Clinical results of cervix cancer treatment using various technologies in radiation therapy

Abstract

BACKGROUND: The study reported clinical results of patients with cervical cancer, who were treated with different methodological approaches of radiation therapy (RT), switching from conventional to conformal irradiation, as well as different brachytherapy (BT) techniques. AIM: To evaluate long-term results of treatment, locoregional and distant control. METHODS: 137 patients having stage IIB–IIIB cervical cancer in 2013–2016 were analyzed retrospectively. 70 patients (51%), divided in two groups of n=35, were treated with conventional RT and two-dimensional (2D) planning of intracavitary BT with 60Сo alone or in combination with cisplatin (40 mg/m2). The total dose (TD) for point A was 75.08±0.57 Gy, for point B — 57.9±0.43 Gy. 67 patients (49%), divided in two groups of n=35 and n=32, were treated with conformal external-beam RT following three-dimensional (3D) planning of intracavitary BT with 192Ir alone or in combination with cisplatin (40 mg/m2), respectively. Total D90 of high-risk clinical target volume was 95.0±0.67 Gy EQD2 (Equivalent Total Dose in 2 Gy fraction). RESULTS: 3- and 5-year overall survival rate with 3D-RT versus 2D-RT was 84.6±4.5% vs 63.1±6.0% and 84.6±4.5% vs 56.1±6.0%, respectively (p=0.030). It was revealed that modern technologies are also important in improving overall survival with image-guided RT: 3-year overall survival rate was higher in the group of image-guided RT combined with 3D-BT — 88.2±6.6% versus 59.0±8.4%, respectively (p=0.027). The use of chemoradiotherapy showed an advantage for 3-year event-free survival in groups with 2D RT — 67.9±8.4% versus 55.2±8.6% (p=0.042). Between the groups where 3D RT was used, no statistically significant differences were recorded. Locoregional control was higher in the 3D RT groups at 3 years of follow-up: 97.0±2.9% versus 82.9±5.3%, p=0.050. Chemoradiotherapy allows to reduce the number of local failures in the pelvis in the follow-up period up to 6 months, regardless of the RT technologies. The number of relapses and metastases in pelvis is lower when using 3D RT (3.0±2.1%) compared with 2D (15.7±4.4%), p=0.05. There was no statistically significant difference in the frequency of detection of metastases: with 2D RT — 5.7±2.8%, and with 3D RT — 9.0±3.5% (p 0.05). CONCLUSIONS: The study proves the improvement of local control when using conformal RT and 3D-BT, which is an important component in the RT program for cervical cancer.