LOCAL VAGINAL ANESTHESIA DURING HIGH-DOSE-RATE INTRACAVITARY BRACHYTHERAPY FOR CERVICAL-CANCER

Purpose: To evaluate the clinical efficacy of local vaginal lidocaine application for pain relief during high-dose-rate (HDR) intracavitary brachytherapy for patients with cervical cancer, and to investigate se quential changes in serum levels of lidocaine during the procedures. M ethods and Materials: This prospective study was designed to examine t he analgesic effect, physical response, and side effects of local anes thesia during HDR intracavitary brachytherapy. Forty patients were enr olled. All patients received 10-15 MV X-rays to the pelvis with a tota l dose of 45-59.4 Gy 5-6 weeks before undergoing HDR intracavitary bra chytherapy. All patients underwent first intracavitary brachytherapy u nder general anesthesia. These patients were randomly allocated to rec eive one of two different treatment protocols as follows: (1) treatmen t session - control session - treatment session - control session; or (2) control session - treatment session- control session - treatment s ession. In the treatment sessions, topical anesthesia was administered using 4 ml of 10% lidocaine solution sprayed liberally on the cervix and vagina during intracavitary brachytherapy. In the control sessions , a placebo was administered in the same manner during brachytherapy. The Hensche's applicators for brachytherapy were inserted into the cer vix and vagina 5 min after lidocaine application. The visual analogue scale (VAS) was used to assess pain and discomfort during brachytherap y. Blood pressure and heart rates were measured to evaluate the physio logical response. Another prospective study was then performed to inve stigate the sequential changes of serum lidocaine levels during the an esthetic procedure. Eleven additional patients with similar disease st ate and demographic characteristics were enrolled and blood samples we re obtained before, and 5, 15, 30, and 45 min after the initiation of lidocaine application. Results: The mean VAS values recorded during th e treatment sessions and control sessions were 49.9 +/- 24.1 versus 60 .1 +/- 24.8, respectively. The value of VAS in the treatment session w as significantly lower than that of the control session (p < 0.001). N o statistically significant differences were found in the changes of b lood pressure and heart rate and in the incidence of side effects duri ng these two types of sessions (p > 0.05). In the drug-level study, se rum levels of lidocaine reached a peak 5 min after the initiation of l ocal anesthesia. The mean peak concentrations (Cmax) of lidocaine were 0.50 +/- 0.45 mu g/ml. Conclusion: Local vaginal anesthesia with 10% lidocaine solution can significantly decrease the degree of painful se nsation during HDR intracavitary brachytherapy, and is safe to adminis ter for the procedure for cervical cancer. (C) 1998 Elsevier Science I nc.