ENDOBRONCHIAL INTERSTITIAL AU-198 IMPLANTATION IN THE TREATMENT OF RECURRENT BRONCHOGENIC-CARCINOMA

Nineteen patients with non-small-cell bronchogenic carcinoma, recurrent following initial conventional external beam radiotherapy, were treated with endobronchial implantation of Au-198 seeds. Seventeen patients were symptomatic with primary symptoms of persistent hemoptysis (9), bronchial obstruction (2), or worsening dyspnea (6). Two patients were asymptomatic and implanted for bronchoscopic evidence of tumor recurrence. The dose delivered was described by three dosimetric parameters: 1) the total activity implanted (m Ci); 2) the midbronchial dose point; and 3) the volume of tissue that received > 20 Gy. Response was determined based on a system reflecting the primary indication for the implant. Seven of nine (78%) presenting with hemoptysis, four of six (67%) with increasing dyspnea, and one of two with bronchial obstruction responded. The overall median survival was 5.25 months (2.5-10 months 95% confidence interval). There was no clear correlation between any of the dosimetric parameters evaluated and a clinical response to therapy. Technical complications related to the inability to penetrate the scirrhous tumor surface adequately often led to less than optimal dose distribution. Endobronchial Au-198 implantation is associated with a poor calculated dose distribution but is, nonetheless, a relatively simple and comparatively inexpensive technique that often produces a clinical response and can be a useful option in the management of patients with recurrent bronchogenic carcinoma.