Ramin Sadeghi - Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Reza Taheri - Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Ali Jangjoo - Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Akbar Pakdel - Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Mohammad-Hassan Arjmand - Transplant Research Center, Clinical research institute, Mashhad University of Medical Sciences, Mashhad, Iran
Mohammad Motiei - Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Bahram Memar - Department of Pathology, Emam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
Mohsen Aliakbarian - Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

Objective(s):  Sentinel lymph node biopsy (SLNB) has been proven as a safe and efficient procedure in some cancers like breast cancer and melanoma with a reduction of complications and side effects of unnecessary lymphadenectomy in many patients. However, the diagnostic value of SLNB in gastric cancer is a point of debate. This study evaluated the diagnostic value of SLNB using radiotracer and isosulphan blue dye injection in patients with Gastric Adenocarcinomas (GA).Methods: This descriptive study was performed at Imam-Reza HOSPITAL on ۳۹ patients diagnosed with GA with no lymphatic metastasis using two methods: the combination of radionuclide with isosulphan together (R&I) method compared with the isosulphan alone method. Lymphatic dissection was performed in all patients. The pathological results were compared between the sentinel lymph nodes (SLN) and other lymph nodes and their accordance rate was calculated.Results: In the T۱ group, the sentinel lymph node biopsy detection rate was ۱۰۰% for the combination of the R&I method and ۶۰% for the isosulphan method and the false negative rate was zero. These values respectively were ۸۸.۸% and ۸۸.۸% in the T۲ group with a false negative rate of ۷۵%. In the T۳ group, the values were ۱۰۰% for the combination of the R&I method and ۹۳.۷% for the isosulphan method with a false negative rate of ۴۰%. In the combination of the R&I method, the sensitivity, specificity, and positive and negative predictive values were ۵۷.۹, ۱۰۰, ۱۰۰, and ۶۹.۲ percent respectively.Conclusion: Based on the false negative rate (۴۷.۴%), SLNB by injection of isosulphan blue dye alone is not a diagnostic enough value for predicting lymph node metastasis in GA. Although, SLNB by combination of the R&I had better accuracy compared to the isosulphan alone, more studies with larger samples are needed to prove this result.

Sentinel Lymph Node Biopsy, Gastric Adenocarcinoma, Metastasis, Isosulphan Blue dye