HIGH-DOSE-RATE INTRACAVITARY BRACHYTHERAPY IN THE TREATMENT OF NASOPHARYNGEAL CARCINOMA

A retrospective study on 61 patients, with local persistent or recurre nt nasopharyngeal carcinoma (NPC), treated during 1990-1992 with high dose rate intracavitary brachytherapy alone or combined with external irradiation, is presented. All 39 patients with persistent disease wer e treated solely with brachytherapy. The actuarial 3-year local failur e-free survival (LFFS) rates of the persistent and recurrent groups we re 82% and 45% respectively, The corresponding disease specific surviv al rates were 82% and 62%, Fifteen patients with recurrence received t he combined modality treatment and their 3-year LFFS rate was 65%. Thr ee out of 7 patients treated by brachytherapy could be controlled loca lly. The total dose given to the floor of sphenoid was an important pr edictor of local control, Of the 23 patients with persistent disease t reated with < 17.5 Gy to this area, 6 failed locally as opposed to non e of the 16 patients receiving a higher dose (p = 0.031), For those wi th recurrence treated by the combined modality, none of the 7 patients given greater than or equal to 57.5 Gy recurred while 5 local failure s were observed among those receiving a smaller dose (p = 0.041), The general implications of these results for the treatment of NPC recurre nce are discussed.