Oesophageal cancer: assessment of tumour response to chemoradiotherapy with tridimensional CT.

Purpose: To investigate whether changes in tumour volume were predictive of histopathological response to neoadjuvant therapy for oesophageal cancer.

Materials And Methods: Thirty-five consecutive patients with locally advanced oesophageal cancer were treated with chemoradiotherapy and surgery in responders from July 2007 to July 2009. Tumour volume (TV) was calculated using innovative tumour volume estimation software which analysed computed tomography (CT) data. Tumour diameter and area were also evaluated. Variations in tumour measurements following neoadjuvant treatment were compared with the histopathological data.

Results: Median baseline tumour diameter, area and volume were 3.51 cm (range 1.67-6.61), 7.51 cm(2) (range 1.79-21.0) and 33.80 cm(3) (range 3.36-101.6), respectively. Differences in TV between the pre- and post-treatment values were significantly correlated with the pathological stage (τ = 0.357, p = 0.004) and the tumour regression grade index (τ = 0.368, p = 0.005). According to the receiver operating characteristic analysis, TV measurements following treatment had moderate predictive values for the pathological T stage (area under the curve, AUC = 0.742, sensitivity = 55.56 %, specificity = 92.86 %, p = 0.005).Comparison of pathological and radiological volume showed a good precision (Pearson rho 0.77).

Conclusions: Changes in TV calculated on CT scans have a limited role in predicting pathological response to neoadjuvant treatment in oesophageal cancer patients. New imaging techniques based on metabolic imaging may provide better results.