Outcomes of Sinonasal Cancer Treated with Proton Therapy
Mené sur 84 patients atteints d'un cancer naso-sinusien (durée médiane de suivi : 2,4 ans), cette étude évalue l'efficacité, du point de vue du contrôle local et des taux de survie à 3 ans, et la toxicité d'une protonthérapie en combinaison ou non avec une chimiothérapie concomitante, puis identifie les facteurs pronostiques associés
Purpose : To report disease outcomes after proton therapy (PT) for sinonasal cancer. Methods and Materials : Eighty-four adult, non-metastatic patients received primary (13%) or adjuvant (87%) PT for sinonasal cancers (excluding melanoma, sarcoma, and lymphoma). Common histologies were olfactory neuroblastoma (23%), squamous carcinoma (22%), and adenoid cystic carcinoma (17%). Advanced stage (T3, 25%, and T4, 69%) and high-grade histology (51%) were common. Surgeries included endoscopic resection alone (45%) with craniotomy (12%) or open resection (30%). Residual gross disease was present in 26%. Most patients received hyperfractionated PT (1.2Gy[RBE] twice daily, 99%) and chemotherapy (75%). Median PT dose was 73.8Gy(RBE) with 85% receiving >70Gy(RBE). Prognostic factors were analyzed using Kaplan-Meier analysis and proportional hazards regression for multiple regression. Dosimetric parameters were evaluated using logistic regression. Serious, late grade 3+ toxicity was reported using CTCAE v4. Median follow-up was 2.4 years for all patients and 2.7 years among living patients. Results : The local control (LC) and neck control, freedom from distant metastases, and disease-free, cause-specific, and overall survival (OS) rates were 83%, 94%, 73%, 63%, 70%, and 68% at 3 years. Gross total resection (GTR) and PT resulted in a 90% 3-year LC rate. The 3-year LC rate was 61% for primary RT and 59% with gross disease. Gross disease was the only significant factor for LC on multivariate analysis while grade and continuous LC were prognostic for OS. Six of 12 local recurrences were marginal. Dural dissemination represented 26% of distant recurrences. Late toxicity occurred in 24% (grade 3+ unilateral vision loss, 2%). Conclusion : Dose-intensified, hyperfractionated PT with or without concurrent chemotherapy results in excellent LC after gross total resection and results with gross disease are encouraging. Patients with high-grade histology are at greater risk from death from distant dissemination. Continuous LC is a major determinant of survival justifying aggressive local therapy in nearly all cases.