Different definitions of esophagus influence esophageal toxicity prediction for esophageal cancer patients administered simultaneous integrated boost versus standard-dose radiation therapy

• Published in: Scientific reports 2017-03, Vol.7 (1), p.120-8, Article 120
• Main Authors: Huang, Bao-tian, Huang, Rui-hong, Zhang, Wu-zhe, Lin, Wen, Guo, Long-jia, Xu, Liang-yu, Lin, Pei-xian, Chen, Jian-zhou, Li, De-rui, Chen, Chuang-zhen
• Format: Article
• Language: English
• Subjects: 631/67/1504/1477; 692/700/565/485; Cancer; Esophageal cancer; Esophagus; Humanities and Social Sciences; multidisciplinary; Radiation standards; Radiation therapy; Science; Science (multidisciplinary); Toxicity; Tumors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-00168-x

We aim to evaluate whether different definitions of esophagus (DEs) impact on the esophageal toxicity prediction for esophageal cancer (EC) patients administered intensity-modulated radiation therapy with simultaneous integrated boost (SIB-IMRT) vs. standard-dose IMRT (SD-IMRT). The esophagus for 21 patients diagnosed with primary EC were defined in the following four ways: the whole esophagus, including the tumor (ESO whole ); ESO whole within the treatment field (ESO infield ); ESO infield , excluding the tumor (ESO infield-tumor ) and ESO whole , excluding the tumor (ESO whole-tumor ). The difference in the dose variation, acute esophageal toxicity (AET) and late esophageal toxicity (LET) of four DEs were compared. We found that the mean esophageal dose for ESO whole , ESO infield , ESO infield-tumor and ESO whole-tumor were increased by 7.2 Gy, 10.9 Gy, 4.6 Gy and 2.0 Gy, respectively, in the SIB-IMRT plans. Radiobiological models indicated that a grade ≥ 2 AET was 2.9%, 3.1%, 2.2% and 1.6% higher on average with the Kwint model and 14.6%, 13.2%, 7.2% and 3.4% higher with the Wijsman model for the four DEs. A grade ≥ 3 AET increased by 4.3%, 7.2%, 4.2% and 1.2%, respectively. Additionally, the predicted LET increased by 0.15%, 0.39%, 1.2 × 10 −2 % and 1.5 × 10 −3 %. Our study demonstrates that different DEs influence the esophageal toxicity prediction for EC patients administered SIB-IMRT vs. SD-IMRT treatment.