Background: This study was designed to evaluate detection rate and anatomical location of sentinel lymph node (SLN) at lymphoscintigraphy, to compare short and long lymphoscintigraphy protocols, and to correlate lymphoscintigraphic and surgical mapping of SLN in patients with early-stage endometrial cancer (EC).
Methods: Subanalysis of the prospective multicenter study Senti-endo performed from July 2007 to August 2009. Patients with stage I and II EC received four cervical injections of 0-2 mL of unfiltered technetium sulphur colloid the day before (long protocol) or the morning (short protocol) before surgery. SLN detection used a combined technetium/patent blue labeling technique, and all patients had a systematic bilateral pelvic lymphadenectomy.
Results: A total of 133 patients were enrolled in the study and 118 (94.5 %) underwent a lymphoscintigraphy. Of these 118 patients, 44 (37 %) underwent a short protocol and 66 (56 %) a long protocol (data on lymphoscintigraphy were not available in eight patients). Lymphoscintigraphic detection rate was 74.6 % (34 % for short protocol and 60.2 % for long protocol). No difference in the detection rate was observed according to lymphoscintigraphy protocol (p = 0.22), but a higher number of SLN was noted for the long protocol (p = 0.02). Aberrant drainage was noted on lymphoscintigraphy in 30.5 % of the patients. Paraaortic SLNs were exclusively detected using the long protocol. A poor correlation was noted between short (κ test = 0.24) or long lymphoscintigraphy (κ test = 0.3) protocol and SLN surgical mapping.
Conclusions: Our study demonstrates that preoperative lymphoscintigraphy allowed a high SLN detection rate and that long lymphoscintigraphy protocol was associated with a higher detection of aberrant drainage especially in the paraaortic area.