Carbon Fiber Transpedicular Screws in Treatment of Spinal Metastatic Disease

The use of convergence factor assessment will allow for comparison of similarity in planned SBRT between all groups. This will allow an indirect assessment of difficulties in planning treatment by a radiotherapist using objective tools.

Using a numerical scale from 0-10, the radiotherapist will assess the difficulty of planning, tumor coverage, and delineation of the spinal cord depending on the group assessed in the study.

Titanium instrumentation generates significant artifacts in radiological imaging used for radiotherapy planning. The use of opaque, radiolucent material allows for radiotherapy planning to cover a smaller area. This may reduce the incidence of radiation-related complications in nearby organs (OAR - organ at risk). These complications will be assessed by the radiation therapist according to the standardized NCI CTC scale. Potentially smaller quantity of organ complications could be an advantage supporting the use of carbon implants.

Titanium and carbon fiber show similar biocompatibility. The biomechanical properties of these materials are also similar. In vitro studies have shown a similar effect failure rate of carbon pedicle screws compared to standard titanium ones. However, carbon rods have greater flexibility and structure connected using these may show more frequent loosening in vivo, especially in cases with impaired sagittal balance. This was not an issue analyzed in the literature. The frequency of instrument failure is of great importance for clinical practice because most such cases require operative revision.

One of the goals of surgical treatment is to treat mechanical pain caused by segmental instability. SBRT is a good method of treating biological pain. There are no comparisons of analgesic effects between transpedicular systems. Greater pain reduction allows for more effective and longer ability to walk, lower consumption of painkillers, and lower incidence of complications related to immobilization (thrombosis, bedsores, respiratory infections), which also has pharmacoeconomic implications.

Postoperative wound infections are an inherent complication of surgical procedures. The longer the procedure, the more often inflammatory complications are observed, especially in oncological population, which has a higher average age of treated patients, a greater number of burdens, frequent immunosuppression due to systemic treatment, and malnutrition in the form of decreased biochemical parameters (total protein and albumin). Titanium has good properties in this aspect. Bacterial biofilms, is rarely formed on it, which means that patients can be treated more often without the need to remove the implants. It is unclear how carbon fiber system will perform in these cases. There are not made of metal, but of carbon fiber embedded in polymer. Assessment of the frequency of inflammatory complications and their course will provide the answer to whether This instrumentation allows for a similar management strategy in clinical settings.