391P - Incremental value of preoperative CT in the surgical management of papillary thyroid cancer
|Date||17 December 2016|
|Event||ESMO Asia 2016 Congress|
|Topics|| Thyroid Cancer
Imaging, Diagnosis and Staging
Surgery and/or Radiotherapy of Cancer
|Citation||Annals of Oncology (2016) 27 (suppl_9): ix112-ix122. 10.1093/annonc/mdw587|
A. Mahajan1, R. Vaish2, N. Sable3, S. Arya3, S.V. Kane4, A. D'Cruz2
Extrathyroidal extension (ETE) and Tracheal invasion (TI) are difficult to be accurately ascertained by preoperative clinical examination, especially if there is no gross invasion The aim was to evaluate the diagnostic value of USG and CT scan for preoperative prediction of the ETE and TI in patients with PTC.
We analyzed the medical records of 50 patients (61 surgical nodules:39 u/l, 11b/l) having PTC. Preoperative USG and CT were performed in all. ETE was categorised into 3 groups based on contact of tumor and disruption of thyroid capsule on both imaging modalities. Tracheal invasion was scored as per SHIN classification on CT scan. Considering histopathology as the gold standard diagnostic performance of pre-operative imaging for predicting ETE and TI was calculated.
Based on HPR ETE was present in 36 (59%) and TI in 15 (24.5%). The frequency of ETE was higher in patients with greater degrees of tumor contact and disruption of capsule, as revealed by both US and CT scans (Sensitivity, specificity, NPV, PPV of 97, 83, 96, 86% and 69, 76, 76, 69%, resp. p value 50% capsular contact. More than 90 degree contact with trachea and associated fat plane loss between trachea and tumor is a predictor of TI. Incidence of LVI and nodal metastasis was found to be statistically higher in patients with ETE+/-TI (p- 0.004).
Our study suggests that ETE and TI can be predicted most accurately by pre-operative CT scans and if included in the diagnostic work-up CT has the potential to better optimize the management. · If > 1mm normal parenchyma is surrounding the nodule can be demonstrated in both of US and CT, the possibility of ETE 1cm and has direct contact with the capsule, ETE might be present in > 80% cases. · Incidence of nodal metastases and LVI is higher in presence of ETE.
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All authors have declared no conflicts of interest.