Central Neck Dissection in Patients with Clinical Node Negative Thyroid Cancer

描述(申请人提供)：乳头状甲状腺癌(PTC)的主要治疗方法是手术切除，包括全甲状腺切除。甲状腺切除术后的淋巴结复发是一个重要的临床问题。为了减少复发，预防性的中央颈淋巴清扫术通常与全甲状腺切除术同时进行。仅根据专家意见，目前的美国甲状腺协会(ATA)实践指南建议预防性中央颈淋巴清扫术。然而，对于大多数患者来说，预防性的中央颈淋巴清扫术可能并不是必要的，而且可能会显著增加术后低钙血症的发病率以及吞咽、沟通功能和健康相关生活质量(HR-QOL)的缺陷。目前尚不清楚这些疾病的可能性和程度。在将常规的颈淋巴清扫术作为一种标准的治疗方法之前，系统地研究这一过程的真正风险和益处是很重要的。只有专家意见指导这一建议的事实表明，有必要进行前瞻性临床试验，以充分评估这一常见的和潜在的病态临床问题。我们的假设是，与仅行甲状腺全切除术的PTC患者相比，预防性中央颈淋巴清扫术的全甲状腺切除术会增加并发症的发生率，而对患者没有相关的益处。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名接受全甲状腺切除的PTC患者在术前没有远处或颈部淋巴结转移的证据将被随机分成两组：预防性中央颈清扫组和不进行中央颈清扫组。这项工作有四个具体的目标，即接受甲状腺全切除术加中央颈淋巴清扫术的PTC患者将与单纯接受全甲状腺切除术的患者进行对比：(1)确定一过性和持续性低钙血症的发生率；(2)确定发声和吞咽问题的发生率；(3)确定HR-QOL的损害程度；以及(4)确定临床复发率。拟议的研究结果将使人们更好地了解预防性中央颈淋巴清扫术对PTC患者头颈部关键功能和癌症复发的影响。由于PTC患者在沟通功能和吞咽方面遇到的潜在的严重和普遍的问题，增加这个知识库，测试干预措施，并为循证实践奠定基础，特别是对于当前使用的未经测试的外科干预措施，是非常重要的。我们的发现很有可能产生有意义的发现和与重要临床问题相关的确凿证据。

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.