The Dosimetric Comparison And Therapeutic Effect Analysis Of Patients Using3DCRT And IMRT With Pelvic Recurrence Of Postoperative Cervical Cancer

The objective:To provide data to support the application of3D-CRT and IMRT by retrospective analysis of dosimetry indicators, radiotherapy toxicity and therapeutic effect of patients with pelvic recurrence of postoperative cervical cancer using them.Method and Materials:Clinical data of32patients with pelvic recurrence of postoperative cervical cancer of our hospital from April2009to October2013,14cases were made of3D-CRT treatment while18of IMRT. Radiotherapy evaluation criteria based on RTOG and EORTC radiation injury grading standards, divided into0-IV grade. The survival was account by Kaplan-Meier and the comparisons between groups by Log-rank test. Comparison of efficacy using Fisher’s exact, acute and late toxicities performed using non-parametric tests rank conversion, dosimetric differences using t test or rank sum test between the two groups. Inspection level of alpha(a) equal to0.05.Result:1.A11patients were followed up for24months, the average survival time was19.6months; the average survival time of group3D-CRT was19.1months, while was19.9months.2.Under the same dose,(1) IMRT group compared with the3D-CRT group, PGTVmax6346.98±168.81Gy and6198.47±54.12Gy, the two groups were significantly different (P=0.023); CIpgtv0.56±0.21and0.26±0.13(P=0.002), CIptv0.77±0.13and0.59±0.07(P=0.004). HIptv1.12±0.11and1.24±0.11(P=0.039) IMRT group CIpgtv, CIptv, HIptv than3D-CRT group.(2) IMRT and3D-CRT group compared to the small intestine V4512.61±9.57and24.58±13.31, there was significant difference (P=0.044); V4016.66±11.98and30.40±12.80, there was significant difference (P=0.032); bladder V4057.22±17.52and76.00±13.18, there was significant difference (P=0.021); V4542.72±16.98and64.79±18.71, there was significant difference (P=0.019); V5030.43±11.50and57.93±19.68, statistically difference (P=0.003); IMRT group intestinal V45, V40, bladder V40, V45, V50irradiated volumes were lower than the percentage3D-CRT group.(3) The remaining indicators, PGTVmax, PGTVmean, PTVmean rectal Dmax, rectum Dmean, rectum V50, rectum V60, left femoral Dmax, the right femoral Dmax, HIpgtv no significant difference (P>0.05)3. Near therapeutic effect:IMRT group compared with3D-CRT group, pain relief rate of93.8%and83.3%, no significant difference (P>0.05); tumor regression efficiency of43.8%and50%, no significant difference (P>0.05).4.Acute and chronic toxicity of radiotherapy:(1) acute intestinal toxicity, IMRT group compared with the3D-CRT group,0degree of25%and8.3%, Ⅰ degree of68.8%and50%, Ⅱ degree of6.3%and33.3%, IMRT with no more Ⅲ degree reaction, the two groups were significantly different (P=0.03); acute bladder toxicity, IMRT group compared with the3D-CRT group,0degrees of81.3%, and50%, Ⅰ degree of18.8%and16.7%, Ⅱ degree of6.3%and33.3%, IMRT with no more than Ⅱ degree reaction,3D-CRT group II and III of the degrees was25%and8.3%, respectively, there was significant difference (P=0.043); acute intestinal and bladder IMRT toxicities were significantly lower than3D-CRT group,(2) chronic bladder toxicity, IMRT group compared with the3D-CRT group,0degree of43.8%and16.7%, Ⅰ degree of37.5%and25%, Ⅱ degree of12.5%and41.7%degree Ⅲ6.3%and8.3%, IMRT with no Ⅳ degree reaction, the two groups were significantly different (P=0.04); chronic intestinal toxicity, IMRT group and3D-CRT group,0degrees of18.8%and0,1degree of50%and41.7%Ⅱ degree of th25%and41.7%, Ⅲ degree of6.3%and8.3%, IMRT group with no IV degree toxicities There was no statistically significant difference (P=0.077)5.1-year survival analysis of overall survival3D CRT and IMRT group group were73.3%and80.4%(χ2=0.170, P=0.680),2-year overall survival rates were51.3%and55.7%(χ2=0.068, P=0.794), consider two patients receiving radiotherapy methods of overall survival was not statistically different.Conclusion:(1)Under the same dose, patients with pelvic recurrence of postoperative cervical cancer, IMRT compared to3D-CRT conformal group, with better radiation conformation and dose homogeneity, with low irradiation of doses of bladder and bowel at the same time.(2) Under the same dose, patients with pelvic recurrence of postoperative cervical cancer, IMRT compared to3D-CRT conformal group, with lower acute and chronic intestinal toxicity and chronic bladder toxicity.IMRT has significant advantages in reducing the acute and chronic toxicity of bladder and bowel complications.(3) IMRT and3D CRT therapy in patients with no significant difference in the2-year overall survival rate, no significant difference in short-term effect.