Cancer Management and Research (Oct 2020)
Nomogram Including Elastography for Prediction of Contralateral Central Lymph Node Metastasis in Solitary Papillary Thyroid Carcinoma Preoperatively
Abstract
Ning Li,1 Ju-hua He,2 Chao Song,3 Li-chun Yang,4 Hong-jiang Zhang,1 Zhi-hai Li1 1Department of Ultrasound, Yunnan Kungang Hospital, Kunming, Yunnan Province, People’s Republic of China; 2Department of Function Examination, Yunnan Provincial Hospital of Traditional Chinese Medicine, Kunming, Yunnan Province, People’s Republic of China; 3Department of Radiology, Yunnan Kungang Hospital, Kunming, Yunnan Province, People’s Republic of China; 4Department of Ultrasound, Yunnan Cancer Hospital, Kunming, Yunnan Province, People’s Republic of ChinaCorrespondence: Chao SongDepartment of Radiology, Yunnan Kungang Hospital, Kunming, Yunnan Province 650302, People’s Republic of ChinaTel +86-13908848395Email [email protected] YangDepartment of Ultrasound, Yunnan Cancer Hospital, Kunming, Yunnan Province 650118, People’s Republic of ChinaTel +86-13888087336Email [email protected]: It is controversial whether contralateral prophylactic central neck dissection (PCND) should be performed for patients with solitary and clinical lymph node negative (cN0) papillary thyroid carcinoma (PTC) although routine ipsilateral PCND is required.Objective: The aim of this study was to develop an improved nomogram including clinical features, ultrasound, and acoustic radiation force impulse (ARFI) elastography for the prediction of contralateral central lymph node metastasis (CLNM) in patients with solitary and cN0 PTC in the preoperative period.Materials and Methods: A total of 340 patients were retrospectively included as the training cohort and 170 patients as the external validation cohort. Patients were grouped according to the pathological results of contralateral CLNM. The association between the clinical characteristics, ultrasound, and ARFI elastography and the risk for contralateral CLNM were analyzed. A nomogram was established based on the result of multivariable logistic analysis to predict the risk of contralateral CLNM, which was assessed by internal and external validation.Results: CLNM was found in 213 patients (41.8%), among whom 142 (27.8%) had ipsilateral CLNM and 95 (18.6%) had contralateral CLNM (including 68 (13.3%) with bilateral CLNM). Multivariable analysis revealed that patients with younger age, male gender, larger tumor size, closer distance from the capsule, microcalcification, and larger SWVmean were independent predictors associated with the contralateral CLNM (P < 0.05), which was served as the basis of the nomogram. It showed good discrimination (C-index: 0.856) and calibration (χ2 = 9.028, P = 0.340, Hosmer–Lemeshow test) in the training cohort, and good discrimination was maintained in the external validation cohort (C-index: 0.792).Conclusion: The nomogram utilizing the features of ultrasound combined with ARFI elastography in preoperatively predicting the risk of contralateral CLNM in patients with solitary and cN0 PTC was established, which showed superior performance both in internal and external validation.Keywords: prophylactic central neck dissection, papillary thyroid carcinoma, central lymph node metastasis, acoustic radiation force impulse, nomogram
