Lymphoscintigraphic localization of sentinel node in early colorectal cancer: results of a monocentric study.

Background and Objectives: Evaluation of the feasibility of the sentinel node technique in early colorectal neoplasms and its overall accuracy in predicting nodal metastases. Methods: Thirty-five patients with colon or rectal lesions or degenerate polyps not radically excised by endoscopy were included. Lymphatic mapping was performed with 99mTc labeled albumin colloid injected submucosally by an endoscopic route the afternoon before the surgical procedure. The day of the intervention, 2.5% patent blue V dye (S.A.L.F: Italy) was injected circumferentially around the tumor. A hand held gamma detecting probe (Scintiprobe m100, Pol-Hi-Tech, Italy) was employed to detect "hot" nodes, in vivo and ex vivo. All sentinel nodes were embedded separately for haematoxylin and eosin staining. No IHC or PCR techniques were employed. Results: Sentinel lymph nodes (SLN) were successfully identified in 35 out of 35 patients. Concordance between SLN and nodal status was observed in 32 out of 35 cases (91.4%); four patients (11.4%) were upstaged. Three skip nodal metastases were observed (false-negative rate: 8.5%). Conclusions: The sentinel node technique with blue dye and radiotracer seems valuable in early colorectal cancers detected by screening programs: a good organization and a learning curve are needed, as further multicentric studies.