SPECT-CT visualization and biopsy of sentinel lymph nodes in patients with stage IAB-IIA cervical cancer

To evaluate the diagnostic accuracy of sentinel lymph node (SLN) biopsy and to determine clinical significance of preoperative single-photon emission computed tomography/computed tomography (SPECT-CT).

We retrospectively evaluate data and images of 55 women with stage IAB-IIA cervical cancer that underwent sentinel lymph node biopsy and subsequent lymph node dissection. ^99mTc-phytate (300 MBq) was injected submucosally in 4 points and SPECT-CT started 2 h after the injection. All lymph nodes (LN) that accumulated radiocolloids were regarded as sentinel. Next day after the mapping radical hysterectomy with complete pelvic and parametrial LN dissection and SLN biopsy were performed according to the institute protocol.

SPECT-CT identified SLNs in 51 of 55 patients. All SLNs were successfully detected during the surgery. The SLN mapping efficacy was 92.7%. LN metastases were diagnosed in 6/51 (11.8%) cases, including 2 patients with positive SLNs. Sensitivity, negative predictive value (NPV) and false-negative rate for SLN biopsy were as follows: 33.4%, 91.8% and 66.6%. In patients with unilateral SPECT-CT localization of SLNs, LN metastases were identified in 4 (20%) of 20 patients but SLN biopsy was false negative in all cases. In 31 women, SPECT-CT detected SLNs on both sides of the pelvis. In this group, regional LN metastases were diagnosed in 2 patients, and in both cases metastases were detected only in SLNs.

In women with SPECT-CT visualization of SLNs on both sides of the pelvis, SLN biopsy had high sensitivity and NPV. In patients with unilateral SLN localization, SLN biopsy cannot be used for the prediction of regional LN status.