A dosimetric comparison of three-dimensional conformal and intensity-modulated radiotherapy in locally advanced pancreatic cancer and a study of the clinical efficacy / 中华放射医学与防护杂志

ABSTRACT

Objective To compare the dose distribution between three-dimensional conformal radiotherapy(3D-CRT) and intensity-modulated radiotherapy (IMRT) in treating locally advanced pancreatic cancer,and report the efficacy of IMRT combined with regional chemotherapy using gemcitabine (GEM).Methods Ten patients with locally advanced pancreatic cancer were enrolled in this study.3D-CRT and IMRT plans were designed for each patient.The dose distributions of target volume and normal tissues were analyzed using the dose volume histogram (DVH).Twenty-five locally advanced pancreatic cancers patients who were treated by IMRT combined with regional chemotherapy using gemcitabine (combined group) were retrospective analyzed,as well as 25 hospitalized patients of the same period who were treated by regional chemotherapy using gemcitabine alone (chemotherapy alone group).The therapeutic efficacy and adverse events were compared between two groups.Results IMRT plans decrease the mean dose and volume of duodenum,liver,stomach,both kidney and small bowel that received highdose irradiation.The 1-,2-year survival rate of the combined group and chemotherapy alone group was 60％,28％ and 36％,12％.The median survival time of two groups was 15 and 10 months,respectively (x2 =4.16,P ＜0.05).The total response rate of the combined group and the chemotherapy alone group was 64％ and 32％,respectively (x2 =5.13,P ＜ 0.05).The upper gastrointestinal side-effect rate of the combined group was higher than that of the chemotherapy alone group(Z =-2.354,P ＜ 0.05).There was no statistic significance in hematologic toxicity,liver and renal functional damage between the two groups.Conclusions Compared with 3D-CRT plan,IMRT plan could reduce the dose of organ at risks.IMRT combined with regional chemotherapy using gemcitabine could significantly improve the survival rate of patients with locally advanced pancreatic cancer with mild adverse events.