2.1.1. Patient Characteristics

Patient characteristics are summarized in Table 1. At initial presentation, +mETE patients showed significantly higher rates of cervical lymph node (N1a/N1b-stage) metastases (46% in +mETE patients (63/138) versus 29% in −mETE patients (91/317), *p*-value 0.001). Furthermore, higher initial radioactive iodine (RAI) activity was administered in +mETE patients as compared to the control group (4.6 ± 2.1 GBq in +mETE patients versus 3.3 ± 1.0 GBq in −mETE patients, *p*-value 0.001). Regarding histology, +mETE patients had significantly more often classical PTC than the follicular variant of PTC (75% in +mETE patients (103/138) versus 62% in −mETE (197/317), *p* = 0.010).
