title: Preoperative Prediction of Cervical Lymph Node Metastasis Using Primary Tumor SUVmax on 18F-FDG PET/CT in Patients with Papillary Thyroid Carcinoma.
abstract: OBJECTIVE
  The aim of the current study was to evaluate the value of preoperative 18F-FDG (FDG) PET/CT in predicting cervical lymph node (LN) metastasis in patients with papillary thyroid carcinoma (PTC).
  
  
  METHODS
  One hundred and ninety-three newly diagnosed PTC patients (M: F = 25:168, age = 46.8 ± 12.2) who had undergone pretreatment FDG PET/CT and had neck node dissection were included in this study. The FDG avidity of the primary tumor and the SUVmax of the primary tumor (pSUVmax) were analyzed for prediction of LN metastasis. Detectability by ultrasonography (US) and FDG PET/CT for cervical LN metastasis were also assessed and compared with the pSUVmax.
  
  
  RESULTS
  The FDG avidity of the primary tumor was identified in 118 patients (FDG avid group: 61.0%, M: F = 16:102, age 47.0 ± 12.7 years) and pSUVmax ranged from 1.3 to 35.6 (median 4.6) in the FDG avid group. The tumor size in the FDG avid group was bigger and there was a higher incidence of LN metastasis compared to the FDG non-avid group (0.93 vs. 0.59 cm, p <0.001 and 49.2 vs. 33.3%, p <0.05). In the FDG avid group, patients with LN metastasis had higher pSUVmax than patients without LN metastasis (8.7 ± 8.3 vs. 5.7 ± 5.1, p <0.001). The incidence of central LN metastasis in patients with a pSUVmax >4.6 was 54%; however, the detectability of central LN metastasis by US and FDG PET/CT were 10.3% and 3.6%, respectively.
  
  
  CONCLUSIONS
  A high FDG avidity of the primary tumor was related to LN metastasis in PTC patients. Therefore, patients with a high pSUVmax should be cautiously assessed for LN metastasis and might need a more comprehensive surgical approach.
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
authors.forename: Ji-hoon
authors.initials: JH
authors.lastname: Jung
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
authors.forename: Choon-Young
authors.initials: CY
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Son
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
authors.forename: Do-Hoon
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
authors.forename: Shin Young
authors.initials: SY
authors.lastname: Jeong
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
authors.forename: Jaetae
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
authors.forename: Byeong-Cheol
authors.initials: BC
authors.lastname: Ahn
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000473:pathology*; D002291:Carcinoma, Papillary; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009333:Neck; D049268:Positron-Emission Tomography / Q000379:methods; D057234:Preoperative Period; D019275:Radiopharmaceuticals / Q000378:metabolism*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014463:Ultrasonography
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18