title: High metabolic tumor volume and total lesion glycolysis are associated with lateral lymph node metastasis in patients with incidentally detected thyroid carcinoma.
abstract: OBJECTIVE
  The objective of this study was to investigate whether total lesion glycolysis (TLG) and metabolic tumor volume (MTV) measured by ¹⁸F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) could predict the aggressiveness and lymph node metastasis (LNM) in patients with incidentally detected differentiated thyroid carcinoma.
  
  
  METHODS
  A total 358 patients with focal FDG-avid thyroid incidentaloma during cancer evaluation were enrolled. Among 235 patients in whom fine-needle aspiration biopsy was performed, 51 patients underwent total thyroidectomy with LN dissection. We analyzed the relationship between volume-based parameters and clinicopathologic characteristics.
  
  
  RESULTS
  The mean age and tumor size were 57.1 ± 11.3 years and 1.15 ± 0.81 cm, respectively. The prevalence of malignancy was 21.7 % (51/235). When SUV(max) > 5.91, MTV2.5 > 2.05 cm³, and TLG2.5 > 9.09 were used as cutoff points, sensitivity, specificity, and area under curve (AUC) for prediction of lateral LNM were 77.9, 69.1 %, 0.716 (P = 0.047), 77.8, 88.1 %, 0.839 (P < 0.001), 77.8, 85.1 %, and 0.815 (P = 0.002), respectively. However, MTV and TLG had no value in prediction of central LNM, extrathyroidal extension, and multifocality. On comparison ROC curve analysis, the MTV and TLG showed the statistical differences for the prediction of lateral LNM compared with SUV(max) (all P's < 0.05).
  
  
  CONCLUSIONS
  This study has shown for the first time that volume-based PET functional parameters had a significant value for the prediction of lateral LNM in incidentally detected PTC. These results suggest that higher MTV and TLG can be potential new risk factors for preoperative risk stratification. The usefulness of TLG and MTV in preoperative risk stratification in patients with PTC needs to be confirmed in further large studies.
authors.affiliation: Department of Internal Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. pons71@hanmail.net.
authors.forename: Bo Hyun
authors.initials: BH
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. growthkim@daum.net.
authors.forename: Seong-Jang
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. 4mura2@hanmail.net.
authors.forename: Keunyoung
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. dinggury84@hanmail.net.
authors.forename: Heeyoung
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. laocone@naver.com.
authors.forename: So Jung
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. bearshow00@hanmail.net.
authors.forename: Won Jin
authors.initials: WJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. puritystar@hanmail.net.
authors.forename: Yun Kyung
authors.initials: YK
authors.lastname: Jeon
authors.affiliation: Department of Internal Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. drsskim7@gmail.com.
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Kim Yong Ki Internal Medicine Clinic, Chungmu-dong 1-ga, Seo-gu, Busan, 602-011, Korea. yongki@pusan.ac.kr.
authors.forename: Yong Ki
authors.initials: YK
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, School of Medicine, Pusan National University and Biomedical Research Institute, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739, Korea. injkim@pusan.ac.kr.
authors.forename: In Joo
authors.initials: IJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006019:Glycolysis; D006801:Humans; D033162:Incidental Findings; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012372:ROC Curve; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Lymphatic metastasis; Metabolic tumor volume; Papillary thyroid carcinoma; Total lesion glycolysis