CT Lymphography Using Lipiodol for Sentinel Lymph Node Biopsy in Early-Stage Oral Cancer.

This study evaluated sentinel lymph node (SLN) identification with CT lymphography (CTL) following peritumoral administration of Lipiodol relative to conventional Tc-nanocolloid lymphoscintigraphy (including SPECT/CT) in 10 early-stage oral cancer patients undergoing SLN biopsy. Patients first underwent early dynamic and static scintigraphy after peritumoral administration of Tc-nanocolloid. Subsequently, Lipiodol was administered at the same injection sites, followed by fluoroscopy and CT acquisition. Finally, late scintigraphy and SPECT/CT were conducted, enabling the fusion of late CTL and SPECT imaging. The next day, designated SLNs were harvested, radiographically examined for Lipiodol uptake and histopathologically assessed. Corresponding images of CT, Tc-nanocolloid lymphoscintigraphy and SPECT/late CTL fusion were evaluated. Tc-nanocolloid lymphoscintigraphy identified 21 SLNs, of which 7 were identified with CTL (33%). CTL identified no additional SLNs and failed to identify any SLNs in four patients (40%). Out of six histopathologically positive SLNs, two were identified by CTL (33%). Radiographic examination confirmed Lipiodol uptake in seven harvested SLNs (24%), of which five were depicted by CTL. CTL using Lipiodol reached a sensitivity of 50% and a negative predictive value (NPV) of 75% (median follow-up: 12.3 months). These results suggest that CTL using Lipiodol is not a reliable technique for SLN mapping in early-stage oral cancer.