Ultrasound Guided Tandem Insertion: Improving Toxicity and Precision of Brachytherapy Applicator Placement in Cervical Cancer

Abstract

To evaluate the benefit of intraoperative ultrasound (IOUS) guidance during intracavitary brachytherapy (ICBT) applicator insertion for the treatment of cervical cancer. Fifty-eight patients with cervical cancer were treated with ICBT at our institution between 1/1/13 and 12/31/16. Patients underwent 2 intraoperative insertions under general anesthesia and were treated using 7 Gy x 4 fractionation. Prior to 2015, IOUS was rarely used to guide tandem insertion. Upon root cause analysis (RCA), on 1/7/15 our institution initiated a policy requiring IOUS guidance for tandem insertions. We retrospectively reviewed clinical data to evaluate rates of intraoperative complications before and after mandating routine IOUS. Complications included uterine perforation and malpositioned applicator. Survival was estimated using the Kaplan Meier method and categorical comparisons were completed using Fisher’s test. One hundred thirty-seven tandem insertions were performed. The 4-yr overall complication rate was 7.4% (7 uterine perforations, 1 vaginal ulceration and 1 malpositioned split ring). Among patients with intraoperative complications, age ranged from 30-74 yrs, tumor size ranged from 1.6-7.2cm, and FIGO Stages included IB (22%), II (33%), III (44%). Prior to implementation of IOUS guidance, 10.1% (7 of 69) of insertions resulted in complications. After 1/7/2015, the complication rate dropped to 4.4% (3 of 68). The number of patients experiencing intraoperative complications was reduced from 25.0% (7 of 27) to 6.5% (2 of 21) of patients, a 74% relative reduction in risk (p = 0.046). At median follow up 11.2 months, overall survival and progression-free survival for these patients were 63.5% and 52% respectively. Among patients with perforation, 4 of 7 patients were treated with post-operative antibiotics. Four were observed 24 hr before discharge, 3 were discharged same day. The location of perforation varied–3 posterior, 2 anterior, and 2 through the fundus. Of note, 3 of 4 patients with highly anteverted uteri had posterior perforations. Six patients returned for reinsertion after 1 week, while one was observed and then underwent reinsertion after 24 hrs. All patients with perforation remained asymptomatic and stable. None developed fever, bleeding, abdominal pain, or vascular, urinary or bowel complications. Of the 9 patients with intraoperative complications, 8 successfully completed treatment on the 2ndattempt. Following incident RCA and implementation of routine IOUS to guide tandem placement, we noted a significant reduction in intraoperative complications. IOUS likely facilitated sounding and intrauterine positioning of the tandem. Eight of 9 patients who experienced complications successfully completed treatment, and none developed negative postoperative clinical sequelae.