Long-term results of 3-D brachytherapy treatment in locally advanced cervical cancer

Abstract

In many advanced studies, image-guided 3D brachytherapy (BT) treatment has been shown to improve survival and reduce treatment-related toxicity in locally advanced cervical cancer. In this study, long-term treatment results, risky organ doses and toxicity results of patients who were admitted to our clinic with the diagnosis of cervical cancer and treated with 3D brachytherapy were examined. Between 2012 and 2015, 152 inoperable cervical cancers were admitted, and long-term (> 12 months) follow-up of our clinic107 cases of inoperable cervical cancer was included in the study. After pelvic radiotherapy, pelvic MRI was performed, and target volumes were determined on CT. Volumes defined by the GEC-ESTRO guideline were, Gross tumor volume (GTV); residual tumor volume after external RT, High-risk clinical tumor volume (HRCTV); entire cervix and residual lesion, Intermediate-risk clinical tumor volume (IRCTV) low-risk volume and rectum, sigmoid and bladder contouring as risky organs, respectively. 3D brachytherapy treatment was performed with the microselectron device of 192 high-dose-rate (HDR) Ir 192 source. The median age was 53 years, and the median follow-up was 45 months. All patients were diagnosed by biopsy, and 81.9% of these patients were diagnosed as squamous cell carcinoma. According to the stages;IB1 was 2 (2%), II was 65 (61%), III was 31 (29%), and IV was 9 (8%). 96% of the patients received cisplatin-based chemotherapy with pelvic 3 D RT. When 3D RT doses of all patients were examined; Median HRCTV was calculated as 90% 6 Gy, EQD2 value 84.7 Gy, IRCTV 95% 3.03 Gy. When we look at risky organ doses; The median rectum 2cc 2.4Gy, EQD2 58.4Gy value, median bladder 2cc 3.52Gy, EQD2 value was 68.8 Gy, median sigmoid 2cc 2.60 Gy, EQD2 value was found to be 60.3 Gy. During the follow-up period, 4 patients had local recurrence, 11 patients had both local and distant metastasis, and 21 patients had only distant metastasis. The overall survival rate of 3 and 5 years was 78.1% and 72.2%. The 3 and 5-year local control rates were 87.4% and 77.3%, respectively. The survival rates of 3 and 5 years without distant metastasis were 66.5% and 61.2%. Rectovaginal fistula developed in 5 patients as late side effects and tumor progression was found in three of these patients. In the treatment of locally advanced cervical cancer 3D BRT, the volumes defined by the GEC-ESTRO guidance are individual. Thanks to the development of imaging techniques during the treatment of these volumes, the survival rates have increased compared to the previous series, and a shallow rate of GIS and GUS side effects are observed.