To Örebro University

BACKGROUND: Base of tongue cancer incidence and patient survival is increasing why treatment sequelae becomes exceedingly important. Osteoradionecrosis (ORN) is a late adverse effect of radiotherapy and brachytherapy (BT) could be a risk factor. Brachytherapy is used in three out of six health care regions in Sweden.

AIMS: Investigate if patients treated in regions using BT show an increased risk for ORN and whether brachytherapy has any impact on overall survival. MATERIAL AND METHODS: We used data from the Swedish Head and Neck Cancer Register between 2008-2014. Due to the nonrandomized nature of the study and possible selection bias we compared the risk for ORN in brachy vs non-brachy regions.

RESULTS: Fifty out of 505 patients (9.9%) developed ORN; eight of these were treated in nonbrachy regions (16%), while 42 (84%) were treated in brachy regions. Neither age, sex, TNM-classification/stage, p16, smoking, neck dissection, or chemotherapy differed between ORN and no-ORN patients. The risk for ORN was significantly higher for patients treated in brachy regions compared to non-brachy regions (HR = 2,63, p = .012), whereas overall survival did not differ (HR = 0.95, p = .782).

CONCLUSIONS AND SIGNIFICANCE: Brachytherapy ought to be used cautiously for selected patients or within prospective randomized studies.