Room: Exhibit Hall
Purpose: For lung cancer treatment recommended photon energy is 6-10MV and desirable technique is intensity modulated radiation therapy (IMRT). However, patients are treated with other photon energies and techniques. This study aims to find out the overall-survival difference while treating small cell lung cancer (SCLC) patients with IMRT and 3D-conformal radiation therapy (3D-CRT) as well as different photon beam energies.
Methods: Analyzed National Cancer Database for SCLC patients with clinical stage I-III, treated from 2004 to 2014. Considered non-surgical patients who received both multi-agent chemotherapy and external beam radiation therapy (EBRT) with different photon energies. Included patients were stratified in two ways and performed two sets of analysis across the stage I-III: (1) based on technique (IMRT vs. 3D-CRT) and (2) based on photon energy used (6-10MV, 11-19MV, >19MV, and mixed energy). Considered valid dose range was 45-70Gy. IBM SPSS version 24.0 was used for statistical analysis; p-value <0.05 was considered statistically significant.
Results: Number of patients in different groups was: clinical stage-I (n=1141), stage-II (n=1066), stage-III (n=7457); 3D-CRT (n=3722), IMRT (n=2803); 6-10MV (n=4444), 11-19MV (n=3195), >19MV (n=556), and mixed energies (n=1469). The median age of the patient population was 65 years (range: 23-90years). The median follow-up was 18.7 months. Median overall-survival was (in months): 19.5, and 18.2 for patients treated with 3D-CRT and IMRT, respectively; 19.3, 18.0, 17.5, and 18.7 for patients treated with 6-10MV, 11-19MN, >19MV and mixed energies, respectively. No statistically significant (p>0.05) difference of overall-survival in different groups based on EBRT technique or energy across the clinical stages was found.
Conclusion: Although IMRT is superior in dose distribution as well as sparing of normal tissues and critical structures as compared to 3D-CRT, this study reveals that the overall-survival is independent of the treatment techniques. Additionally, it appears that photon beam energy has no effect on overall-survival.