Mijin Kim1, Sae Rom Chung2, Min Ji Jeon3, Minkyu Han4, Jeong Hyun Lee2, Dong Eun Song5, Jung Hwan Baek2, Tae Yong Kim3, Won Bae Kim3, Young Kee Shong3, Won Gu Kim3. 1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Biomedical Research Institute, Pusan National University Hospital, Busan, Korea. 2. Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. 3. Division of Endocrinology and Metabolism, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. 4. Departments of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. 5. Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Abstract
Background: Tumor volume doubling time (TVDT) is considered as a dynamic indicator of tumor growth and progression. We aimed to clarify whether TVDT should be considered in the cytological diagnosis of follicular neoplasms (FNs). Methods: This retrospective cohort study included 100 consecutive FN patients with a TVDT >1 year for whom surgical resection was delayed for >1 year. Changes in tumor volume and the TVDT of each nodule were calculated by serial neck ultrasonography (US) over a median follow-up of 50 months. Results: Among 100 surgically resected FNs, 58 (58%) were benign and 42 (42%) were malignant tumors. At the 5-year follow-up, most FN nodules showed volume increases of >50%, accounting for 65% of benign and 62% of malignant nodules. No significant difference was observed in tumor growth rates and time to a >50% increase in tumor volume between benign and malignant nodules (p = 0.299 and p = 0.378, respectively). The calculated TVDT and a >50% volumetric increase showed a linear relationship with a high concordance (R2 = 0.883; p < 0.001). The risk of malignancy was not significantly associated with TVDT (relative risk = 1.00; [95% confidence interval 0.99-1.01]; p = 0.784). Even when US features were considered, no significant association was found between TVDT and the risk of malignancy. Conclusions: The size of most FNs increased exponentially with time; the tumor growth rates of benign and malignant nodules were similar. Despite the usefulness of TVDT as an indicator of growing velocity of FN nodules, TVDT could not predict malignancy in FNs. Clinical surveillance based on the growth of thyroid nodules categorized as FNs on serial neck US does not predict the risk of malignancy.
Background: Tumor volume doubling time (TVDT) is considered as a dynamic indicator of tumor growth and progression. We aimed to clarify whether TVDT should be considered in the cytological diagnosis of follicular neoplasms (FNs). Methods: This retrospective cohort study included 100 consecutive FN patients with a TVDT >1 year for whom surgical resection was delayed for >1 year. Changes in tumor volume and the TVDT of each nodule were calculated by serial neck ultrasonography (US) over a median follow-up of 50 months. Results: Among 100 surgically resected FNs, 58 (58%) were benign and 42 (42%) were malignant tumors. At the 5-year follow-up, most FN nodules showed volume increases of >50%, accounting for 65% of benign and 62% of malignant nodules. No significant difference was observed in tumor growth rates and time to a >50% increase in tumor volume between benign and malignant nodules (p = 0.299 and p = 0.378, respectively). The calculated TVDT and a >50% volumetric increase showed a linear relationship with a high concordance (R2 = 0.883; p < 0.001). The risk of malignancy was not significantly associated with TVDT (relative risk = 1.00; [95% confidence interval 0.99-1.01]; p = 0.784). Even when US features were considered, no significant association was found between TVDT and the risk of malignancy. Conclusions: The size of most FNs increased exponentially with time; the tumor growth rates of benign and malignant nodules were similar. Despite the usefulness of TVDT as an indicator of growing velocity of FN nodules, TVDT could not predict malignancy in FNs. Clinical surveillance based on the growth of thyroid nodules categorized as FNs on serial neck US does not predict the risk of malignancy.
Entities:
Keywords:
follicular neoplasm; growth kinetics; malignancy; ultrasonography; volume doubling time
Authors: Eun Ju Ha; Sae Rom Chung; Dong Gyu Na; Hye Shin Ahn; Jin Chung; Ji Ye Lee; Jeong Seon Park; Roh-Eul Yoo; Jung Hwan Baek; Sun Mi Baek; Seong Whi Cho; Yoon Jung Choi; Soo Yeon Hahn; So Lyung Jung; Ji-Hoon Kim; Seul Kee Kim; Soo Jin Kim; Chang Yoon Lee; Ho Kyu Lee; Jeong Hyun Lee; Young Hen Lee; Hyun Kyung Lim; Jung Hee Shin; Jung Suk Sim; Jin Young Sung; Jung Hyun Yoon; Miyoung Choi Journal: Korean J Radiol Date: 2021-10-26 Impact factor: 3.500