Composite PEEK/Carbon fiber implants can increase the effectiveness of radiotherapy in the management of spine tumors.

BACKGROUND Combination of surgery and radiotherapy in the treatment of primary spine tumour can be indicated in some cases where a satisfactory oncological margin cannot be achieved. The presence of metal hardware has always limited post-operative radiotherapy due to the scattering effects of ionizing radiation or particles. The use of a fixation system (including rods and screw) fully made in PEEK embedded Carbon fiber (CFR-PEEK) could make easier and more effective the post-operative radiotherapy as it is radiolucent and does not interfere with ionizing radiation and accelerated particles. METHODS An ambispective study was performed on the first 22 consecutive primary tumor patients, who underwent spinal surgery including a composite CFR-PEEK fixation system. Oncologic surgery was palliative decompression and fixation in 3 cases; tumor excision in 15; en bloc resection in 4. The incidence of complications (intra- and postoperative), local control (LC) and local recurrence (LR), and changes in neurological status were considered. RESULTS Only one intraoperative screw breakage occurred and one case of loosening of sacral screws were found at 12 months in one patient. No rod breakage, neither any screw/rod disconnection was found. Post-operative RT has been performed in 19 patients. The overall number of progression of the tumour or LR was 7. The actuarial rate of LR or progression of the tumour, calculated according to the Kaplan-Meier method, was 17.6% at 12 months. CONCLUSIONS The CFR-PEEK fixation system is comparable to standard titanium system in term of intraoperative complications, stability at weight bearing and at functional recovery. Thanks to radiolucency CFR-PEEK stabilization devices are more suitable in patients eligible for RT: the absence of image artifacts together with significantly less dose perturbation improve the treatment accuracy. Moreover the radiolucency is useful in the follow-up of patients thus allowing early detection of LR.