Appendix 1. Details of the patients involved in this study

Patient number / Age (years), gender / Sacral location; Enneking stage / Previous treatments / PSE / Surgical margins, approach / Local adjuvants / Radiation therapy / Followup (months) / LR, lung metastases / Preoperative neurologic deficits / Postoperative neurologic deficits
1 / 16, M / S1; Stage 3 / + / Intralesional, posterior laminectomy (L5-S3) / 276 / NED / S1 paralysis, absent Achilles reflex (L) / S1 paralysis, absent Achilles reflex (L)
2 / 23, F / S1, ala; Stage 3 / + / Intralesional, anterior and posterior (S1-S2) / Postoperative (36 Gy) / 216 / NED / Low back and leg pain (R)
3 / 32, F / S1-S2, ala; Stage 3 / - / Intralesional, posterior laminectomy (L5-S3) / Postoperative (44 Gy) / 226 / NED / Saddle anesthesia, low back and leg pain / Neurogenic bladder, constipation, loss of sexual sensibility, saddle anesthesia
4 / 19, M / S1-S2, ala; Stage 3 / Intralesional excision and radiation therapy / - / Intralesional, posterior laminectomy (L5-S3) / Phenol / Preoperative (47.5 Gy) / 207 / NED / Low back and leg pain
5 / 34, F / S1-S5, SI joint and iliac ala (R); Stage 3 / + / Intralesional, anterior and posterior / Liquid nitrogen / Postoperative (40 Gy) / 206 / NED / Cauda equina syndrome
6 / 68, F / S1, sacrum and iliac ala (R); Stage 3 / + / Intralesional, posterior laminectomy / Phenol and liquid nitrogen / Postoperative (50.6 Gy) / 72 / NED / Reduction of reflexes bilaterally, mild cauda equina syndrome
7 / 14, F / S1-S5, SI joint and iliac ala (R); Stage 3 / Intralesional excision and embolization / + / Intralesional, anterior and posterior / Phenol and liquid nitrogen / Postoperative (56 Gy) / 185 / NED / S1-S2 radiculopathy, saddle anesthesia, bowel and bladder dysfunction / Chronic constipation, saddle and posterior thigh anesthesia
8 / 17, F / S2-coccyx; Stage 3 / + / Intralesional, partial sacrectomy (S4), anterior and posterior laminectomy (S1) / Phenol / 182 / NED / Low back and leg pain (bilateral)
9 / 22, F / S1-S2, ala; Stage 3 / + / Intralesional, posterior laminectomy / 57 / NED / Foot drop (bilateral)
10 / 50, F / S1-S3, ala; Stage 3 / + / Intralesional, posterior laminectomy (L5-S3) / Phenol / Postoperative (40 Gy) / 172 / NED / Low back and leg pain, S1 paralysis (R) / L5 paralysis (R)
11 / 26, F / S1-coccyx; Stage 3 / + / Intralesional, partial sacrectomy (S4), curettage, anterior and posterior laminectomy / Postoperative (40 Gy) / 159 / NED / Low back and leg pain (S1) (L) / Marked constipation, saddle anesthesia, absence of reflexes bilaterally, loss of strength in lower limbs, cavus feet, difficulty in walking
12 / 18, F / S2-coccyx; Stage 3 / - / Intralesional, anterior and posterior / Phenol / Postoperative (40 Gy) / 60 / LR at 34 months* / Low back pain with antalgic position
13 / 17, F / S1, ala; Stage 3 / + / Intralesional, anterior and posterior laminectomy (L5-S3) / Postoperative (40 Gy) / 138 / NED / L5-S4 radiculopathy
14 / 26, F / S2-coccyx; Stage 3 / Intralesional excision / + / Intralesional, anterior / 14 days / Dead (massive pulmonary embolism)
15 / 31, F / S1-S3, sacral and iliac ala and SI joint (R); Stage 3 / - / Intralesional, posterior / Phenol / Postoperative (40 Gy) / 139 / NED / Low back and leg pain (R) / Reduction of sexual sensibility, cutaneous anesthesia, reduction of strength in right lower limb
