Sentinel lymph node detection using methylene blue in patients with early stage cervical cancer.
OBJECTIVE
To evaluate the feasibility of sentinel lymph node (SLN) detection in patients with cervical cancer using the low-cost methylene blue dye and to optimize the application procedure.


METHODS
Patients with stage Ib(1)-IIa cervical cancer and subjected to abdominal radical abdominal hysterectomy and pelvic lymphadenectomy were enrolled. Methylene blue, 2-4 ml, was injected into the cervical peritumoral area in 77 cases (4 ml patent blue in the other four cases) 10-360 min before the incision, and surgically removed lymph nodes were examined for the blue lymph nodes that were considered as SLNs.


RESULTS
High SLN detection rate was successfully achieved when 4 ml of methylene blue was applied (93.9%, 46/49). Bilaterally SLN detection rate was significantly higher (78.1% vs. 47.1% P=0.027) in cases when the timing of application was more than 60 min before surgery than those with timing no more than 30 min. The blue color of methylene blue-stained SLNs sustained both in vivo and ex vivo, compared with the gradually faded blue color of patent blue that detected in 3 of 4 cases unilaterally. In the total of 112 dissected sides, the most common location of SLNs was the obturator basin (65.2%, 73/112), followed by external iliac area (30.4%, 34/112) and internal iliac area (26.8%, 30/112). Three patients who gave false negative results all had enlarged nodes.


CONCLUSIONS
Methylene blue is an effective tracer to detect SLNs in patients with early stage cervical cancer. The ideal dose and timing of methylene blue application are 4 ml and 60-90 min prior surgery, respectively.
Yuan
Song-Hua
SH
Department of Gynecologic Oncology, Cancer Center, Sun Yat-Sen University, Guangzhou, State Key Laboratory of Oncology in Southern China, China.
Xiong
Ying
Y
Wei
Mei
M
Yan
Xiao-Jian
XJ
Zhang
Hui-Zhong
HZ
Zeng
Yi-Xin
YX
Liang
Li-Zhi
LZ
D000328:Adult; D005188:False Negative Reactions; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007044:Hysterectomy; D007150:Immunohistochemistry; D007202:Indicators and Reagents; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008751:Methylene Blue; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012394:Rosaniline Dyes; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D002583:Uterine Cervical Neoplasms / Q000473:pathology* / Q000601:surgery
D007202:Indicators and Reagents; D012394:Rosaniline Dyes; C008769:sulfan blue; D008751:Methylene Blue