Predictive factors for acute radiation pneumonitis in postoperative intensity modulated radiation therapy and volumetric modulated arc therapy of esophageal cancer.
BACKGROUND
Radiation pneumonitis (RP) is a common side reaction in radiotherapy for esophageal cancer. There are few reports about RP in esophageal cancer patients receiving postoperative intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). This study aims to analyze clinical or dosimetric factors associated with RP, and provides data for radiotherapy planning.


METHODS
We reviewed 68 postoperative esophageal cancer patients who were treated with radiotherapy at the West China Hospital from October 2010 to November 2012 to identify any correlation between the clinical or dosimetric parameters and acute radiation pneumonitis (ARP) or severe acute radiation pneumonitis (SARP) by t-test, chi-square test, and logistic regression analysis.


RESULTS
Of the 68 patients, 33 patients (48.5%) developed ARP, 13 of which (19.1%) developed SARP. Of these 33 patients, 8 (11.8%), 12 (17.6%), 11 (16.2%), and 2 (2.9%) patients were grade 1, 2, 3, and 4 ARP, respectively. Univariate analysis showed that lung infection during radiotherapy, use of VMAT, mean lung dose (MLD), and dosimetric parameters (e.g. V20, V30) are significantly correlated with RP. Multivariate analysis found that lung infection during radiotherapy, MLD ≥ 12 Gy, and V30 ≥ 13% are significantly correlated with an increased risk of RP.


CONCLUSIONS
Lung infection during radiotherapy and low radiation dose volume distribution were predictive factors associated with RP and should be accounted for during radiation planning.
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Yaqin
Y
Zhao
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Lu
L
Chen
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Shu
S
Zhang
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Qiang
Q
Wu
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Xiaoqin
X
Jiang
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Hong
H
Zhu
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Jin
J
Wang
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Zhiping
Z
Li
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Yong
Y
Xu
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Ying Jie
YJ
Zhang
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Sen
S
Bai
Cancer Center, West China Hospital, Sichuan University Chengdu, China.
Feng
F
Xu
Esophageal cancer; predictive factor; radiation pneumonitis