Lapeyre M, Bellière A, Hoffstetter S, Peiffert D
Département de radiothérapie, centre Jean-Perrin, 58, rue Montalembert, 63011 Clermont-Ferrand cedex 1, France.
Cancer Radiother. 2008 Nov;12(6-7):515-21. doi: 10.1016/j.canrad.2008.08.276. Epub 2008 Sep 27.
Brachytherapy is one of the standard treatments of head and neck cancers. The main indications are: the oral cavity, the oropharynx, the lips, the peri-orificial skin carcinomas on the face, the postoperative treatments for T1-2/N0 cancers of the oral cavity with close or positive margins, the second cancers in previously irradiated areas, the intra-operative brachytherapy for recurrent cervical lymph node metastases from previously irradiated tissues after maximal surgical debulking. The major prognostic factors published allowed to improve the technique: using a leaded protection of the mandible, the intersource spacing (1,2-1,4 cm), the volume treated (30 cm3, i.e. three loops), the safety margin (5 mm), the dose rate (0,5 Gy/h), the total dose (65 Gy in case of exclusive brachytherapy, 25 Gy in case of a combination of external beam irradiation [50 Gy] and brachytherapy in the oropharyngeal carcinomas, 35 Gy in case of a combination of external beam irradiation [40 Gy] and brachytherapy in the oral cavity carcinomas, 60 Gy in case of a second cancer in previous irradiated tissues), the delay between external irradiation and brachytherapy (< 20 days). The pulse dose rate brachytherapy should improve results with the control of the dose rate and the optimization of the dose distribution. For high dose rate brachytherapy, more results are needed to recommend this technique for routine use.
近距离放射治疗是头颈部癌症的标准治疗方法之一。主要适应证包括:口腔、口咽、唇部、面部口周皮肤癌、口腔T1-2/N0癌症切缘接近或阳性的术后治疗、既往放疗区域的二次癌、最大程度手术减瘤后对既往放疗组织复发的颈部淋巴结转移灶进行术中近距离放射治疗。已发表的主要预后因素有助于改进该技术:采用下颌骨铅防护、源间间距(1.2 - 1.4厘米)、治疗体积(30立方厘米,即三个环)、安全边缘(5毫米)、剂量率(0.5戈瑞/小时)、总剂量(单纯近距离放射治疗时为65戈瑞,口咽癌外照射[50戈瑞]与近距离放射治疗联合时为25戈瑞,口腔癌外照射[40戈瑞]与近距离放射治疗联合时为35戈瑞,既往放疗组织二次癌时为60戈瑞)、外照射与近距离放射治疗之间的间隔时间(<20天)。脉冲剂量率近距离放射治疗应通过控制剂量率和优化剂量分布来改善治疗效果。对于高剂量率近距离放射治疗,还需要更多结果才能推荐该技术常规使用。