Abstract: 【Objective】 To explore the suitable way for esophagus cancer radiotherapy by dosimetric comparison of three-dimensional conformal radiotherapy (3DCRT)

intensity modulation radiation therapy (IMRT) and volumetric modulation arc therapy (VMAT). 【Methods】 Ten patients with multiple primary cancers of the esophagus were enrolled. 3DCRT

5-field IMRT

7-field IMRT

single arc VMAT and partial-arc VMAT plans were generated for each patient. Conformity index (CI)

heterogeneity index (HI)

dose to organs at risk (OAR)

deliverytime and monitor units (MU) were all recorded as dosimetric indices for plan comparison.【Results】 IMRT and VMAT plans were superior to 3D-CRT concerning target coverage

conformity and dose heterogeneity. Both IMRT and VMAT can significantly reduce the maximum radiation dose to the spinal cord and heart

and decrease the low-dose radiation volume V5 and V10 for lung. Compared to IMRT

VMAT requires the shortest delivery time and smallest MU.【Conclusion】 VMAT can save treatment delivery time while improving the dose distribution for both target and critical structures. It was thus recommended for esophagus cancer radiotherapy.