16 / 54, F / S1-S3, sacral and iliac ala (L); Stage 3 / + / Intralesional, anterior and posterior / Postoperative (40 Gy) / 159 / NED / Low back and leg pain (L) / Marked constipation, saddle and anterior left thigh anesthesia, bladder dysfunction
17 / 19, M / S1-S3, ala (bilateral); Stage 3 / + / Intralesional, anterior and posterior / Phenol / Postoperative (40 Gy) / 134 / LR at 15 months† / L5-S1 paralysis / Marked constipation, erectile and bladder dysfunction
18 / 31, F / S1-S3, ala and SI joint (L); Stage 3 / - / Intralesional, posterior laminectomy (L5-S1) / Phenol / Postoperative (54 Gy) / 126 / NED / Low back and leg pain (L)
19 / 34, F / S1-S5, sacral ala, SI joint and iliac ala (R); Stage 3 / + / Intralesional, anterior and posterior / Phenol / Postoperative (40 Gy) / 134 / NED / Low back and leg pain (R) / Bladder dysfunction, reduction of sexual sensibility, saddle anesthesia
20 / 14, F / S1-S2, ala (bilateral); Stage 2 / - / Intralesional, posterior laminectomy (S1-S2) / Phenol / 108 / NED / Low back and leg pain (S1) (R)
21 / 19, M / S1-S5; Stage 3 / + / Intralesional, anterior and posterior laminectomy (L5-S1) / Phenol / Postoperative (46 Gy) / 89 / NED / Low back pain
22 / 27, M / S1-S5; Stage 3 / Intralesional excision and embolization / + / Intralesional, anterior and posterior / Postoperative (44 Gy) / 77 / NED / Low back and leg pain / Erectile and bladder dysfunction, mild constipation, saddle anesthesia
23 / 57, F / Sacral and iliac ala (L); Stage 3 / + / Intralesional, posterior / Phenol / Postoperative (44 Gy) / 72 / NED
24 / 36, F / S1-S5; Stage 3 / + / Intralesional, posterior / Phenol / Postoperative (44 Gy) / 72 / NED / S1-S4 radiculopathy / Chronic constipation, saddle anesthesia
25 / 55, F / S1-S5; Stage 3 / + / Intralesional, anterior and posterior / Phenol / Postoperative (44 Gy) / 74 / NED / Low back and leg pain (bilateral) / Neurogenic bladder, bowel constipation, loss of strength in lower limbs
26 / 23, F / S1-coccyx; Stage 3 / +
twice / Intralesional, posterior / Phenol / 67 / LR at 8.5 months‡ / Low back and leg pain (L) / Neurogenic bladder, bowel constipation
27 / 43, M / S2-S5, ala; Stage 3 / + / Intralesional, partial sacrectomy (S4), curettage, anterior and posterior / 40 / NED / Local pain
28 / 18, M / S1; Stage 3 / + / Intralesional, posterior laminectomy (L5-S2) / Phenol / 36 / NED / Low back and leg pain (bilateral)
29 / 18, F / S1-S5; Stage 3 / +
twice / Intralesional, anterior and posterior / Postoperative (40 Gy) / 60 / NED / Local pain
30 / 19, M / S3-S5; Stage 3 / - / Intralesional, posterior / 36 / NED / Local and perineal pain
31 / 35, M / S3-S5; Stage 3 / - / Intralesional, posterior / 36 / NED / Local and perineal pain

*Then embolization, repeat intralesional surgery, phenol ablation and radiation therapy (30 Gy); developed high-grade sarcoma and died at 24 months with lung metastases; †then repeat intralesional surgery with phenol; no LR at 134 months; ‡treated with radiofrequency ablation; no LR at 67 months; PSE = preoperative selection embolization; LR = local recurrence; M = male; F = female; SI = sacroiliac; R = right; L = left; NED = no evidence of disease.