High dose rate brachytherapy in the treatment of oral cancer--the preliminary one institution experience.

Low dose rate brachytherapy is well established treatment modality of oral cancer. Data about high dose rate brachytherapy (HDR BT) are still scarce with heterogenous results. The aim of our study was to evaluate preliminary results in a small group of oral cancer patients treated by HDR BT. Seventeen applications were performed on 16 patients in years 2001-2004, in 15 cases for new tumor (mobile tongue 10x, floor of mouth 2x, lip 3x) and in 2 cases for local recurrence after radiotherapy. Ten treatments (for T1-2N0 tumors and recurrences) were performed with brachytherapy alone (18 x 3 Gy twice daily), seven patients (T2-3 N0-2 tumors) were treated with a combination of external beam radiotherapy (40-68 Gy) and brachytherapy (2-6 x 3 Gy twice daily). The plastic tubes technique was used for brachytherapy. Follow-up periods were between 8-46 months (median 17). Fifteen patients were disease free during follow-up period. One patient (brachytherapy alone for T2N0M0 mobile tongue cancer) died immediately after neck dissection for the neck recurrence due to the heart failure. The other one died due to distant metastases but without local recurrence. Acute complications were mucositis gr. II at maximum, late complications were ulcer of soft tissues in 3 and superficial bone necrosis in 2 cases. The evaluation of the brachytherapy implants was done according ICRU 58 recommendations. Hyperfractionated high dose rate brachytherapy alone or as a boost to external beam radiotherapy is feasible with promising local control. Carefull planning of the implant and mandibular shielding are necessary to avoid complications.