Cervical And Upper Thoracic Esophageal Cancer Radiotherapy Dosimetry

Objective: Analysis and Comparison of conventional (CRT), three-dimensional conformal (3DCRT) and intensity modulated (IMRT) of three methods on the treatment of cervical and thoracic esophageal target can be achieved when the maximum safe dose of the prescription dose and to compare three methods of target dose distribution homogeneity and conformal degrees.Methods: 10 cases ofⅡ-Ⅲperiod on cervical and thoracic esophageal cancer patients, the use of CT positioning SIMENS64 row and Sichuan University TPS their CRT, 3DCRT, IMRT 3 Therapeutic plan design and calculation, divided into groups and LFI EFI50Gy + LFI group. DVH analysis of the plan, such as curves and two-dimensional dose distribution line, research the following questions: (1) prescription dose of 70Gy, the three kinds of methods of lung V20 and whole lung average dose (MLD) and suffered spinal cord maximum dose (Dmax ). (2) separately or simultaneously satisfy the lung V20 = 25%, MLD = 13Gy spinal cord Dmax = 45Gy, the target can reach the maximum prescribed dosage. (3) prescription dose of 70Gy to the design of a treatment program, compared three kinds of methods of target volume dose distribution uniformity and target conformal degrees.Results: (1) prescription dose of 70 Gy when, LFI group lung V20 three methods were 31.57%, 25.42%, 23.12%; whole lung MLD respectively 17.45Gy, 15.29 Gy, 11.26 Gy; spinal cord Dmax respectively 47.44Gy , 44.21Gy, 42.64 Gy. EFI50Gy + LFI group lung V20 three methods were 32.79%, 26.45%, 24.60%; whole lung MLD respectively 18.00Gy, 15.76 Gy, 12.59Gy; spinal cord Dmax respectively 48.97Gy, 47.12Gy, 43.78 Gy. Each group were statistically significant differences (P <0.05). (2) LFI group, three ways to meet the V20 = 25%, the target can reach the maximum prescription dose, respectively 62.01Gy, 67.08 Gy, 75.15Gy; Satisfied MLD = 13Gy when the target can reach the largest prescription dose, respectively 60.23Gy, 66.82Gy, 74.43 Gy; meet the spinal cord Dmax = 45Gy, the target can reach the maximum prescription dose, respectively 61.02Gy, 66.33 Gy, 75,05 Gy; simultaneously satisfy the lung V20 = 25%, MLD = 13Gy, spinal cord Dmax = 45Gy, the target can reach the maximum prescription dose, respectively 59.97Gy, 66.05Gy, 73.85Gy. EFI50Gy + LFI group, three ways to meet the V20 = 25%, the target can reach the maximum prescription dose, respectively 60.20Gy, 63.25 Gy, 73.04 Gy; Satisfied MLD = 13Gy target can be achieved when the largest dose prescription were 59.16 Gy, 62.30Gy, 72.81Gy; meet the spinal cord Dmax = 45Gy, the target can reach the maximum prescription dose, respectively 57.34Gy, 61.47 Gy, 72.65 Gy; simultaneously satisfy the lung V20 = 25%, MLD = 13Gy, spinal cord Dmax = 45Gy when the target can reach the maximum prescription dose, respectively 57.25Gy, 61.29Gy, 72.57Gy. Each group were statistically significant differences (P <0.05). (3) prescription dose of 70Gy, theConclusion: cervicothoracic esophageal up at the same time meet the lung and spinal cord at the maximum tolerated dose, LFI group, three-dimensional conformal and intensity modulated radiation therapy can achieve radical dose (66.05Gy and 73.85Gy), EFI50Gy + LFI group, only IMRT can achieve radical dose (72.57Gy), and three kinds of methods of target IMRT dose distribution is more uniform, better conformal degrees.