Central Neck Dissection in Patients with Clinical Node Negative Thyroid Cancer

描述（由申请人提供）：甲状腺乳头状癌（PTC）的主要治疗方法是手术切除，包括甲状腺全切除术。甲状腺切除术后淋巴结复发是一个重要的临床问题。为了减少复发，预防性中央颈部清扫术常与甲状腺全切除术同时进行。仅根据专家意见，目前美国甲状腺协会（ATA）的实践指南建议预防性中央颈部清扫术。然而，对于大多数患者来说，预防性中央颈部清扫术可能不是必需的，并且可能会大大增加术后低钙血症和吞咽、交流功能和健康相关生活质量（HR-QOL）缺陷的发病率。这些疾病的发生率和范围目前尚不清楚。在常规中心性颈部清扫作为标准治疗之前，系统地检查该手术的真正风险和益处是很重要的。只有专家意见才能指导这一建议，这一事实表明有必要进行前瞻性临床试验，以充分评估这一常见和潜在病态的临床问题。我们的假设是，与单纯甲状腺全切除术治疗PTC相比，甲状腺全切除术联合预防性中央颈部清扫导致并发症发生率增加，但对患者没有相关益处。我们将通过一项随机临床试验来验证这一假设，在该试验中，140名术前没有远处或颈部淋巴结转移证据的PTC患者接受甲状腺全切除术，随机分为两组：预防性中枢性颈部清扫或无中枢性颈部清扫。这项工作有四个具体目的，将PTC患者行甲状腺全切除术合并中央颈部清扫术与单纯行甲状腺全切除术的患者进行比较：(1)确定短暂性和持续性低钙血症的发生率；(2)确定声音和吞咽问题的发生率；(3)确定HR-QOL的受损程度；(4)确定临床复发率。拟议的研究结果将导致对预防性中枢性颈部清扫影响头颈部关键功能和PTC患者癌症复发的方式的进一步了解。由于PTC患者在沟通功能和吞咽方面存在潜在的严重和普遍的问题，因此增加这一知识库，测试干预措施，并为循证实践奠定基础，特别是目前使用的未经测试的手术干预措施，具有重要意义。我们的发现很有可能产生与重要临床问题相关的有意义的发现和确凿的证据。

DESCRIPTION (provided by applicant): The mainstay of therapy for papillary thyroid cancer (PTC) is surgical excision, consisting of total thyroidectomy. Lymph node recurrence following thyroidectomy is a substantial clinical problem. In an attempt to decrease recurrence, prophylactic central neck dissection is often performed along with total thyroidectomy. Based only on expert opinion, current American Thyroid Association (ATA) practice guidelines recommend prophylactic central neck dissection. However, addition of a prophylactic central neck dissection may not be necessary for the majority of patients and may substantially increase postsurgical morbidities of hypocalcemia and deficits in swallowing, communicative function and health-related quality of life (HR-QOL). The probability and extent of these morbidities are currently unknown. Before routine central neck dissection can be adopted as a standard treatment it is important that the true risks and benefits of this procedure are systematically examined. The fact that only expert opinion guides this recommendation argues for the need for a prospective clinical trial to fully evaluate this common and potentially morbid clinical problem. Our hypothesis is that total thyroidectomy with prophylactic central neck dissection results in an increased rate of complications in comparison with total thyroidectomy alone for PTC without an associated benefit to the patient. We will test this hypothesis with a randomized clinical trial in which 140 patients undergoing total thyroidectomy for PTC with no preoperative evidence of distant or cervical lymph node metastasis will be randomized into one of two groups: prophylactic central neck dissection or no central neck dissection. This work has four specific aims in which patients with PTC undergoing total thyroidectomy with central neck dissection will be contrasted with those undergoing total thyroidectomy alone: (1) To determine the rate of transient and persistent hypocalcemia; (2) To determine the rate of voice and swallowing problems; (3) To determine the degree to which HR-QOL is compromised; and, (4) To determine clinical recurrence rates. The results of the proposed research will lead to an increased understanding of the manner in which prophylactic central neck dissection affects critical functions of the head and neck and cancer recurrence in patients with PTC. Due to the potentially serious and pervasive problems encountered in communicative function and swallowing in patients with PTC, it is of great importance to add to this knowledge base, to test interventions, and to lay the groundwork for evidence-based practice, particularly for untested surgical interventions in current use. Our findings have a high likelihood of yielding meaningful findings and solid evidence related to an important clinical issue.