Ultrasound-guided transperineal interstitial implantation of gynecologic malignancies: Description of the technique

The efficacy of transperineal interstitial implantation of locally advanced and recurrent gynecologic malignancies is well established. Available treatment systems entail the introduction of multiple needles through the perineum via a template into a pelvic tumor. Ideal implants are achieved when these needles are directed into a tumor to an optimum depth while avoiding inadvertent penetration of the bladder, rectum, sigmoid, and low-lying loops of small bowel. The use of ultrasound to assist in this process is explored. Twenty patients underwent transabdominal ultrasound during interstitial implantation of advanced or recurrent gynecologic malignancies using the Syed-Neblett template and needle system, transabdominal ultrasound during needle insertion is useful in defining the bladder and implantable structures, such as the cervix, uterus, cervicouterine junction, and vaginal cuff. Anterior needles on the Syed-Neblett obturator and template are inserted with continuous monitoring of the position of the needle tips in relation to the superior boundary of the uterus and posterior bladder wall. Transabdominal ultrasound does not always help to define the rectosigmoid. The relationships of the endocervical canal, cervicouterine junction, and intrauterine tandem to the needles are readily established confirming the preplanned depth of insertion. Multiple needles can be distinguished on the ultrasound images as they are being manipulated. Transabdominal ultrasound during transperineal interstitial implantation is extremely helpful in guiding needle placement. This may reduce the risk of complications and help to achieve optimum tumor volume coverage.