Background:Postoperative recurrence of sacrococcygeal chordomas presents significant clinical challenges due to unusual recurrence patterns. This study aimed to characterize these patterns of recurrence to inform improved adjuvant radiotherapy planning.Methods:We retrospectively analyzed 31 patients with recurrent sacrococcygeal chordoma following surgery, assessing recurrence locations considering initial tumor extent, resection levels, and postoperative anatomical changes on MRI. In 18 patients, pre- and postoperative imaging enabled the spatial mapping of early recurrence origins relative to the initial tumor volume using isotropic expansions. The median initial gross tumor volume was 113 mL.Results:Recurrences were mostly multifocal and predominantly involved soft tissues (e.g., mesorectal/perirectal space (80.6%), piriformis and gluteal muscles (80.6% and 67.7%, respectively) and osseous structures, particularly the sacrum (87.1%)). The median time to recurrence was 15 months. The initial surgery was R0 in 17 patients (55%). The highest infiltrated sacral vertebra was S1 in 3%, S2 in 10%, S3 in 35%, S4 in 23%, S5 in 10%, and coccygeal in 19%. Anatomical changes post-resection, including rectal herniation into gluteal and subcutaneous tissues, significantly affected radiotherapy planning. Expansion of the initial tumor volume by 2 cm failed to encompass all recurrence origins in 72% of cases. A 5 cm expansion was required to achieve full coverage in 56% of patients, though 22% of recurrences still lay beyond this margin and the remaining were covered only partially.Conclusions:Recurrent sacrococcygeal chordomas exhibit complex, soft-tissue-dominant patterns and are influenced by significant anatomical displacement post-surgery. Standard target volume expansions are often insufficient to cover the predominantly multifocal recurrences.
背景：骶尾部脊索瘤术后复发因其不典型的复发模式而构成显著的临床挑战。本研究旨在描述这些复发模式，以指导改进辅助放疗计划。 方法：我们回顾性分析了31例术后复发的骶尾部脊索瘤患者，结合初始肿瘤范围、切除层面及术后MRI显示的解剖结构变化评估复发部位。其中18例患者通过术前与术后影像，利用等向性扩展方法对早期复发起源相对于初始肿瘤体积进行了空间定位。初始大体肿瘤体积中位数为113 mL。 结果：复发多为多灶性，主要累及软组织（如直肠系膜/直肠周围间隙（80.6%）、梨状肌与臀肌（分别为80.6%和67.7%））以及骨性结构，尤其是骶骨（87.1%）。复发中位时间为15个月。初始手术达到R0切除者17例（55%）。最高受累骶椎分布为：S1占3%，S2占10%，S3占35%，S4占23%，S5占10%，尾骨占19%。切除术后解剖结构改变（包括直肠疝入臀部和皮下组织）显著影响放疗计划。初始肿瘤体积外扩2 cm未能覆盖所有复发起源的情况占72%；需外扩5 cm才能在56%的患者中实现完全覆盖，但仍有22%的复发灶超出此边界，其余部分仅被部分覆盖。 结论：复发性骶尾部脊索瘤呈现复杂的、以软组织为主的复发模式，并受术后显著解剖位移的影响。常规靶区外扩范围常不足以覆盖以多灶性为主的复发灶。
肿瘤(癌症)患者之家