Analysis of complications in a prospective randomized trial comparing two brachytherapy low dose rates in cervical carcinoma

Abstract

Purpose : The analysis of complications in a prospective randomized trial comparing two preoperative brachytherapy low-dose rates in early stage cervical cancer is presented. Methods and materials : Between 1985 and 1988, 204 patients with Stage I and limited Stage Il cervical cancer were randomized to receive one of two preoperative brachytherapy low-dose rates (0.4 and 0.8 Gy/hr). The objective of this trial was to determine the benefits, if any, of the higher-dose rate within the therapeutic arsenal for this patient population, in terms of survival, local control, and complications. The type and severity of all complications were evaluated according to a common glossary and a strict follow-up schedule was established given that the treatment of cervical cancer is multidisciplinary, involving gynecologists, surgeons, and radiotherapists. Results : Overall survival: 85% at 2 years and local control: 93% at 2 years, were similarly distributed between the two groups. Regardless of their nature and severity, 139 and 175 complications were observed among 63% and 75% of patients, in the 0.4 and 0.8 Gy/h dose rate groups respectively. Gynecologic and urinary complications were the most frequent (38% and 28% of all complications), followed by vascular (15%), digestive (10%), nervous (5%) and cutaneous (5%). A total of 14 and 17 severe complications (Grade 3) were observed in 7% and 13% of patients, respectively in the 0.4 and 0.8 Gy/h dose rate groups ( p = 0.12). Nonparametric survival methods used to compare the time to the first complication did not show a significant difference between the two groups: 62% and 72% at 2 years ( p = 0.27). When the first complication and its evolution were considered (early complications), the prevalence of complications was not significantly different between the two groups: 28% vs. 34% at 2 years ( P = 0.31). In this prospective trial, patients were regularly followed-up and complications of varying nature and severity were observed in succession during follow-up. When successive complications and their evolution were taken into account, the prevalence of complications was significantly greater in the higher-dose rate group: 30% vs. 45% at 2 years ( p = 0.03). Conclusion : The results of this trial showed that long-term effects of treatment, when represented by prevalence of complications over time, were more frequent in the higher dose rate group. This underlines the importance of the regular follow-up of patients and of coding, not only the occurrence of all complications, but also their evolution over time.