The Comparative Analysis Of MRI-guided Accelerated Fractionation Versus Conventional Fractionation Adaptive Brachytherapy For The Cervical Cancer

Background and purpose:External beam radiotherapy（EBRT）in combination with brachytherapy（BT）is the common treatment approach for cervical cancer,of which the BT is a critical component of cervical cancer treatment.Previous studies have demonstrated that the overall treatment time（OTT）of > 7-8 weeks significantly influenced the treatment efficacy that was manifested by the reduction of the local control rate（LC）of tumor and overall survival（OS）.Currently,when the EBRT is performed in combination with the BT,the BT is generally carried out in conventional fractionation mode with5-7 Gy in each time and once time in each week.In some patients,the OTT is prolonged to more than 7-8 weeks due to various causes.To shorten the OTT,2 BT could be performed every week for the patients receiving intracavitary brachytherapy（ICBT）after the EBRT;while for the patients receiving hybrid intracavitary and interstitial（IC/IS）BT,2 BT could be performed in 1 application to reduce the risk from the repeated general anesthesia within a short term.This study evaluated and compared the treatment outcomes and toxicities of using MRI-guided accelerated fractionated and conventional fractionation adaptive brachytherapy for cervical cancer.Material/Method（s）:One hundred and twenty patients with cervical cancer received EBRT combined with or without concurrent chemotherapy,which was followed by the BT.The BT in 63 patients had 1 BT in each application（conventional fractionation group）,while in the other 57 patients,at least one treatment was 2 continuous BT every other day in 1 application（accelerated fractionation group）.For the patients who received 2 BT in1 application,the IC/ISBT was used for the corresponding BT.Overall treatment time（OTT）and clinical outcomes including overall survival（OS）,cancer specific survival（CSS）,progression free survival（PFS）,local control（LC）were analysed.BT-related toxicities were evaluated,which included pain,dizziness,nausea/vomiting,fever/infection,blood loss during the removal of applicator and needle,the DVT,and other acute toxicities.The Common Terminology Criteria for Adverse Events（CTC-AE5.0）was used to evaluate the incidence and severity of toxicities of the urinary system,lower digestive system,and reproduction system.Kaplan-Meier and the Log-rank test were used to analyse the clinical outcomes and toxicities.At the same time,the personnel input and medical cost of accelerated s fractionation group and conventional fractionation group in cervical cancer adaptive BT were also compared.Results:1.The OTT was significantly shorter in accelerated fractionation group than conventional fractionation group（60 vs.64 d;P=0.017）.Compared to the the conventional fractionation group,median OTT of the accelerated fractionation group patients who received both EBRT and BT in our hospital was shortened to less than 8 weeks.2.The median follow-up time of the patients in conventional fractionation group and accelerated fractionation group was 23.5 and 12.0months,respectively.The overall survival（OS）,cancer-specific survival（CSS）,progression-free survival（PFS）,and local control rate（LC）in conventional fractionation group and accelerated fractionation group during the whole follow-up period were 77.8% vs.86.0%（P =0.632）,77.8% vs.87.7%（P =0.821）,68.3% vs.70.2%（P =0.207）,and 92.1% vs.94.7%（P =0.583）,respectively.And one year overall survival（OS）,cancer-specific survival（CSS）,progression-free survival（PFS）,and local control rate（LC）in conventional fractionation group and accelerated fractionation group were 93.7% vs.92%（P =0.707）,93.7% vs.92%（P =0.707）,85.7% vs.80%（P =0.552）,98.4% vs.98%（P =0.863）,respectively.3.The highest NRS of the pain during brachytherapy（BT）waiting period（2.22±1.84 vs.3.02±1.65;P<0.001）and at the time of the removal of the applicator（4.69±1.49 vs.5.30±1.18;P<0.001）in the patients who received 1 BT in 1 application and 2 continuous BT every other day in 1application were significantly different.The incidences of the other BT processes-related toxicities were not significantly different between the two groups.4.Acute toxicities,and late toxicities were not significantly different between the two groups.The incidence of grade 3 late toxicities of the lower digestive system was 1.6% and 1.8%（P =0.970）,and the incidence of grade 3 toxicities of the reproduction system was 1.6% and1.8%（P =0.513）in conventional fractionation group and accelerated fractionation group,respectively.5.Compared with the conventional fractionation group,the accelerated fractionation group required more personnel input during BT,but saved about 27% of the medical expenses related to BT.Conclusion:1.In cervical cancer,the accelerated fractionation mode is a logistically applicable,safe,and effective treatment strategy.2.In cervical cancer,compared with the conventional fractionation mode,the accelerated fractionation mode could shorten the overall treatment time and reduce the medical cost.