Objective   This work aimed to compare the three-year results, prognostic analysis, and adverse reactions of intensity-modulated radiation therapy (IMRT) positioned by PET-CT and conventional radiotherapy in locally advanced non-small cell lung cancer (NSCLC) patients who underwent concurrent chemotherapy.

  Methods   A clinical trial was carried out in Qingdao Cancer Hospital.The patients who joined our study were divided into IMRT and conventional radiotherapy (CRT) groups.A total of 48 patients were in the IMRT group and another 40 were in the CRT group.The total dose was 60 Gy throughout the 6-week treatment.The platinum-based concurrent chemotherapy, combined with regimens such as docetaxel, navelbine, and pemetrexed, was conducted for two cycles followed by two to four cycles of consolidation chemotherapy.

  Results   Significant differences were observed between the curative ratio of the IMRT (77.1%) and CRT (52.5%) groups (P=0.015).No significant difference existed between the short-term survival rates of the two groups.The 1-, 2-and 3-year survival rates were 77.1%, 54.2%, and 22.9% in the IMRT group, as well as 65.0%, 47.5%, and 17.5% in the CRT group, respectively.Significant differences existed in some adverse reactions between the two groups, such as radiation gastrointestinal reactions, esophagitis, and pneumonia.More patients died of local recurrence and radiation pneumonia in the CRT group than in the IMRT group.The local recurrence rate was also lower in the IMRT group than in the CRT group.

  Conclusion   IMRT has obvious advantages in improving the short-term curative effect and reducing adverse reactions.Regarding the survival rate, a long-term follow-up of the two groups is required in the future.