Change in clinical management of sentinel lymph node location in early stage cervical cancer: the role of SPECT/CT

Objective: The aim of this study was to investigate the feasibility of the sentinel lymph node (SLN) identification with SPECT/CT lymphoscintigraphy imaging in the early stage invasive cervical cancer in patients undergoing radical hysterectomy and pelvic lymphadenectomy.

Methods: Between March 2007 and June 2009, a prospective consecutive study was designed for SLN mapping. Twenty-two patients with cervical cancer FIGO stage IB1 (n=20) or stage IIA1 (n=2) underwent SLN identification with preoperative SPECT/CT and planar images (technetium-99m colloid albumin injection around the tumor) and posterior intraoperative detection with both blue dye and a handheld or laparoscopic gamma probe. Complete pelvic lymphadenectomy was performed in all cases by open (n=2) or laparoscopic (n=20) surgery.

Results: In the present series, a total of 35 SLN were detected with planar images and 40 SLN were identified and well located by SPECT/CT lymphoscintigraphy (median 2.0 nodes per patient). In 5/22 patients (22.7%) SPECT/CT procedure improves the number of localized SLN. Intraoperatively, 57 SLNs were identified, with a median of 3 SLNs per patient by gamma probe (a total of 53 hot nodes) and a median of 2 nodes per patient after blue dye injection (a total of 42 blue nodes). Microscopic nodal metastases (eight nodes, corresponding to four patients) were confirmed in 18.18% of cases; all these lymph nodes were previously detected as SLN. The remaining 450 nodes, including SLNs, following complete pelvic lymphadenectomy, were histologically negative.

Conclusions: Sentinel lymph node detection is improved by SPECT/CT imaging because of the increased number of SLN detected and the better tridimensional anatomic location, allowing easier intra-operative detection with gamma probe and showing, in this series, a 100% negative predictive value.