Dilution of dye improves parametrial SLN detection in patients with cervical cancer

Abstract Objective. Aim of this study to improve the detection rate of parametrial sentinel nodes in patients with early cervical cancer by using a new dosage of blue dye in a randomized trial. Methods. Standard labelling volume of 4 ml Patent Blue ® was compared to 2 ml Patent Blue ® diluted with 8 ml NaCl 0.9% in 60 patients using a randomized protocol. Tc-99 was not applied in any patient. All patients underwent open lymphadenectomy. Results. In each arm 30 patients were enrolled. Overall detection rate of sentinel nodes was 93.3%. Both groups did not differ with regard to patient's age, BMI, tumor stage, number of lymph nodes harvested, number of sentinel nodes detected and detection rate. Significantly more patients with parametrial sentinel nodes were detected in the diluted protocol (37.0% vs. 10.3%) which is due to the lateral part of the cardinal ligament (29.6% vs. 6.9%). Conclusion. In our study overall detection of sentinel nodes using a dye was high. The diluted solution of Patent Blue ® led to a higher detection rate of parametrial sentinel nodes. These findings might help explain the discrepancy between the high reported rate of parametrial lymph nodes in anatomical studies compared with the low rates in clinical sentinel series.