Lymphatic mapping and sentinel node biopsy using 99mTc tin colloid in gastric cancer.
OBJECTIVE
The aim of this study was to determine the feasibility of sentinel lymph node (SLN) biopsy in patients with gastric cancer for the assessment of regional lymph node status.


BACKGROUND
SLN is the first draining node from the primary lesion, and it is the first site of lymph node metastasis in malignancy. SLN mapping and biopsy are of great significance in the determination of the extent of lymphadenectomy, allowing patients with gastric cancer to have a better quality of life without jeopardizing survival.


METHODS
The SLN biopsy was performed in 46 consecutive patients having gastric cancer with a preoperative imaging stage of T1/T2, N0, or M0. Three hours prior to each operation, Tc tin colloid (2.0 mL, 1.0 mCi) was endoscopically injected into the gastric submucosa around the primary tumor. Subsequently, serial lymphoscintigraphy was performed using a dual-head gamma camera. After the SLN biopsy had been performed using a gamma probe, all patients underwent radical gastrectomy (D2 or D2+alpha). The SLN was cut and immediately frozen-sectioned. A paraffin block was then produced for permanent hematoxylin-eosin staining and immunohistochemistry (IHC).


RESULTS
SLNs were successfully identified in 43 of 46 patients (success rate, 93.5%). On average, 2 (range, 1-8) SLNs were identified per patient. The positive predictive value, negative predictive value, sensitivity, and specificity of SLN biopsy were 100% (11 of 11), 93.8% (30 of 32), 84.6% (11 of 13), and 100% (30 of 30), respectively. SLNs were located at the level I lymph nodes in 38 (88.4%), the level I+II nodes in 2 (4.7%), and the level II nodes in 3 (7.0%). No micrometastases of SLNs was found on IHC for cytokeratin.


CONCLUSIONS
SLN biopsy using a radioisotope in patients with gastric cancer is a technically feasible and accurate technique, and it is a minimally invasive approach in the assessment of patient nodal status.
Kim
Min-Chan
MC
Department of Surgery, Dong-A University College of Medicine, Busan, South Korea.
Kim
Hyung-Ho
HH
Jung
Ghap-Joong
GJ
Lee
Jong-Hun
JH
Choi
Seok-Ryeol
SR
Kang
Do-Young
DY
Roh
Mee-Sook
MS
Jeong
Jin-Sook
JS
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D005240:Feasibility Studies; D006801:Humans; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D017556:Technetium Compounds; D017971:Tin Compounds
D019275:Radiopharmaceuticals; D017556:Technetium Compounds; D017971:Tin Compounds; C033493:technetium Tc 99m tin colloid