A novel method for sentinel lymph node mapping using magnetite in patients with non-small cell lung cancer.
OBJECTIVE
The detection rate of sentinel lymph nodes in patients with non-small cell lung cancer using isosulfan blue dye is too low for clinical use. Although exposure to radioactivity is reportedly minimal, special procedures are nonetheless required when a radioactive isotope is used as a tracer. Therefore, to eliminate the need for a radioactive tracer and to obtain a better detection rate than is obtained with isosulfan blue dye, we have developed a novel method that employs magnetite as the tracer. The aim of the present study was to test the feasibility of this technique.


METHODS
The tracer employed was ferumoxides, a colloidal superparamagnetic iron oxide of nonstoichiometric magnetite. Thirty-eight non-small cell lung cancer patients participated in the study; each received 5 mL of ferumoxides, injected around the tumor intraoperatively. Fifteen minutes after injection, lung resection and lymph node dissection were carried out. The magnetic force within the lymph nodes was measured using a highly sensitive handheld magnetometer ex vivo. All lymph nodes were also subjected to conventional histological analysis.


RESULTS
The rate of detection of sentinel lymph nodes was 81.6% (31/38). The accuracy, sensitivity, and false-negative rates were 96.8% (30/31), 85.7% (6/7), and 14.3% (1/7), respectively.


CONCLUSIONS
Intraoperative sentinel lymph node mapping using ferumoxides and a highly sensitive magnetometer is a safe, accurate, and sensitive way to detect sentinel lymph nodes in non-small cell lung cancer patients.
Nakagawa
Taku
T
Second Department of Surgery, Akita University School of Medicine, 1-1-1 Hondo, Akita City 010-8543, Japan.
Minamiya
Yoshihiro
Y
Katayose
Yoshihisa
Y
Saito
Hajime
H
Taguchi
Kousei
K
Imano
Hiroshi
H
Watanabe
Hitoshi
H
Enomoto
Katsuhiko
K
Sageshima
Masato
M
Ueda
Tomoaki
T
Ogawa
Jun-ichi
J
D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D003287:Contrast Media; D003911:Dextrans; D005188:False Negative Reactions; D005260:Female; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000473:pathology; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010087:Oxides; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide