A systematic review of particle-based treatment modalities for adenoid cystic carcinomas of the head and neck

Abstract

Purpose: Determine efficacy (local control, overall survival, and toxicities) of particle-based therapy (fast neutron therapy (FNT), proton beam therapy (PBT), carbon ion radiotherapy (CIRT)) in the treatment of adenoid cystic carcinomas (ACCs) of the head and neck.

Methods: This systematic literature review was conducted with adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All published work on the treatment of ACCs through particle-based treatment modalities (FNT, PBT, CIRT) with adequate reporting of patient outcomes in the English language were considered eligible for this systematic review.

Results: 44 studies (6 FNT, 16 PBT, 12 CIRT, and 10 multiple particles) reporting on ACC patient outcomes following particle therapy were included in this review. There were 41 retrospective and 3 prospective studies. Each particle modality was split into 2 series to ensure equitable evaluation. The median local control (LC) and overall survival (OS) rates were as follows: FNT consecutive 5-year 57 % & 72 %, FNT independent 5-year 61 % & 89.4 %, PBT ACC 2-year 94 % & 5-year 76 %, PBT mixed histology 2-year 89 % & 3-year 77.7 %, CIRT ACC 5-year 68.6 % & 74 %, and CIRT mixed histology 5-year 68% & 59.7%. The most common toxicities across the modalities were mucositis, dermatitis, brain/bone necrosis, and visual/auditory abnormalities.

Conclusion: This literature review suggests that PBT and CIRT are the preferred RT modality for ACC treatment with excellent LC rates and acceptable toxicity profiles in the adjuvant and definitive setting.

Keywords: Adenoid cystic carcinoma; Carbon-ion radiotherapy; Fast neutron radiotherapy; Particle-based radiotherapy; Proton-based radiotherapy.