Methods Patients Unselected, forty female adults, aged 20 years old or older, diagnosed with cervical cancer and treated with brachytherapy as outpatients at Chulabhorn Hospital, Thailand between June 2011 and September 2012 were enrolled in the study with their informed consents. The study was approved by The Chulabhorn Research Institutional Review Board and Chulabhorn Ethics committee. All the patients were treated with four sessions of ICRT(Intracavitary Radiation Therapy). Inclusion criteria were: Age 20 - 80 years, can understand and provide information, no trouble hearing and good conscious, agree to participated and had performance levels at ECOG 0-2. The patients were randomized to receive either meperidine (1 mg/kg) or fentanyl (1 ug/kg) with diazepam 10 mg both. Nursing staffs who prepared the drugs picked the drugs from lotteries organized into 6 lots on it.