Optimization of high-dose-rate cervix brachytherapy applicator placement: the benefits of intraoperative ultrasound guidance.

PURPOSE: To promote efficient workflow for image-guided high-dose-rate (HDR) brachytherapy (BT) for cervix cancer by implementing intraoperative ultrasound (US) guidance for placement and optimization of intrauterine applicators. We sought to establish this as part of routine radiation oncology practice without radiology consultation. METHODS AND MATERIALS: Thirty-five consecutive insertions were performed in 21 women between July 2006 and March 2007. Cervical dilation, tandem selection and insertion were guided by transabdominal US. Final tandem position following vaginal applicator insertion was also confirmed by US. Computed tomography (CT) imaging was used for treatment planning and to assess perforation and applicator suitability for each patient anatomy.
RESULTS: Intrauterine tandem insertion was successfully guided by US in the majority of procedures (34/35). CT imaging confirmed accurate placement within the uterine canal in each case, compared with a historic institutional perforation rate of 10%. Visualizing patient anatomy during insertion altered the selection of tandem length and angle in 49% of cases, resulting in improved applicator matching to anatomy. Average insertion time significantly decreased from 34 to 26 minutes (p=0.01). Requests for assistance from gynecologic surgical oncology declined from 38% to 5.7% of procedures.
CONCLUSIONS: Intraoperative US guidance for cervix BT has been successfully implemented with staff and equipment from radiation oncology. Using US during every insertion has led to improved applicator selection and placement while decreasing procedure time and reducing out of department consultations. These changes have eliminated repeat insertions due to unfavorable applicator placement (as revealed on postoperative CT), thus improving department efficiency and quality of patient care.