tokens: Materials and methods From December 2014 to March 2018 , 10 metastatic LNs(mean volume 0.30 ± 0.38 ml , range 0.06 - 1.23ml ) in 5 children and adolescents ( 3 females , 2 males ; mean age 15.60 ± 2.97 years , range 12 - 19 years ) with PTC treated by RFA were evaluated in this study .