TomoDirect in the clinical implementation of mid-esophageal carcinoma

Abstract

Objective To evaluate the use of TomoDirect (TD) for the treatment of esophageal cancer in terms of plan quality and treatment efficiency. Methods In total of ten patients for locally advanced esophageal cancer with radical intent were planned for TD, Helical tomotherapy (HT) and IMRT, where TD and HT plans were designed in TomoTherapy and IMRT plans in Pinnacle3. Dose conformity index (CI), dose homogeneity index (HI) and dose for OARs were analyzed to evaluate the plan quality. Treatment time and monitor units were used to assess delivery efficiency. Results TD and HT plans showed significant improvement over IMRT plans in terms of CI and HI (t=5.261, 10.419, -5.463, -6.862, P<0.05). TD plans had a little worse CI and HI than those of HT plans (t=-7.055, 2.325, P<0.05). Mean V20,V30 and averaged dose of lungs were significantly improved by TD and HT plans in comparison with IMRT plans (t=-5.372, -6.296, -5.372, -6.296, -2.865, -4.632, P<0.05). Compared with HT plans, the averaged dose of heart was worse than those of TD and IMRT plans (t=-3.112, 2.829, P<0.05), while the maximum dose of heart was better than those of TD and IMRT plans (t=3.154, -3.348, P<0.05). The maximum dose of cord and averaged dose of normal tissue for TD were worse than that of HT plans (t=3.071, 5.076, P<0.05). The treatment time and machine monitor unit of TD plans was reduced by 12.0% and 37.2% compared with HT plans, respectively (t=-4.095, -12.559, P<0.05). IMRT plans had the shortest treatment time. Conclusions The TD technique is feasible to treat esophageal cancer. It not only can reduce the treatment time and improve radiation efficiency compared with HT, but also provide an advantage in terms of CI and HI, and V20,V30 and averaged dose of lungs in comparison with IMRT. Key words: TomoDirect; Mid-Esophageal carcinoma; Radiotherapy