Application of cervix-uterine ITV in volumetric modulated arc therapy for cervical cancer under different bladder filling status / 中华放射肿瘤学杂志

ABSTRACT

Objective:To investigate the clinical application of cervix-uterine internal target volume (ITV) in volume-modulated arc therapy (VMAT) for cervical cancer under different bladder filling conditions, aiming to obtain more accurate planning target volume (PTV).Methods:Sixty-two patients with cervical cancer receiving radiotherapy rather than surgery were selected and randomly divided into the study ( n=31) and control groups ( n=31). In the study group, individualized ITV, PTV and PTV margin were obtained under three bladder filling status by localization CT scan to compare the VMAT. The target area and organs at risk (OARs) within the target area were statistically compared between two groups. The target missing rate in CBCT, adverse events and short-term efficacy of radiotherapy were analyzed in two groups. Results:There was no significant difference in the volume of target area and OARs in the target area between two groups (both P>0.05). In the study group, the target missing rate and target missing volume were significantly lower compared with those in the control group (both P<0.05). There was no significant difference in the incidence of acute radiation-induced adverse events between two groups ( P>0.05). The 1-, 2-year overall survival and progress-free survival did not significantly differ between two groups (all P>0.05). One patient in the study group had uterine recurrence and 2 cases in the control group. Conclusion:Application of individualized cervix-uterine ITV and PTV in definitive VMAT under different bladder filling conditions can improve the accuracy of target area contouring and improve the local control rate in cervical cancer patients.