Ultrasonographical approach for the diagnosis on the depth of invasion in early bronchogenic squamous cell carcinoma

It is important to evaluate the depth of invasion to determine the appropriate treatment for roentgenographically occult bronchogenic squamous cell carcinoma (ROSCC). In order to evaluate the actual significance of TUS as a diagnostic tool of intraluminal carcinoma invasion, we have conducted a prospective trial. TUS was performed on 29 lesions of ROSCCs. We ultrasonographically classified the degree of the depth of intraluminal invasion into 2 groups; A: "inside of cartilaginous layer" and B: "cartilaginous layer or over". The patients were treated by irradiation, photodynamic therapy (PDT) or surgical resection. Clinicopathological findings and response to the treatment were compared with this ultrasonographical classification. In the evaluation of invasion within cartilage, the sensitivity was 88.2%, the specificity was 77.8%, the accuracy was 84.6%, and the positive predictive value was 88.2%. With TUS, the decision of treatment modality would be more appropriate.