Therapeutic effects of extended-field and involved-field irradiation in three-dimensional radiotherapy in patients with esophageal cancer: a meta-analysis

Abstract

Objective To investigate the therapeutic effects, adverse effects, and patterns of failure of elective irradiation of lymphatic drainage area (extended-field) and involved-field irradiation in three-dimensional radiotherapy (3DRT) in patients with esophageal cancer via a Meta-analysis. Methods The databases Wanfang Data, CNKI, VIP, CBM, PubMed, Embase, and Cochrane Library were searched to collect the controlled clinical trials on extended-field irradiation and involved-field irradiation in 3DRT in patients with esophageal cancer. Stata 11.0 was used for data analysis. The odds ratio (OR) with 95% confidence interval was used to describe the differences between two groups. Results According to the inclusion and exclusion criteria, a total of 12 controlled clinical trials involving 1 095 patients with esophageal cancer were included in this meta-analysis. The results of the meta-analysis showed that compared with the involved-field irradiation group, the extended-field irradiation group had a significantly reduced rate of out-field failure in patients with esophageal cancer who received 3DRT (OR=3.727, P=0.007), but showed significantly higher rates of grade ≥3 acute radiation pneumonitis and radiation esophagitis (acute radiation pneumonitis: OR=0.348, P=0.001; radiation esophagitis: OR=0.385, P=0.000). The two groups had similar 1-, 2-, and 3-year local control rate and overall survival rate (local control rate: OR=0.966/0.946/0.732, P=0.837/0.781/0.098; overall survival rate: OR=0.952/1.149/0.768, P=0.756/0.422/0.120), as well as a similar distant metastasis rate (OR=0.986, P=0.937). Conclusions Compared with involved-field irradiation, extended-field irradiation can reduce the rate of out-field failure in patients with esophageal cancer who receive 3DRT. However, it does not have significant advantages in local control rate and overall survival rate and has an increased incidence rate of adverse effects. Key words: Esophageal neoplasms/three-dimensional radiotherapy; Three-dimensional radiotherapy, elective nodal; Three-dimensional radiotherapy, involved-field; Meta-analysis