Jereczek-Fossa Barbara A, Orecchia Roberto
Division of Radiotherapy, European Institute of Oncology, via Ripamonti 435, 20141 Milan, Italy.
Cancer Treat Rev. 2002 Feb;28(1):65-74. doi: 10.1053/ctrv.2002.0254.
The mandible is among the bones most frequently affected by irradiation. The most severe post-radiation injury of the mandible is osteoradionecrosis (ORN). Conflicting data have been reported on the incidence of this complication, its aetiology and management. The incidence of mandibular ORN in head and neck cancer patients managed with radical or postoperative irradiation, has varied widely in the literature from 0.4% to 56%. The interpretation of data derived from particular series are difficult due to the different scoring methods and classification systems used for the evaluation of post-radiation bone damage. Although ORN occurs typically in the first three years after radiotherapy, patients probably remain at indefinite risk. The diagnosis of ORN is principally based on the clinical picture of chronically exposed bone. Radiological symptoms include decreased bone density with fractures, cortical destruction and loss of spongiosa trabeculation. Numerous factors that may be associated with the risk of ORN include treatment-related variables (for example, total radiotherapy dose, biologically effective dose, photon energy, brachytherapy dose rate, combination of external beam irradiation and interstitial brachytherapy, field size, fraction size, volume of the mandible irradiated with a high dose), patient-related variables (like deep parodontitis, pre-irradiation bone surgery, bad oral hygiene, alcohol and tobacco abuse, bone inflammation, dental extraction after radiotherapy) and tumour-related factors (tumour size or stage, proximity of the tumour to bone, anatomic tumour site). Primary management of post-radiation bone lesions include conservative modalities such as saline irrigations, antibiotics during infectious episodes, topically applied antiseptics, gentle sequestrectomy and removal of visibly loosened bone elements as well as treatment with hyperbaric oxygen (HBO). Surgery is reserved for persistent ORN and includes radical resection of the lesion(sequestrectomy, hemimandibulectomy etc.) with reconstruction. In recent years the introduction of preventive oral hygiene measures and meticulous dental evaluations before and after irradiation, improvement in radiotherapy techniques and the development of reliable diagnostic and therapeutic procedures have resulted in a decreased incidence of ORN. Nevertheless, given the severe impact of ORN on patient quality of life, research should be continued to further ameliorate this problem.
下颌骨是最常受辐射影响的骨骼之一。下颌骨最严重的辐射后损伤是放射性骨坏死（ORN）。关于这种并发症的发生率、病因和治疗，已有相互矛盾的数据报道。在接受根治性放疗或术后放疗的头颈癌患者中，下颌骨ORN的发生率在文献中差异很大，从0.4%到56%不等。由于用于评估放疗后骨损伤的评分方法和分类系统不同，对特定系列数据的解释很困难。虽然ORN通常发生在放疗后的头三年，但患者可能会一直面临不确定的风险。ORN的诊断主要基于长期暴露骨的临床表现。放射学症状包括骨密度降低伴骨折、皮质破坏和松质骨小梁消失。许多可能与ORN风险相关的因素包括治疗相关变量（例如，总放疗剂量、生物有效剂量、光子能量、近距离放疗剂量率、外照射和组织间近距离放疗的联合、野大小、分次剂量、高剂量照射的下颌骨体积）、患者相关变量（如重度牙周炎、放疗前骨手术、口腔卫生差、酗酒和吸烟、骨炎症、放疗后拔牙）和肿瘤相关因素（肿瘤大小或分期、肿瘤与骨的接近程度、肿瘤解剖部位）。放疗后骨病变的主要治疗方法包括保守治疗，如生理盐水冲洗、感染发作时使用抗生素、局部应用防腐剂、轻柔的死骨切除术和清除明显松动的骨成分，以及高压氧（HBO）治疗。手术适用于持续性ORN，包括对病变进行根治性切除（死骨切除术、半侧下颌骨切除术等）并进行重建。近年来，预防性口腔卫生措施的引入以及放疗前后细致的牙科评估、放疗技术的改进以及可靠的诊断和治疗程序的发展，导致ORN的发生率有所下降。然而，鉴于ORN对患者生活质量的严重影响，应继续开展研究以进一步改善这一问题。
