Impact of Surgical Margins and Adjuvant Radiotherapy on Local Recurrence and Survival in Sacral Chordoma

<b>Background:</b> This study aimed to evaluate the impact of surgical margin status, tumor size, and adjuvant radiotherapy on local control, overall survival, and postoperative complications in patients undergoing surgery for sacral chordoma. <b>Methods:</b> This retrospective analysis included 18 patients who underwent surgical treatment for primary sacral chordoma between 2002 and 2019. The variables assessed included patient demographics, tumor size and volume, surgical margin status, adjuvant radiotherapy, local recurrence, overall survival, and postoperative complications. Survival analysis was performed using the Kaplan-Meier method, and appropriate parametric or non-parametric tests were used for group comparisons. <b>Results:</b> The cohort's mean age was 62.6 ± 7.9 years, with a mean follow-up of 8.8 ± 4.1 years and an average tumor volume of 235 cm³. Negative surgical margins (R0) were achieved in 44% of patients. Local recurrence occurred in 50% of R0 cases and 83% of R2 cases. Negative surgical margins (R0) were associated with significantly lower local recurrence rates compared to R1 and R2 resections (Fisher's exact test, <i>p</i> = 0.043), and showed a trend toward improved overall survival (<i>p</i> = 0.077). Overall survival was significantly lower in patients with tumors measuring ≥ 5 cm (<i>p</i> = 0.031). Adjuvant radiotherapy did not significantly reduce local recurrence (<i>p</i> = 0.245); however, an increase in complication rates was observed, although this association did not reach statistical significance (<i>p</i> = 0.108). Bladder dysfunction was significantly more frequent in patients undergoing S1-S2 resections (<i>p</i> = 0.036). <b>Conclusions:</b> Achieving negative surgical margins improves local control and may prolong survival. Larger tumors (≥5 cm) were associated with worse prognosis. While adjuvant RT may be considered in selected high-risk cases, its efficacy in preventing recurrence is unclear and may increase complication rates.