A Multicenter Study of Carbon-ion Radiotherapy for Adenoid Cystic Carcinoma of the Head and Neck : Sub-analysis of the Japan Carbon-ion Radiation Oncology Study Group (J-CROS) Study (1402 HN)
Menée au Japon auprès de 289 patients atteints d'un carcinome adénoïde kystique de la tête et du cou (âge médian : 58 ans ; durée médiane de suivi : 30 mois), cette étude multicentrique évalue l'efficacité, du point de vue du contrôle de la maladie et des taux de survie, et la toxicité d'une radiothérapie par ions carbone
Purpose : Local control of adenoid cystic carcinoma (ACC) of the head and neck remains a challenge because of its insidious local growth pattern and relative radioresistance. We therefore retrospectively analyzed the treatment outcomes of carbon-ion radiotherapy (C-ion RT) for ACC of the head and neck at four active carbon-ion facilities in XXXX. Methods and Materials : A total of 289 patients who underwent C-ion RT for histology-proven ACC of the head and neck at four institutions in XXXX between November 2003 and December 2014 were included in this study. Results : Median patient age was 58 years (range, 12–83 years). Tumor sites included the nasal cavity and paranasal sinuses (42%), nasopharynx and oropharynx (19%), oral cavity (12%), major salivary glands (12%), and others (15%). T classifications were T4 in 200 (69%) patients, T3 in 45 (16%), T2 in 22 (8%), T1 in 15 (5%), and unclassified in seven (2%). The median total dose was 64 Gy (relative biological effectiveness [RBE]; range, 55.2–70.4 Gy [RBE]) in 16 fractions (range, 12–32 fractions). Median follow-up time was 30 months (range, 2–118 months). The 2-year overall survival (OS), progression-free survival (PFS), and local control (LC) rates were 94%, 68%, and 88%, respectively. Estimated 5-year OS, PFS, and LC rates were 74%, 44%, and 68%, respectively. In all, 43 patients (15%) experienced ≥grade 3 late toxicity, of which osteonecrosis of the jaw bone was the most common. Two patients treated for nasopharyngeal ACC died from a bleeding ulcer at the tumor site (grade 5 toxicity). Conclusions : C-ion RT appears to be a promising treatment for ACC of the head and neck.