Comparison of cervical esophagus dose-volumes for three radiotherapy techniques for head and neck cancer.

Abstract

This study compares the radiation dose-volume of the cervical esophagus during head and neck radiotherapy using three different techniques. Treatment plans of 58 patients from 3/04 to 1/06 treated with bilateral head and neck radiotherapy were analyzed retrospectively. A comparison of the cervical esophagus dose with three-field 3D conformal RT (3DRT, n=34), whole-field IMRT (WF-IMRT, n=12), and half-beam IMRT (HB-IMRT, n=12) was performed. The volumes of esophagus receiving > or =50Gy (V50), > or =54Gy (V54) and > or = 60Gy (V60) and lengths receiving circumferential dose > or = 50Gy (L50) and > or = 54Gy (L54) were evaluated. Maximum dose, V54 and L54 were greater for the first 2cm and entire cervical esophagus with WF-IMRT than HB-IMRT or 3DRT. In patients requiring a high match, WF-IMRT was associated with a greater maximum dose, V54 and L54 than HB-IMRT and 3DRT (p<0.05). In the low match group, WF-IMRT was associated with a greater V54 and L54 (p<0.05). Low neck disease, low primary site, and definitive radiotherapy were associated with increased irradiation of the esophagus. Treatment of the lower neck with IMRT is associated with increased irradiation to the cervical esophagus, and dose constraints should be included to reduce toxicity.