[Experience of gamma-detecting probe for the survey of sentinel node in gastroesophageal malignancies].

Abstract Gamma-detecting probe NAVIGATOR GPS (Autosuture Japan) was evaluated by using of 99mTc. Linearlity of counting in radioactivity was fairly good, but the sensitivity of the prove is so low, that sentinel node (SN) should contain the 3.7 x 10(-3) MBq (0.1 microCi) of 99mTc or more for the most effective use of it. And the count rate of the gamma-detecting probe was influenced by the distance and angle from the 99mTc source variously. It is important for the operator to know such characteristics of the gamma-detecting probe in order to obtain the correct SN judging.