Brachytherapy for Buccal Cancer: From Conventional Low Dose Rate (LDR) or Mold Technique to High Dose Rate Interstitial Brachytherapy (HDR-ISBT)

Background/aim To examine the effectiveness of newly-installed high-dose-rate interstitial brachytherapy (HDR-ISBT) for buccal cancer. Patients and methods We retrospectively reviewed 36 patients (25 men and 11 women) with buccal cancer treated with curative brachytherapy with or without external radiotherapy with a median follow-up of 99 months. A total of 15 HDR-ISBT (median 48 Gy/ 8 fractions, range=24-60 Gy) patients were compared to conventional 15 cases LDR-ISBT (70 Gy, range=42.8-110 Gy) and 7 molds techniques (15 Gy, range=9-74 Gy). A total of 31 patients also underwent external radiotherapy (30 Gy, range=24-48 Gy). They comprised of 3T1, 23 T2, 8 T3, 3 T4 including 11 node positive cases. Results HDR-ISBT provided 82% of local control rate at 5 years, whereas conventional brachytherapy showed 72% [p=0.44; LDR-ISBT (65%), mold therapy (85.7%)]. Patients with early lesions (T1-2 or stage I-II) showed better local control rates than those with advanced lesions (T3-4 or stage III-IV). Severe late grade 3 complications developed in two patients treated with LDR-ISBT and EBRT. There is no significant difference in toxicity grade ≤2 between conventional brachytherapy (5/15=33%) and HDR-ISBT (7/32=32%, p=0.92). Conclusion HDR-ISBT achieved good and comparable local control rates to conventional brachytherapy without elevating the toxicity.