Opioid consumption and pain in gynecological cancer patients treated with interstitial brachytherapy

Purpose Interstitial brachytherapy (ISBT) has advantages over the intracavitary techniques in the treatment of gynecological malignancies. The insertion of catheters into tumor enables higher dose conformality and normal tissue sparing. However ISBT can be associated with pain due its invasiveness. The goal of this study is to assess pain and opioid consumption of patients implanted with a perineal ISBT applicator. Methods and Materials Forty-eight patients were treated with ISBT from September 2014 to April 2016. Mean age was 63. Malignancies included 18 cervical cancers, 12 vaginal, 14 recurrent endometrial, and four others. Patient characteristics and technical ISBT data were collected. Opioid consumption was quantified as oral morphine equivalent per day (OMEq/day) from postimplant until removal. Pain score levels were collected by using an 11-point scoring system. Results Twenty-three patients had a single ISBT implantation, whereas 25 had a second. Twenty-eight patients required IV-patient-controlled analgesia. Mean OMEq/day for the first insertion was 55 mg. In the second insertion, an increase of 22 mg was seen (p = 0.0004). Patients with IV-patient-controlled analgesia had higher opioid consumption (OMEq/day 69.8 mg vs 32.1 mg, p = 0.001) and maximum pain scores (5.5 vs 3.4, p = 0.007) as compared with patients on oral opioids. Higher levels of pain were detected in the first hours postimplant. Previous opioids and age were associated with increased opioid consumption. Conclusions Pain from perineal-ISBT can be managed with oral opioids in a select group of patients. For repeat insertions, there may be an increase in opioid consumption. While age and previous opioids affected opioid requirements, other factors such as number of needles and insertion depth were not associated factors.