Three-dimensional conformal reirradiation for locoregionally recurrent lung cancer previously treated with radiation therapy.

Background: To evaluate the efficacy and toxicity of reirradiation using three-dimensional conformal radiotherapy (3D-CRT) in symptomatic patients with locoregionally recurrent lung cancer.

Methods: Between 2005 and 2012, 15 patients with locoregionally recurrent lung cancer were retreated with 3D-CRT after previously receiving thoracic radiotherapy. The median interval between the initial irradiation and reirradiation was 12 months (range, five to 41 months). The median initial radiotherapy dose was 63 Gy (range, 45-70 Gy), and reirradiation doses ranged from 25.2 to 45.2 Gy (median, 36 Gy), with daily fractions of 1.8-4 Gy (median, 2 Gy).

Results: After reirradiation, 80% of the patients experienced resolved or diminished symptoms for one or more of their symptoms, with an 83% improvement in a total of 24 symptoms. The overall tumor response rate to reirradiation was 46.7%, with progressive disease occurring in only one patient. The median overall survival (OS) time was 11 months (range, one to 27 months), and the one-year OS rate was 47%. The progression-free survival time ranged from one to 10 months (median, five months). In univariate analysis, the use of combined chemotherapy and a higher reirradiation dose showed a trend toward improved survival after reirradiation. Treatment-induced toxicity included grade 2 radiation pneumonitis in only one patient, and there were no other complications, such as radiation esophagitis or myelopathy.

Conclusions: Reirradiation using 3D-CRT with moderate doses for locoregionally recurrent lung cancer can provide palliative benefits without severe complications to the majority of selected patients with symptoms as a result of a regrowing tumor.