Department of Oral and Maxillo-Facial Surgery, Francois Baclesse Center, Caen, France.
Seattle Cancer Care Alliance Proton Therapy Center, Seattle, WA, USA.
Support Care Cancer. 2022 Oct;30(10):8377-8389. doi: 10.1007/s00520-022-07076-5. Epub 2022 May 5.
Despite reduction of xerostomia with intensity-modulated compared to conformal X-ray radiotherapy, radiation-induced dental complications continue to occur. Proton therapy is promising in head and neck cancers to further reduce radiation-induced side-effects, but the optimal dental management has not been defined.
Dental management before proton therapy was assessed compared to intensity-modulated radiotherapy based on a bicentric experience, a literature review and illustrative cases.
Preserved teeth frequently contain metallic dental restorations (amalgams, crowns, implants). Metals blur CT images, introducing errors in tumour and organ contour during radiotherapy planning. Due to their physical interactions with matter, protons are more sensitive than photons to tissue composition. The composition of restorative materials is rarely documented during radiotherapy planning, introducing dose errors. Manual artefact recontouring, metal artefact-reduction CT algorithms, dual or multi-energy CT and appropriate dose calculation algorithms insufficiently compensate for contour and dose errors during proton therapy. Physical uncertainties may be associated with lower tumour control probability and more side-effects after proton therapy. Metal-induced errors should be quantified and removal of metal restorations discussed on a case by case basis between dental care specialists, radiation oncologists and physicists. Metallic amalgams can be replaced with water-equivalent materials and crowns temporarily removed depending on rehabilitation potential, dental condition and cost. Implants might contraindicate proton therapy if they are in the proton beam path.
Metallic restorations may more severely affect proton than photon radiotherapy quality. Personalized dental care prior to proton therapy requires multidisciplinary assessment of metal-induced errors before choice of conservation/removal of dental metals and optimal radiotherapy.
尽管与适形 X 射线放疗相比，强度调制放疗可减少口干症，但放射性牙科并发症仍会发生。质子治疗对头颈部癌症有很大的应用前景，可以进一步减少放射性副作用，但最佳的牙科管理尚未确定。
根据一项双中心经验、文献回顾和案例说明，评估了质子治疗前的牙科管理与强度调制放疗相比的情况。
保留的牙齿通常含有金属牙科修复体（汞合金、牙冠、种植牙）。金属会使 CT 图像模糊，在放疗计划中对肿瘤和器官轮廓产生误差。由于质子与物质的物理相互作用，它们比光子对组织成分更敏感。修复材料的组成在放疗计划中很少被记录，会导致剂量误差。手动勾画伪影校正、金属伪影减少 CT 算法、双能或多能 CT 以及适当的剂量计算算法，不足以补偿质子治疗过程中的轮廓和剂量误差。物理不确定性可能与质子治疗后肿瘤控制概率降低和副作用增加有关。金属诱导的误差应在牙科专家、放射肿瘤学家和物理学家之间进行定量，并根据具体情况讨论金属修复体的保留或去除。金属汞合金可以用与水等效的材料替代，牙冠也可以根据修复潜力、牙齿状况和成本暂时去除。如果种植体位于质子束路径中，可能会对质子治疗产生禁忌。
金属修复体可能会比光子放疗更严重地影响质子放疗的质量。质子治疗前的个性化牙科护理需要在选择保留/去除牙科金属和最佳放疗之前，进行多学科的金属诱导误差评估。
