Ultrasonographic monitoring of high dose rate interstitial implant using template technique for oral tongue cancer.

192Ir high dose rate (HDR) fractionated interstitial brachytherapy was performed on two patients with tongue cancer with the aid of real-time intraoral ultrasonographic (US) guidance and the template technique. Blind-ended catheters with metallic rods (Obturator, Nucletron, the Netherlands) were inserted into the tongue from the submandibular region. This US monitoring allows for detection of the accurate location of both tumor and catheters in real-time motion. After implantation, we reconfirmed the position of the catheters by CT examination. Intraoral US monitoring was thus found to be a useful procedure for accurate implantation of brachytherapy for tongue cancer.