Dosimetric comparison on heart and lung among three modalities in treatment of thoracic esophageal cancer / 中华放射医学与防护杂志

ABSTRACT

Objective To compare the dosimetric differences in heart and lung among three radiotherapy techniques in the treatment of thoracic esophageal cancer. Methods A total of 15 thoracic esophageal cancer patients treated in Zhejiang Cancer Hospital during the period of January 2015 to February 2016 were enrolled in this retrospective dosimetric study. Three radiotherapy treatment plans, including intensity-modulated radiotherapy ( IMRT) , volumetric intensity modulated arc therapy ( VMAT) with Raystation 4. 0v TPS, and tomotherapy (TOMO) plans with TomoTTM v2. 0. 5 TPS were generated for each patient with a prescribed dose of 60 Gy at 2 Gy per fraction. Dosimetric differences in planning target volume ( PTV) , heart, cardiac subunits and lung were compared. Results The mean volumes of PTV, heart and lung were (399 ±355), (671 ±274) and (3907 ±1717)cm3, respectively. Compared with VMAT and IMRT, TOMO reduced the maximum dose of PTV, heart, left atrium and lung ( H=10. 889, 7. 433, 12. 080, 11. 401, P <0. 05). No difference was observed in conformity or homogeneity among these three plans. Conclusions TOMO reduced the maximum dose to PTV, heart, left atrium and lung compared with VMAT and IMRT, However, no difference in conformity and homogeneity was observed. The impact of dosimetric advantage of TOMO needs further verification due to the interaction between heart and lung for thoracic esophageal cancer patients.