title: Sentinel lymph node biopsy is unsuitable for routine practice in younger female patients with unilateral low-risk papillary thyroid carcinoma.
abstract: BACKGROUND
  Sentinel lymph node (SLN) biopsy has been used to assess patients with papillary thyroid carcinoma (PTC). To achieve its full potential the rate of SLN identification must be as close to 100 percent as possible. In the present study we compared the combination of preoperative lymphoscintigraphy scanning by sulfur colloid labeled with 99 m Technetium, gamma-probe guided surgery, and methylene blue with methylene blue, alone, for sentinel node identification in younger women with unilateral low-risk PTC.
  
  
  METHODS
  From January 2004 to January 2007, 90 female patients, ages 23 to 44 (mean = 35), with unilateral low-risk PTC (T1-2N0M0) were prospectively studied. Mean tumor size was 1.3 cm (range, 0.8-3.7 cm). All patients underwent unilateral modified neck dissection. Prior to surgery, patients had, by random assignment, identification and biopsy of SLNs by methylene blue, alone (Group 1), or by sulfur colloid labeled with 99 m Technetium, gamma-probe guided surgery and methylene blue (Group 2).
  
  
  RESULTS
  In the methylene blue group, SLNs were identified in 39 of 45 patients (86.7%). Of the 39 patients, 28 (71.8%) had positive cervical lymph nodes (pN+), and 21 patients (53.8%) had pSLN+. In 7 of the 28 pN+ patients (25%), metastases were also detected in non-SLN, thus giving a false-negative rate (FNR of 38.9% (7/18), a negative predictive value (NPV) of 61.1% (11/18), and an accuracy of 82.1% (32/39). In the combined technique group, the identification rate (IR) of SLN was 100% (45/45). Of the 45 patients, 27 (60.0%) had pN+, 24 (53.3%) had pSLN+. There was a FNR of 14.3% (3/21), a NPV of 85.7% (18/21), and an accuracy of 93.3% (42/45). The combined techniques group was significantly superior to the methylene blue group in IR (p = 0.035). There were no significant differences between two groups in sensitivity, specificity, NPV, or accuracy. Location of pN+ (55 patients) in 84 patients was: level I and V, no patients; level II, 1 patient (1.2%); level III, 6 patients (7.2%); level III and IV, 8 patients (9.5%); level IV, alone, 8 patients (9.5%); level VI, 32 patients (38.1%). In all 90 patients, IR of SLN was 93.3%, FNR, 25.6%, NPV, 74.4%, and accuracy rate, 88.1 percent.
  
  
  CONCLUSIONS
  Compared to a single technique, there was a significantly higher SLN identification rate for the combined technique in younger female with ipsilateral, low-risk PTC (T1-2N0M0). Thus, a combined SLN biopsy technique seems to more accurately stage lymph nodes, with better identification of SLN located out of the central compartment. Regardless of the procedure used, the high FNR renders the current SLN techniques unsuitable for routine practice. Based on these results, prophylactic node dissection of level VI might be considered because 38.1% of our patients had such node metastases.
authors: Department of Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025, China.
authors: Ou
authors: O
authors: Huang
authors: WeiLi
authors: W
authors: Wu
authors: OuChen
authors: O
authors: Wang
authors: Jie
authors: J
authors: You
authors: Quan
authors: Q
authors: Li
authors: DuPing
authors: D
authors: Huang
authors: XiaoQu
authors: X
authors: Hu
authors: JinMiao
authors: J
authors: Qu
authors: Cun
authors: C
authors: Jin
authors: YouQun
authors: Y
authors: Xiang
authors: Kai
authors: K
authors: Yang
authors: ShuMei
authors: S
authors: Zhou
authors: XueMin
authors: X
authors: Chen
authors: YiFei
authors: Y
authors: Pan
authors: GuiLong
authors: G
authors: Guo
authors: XiaoHua
authors: X
authors: Zhang
mesh_terms: D000328:Adult; D002277:Carcinoma; D002291:Carcinoma, Papillary; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008751:Methylene Blue; D037981:Neck Dissection; D009362:Neoplasm Metastasis; D011446:Prospective Studies; D011877:Radionuclide Imaging; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D025321:Surgery, Computer-Assisted; D013667:Technetium; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D055815:Young Adult
chemical_list: D013667:Technetium; D008751:Methylene Blue