Intraoperative radiation therapy combined with external irradiation in nonresectable non-small-cell lung cancer: Preliminary report

Abstract

Twenty-one patients with nonresectable non-small-cell lung cancer (15 squamous-cell, 4 adeno, 2 large-cell; T1–T3, N0–N2, all M0) underwent lymph node dissection and intruoperative irradiation of the tumor (IORT) with doses between 10 and 20 Gy (energies: 7 to 20 MeV electron beam). Postoperatively, 46–56 Gy external beam irradiation (8 or 23 MeV photon beam) were delivered to the mediastinum and 46 Gy to the tumor bearing area. Fifteen patients were available for follow-up investigations. The CT-scan tumor volumetry 4 weeks postoperatively showed a significant overall decrease (Wilcoxon test: p<0.05) with eight minor responses (MR) (tumor regressions between 4 and 45%) and six partial responses (PR) (between 50 and 84%). One case was not evaluable. A second volumetry after external irradiation was done in 14 patients, 18 weeks after IORT, showing 3 complete responses, 10 partial responses (62 to 840%), and 1 minor response (28%). The recent volumetries (10 patients) between 4.5 and 16.5 months after IORT showed 7 complete responses and 3 partial responses (63 to 940%). One patient died from intrabronchial hemorrhage at 7 weeks. Three others died from unrelated causes, 6, 12 and 14 months, respectively, after IORT and in one further case the cause of death at 15 months was local tumor regrowth. Within the median time elapsed since IORT (12 months) only this one case of local regrowth and one further case of distant spread were observed.