Intestinal Image Manifestation And The Study Of Intestinal Flora Alteration In Patients Undergoing Pelvic Radiotherapy

Part1 Intestinal ultrasound and magnetic resonance imaging in patients undergoing pelvic radiotherapyObjective: To explore the value of endorectal ultrasound(ERUS)and magnetic resonance enterography(MRE)in the diagnosis of radiation enteritis.Methods: 8 patients with severe diarrhea after pelvic radiotherapy were enrolled in the study,ERUS was performed on 5 patients and MRE was performed on 3patients.Intestinal image manifestation were observed.Results: The image of ERUS showed thickening of the rectal wall,mainly in the submucosa.The thickening of rectum wall and sigmoid colon wall were showed in the image of MRE.Conclusion: ERUS and MRE were auxiliary means to diagnose radiation enteritis.Part2 Alteration of intestinal flora in patients undergoing pelvic cancer radiotherapyObjective: To investigate the effect of pelvic radiotherapy on intestinal flora,the correlation between radiation enteritis and intestinal flora,and the effect of probiotics intervention on intestinal flora and the prognosis of radiation enteritis.Methods: A total of 22 patients admitted to our hospital were enrolled in the study,including 5 patients with colorectal cancer,15 patients with cervical cancer and 2 patients with endometrial carcinoma.5 patients with cervical cancer received oral administration of probiotics.10 healthy persons were enrolled as control group.Stool samples were collected from each patient at time points before and just afterradiotherapy,and 16 S rDNA sequencing technology was used to detect fecal flora and analyze the effect of radiotherapy on intestinal flora.Results: 16 S rDNA sequencing showed that the main composition of patients’ intestinal flora is firmicutes,bacteroidetes,unclassified bacteria and proteobacteria,which is similar to healthy people,but the abundance of bacteria is significantly different.There were differences in intestinal flora of patients before and after radiotherapy.Microbial diversity and abundance were significantly altered after radiotherapy,especially in patients who later developed severe diarrhea(P<0.05).The Firmicutes/Bacteroidetes ratio was altered after radiotherapy.The abundance of Escherichia-Shigella and Fusobacterium increased after radiotherapy in patients who developed severe diarrhea.Oral administration of probiotics could alleviate the symptoms and reduce the decline of microbial diversity and abundance.Conclusion: Microbial diversity,richness,and the Firmicutes/Bacteroidetes ratio were altered after radiotherapy,especially in patients who later developed severe diarrhea.Oral administration of probiotics can alleviate the symptoms.