The sentinel node approach in gynaecological malignancies

Abstract

This review discusses the state-of-the-art of sentinel lymph node mapping in gynaecological malignancies, including cervical cancer, endometrial cancer, and vulvar cancer, with an emphasis on new technological advances. For this objective, PubMed/MEDLINE was searched for relevant studies about the sentinel lymph node procedure in gynaecology. In particular, the use of preoperative lymphatic mapping with lymphoscintigraphy and single photon emission tomography/computed tomography (SPECT/CT) was identified in 18 studies. Other recent advances as hybrid tracers (e.g. ICG-^99mTc-nanocolloid) and intraoperative tools (portable γ-camera and 3D navigation devices) appear to also represent a useful guide for the surgeon during the operation. Concerning vulvar and cervical cancers, the sentinel lymph node procedure has been incorporated to the current guidelines in Europe and North America, whereas for endometrial cancer it is considered investigative.

Keywords: Cervical cancer; Endometrial cancer; SPECT/CT; Sentinel lymph node; Vulvar cancer.

Fig. 1

Anatomical sentinel lymph-node (SLN) distribution in gynaecological malignancies. In vulvar cancer (Ref. [48]), SLNs are limited to the groin and are predominantly found in the superior, central, and medial inferior inguinal Daseler’s zones (a). By contrast, in cervical cancer. (b) SLNs are mainly located along the iliac vessels (Ref. [15]), whereas in endometrial cancer (c) also para-aortic drainage is frequently observed (Ref. [17])

Fig. 2

Cervical cancer. Planar images show a bilateral drainage in pelvic area (a–c). Volume-rendering image displays the level of sentinel nodes (d). SPECT/CT axial-fused images showing two separate nodes with high tracer uptake in right obturator fossa as well as three tiny nodes in left side (e). Corresponding axial CT slice (f)

Fig. 3

Endometrial cancer. Early planar image showed a very faint left node. A lied shield covered the injection area and high activity on the right side was supposed to be a partial zone of the injection area (a). Delayed planar image displays a right sentinel node (red arrow) and the previously observed left sentinel node (blue arrow). 3D volume-rendering image shows the same node distribution like b (c). A more detailed analysis of SPECT/CT data and 3D reconstructed images showed two posterior and caudal nodes (dotted circle) previous to the marked as sentinel node in b corresponding to external iliac nodes during surgery (arrow)

Fig. 4

In a patient with vulvar cancer, delayed planar imaging (a) shows one SLN in the right groin (red arrow) corresponding with one allocated SLN uptake (red arrow) on transversal-fused SPECT/CT (b) and two not enlarged lymph nodes on transversal CT (c) (double arrows). In another patient, delayed planar image (d) shows unilateral lymphatic drainage with a single SLN in the right groin (red arrow), while transversal-fused SPECT/CT (e) shows bilateral drainage with also a contralateral SLN (red arrow) corresponding with a not enlarged lymph node in the left groin on CT (f)