Photodynamic laser therapy to alleviate complete bronchial obstruction: comparison of CT and bronchoscopy to predict outcome.

Photodynamic laser therapy is used in the palliation of advanced lung cancer. To minimize the complications of this form of therapy, physicians must evaluate correctly the extent of extraluminal disease. We undertook a study to compare CT and bronchoscopy in the evaluation of extent of disease before laser therapy in 20 patients with complete bronchial obstruction. The relative contribution of intraluminal and extraluminal tumor to the obstruction and its influence on response to therapy was assessed by using both techniques. Adequate response was defined as greater than or equal to 50% relief of the obstruction on bronchoscopy performed within 1 week of therapy and by any improvement of the postobstructive atelectasis and consolidation on follow-up chest radiographs. Nine patients had predominately intraluminal tumor on both CT and bronchoscopy before laser therapy. Eight of these had a bronchoscopic response and radiographic improvement after therapy. Ten patients had predominately extrinsic compression by tumor on CT. Of these, only two had a bronchoscopic response and none had radiographic improvement after treatment. The differences in bronchoscopic and radiographic response between the two groups were significant (p less than .01). In the 10 patients with predominately extraluminal tumor on CT, bronchoscopy agreed with CT in suggesting mainly extrinsic compression in five, but it incorrectly suggested mainly intraluminal tumor in the remaining five. In one patient with a left upper-lobe tumor, the relative intra- and extraluminal components could not be assessed on CT. We conclude that in complete bronchial obstruction, CT is superior to bronchoscopy in evaluating the extent of extrinsic compression by tumor. The presence of predominately extraluminal tumor compression on CT correlates with a poor response to laser therapy.