-modulated radiation therapySTR, subtotal resectionUCSF, University of California, San Francisco.Neurosurgery 02/2015; 76(2):179-186. DOI:10.1227/NEU.0000000000000611 · 3.03 Impact Factor
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ABSTRACT: Objective: Skull base chordomas (SBC) are characterized by persistent progression. Conventional radiation following resection increases 5- and 10-year local control (LC) to 36 and 23 %, respectively. Patients treated with protons result in 10-year LC of 50 %. Brainstem dose constraints have inhibited higher prescription doses with photons. We reviewed our experience using high-dose fractionated stereotactic photon radiation therapy (HD-FSRT) to 81 Gy for SBC. Methods: We reviewed patients diagnosed with SBC and treated with radiation from 1999 to 2010. We excluded those with metastatic disease and prior radiation. Dose distributions and target volumes were obtained from radiation records. Results: Twelve patients met the search criteria. Median dose was 81 Gy (76.8–82.5) using a hyperfractionated regimen. Eleven patients with available data had median max and mean doses to the brainstem of 81 Gy (46.7–85.7) and 38 Gy (6.6–58.1). Mean target volume was 22 cm3 (5.3–193. 3). LC at 3 and 5 years was 69 and 46 %. Overall survival was 90 and 68 % with a mean follow-up of 55 months. There was a trend for improved LC in patients treated adjuvantly. Conclusion: HD-FSRT can achieve comparable doses to proton therapy plans, and preliminary results are an improvement from conventional photon therapy.03/2014; 3(1):57-64. DOI:10.1007/s13566-013-0122-7