[Outcome of three-dimensional conformal radiotherapy for early stage non-small cell lung cancer patients who met or not inclusion criteria for stereotactic-body radiation therapy].

Introduction: In early stage non-small cell lung cancer (NSCLC) the stereotactic body radiation therapy (SBRT) gives promising results, similar to the results of surgical series. However, not all such patients are the candidates for this treatment method. The retrospective analysis of the results of three-dimensional conformal radiotherapy (3D-CRT) in stage I and II of NSCLC was undertaken, with a special focus on the patients who were candidates for SBRT treatment, but received 3D-CRT due to no access to the SBRT.
Material and Methods: One hundred thirty-two consecutive stage I-II NSCLC patients who received radical 3D-CRT between 1998 and 2009 were included. Different radiotherapy schedules were used; thus the biologically equivalent doses (BED) were calculated for all. Sixty-eight patients met criteria of qualification for SBRT (peripheral T1-3N0 tumors with diameter £ 5 cm). Overall survival and local progression free survival (LPFS) were estimated for the whole group and compared for patients being and not being candidates for SBRT. Uni- and multivariate analyses were performed for prognostic factors.
Results: Median BED value was 74 Gy (58-82 Gy). Patients who met SBRT criteria had significantly smaller gross tumor volume (GTV) comparing to the remainder (p 〈 0.00001). Three-year overall and local progression free survival rates were 37% and 50%, respectively. In comparison of SBRT candidates and others, only significant difference in three-year LPFS was obtained, 58% and 35%, respectively, p = 0.04. However, in the multivariate analysis, GTV, performance status, and stage were the only three prognostic factors for LPFS.
Conclusions: After 3D-CRT, superior local control for early stage NSCLC patients who met criteria of inclusion for SBRT in comparison with the remainder was demonstrated. However, this outcome was inferior to the local control after SBRT reported in the literature.