Role of lymphoscintigraphy and SPECT-CT in sentinel lymph node detection in early stage squamous cell carcinoma of oral cavity: Our experience

Objective: A multidisciplinary team trial in a tertiary care centre in patients with early stage oral cancer to review the role of advanced imaging
modalities like lymphoscintigraphy and SPECT-CT in sentinel lymph node identification and to layout our experience in performing this modality.
Methods: A randomised, prospective, case control study of diagnosed cases of T1/T2 N0 squamous cell carcinoma of oral cavity from December
2016 to January 2018 at our institution. Patients in study group underwent SLNB guided neck dissection and patients in control group underwent
Elective Neck Dissection. We compared both groups statistically for operating time, postop histopathology, diagnostic accuracy and outcomes. Also
we analyzed efficacy of static and dynamic lymphoscintigraphy followed by SPECT-CT in identifying sentinel lymph node areas in neck and intraoperative
gamma probe to precisely locate sentinel nodes.
Results: Out of 40 patients, 20 each in study and control groups were included. The SLN identification rate was 100% with combined SPECT-CT and
gamma probe use whereas it was 70% with imaging alone. The sensitivity, specificity, positive predictive value and negative predictive value of SLNB
and END were 80%, 56.58%, 9.61%, 98% and 78.5 %, 73.48%, 10.67 %, 98.8 % respectively. Operating time was less in SLNB group with statistically
significant difference between two groups.
Conclusion: High SLN identification rate with combined use of SPECT-CT and gamma probe and high NPV render SLNB as a reliable modality in
the management of early stage oral cavity cancers in a centre with a multidisciplinary team set up and appropriate facilities.