Sentinel lymph node detection by nuclear technique in patients with cN0 laryngeal carcinoma

Objectives To evaluate the value of nuclear technique for sentinel lymph node(SLN) detection in pts with cN₀ larynx neoplasms.

Methods Thirty pts with cN₀ laryngeal carcinoma were eligible for the study.Preoperative ⁹⁹Tc^m-SC was injected with laryngotracheoscopy guided by the endoscopic sprinkler pipe into the laryngeal carcinoma.Planar images were taken at 15min,30min,45min,1h,3h after injection respectively until the SLN was visualized.SPECT-CT images were performed when the SLN was detected.All pts underwent intraoperative lymphatic mapping with a handheld gamma probe.

Results (see table 1)The number of SLN was discrepant between planar image(61 SLN) and SPECT-CT(66 SLN) in 4/30 pts.SLN was detected in 28/30 pts(93.3%),27/30 pts(90.0%) with SPECT-CT and gamma probe respectively ,relative rate was 78.6%(22/28).The number of SLN detected with the gamma probe(70 SLN) didn't significantly differ from the number of SLN detected by SPECT-CT(p>0.05),but it was significantly higher than that with planar image (p<0.05).Six(20.0%) pts had lymph node metastasis diagnosed by histology.The sensitivity and specificity of SLN detection with SPECT-CT were respectively 83.3% and 95.8%.

Conclusions It was a effective and practible method that ⁹⁹Tc^m-SC was injected into the tumor by endoscopic sprinkler pipe to perform SLN imaging.SPECT-CT lymphoscintigraphy and lymphatic mapping with the handheld gamma probe may help to trace the SLN in pts with cN₀ laryngeal carcinoma and can also help to improve the accuracy of SLN detection.