DOES ADDITIONAL BRACHYTHERAPY IMPROVE THE EFFECT OF EXTERNAL IRRADIATION - A PROSPECTIVE, RANDOMIZED STUDY IN CENTRAL LUNG-TUMORS

Purpose: Endobronchial brachytherapy has become more widely used to in crease the total local dose of irradiation (''boost'') applied for the treatment of lung cancer, Apart from treatment for local stenosis, en dobronchial brachytherapy in combination with external irradiation (EI ) has the potential to improve local tumor control and perhaps prolong survival, but the real benefit has not been proven yet, To evaluate t he possible effects of external irradiation with an additional boost o f high dose rate (HDR) brachytherapy, we conducted a prospective rando mized study. Methods and Materials: Design-two groups were compared: G roup 1 was treated with external radiotherapy alone (planned dose 60 G y); Group 2 received an additional boost of HDR brachytherapy of sched uled 4.8 Gy each (at 10 mm from the source axis) before and after exte rnal irradiation, Patients-98 patients with advanced inoperable lung c ancer were included in the study, 42 in Group 1 and 56 in Group 2, Bot h groups were comparable with respect to age, sex, tumor stage, Karnof sky performance status (KPS), and histology. Results: A mean total ext ernal irradiation dose of 50.5 +/- 14.1 Gy in Group 1 and 50 +/- 12.5 Gy in Group 2 was applied, Group 2 received an additional dose of 7.44 +/- 2.6 Gy (at 10 mm depth) through brachytherapy. The median surviva l time in both groups was comparable (28 weeks and 27 weeks, respectiv ely), In patients with squamous cell carcinoma (68 patients) Group 2 s howed an advantage in median survival with borderline significance (40 vs, 33 weeks, p = 0.09), Group 2 showed also a better local tumor con trol in all patients; patients with squamous cell carcinoma had a sign ificantly longer period of local tumor control, Fatal hemoptysis was t he cause of death in 6 (14.2%) patients in Group 1 and 11 (18.9%) in G roup 2 (p = 0.53). Conclusions: High dose rate brachytherapy in patien ts with inoperable lung cancer increased local control in our randomiz ed study when used in combination with external irradiation, Survival time was also longer, but with no clear statistical significance, This applied especially to patients with squamous cell carcinomas, There w as no statistically significant difference in the incidence of fatal h emoptysis between the two groups. (C) 1997 Elsevier Science Inc.