Nonmetallic Carbon Fiber-Reinforced Polyetheretherketone Implants Vs Titanium Implants: Analysis of Clinical Outcomes and Influence on Postoperative Radiotherapy Planning in Metastatic Spine Tumor Surgery.

Background: Titanium has been the conventional implant material of choice for fixation in both primary and metastatic spine tumor surgeries (MSTS). However, these implants result in artifact generation during postoperative computed tomography or magnetic resonance imaging, resulting in poor planning of radiotherapy (RT) and suboptimal tumor surveillance. Carbon fiber-reinforced polyetheretherketone (CFR-PEEK) implants have gained momentum for instrumentation in MSTS due to their radiolucent properties. In this study, the perioperative outcomes, postoperative imaging artifacts, and dosimetric data of CFR-PEEK implants to titanium implants were compared to assess for potential benefits in postoperative RT planning in patients undergoing MSTS.

Methods: This is a retrospective study involving 62 patients who underwent operations for MSTS. The cohort of CFR-PEEK fixations (n = 20) was compared with a series of patients operated using titanium implants (n = 42). Patient-related data, including demographics, tumor pathology and extent of morbidity, intraoperative data, functional outcome, and RT-related data, were recorded for both groups. Primary outcome measures for RT data were amount of artifact generated on postoperative imaging and the time taken to contour them. All patients were followed up postoperatively for a minimum of 2 years or until death, whichever was earlier.

Results: Both groups had similar clinical outcomes for pain and overall survival predictability preoperatively (P = 0.786). The mean number of levels instrumented by titanium screws was 5.69 ± 2.64, while for CFR-PEEK screws it was 4.26 ± 1.05. Mean volume of artifact generated during postoperative computed tomography was 73.4 ± 50.43 mm³ in the titanium group and 20.0 ± 20.7 mm³ in the CFR-PEEK group (P < 0.001). The mean time taken to contour the artifacts was 17.3 ± 5.84 minutes in titanium group and 9.60 ± 7.17 minutes in CFR-PEEK group (P = 0.049).

Conclusion: Our study confirms that CFR-PEEK screws significantly reduce artifact generation and the time taken to contour them during postoperative RT planning while delivering equivalent clinical and functional outcomes as compared with standard titanium implants.

Level of evidence: 2: