Inoperable endobronchial obstructing lung cancer treated with combined endobronchial and external beam irradiation: a dosimetric analysis.

PURPOSE

This study is a dosimetric review of our experience incorporating both external beam radiotherapy and endobronchial brachytherapy in the treatment of inoperable endobronchial obstructing lung cancer.

METHODS AND MATERIALS

Sixty-five patients with symptomatic inoperable endobronchial obstructing lung cancer received combined external beam radiotherapy and temporary endobronchial iridium (Ir)-192 implants between February 1987 and May 1991. External beam irradiation doses ranged from 55 to 66 Gy. Patients were given 2 to 4 temporary Ir-192 endobronchial implants at the site of endobronchial obstruction. Individual implant doses ranged from 2.7 to 10 Gy. Total implant doses ranged from 6 to 35 Gy. Total treatment doses ranged from 61 to 96.6 Gy.

RESULTS

Sixty-three percent of patients had a complete local endobronchial response to treatment and 23% had a partial response. Forty-seven percent of patients receiving a total dose of less than 70 Gy experienced a complete local endobronchial response to treatment while 83% of patients receiving a total dose of 85 Gy or greater experienced a complete local endobronchial response to treatment. Sixty-six percent experienced an improvement in their performance status using an Eastern Cooperative Oncology Group performance scale. Survival from the end of treatment was 38% at 1 year and 23% at 2 years, with the median survival at 8 months. Complications occurred in 9/65 (14%) of patients; 0% in patients receiving a total dose of less than 70 Gy, 10% in patients receiving a total dose of 70 to 84.99 Gy, and 24% of patients receiving a total dose of 85 Gy or higher.

CONCLUSION

The data from this study again confirms the feasibility of this form of treatment for inoperable endobronchial obstructing lung cancer. In addition, there appears to be a dose response for both local response and complications.