CT lymphography for sentinel lymph node mapping of clinically N0 early oral cancer

Abstract

BackgroundThe objectives of this retrospective study were to evaluate the usefulness of computed tomography lymphography (CTL) and to clarify the optimal timing of CTL in sentinel lymph node (SLN) mapping of clinically N0 early oral cancer.MethodsTwenty patients with clinically N0 early oral cancer underwent CTL with a 128 multi-detector row CT scanner to detect SLN the day before resection of primary tumor and SLN biopsy with indocyanine green (ICG) fluorescence guidance. CT scanning was performed in the first 10 patients at 2, 5, and 10 min after submucosal injection of iopamidol and in the remaining 10 patients at 2, 3.5, 5, and 10 min after the injection of contrast medium. We evaluated the SLN detection rate at each scan timing and the number and location of SLNs. We evaluated whether CTL-enhanced SLNs could be identified intraoperatively as ICG fluorescent lymph nodes.ResultsSLNs were detected by CTL in 19 of the 20 patients (95.0%), and the mean number of SLNs was 2 (range, 1–4). All SLNs were located on the ipsilateral side; 35 of 37 SLNs were located at level I and II, and 2 SLNs were lingual lymph nodes. All SLNs could be detected 2 min and 3.5–5 min after contrast medium injection, and CTL-enhanced SLNs could be identified intraoperatively as fluorescent lymph nodes.ConclusionsCTL could facilitate the detection of SLNs in early oral cancer, and the optimal timing of CT scanning was at 2 and 5 min after injection of contrast medium.

New Developments in Imaging for Sentinel Lymph Node Biopsy in Early-Stage Oral Cavity Squamous Cell Carcinoma

“…For reviewing the application of CT lymphography in early-stage OSCC, the systematic literature search led to retrieval of 112 PubMed indexed articles for CT lymphography, of which 17 were considered relevant [ 26 , 27 , 28 , 29 , 30 , 31 , 40 , 41 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 ]. Of these 17 articles, 11 were animal studies [ 40 , 41 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 ].…”

“…More recently, Sugiyama et al [ 30 ] performed CT lymphography in 20 early-stage OSCC patients. Following peritumoral administration of 2.0 mL iopamidol, SLNs and lymphatic vessels draining the injection site were detected in 95% and 90% of patients, respectively.…”

“…In the sequel study of Sugiyama et al [ 26 ], preoperative CT lymphographic images were reevaluated in 32 early-stage OSCC patients with an approach similar to their previous study [ 30 ]. During follow-up 4/27 patients with negative SLNB (14.8%), based on CT lymphography, developed regional recurrence and 1/5 patients with SLN metastasis (20%) developed recurrence between primary tumor site and the neck.…”

“…This paper reviewed new developments in preoperative SLN imaging techniques in patients with early-stage OSCC. None of the included clinical studies contradicted outcomes or clinical translation predictions from corresponding animal studies, in regard of SLN identification using these novel techniques [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 42 , 43 , 44 , 45 , 46 , 50 , 51 , 64 , 66 , 67 , 69 , 70 , 71 , 72 ]. The overall reported rate of patients in which SLNs were identified using the presented techniques ranged from 89–100%.…”

“…CT lymphography has been proposed as a high potential alternative for conventional lymphoscintigraphy, with a sensitivity ranging from 56–80% and a NPV ranging from 82–96% [ 26 , 27 , 28 , 29 ]. Two series reported enhanced lymphatic vessel visualization in 90% of their patients [ 29 , 30 ]; in two studies lingual lymph nodes were identified as SLNs using CT lymphography [ 30 , 31 ].…”