Late toxicities in concurrent chemoradiotherapy using high-dose-rate intracavitary brachytherapy plus weekly cisplatin for locally advanced cervical cancer: a historical cohort comparison against two previous different treatment schemes.

To determine the long-term toxicity of concurrent chemoradiotherapy (CCRT), using high-dose rate intracavitary brachytherapy (HDRICB) compared to radiation (RT) alone in patients with advanced cervical cancer using a control-cohort study. A total of 332 cases of Stage IIB-III disease were included in this comparative study. Seventy-three patients were treated with a 3-insertion schedule and labeled group A, whereas the other 146 patients with a 4-insertion schedule became group B. One hundred and thirteen patients treated by a 4-insertion protocol with concurrent weekly cisplatin were labeled group C. The cumulative rate of grade 2 or above rectal complication was 13.7% for group A, 9.6% for the group B and 15.9% for group C (p = 0.76), whereas the grade 3 to 4 non-rectal radiation-induced intestinal injury was 6.8% for group A, 6.2% for group B and 9.7% for group C (p = 0.20). Grade 2 to 4 late bladder toxicity was higher in group C, with the cumulative rate being 5.5% for group A, 4.8% for group B and 15.0% for group C (p = 0.004). The independent factor for a rectal complication was the occurrence of a bladder complication (p = 0.01, hazard ratio 3.06). The independent factors for bladder complications were the use of CCRT (p = 0.01, hazard ratio 2.08), and the occurrence of rectal complications (p = 0.02, hazard ratio 2.77). When treating advanced cervical cancer, HDRICB consisting of four 6 Gy insertions and weekly cisplatin shows a trend of increasing late bladder complications. The interval between drug administration and HDRICB should be kept long enough to avoid any synergistic effect of both regimens.