| Objective: To compare and analyze the dosimetric and clinical outcomesof cervical esophageal carcinoma treated with three-dimensional conformalradiotherapy (3D-CRT) and intensity modulated radiation therapy (IMRT),and to explore the related prognostic factors.Methods: From January2006to August2012,68patients of cervicalesophageal squamous cell carcinoma were treated with3D-CRT or IMRT inour hospital, among them,31cases with3D-CRT and37cases with IMRT. Weevaluated the short term effect，acute side effect and failure modes oftreatment. Their dosimetric and clinical data were compared and analyzedretrospectively．Kaplan-Meier method was used calculate the local controlrates and survival rates, Logrank test and COX regression test were used toanalyze prognostic factors.Results:1. Dosimetric comparison between3D-CRT plans and IMRTplans: The Dmin D95and HI of GTV in the two groups were5955.1±320.4cGy,6191.8±261.1cGy,0.05±0.03and6188.5±364.9cGy,6357.5±354.8cGy,0.07±0.02, respectively. The IMRT group was obviouslybetter than the control group (P＜0.05). The V90and V95were98.3±3.4%,96.5±5.5%in3D-CRT group and99.7±0.5%,98.8±2.1%in IMRT group,respectively. Significant difference was found between both groups (P＜0.05).Moreover,CI of GTV and PTV in IMRT plans was superior to3D-CRTplans(P=0.074,0.060). The V40of cord in IMRT group was obviously lowerthan3D-CRT(P=0.048), while its V10of lung was higher than3D-CRT(P=0.037).The other physical parameters in the two groups were nostatistically significance.2. The clinical efficacy: The complete response (CR)were19patients, the partial response (PR)46patients and no response(NR)3 patients. The overall symptom remission(CR+PR) rate was95.59%,3D-CRTarm was93.55%, IMRT was97.30%. The median follow-up time was52months. The l-,3-and5-year local control rates were84.8%,65.4%and48.3%, respectively. The l-,3-and5-year survival rates were83.8%,62.4%and43.7%in the whole group, respectively. The l-,3-,4-and5-year localcontrol rates of the group of3D-CRT were86.9%,62.2%,58.0%and46.4%respectively. The l-,3-,4-and5-year survival rates were83.9%,59.6%,55.3%and49.8%, respectively. The l-,3-,4-and5-year local control rates ofthe group of IMRT were82.9%,63.0%,56.0%and56.0%, respectively. Thel-,3-,4-and5-year survival rates were83.8%,65.6%,54.5%and27.3%respectively. There were no significant differences in the local control ratesand overall survival rates between3D-CRT and IMRT groups(P=0.761,0.645).3. Univariate and multivariate analysis: Univariate analysis showed that GTVvolume, the largest diameter of tumor, T stage and short term effect were theprognotic factors(P＜0.05). However, gender, age, lesion length in bariumesophagogram，dose of primary lesion, supraclavicular lymph node metastasis,elective nodal irradiation and chemotherapy were not correlated withprognosis(P＞0.05). Multivariate analysis showed that short term effect wasindependent prognostic factor(P=0.005).4. Acute toxicity: There was onlyone case with grades3acute radiation esophagitis and no acute pneumonitis ofgrades2-4, intestinal reactions0f grades3-4and Bone marrow suppression ofgrade4in the whole group. The two groups’acute toxicity was similar.5. Themain reason of treatment failures was the local failure (84.8%). There was nosignificant difference between3DCRT and IMRT group (48.4%VS35.13%,P＞0.05).Conclusion:1. IMRT still have better dosimetric advantage than3D-CRT and would not increase acute radiation injury while raising theradiation dose and enlarging target regin range of cervical esophagealcarcinoma.2.3D-CRT and IMRT are safe and effective in the treatment ofcervical esophageal carcinoma.There is no significant advantage of IMRT over3D-CRT in survival.3. GTV volume, the largest diameter of tumor, T stage and short term effect were the prognotic factors. While short term effect wasindependent prognostic factor.4. Local failure is still the main reason oftreatment failures. |
PDF Full Text Request