The Feasibility Of Involved-field Irradiation In Old Patients With Esophageal Squamous-cell Carcinoma

Background:To assess the outcomes of involved field irradiation (IFI) and elective nodal irradiation (ENI) in patients older than 70 years with esophageal squamous-cell carcinoma (SCC) receiving radical IMRT, and to determine whether IFI is feasible in these patients.Methods:79 patients older than 70 years diagnosed with SCC without distant metastases were collected from 2007 to 2010.48 patients received IFI, and the other 31 were treated with ENI. In IFI group, the Gross Tumor Volume (GTV) included the primary lesion and metastatic lymph nodes. The Clinical Target Volume (CTV) was defined as 0.5-0.8cm of uniform expansions over positive lymph nodes, and0.5-0.8cm of circumferential, and 3 cm of proximal/distal expansions over the primary lesion. In the ENI group, GTV and CTV1 were defined the same as the GTV and CTV of the IFI group, and CTV2 contained prophylactic regional lymph nodes. The prescribed dose was 54-71Gy in both groups. With a median follow-up time of 24 months, the disease-free survival (DFS), the overall survival(OS), patterns of failure, irradiated lung dose and complicated radiation pneumonitis (RP) were observed and compared between IFI and ENI groups.Results:In IFI and ENI arm, the DFS at 1,2,3 years were 60.4%,34.9%,29.7% and 64.5%, 54%,35%, respectively, with P value 0.132.The 1-,2-, and 3-year OS rates were 72.9%, 43.4%,31.5% for the IFI group, and 73%,53%,38,3% for the ENI group (P>0.05). The ENI group had a tendency, for batter OS, but the difference was not statistically(.P>0.05). The patterns of failure also had no difference between the two groups. Distant failure, local failure, uninvolved nodal failure in IFI arm were 22.9%,27%,4.2%, while in ENI arm were 25.8%,19.4%,0%, all of them had no significant difference (P>0.05). However, the lung V5, V20, and mean lung dose in ENI group were higher than that in IFI and all of them had a significantly differences (t=4.66,29.9,1563, P=0.03,<0.001, <0.001, respectively). The radiation pneumonitis rates were higher in ENI than in IFI arm, and the rates of degree 1-2 and degree 3 RP were 22% and 19% versus 13% and 4% in the two groups respectively, which were of statistically significantly difference (χ2=4.55,4.77, P=0.033,0.029, respectively).Conclusions:With merits of comparable DFS and OS but significantly less pulmonary toxicity, it is feasible to use definitive involved field irradiation for the elderly patients with esophageal SCC.