Clinical Analysis Of Prophylactic Para-aortic Intensity-modulated Radiation In Cervical Cancer

Objective:To compare and evaluate the survivals,prognosis,treatment failures and toxicities of two treatment regimens,one of which is prophylactic para-aortic and pelvic intensity-modulated radiation combined concurrent chemotherapy and the other is pelvic intensity-modulated radiation combined concurrent chemotherapy,for cervical cancer patients radiologically diagnosedwithpelviclymphadenopathyandwithoutpara-aortic lymphadenopathy.Methods:From August 2012 to August 2016,31 cases of cervical cancer were prospectively selected for primarily treatment as the extended-field intensity-modulated radiation group（EF-IMRT group）,and 37 cases were chosen simultaneously as the pelvic intensity-modulated radiation group（P-IMRT group）.Both groups were diagnosed with pelvic lymphadenopathy without para-aortic lymphadenopathy before treatment by radiology.Pelvic and para-aortic intensity modulated radiation therapy（IMRT）was employed in EF-IMRT group with the exposed upper level of left renal vein,while pelvic IMRT was employed in P-IMRT group.Both groups were treated with¹⁹²Ir high dose rate brachytherapy and platinum-based concurrent chemotherapy.The toxicities were observed and recorded during treatment time and the clinical efficacy and toxicities were recorded regularly after treatment.SPSS 21.0 software was used for statistical analysis of Overall survival（OS）,Progression-free Survival（PFS）,Para-aortic lymph node metastasis-free survival（PAMFS）and clinical data.Results:1.For short-term efficacy:all cases in EF-IMRT group reached Complete response（CR）with CR rate of 100%,and 3 cases in P-IMRT group were Partial response（PR）,while all the remaining cases reached CR with CR rate of 91.89%（P=0.304）.2.For long-term efficacy:The 3-year OS,PFS and PAMFS of the EF-IMRT group and P-IMRT group were 87.0%vs74.6%,83.6%vs 61.7%and 96.0%vs 80.5%;There were 26 cases and 20 cases（83.87%vs 54.05%,P=0.009）in EF-IMRT group and P-IMRT group without treatment failure.3.Treatment regimens,tumor size and radiation time were all independent prognostic factors of OS and PFS.Treatment regimens,tumor size,and total Equivalent Dose in 2 Gy/f（EQD2）of point A were independent prognostic factors of PAMFS.4.In terms of acute hematologic toxicities,there were 16 cases vs 10cases of leukopenia at grade 3 and above（P=0.038）.Nevertheless they could return to normal under medication.No difference was found in Thrombocytopenia between the EF-IMRT group and the P-IMRT group.Both groups didn’t show significant differences in gastrointestinal and genitourinary toxicities.Conclusions:1.The risk of mortality,tumor progression and metastasis of para-aortic lymph nodes were significantly reduced by EF-IMRT compared with P-IMRT in patients with pelvic lymphadenopathy and without para-aortic lymphadenopathy.2.EF-IMRT showed satisfactory clinical efficacy,which could effectively reduce the incidence of metastasis outside pelvis and the total failure patterns.3.Treatment regimens,tumor size,radiation time were independent prognostic factors of OS and PFS.Treatment regimens,tumor size,EQD2 for point A were independent prognostic factors of PAMFS.4.EF-IMRT increased the incidence of bone marrow suppression,while all patients finished treatment schedules after supportive management.It did not show increase in incidence of gastrointestinal toxicities and genitourinary toxicities,and the late toxicities were mild.