Inclusion Criteria:  Patients more than 18 years old. Either genders. Cancer-related pelvic pain. American Society of Anesthesiologists Physical Status class I and II. Patients receiving opioids for pelvic cancer pain with visual analogue pain scale more than 4. BMI < 30.  Exclusion Criteria:  . patient refusal. local or systemic sepsis. Coagulopathy. unstable cardiovascular and respiratory diseases. previous neurological deficits, history of psychiatric disorders history of drug abuse distorted local anatomy. allergy to the used medications.