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  • br histogram DVH parameters associated

    2019-11-11


    histogram (DVH) parameters associated with esophagitis, such as mean Ko 143 dose and V50 [21–22]. With the advent of novel technologies such as intensity modulated radiation therapy, 4DCT, gating and image guided radiation therapy, studies focused on how to deliver lethal doses to cancer while reducing treatment-related toxicity. However, ARIE was still inevitable due to the physical properties of X-rays and the genetic susceptibility of patients [23]. In the meta-analyses and prospective trials, the incidence of grade 3–4 acute esophagitis caused by concurrent chemoradiotherapy was usually about 20–30% [24–26]. The pro-portion of high-grade esophagitis was lower in our study, even in the mLDG-treated group. This was probably an effect of efficacity of supportive care. Other possible explanations might not be excluded, such as the presence of sequential CRT, novel radiation technologies, the differences in chemotherapy regimens, the small sample sizes and the low total doses.
    Radiation protective chemical/biological agents were applied as the other main method for the prevention and treatment of ARIE. Radiation protectants, including sulfhydryl compounds, nitroxides, antioxidant compounds and non-antioxidant radioprotectors, had been tried orally or intravenously with some success [27]. Estab-lished clinical efficacy, no tumor protection, and acceptable toxic-ity were the important considerations for developing these agents [28]. EGCG and honey, which a traditional Chinese medicine called the drug homologous food, had been tested as a way to reduce radiation-induced normal tissue toxicity and complications recently. A retrospective study showed that a skin care program containing tea extracts helped to restore skin integrity for Grade 2 skin lesions in the head and neck and pelvic regions [29]. A ran-domized phase II trial of prophylactic manuka honey during the treatment of lung cancer (NRG Oncology RTOG 1012) showed honey was not superior to best supportive care in preventing radi-ation esophagitis. And the active species in the agent were incom-pletely known [30].
    This trial supported the hypothesis that EGCG was more effec-tive than conventional therapy (mLDG) in preventing or minimiz-ing radiation-induced dermatitis. There was an overall difference in prevention or duration of radiation-induced dermatitis between EGCG and mLDG. The data also showed the earlier EGCG was applied, the more benefits patients had for AEI. The severity of esophagitis in group A was lower than that in group B, and five patients in arm A had no esophagitis. No significant differences were found due to relatively small number of patients. This study also showed that the use of EGCG can improve the patient’s dys-phagia and pain symptoms. Instead of progression of its severity, a rapid regression of esophagitis was noted in most cases in arm 
    B, which was consistent with our previous research. The area under grade-duration curve was similar in arm A and B, but patients in arm A had less pain and dysphagia. These might mean a better quality of life and a medication adherence. EGCG was generally considered a safe food like honey, and only few patients were aller-gic to it. All of the reported events with large-quantity application were rated as mild events, such as excess gas, nausea, heartburn, abdominal pain [31]. The adverse events associated with EGCG were also mild in this study. Previous studies on NSCLC and SCLC with concurrent radiotherapy reported an ORR of 63–76% and 77–90%, respectively [32–35]. In our study, concurrent radiother-apy yielded an ORR of 78%. However, the results of these studies might be not necessarily comparable due to differences in patient selection, staging procedures, chemotherapy, CRT timing and schedules, and response evaluation.
    From what had been discussed above, ECGC could be safely used as a radioprotectant for patients undergoing radiotherapy and occupationally exposed individuals. However, some limita-tions of this study should be emphasized. Firstly, no Kuwahata’s endoscopic grade of esophagitis was obtained, and the esophagitis scores and treatment interruption were mainly according to the clinical symptoms. However, invasive procedure would worsen the condition of esophagitis and compromise the interests of human subjects. Secondly, a wide range of total radiation doses, loss of appropriate sample stratification and large ranges of eso-phageal doses might also have an impact on the demonstrated findings, although there was no statistical difference in all the pre-treatment characteristics Ko 143 among the three groups. Thirdly, Similar to most double blinded trials on other radio-protective agents, an unconscious bias toward experimental agents might be not com-pletely excluded [36]. In addition, the impact of EGCG on survival would be evaluated in further researches.