Single photon emission computed tomography SPECT-CT improves sentinel node detection and localization in cervical and...

Planar lymphoscintigraphy (LSG) is frequently performed for the assessment of the sentinel lymph nodes (SLN) in gynecologic malignancies. Planar imaging helps to localize hot nodes but lacks accuracy of the anatomic location of those nodes. In this study, we compared SPECT-CT to planar LSG in endometrial and cervical cancer to assess its ability to localize SLN.

We conducted a prospective nonrandomized study of SLN mapping in women with endometrial and cervical cancer. Forty patients with endometrial cancer and 10 with cervical cancer underwent pre-operative LSG with 1 or 4 mCi of (99m)Tc sulfur colloid administered as injections into the cervix. All patients were scanned immediately with planar LSG obtained in the anterior and lateral views. SPECT-CT imaging was obtained following the planar imaging.

Planar LSG alone localized SLN in 30/40 (75%) endometrial cancer patients while SPECT-CT localized SLN in all 40 patients (100%). In the 10 cases where SLN was not identified with planar imaging, SPECT-CT localized nodes in the external iliac, internal iliac, common iliac and obturator groups. In cervical cancer, planar LSG alone localized sentinel lymph nodes in 8/10 patients (80%) as compared to SPECT-CT, which localized nodes in all 10 patients (100%). SPECT-CT imaging was especially useful in delineating external iliac versus internal iliac or obturator nodes, and the parametrial nodal uptake.

SPECT-CT appears to improve sentinel lymph node detection and anatomic localization as compared to planar imaging in cervical and uterine cancer.