Case reports that high-dose-rate brachytherapy using custom-designed mouthpiece mold for early-stage squamous cell carcinoma of the hard palate is useful.

BACKGROUND: Surgery is the primary therapy for hard palate cancer, but this sometime worsens oral function and unavailable for patients with several comorbidities. Radiotherapy represents an alternative curative treatment option to preserve oral function, however, there are few reports on the use of radiotherapy for squamous cell carcinoma of the hard palate (SCCHP). High-dose-rate (HDR) brachytherapy has been known as an effective treatment for SCCHP, which seems to be less invasive when mold technique is used. In our hospital, the HDR customized mold brachytherapy (HDR- customized MBT) is available for patients with SCCHP. This study aimed to report the efficacy and toxicity of HDR- customized MBT for patients with early-stage SCCHP.

CASE PRESENTATION: Four patients with early-stage SCCHP were treated with mainly HDR- customized MBT between June 2015 and May 2023. Three of four patients received the combined radiotherapy: one patient underwent short-term external beam radiotherapy (EBRT) before the HDR- customized MBT; two patients underwent single-fraction interstitial brachytherapy before HDR- customized MBT. The total biological effective dose was 77-110 Gy (α/β = 10). All patients completed HDR- customized MBT with or without the combined radiotherapy and experienced no local recurrence. The acute toxicity was only mucositis limited to the irradiated area: one case with EBRT developed grade 2 mucositis. Only this case had late grade 2 mucositis; no late adverse events were observed in the other cases. No oral dysfunction or cosmetic problems occurred in any of the patients.

CONCLUSIONS: This study might show that HDR-customized MBT is useful for early-stage SCCHP and might be an alternative curative treatment option for them to preserve oral function.