Consistency of bladder filling during intensity-modulated radiotherapy for cervical cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the effect of the bladder scanner upon maintaining the consistency of bladder filling in cervical cancer patients during the intensity-modulated radiotherapy.Methods The bladder volume change of 20 patients diagnosed with cervical cancer throughout radiotherapy were retrospectively analyzed to determine the timing of introducing the bladder scanner. Ten patients undergoing cervical cancer radiotherapy were selected to analyze the consistency between the bladder volume measured by bladder scanner and cone-beam CT (CBCT).The changes of bladder volume before and after the intervention of bladder scanner were statistically compared. Results In total,100 CBCT images of 20 patients were retrospectively analyzed. Nonparametric test demonstrated that the bladder volume significantly differed compared with the planning volume ( P< 0. 05). Bland-Altman plot illustrated high consistency between the bladder volume measured by the bladder scanner and CBCT images with a mean difference of-6. 66 cm3 (95％CI - 53. 1-39. 83 cm3 ). Paired-t test showed there was statistical difference between the bladder volume before intervention and the planning bladder volume (P= 0. 000).The bladder volume after intervention did not significantly differ from the planning bladder volume (P= 0. 745). Conclusions The bladder volume significantly varies throughout the treatment process. Bladder scanner should be utilized prior to treatment. The bladder volume measured by the portable bladder scanner is consistent with the planning bladder volume.