Impact of dose distribution by a 3D planning system for brachytherapy with ¹⁹⁸Au grains for head and neck cancer.

Abstract

There has been no study in which the correlation between clinical results and dosimetry based on a 3D treatment planning system in patients with ¹⁹⁸Au grains for head and neck cancer was evaluated. Thirty-two patients who were treated with ¹⁹⁸Au grains for head and neck cancer were reviewed. Twenty-five patients were treated with brachytherapy alone and seven patients were treated with a combination of brachytherapy and neoadjuvant external beam radiation therapy. With a median observation period of 60 months, the 5-year local control rate was 82.9%. V_85Gy of CTV in patients with local recurrence tended to be lower than that in patients without local recurrence (p = 0.07). The maximum dose of the keratinized gingiva in patients in whom bone exposure occurred was significantly higher than that in patients in whom bone exposure did not occur (p = 0.001). Dose distribution with ¹⁹⁸Au grains can predict local control and late adverse events.