Postoperative Radiotherapy Is Associated with Instrumentation Failure After Resection of Primary Spinal Chordomas

Introduction: Chordomas are locally aggressive, malignant tumors that arise from the notochord. En-bloc surgical resection and instrumentation remains the primary treatment modality, yet hardware failure can complicate recovery and negatively impact patient outcomes. This study aims to identify the risk factors associated with hardware failure following resection of primary spinal chordomas.

Methods: A retrospective, single-center study identified adult patients that underwent surgical resection and instrumentation for primary spinal chordomas from 2004—2020. Univariate analyses were used to compare demographics, operative details, the primary outcome (hardware failure), and other complications. Variables with α≤0.15 were entered into a stepwise multivariable logistic regression model assessing independent risk factors of instrumentation failure.

Results: Of the 101 patients included in the study, the majority were white (n=84, 83%) and male (n=57, 56%) with a mean age of 54 ± 15 years. Seven patients (7%) experienced hardware failure requiring revision surgery at a median time of 21 months (IQR 12 - 46). Lumbar chordomas were more common among patients with hardware failure (57% vs 13%), while sacrococcygeal chordomas were more common among patients without failure (14% vs 69%, p=0.025). Patients with hardware failure also had significantly greater rates of intralesional resection (57% vs 10%, p=0.010) and adjuvant radiotherapy (57% vs 13%, p=0.003). Multivariable regression analysis revealed that adjuvant radiotherapy was the only independent risk factor associated with instrumentation failure (OR 8.02, p=0.043). Total adjuvant radiation dose, number of fractions, and dose per fraction were not significantly associated with failure.

Conclusion : Our results indicate that adjuvant radiotherapy significantly increases the risk of hardware failure. However, given the highly recurrent nature of chordomas, there is a clinical need for postoperative radiation. Therefore, future studies should focus on optimizing radiation protocols, such as by comparing high-dose radiation therapy with hypofractionation, as the latter shows promise in reducing toxicity to patients while maintaining clinical effectiveness.