Search

Background and Purpose: To evaluate clinical results and safety of a dose adaptive protocol based on tumor volume coverage and critical structure constraints, for the treatment of skull base chordomas., Material and Methods: Between May 2006 and October 2012, 106 patients with skull base chordoma were treated by combined photon and proton irradiation. Prescribed dose levels were 68.4, 70.2, 72 and 73.8 Gy(RBE) in once daily fractionation of 1.8 Gy(RBE). Dose level and dosimetric constraints to organs at risk depended on postoperative residual Gross Tumor Volume (GTV) coverage. Local control (LC) and overall survival (OS) were evaluated using the Kaplan-Meier method., Results: With a median follow-up of 61 months, the 2-year, 4-year, and 5-year LC rates were 88.6%, 78.3%, and 75.1%, respectively. GTV > 25 mL (p = 0.034, HR = 2.22; 95%CI 1.06-4.62) was an independent unfavorable prognostic factor of LC. The 2-year, 4-year, and 5-year OS rates were 99%, 90.2%, and 88.3%, respectively. Grade 3-5 late toxicity was observed in 7 patients, resulting in 93% 5-year freedom from high-grade toxicity., Conclusions: This study suggests that the probability of LC of skull base chordomas depends on postoperative GTV. The dose adaptive protocol achieves acceptable local control. Future studies should investigate whether further dose escalation to doses in excess of 74 Gy(RBE) would achieve better results., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Chordomas (CHs) are tumors with benign histopathology but exhibit aggressive clinical behavior with invasive and metastatic potential. CHs are challenging tumors to treat, and there are still many questions especially about their optimum treatment. Radical resection at first presentation should be applied on all CHs. Complementary proton therapy irrespective of the quality of resection is now routinely proposed even if its efficacy is not clearly demonstrated in case of incomplete resection. The future of CH treatment is certainly related to a better understanding of the molecular biology and oncogenesis of CHs and consequently to the development of efficient targeted chemotherapies., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective  To investigate on the feasibility and safety of a new approach which consists of delaying instrumentation after destabilizing craniovertebral junction (CVJ) chordoma surgery, allowing proton beam radiotherapy to be performed in a metal-free tumoral cavity. Design  This is a retrospective series of a prospectively maintained database. Participants  Five consecutive patients operated on for a CVJ chordomas for which instrumentation after tumor resection was deferred to after radiotherapy treatment. Main Outcome Measures  The main outcome consisted of measurements of the following parameters: C0–C2 angle, atlanto-dens interval (ADI), condylar gap, and the position of the dens relative to McGregor's line and coronal inclination, performed at 3 different times for all patients: before tumor surgery (baseline), before instrumentation surgery, and after instrumentation surgery. Results  For all patients, CVJ parameters deteriorated during the delay period, but stayed within normal limits for most. Because of radiological instability, one patient necessitated instrumentation before receiving radiotherapy. All parameters except condylar gap were partially corrected after instrumentation. No new neurological symptom or evolving neck pain occurred during the delay period. Conclusion  Delayed instrumentation of CVJ chordomas can be a safe alternative that might lead to improved subsequent radiotherapeutical treatment. Patient's selection and close clinical and radiological follow-up are mandatory for the success of this approach. [ABSTRACT FROM AUTHOR]

Background and purpose To evaluate clinical results and safety of a dose adaptive protocol based on tumor volume coverage and critical structure constraints, for the treatment of skull base chordomas. Material and methods Between May 2006 and October 2012, 106 patients with skull base chordoma were treated by combined photon and proton irradiation. Prescribed dose levels were 68.4, 70.2, 72 and 73.8 Gy(RBE) in once daily fractionation of 1.8 Gy(RBE). Dose level and dosimetric constraints to organs at risk depended on postoperative residual Gross Tumor Volume (GTV) coverage. Local control (LC) and overall survival (OS) were evaluated using the Kaplan–Meier method. Results With a median follow-up of 61 months, the 2-year, 4-year, and 5-year LC rates were 88.6%, 78.3%, and 75.1%, respectively. GTV > 25 mL ( p  = 0.034 , HR = 2.22; 95%CI 1.06–4.62) was an independent unfavorable prognostic factor of LC. The 2-year, 4-year, and 5-year OS rates were 99%, 90.2%, and 88.3%, respectively. Grade 3–5 late toxicity was observed in 7 patients, resulting in 93% 5-year freedom from high-grade toxicity. Conclusions This study suggests that the probability of LC of skull base chordomas depends on postoperative GTV. The dose adaptive protocol achieves acceptable local control. Future studies should investigate whether further dose escalation to doses in excess of 74 Gy(RBE) would achieve better results. [ABSTRACT FROM AUTHOR]