Table 1.

General characteristics of studies included in the present systematic review

Ref.	First author	Country	Year	Journal	Case enrolment	Study period	MTC
[19]	Zhao	China	2021	Endocrine	Retrospective	2010–2015	189
[20]	Zhu	China	2021	BMC Cancer	Retrospective	2009–2018	74
[21]	Zhao	China	2021	Cancer Imaging	Retrospective	2015–2017	78
[22]	Ning	China, South Korea	2021	Asian J Surgery	Retrospective	2006–2018	127
[23]	Matrone	Italy	2021	Eur J Endocrinol	Retrospective	2014–2020	152
[24]	Hahn	South Korea	2021	Acta Radiol	Retrospective	1999–2017	129
[25]	de Oliveira	Brasil	2021	Arch Endocrinol Metab	Retrospective	2013–2018	19
[26]	Wang	China	2020	Technol Cancer Res Treat	Retrospective	2008–2018	73
[27]	Li	China	2020	Clin Endocrinol (Oxf)	Retrospective	2010–2019	29
[28]	Guo	China	2019	Chin Med J (Engl)	Retrospective	2011–2016	71
[29]	Yun	South Korea	2018	Endocrine	Retrospective	2003–2016	57
[30]	Wang	China	2016	Pak J Pharm Sci	Retrospective	2014–2015	20
[31]	Valderrabano	USA	2016	Thyroid	Retrospective	1998–2014	30
[32]	Cho	South Korea	2016	Asian Pac J Cancer Prev	Retrospective	2007–2010	130
[33]	Bao	China	2016	Zhonghua Yi Xue Za Zhi	Retrospective	1993–2013	72
[34]	Zhou	China	2015	J Ultrasound Med	Retrospective	2008–2013	38
[35]	Trimboli	Switzerland, Italy	2014	J Exp Clin Cancer Res	Retrospective	2007–2013	134
[36]	Sesti	Austria	2014	Anticancer Res	Retrospective	2003–2009	28
[37]	Choi	South Korea	2011	Acta Radiol	Retrospective	2000–2008	36
[38]	Lee	South Korea	2010	AJR Am J Roentgenol	Retrospective	1997–2008	46
[39]	Cai	China	2010	Chin Med J (Engl)	Retrospective	1998–2009	35
[40]	Kim	South Korea	2009	Korean J Radiol	Retrospective	2002–2007	21
[41]	Fukushima	Japan	2009	World J Surg	Retrospective	1988–2007	77
[42]	Boér	Hungary	2003	Eur J Surg Oncol	Retrospective	1992–2000	14
[43]	Saller	Germany	2002	Exp Clin Endocrinol Diabetes	Retrospective	1995–2001	19

Note: Records are ordered according to their year of publication.

Abbreviation: MTC, medullary thyroid carcinoma.