Intestinal injury is an important toxic response during radiation therapy of pelvic tumors. With the widespread use of precision radiotherapy techniques such as intensity modulated radiation therapy (IMRT), the dose exposed to normal tissues and organs has been significantly reduced. However, the toxic response of the bowel still limits the increase of the dose to the target volume. Therefore, the protection of important organs at risk (OAR), such as the bowel, becomes more and more important while giving adequate irradiated dose to the target volume. Most current studies used loop to contour bowel. For patients who underwent IMRT, the meaningful dose-volume predictors of grade 2 acute intestinal adverse events using bowel loop (small loop + big bowel) delineation included V45 Gy < 50 cm 3,V50 Gy < 13 cm 3, and V55 Gy < 3 cm 3, and the corresponding predicators using bowel bag delineation were V40 Gy < 170 cm 3,V45 Gy < 100 cm 3, and V50 Gy < 33 cm 3.

Objective:To evaluate the early side effects and influencing factors in patients undergoing intensity-modulated radiation therapy after cervical cancer surgery.Methods:A retrospective analysis of 106 patients with cervical cancer who underwent postoperative intensity-modulated radiation therapy in our hospital from January 2014 to December 2017 was conducted. The occurrence of toxic and side effects were summarized, and the related clinical indicators were analyzed using univariate and multivariate analyses.Results:The 3-year overall survival rate was 88.1%, and the 3-year progression-free survival rate was 84.8%. The incidence of acute hematologic toxicity greater than grade 3 was 33%. The incidence of early intestinal reactions was 35%, of which only 1.8% was greater than grade 3. Univariate analysis demonstrated that severe acute hematologic side effects were statistically significant ( χ2=1.789-17.895, P<0.05) with the level of hemoglobin before radiotherapy, radiation in the abdominal aortic lymphatic drainage area or not, an increase of local radiotherapy dose in the target area, and chemotherapy or not. Multivariate analysis showed that concurrent chemotherapy significantly increased the incidence of severe acute hematologic toxicity ( χ2=3.929, P<0.05). Conclusions:In patients with cervical cancer undergoing postoperative intensity-modulated radiation therapy, grade 3 and greater toxic side effects are mainly related to hematological toxicity, and the incidence of severe bowel toxicity in the early stage is low.

Objective:To identify dose-volume parameters to predict the incidence of acute intestinal toxicity in cervical cancer patients after postoperative adjuvant radiotherapy.Methods:Clinical data of 93 cervical cancer patients who underwent postoperative adjuvant intensity-modulated radiotherapy (IMRT) were retrospectively evaluated. The dose-volume parameters comprised the absolute volume of the bowel receiving 5-45 Gy (5 Gy interval) radiation dose and the total volume of the bowel. The acute radiation-induced intestinal toxicity was evaluated by Radiation Therapy Oncology Group (RTOG) criteria. The association between the irradiated bowel volume and acute intestinal toxicity was analyzed.Results:A total of 26 (28%) patients experienced grade ≥2 acute intestinal toxicity. A strong relationship between grade ≥2 acute intestinal toxicity and the irradiated small bowel volume was observed at the total volume of small bowel, small bowel V 5 Gy, V 10 Gy and V 15 Gy (all P<0.05). Small bowel V 10 Gy ( HR=1.028, 95% CI, 0.993-1.062, P=0.029) and small bowel ?V 15 Gy( HR=0.991, 95% CI, 0.969-1.013, P=0.034)were the independent risk factors for evident acute intestinal toxicity. Conclusion:Dose-volume parameters of the small bowel can be used as predictors for the occurrence of grade ≥2 acute intestinal toxicity in cervical cancer patients undergoing postoperative adjuvant radiotherapy.

Pancreatic cancer, as a common malignant tumor of the digestive system, has a very low survival rate. In recent years, pancreatic cancer has made great progress in diagnostic methods, radiation therapy techniques, and systemic chemotherapy, but its therapeutic effect has not been considerably improved. As a new type of tumor research platform, organoids have made research progress in many fields. Constructing pancreatic cancer organoids is of great research value to guide the individualized treatment of pancreatic cancer. This article reviews the research and clinical application prospect of organoid model in radiotherapy of pancreatic cancer.