Abstract 956P
Background
The presence of metastatic neck node and extracapsular spread(ECS) has a poorer survival impact on oral squamous cell carcinoma(OSCC) patients. The debate of addressing the neck in superficial tumors <3 mm is still ongoing. Moreover, ECS has been recently added in the new clinical staging system and imaging plays an important role for the same. There are several studies reporting accuracy of individual imaging modalities in detecting metastatic node. However, combined use of these imaging techniques may be supplementary, especially with equivocal finding. This is the only study reporting combined accuracy of computed tomography(CT) and magnetic resonance imaging(MRI) in detecting both, metastatic node and ECS.
Methods
The study includes 107 treatment naïve consecutive OSCC patients operated between February 2016 and February 2020. All patients underwent CT and MRI within six weeks of surgery. Surgery for all patients involved excision of tumor and neck dissection. Taking histopathology report as a gold standard, level (Level I-IV)wise and overall accuracy of combined CT and MRI imaging in detecting metastatic node and ECS was analyzed.
Results
The mean age of study population was 57.5 years. Majority of the patients had T1,2 (68.22%; 73/107) cancer and 34 patients(31.8%) had advanced T stage cancer. Metastatic node was present in 38 patients (35.5%) and ECS was present in 27 patients (25.23%)The table shows the level wise and overall accuracy of combined (CT and MRI) imaging in detecting metastatic node and ECS. Table: 956P
| Sensitivity | Specificity | NPV | PPV | Accuracy | |
| Level I | 72.72 | 89.41 | 92.68 | 64 | 85.98 |
| Level II | 65.50 | 96.15 | 88.23 | 86.36 | 85.83 |
| Level III | 31.25 | 96.70 | 88.88 | 62.50 | 86.92 |
| Level IV | 50 | 99.04 | 99.04 | 50 | 98.13 |
| Overall | 78.94 | 94.20 | 89.04 | 88.23 | 88.79 |
| ECS | 10 | 100 | 100 | 76.92 | 77.5 |
Conclusions
Combined reporting of CT and MRI improves imaging sensitivity and accuracy without compromising its specificity in detecting metastatic node. Combined imaging is very specific in detecting ECS, however, sensitivity of detecting ECS is very low. With regards to level-wise accuracy, ability of imaging in correctly detecting a metastatic node is highest at level I and correctly rule out metastatic node is highest at level IV.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.