为了确定局部浸润性分化型甲状腺癌（DTC）患者的手术范围，制定基于证据的建议。局部浸润性DTC具有毛状甲状腺外侵扰周围解剖结构的现象，可能导致多种功能缺陷和不良的肿瘤结果。目前，局部浸润性DTC的最佳手术范围仍存在争议，缺乏充分的指南。在2021年10月8日，四名专家搜索了PubMed、EMBASE和Cochrane Library数据库，由39名甲状腺和头颈外科专家审查了所发现的文献。采用评级推荐、评估、发展和评估（GRADE）方法评估证据质量，制定和报告建议。建议的强度反映了指南小组对于干预所产生的有益影响比负面影响更大的信心，适用于所有适用于该建议的患者。完成草案指南后，韩国头颈外科学会成员完成了Delphi问卷调查。为多种因素制定了27项基于证据的建议，包括术前检查、甲状腺切除术的手术范围、当癌症侵犯带肌、喉返神经、喉框架、气管或食管时的手术及中央和侧颈淋巴结侵犯患者的手术。 制定了基于证据的指南，以帮助临床医生制定更安全、更有效的临床决策，以优化局部浸润性DTC患者的手术治疗。

To develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroid extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains controversial; there are no adequate guidelines.On October 8, 2021 four experts searched the PubMed, EMBASE, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to assess the quality of evidence, and develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery.Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery when the cancer invades the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement.Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decision for optimal surgical treatment of patients with locally invasive DTC.