鼻咽癌放疗后遗症112例发病因素分析

目的通过我院鼻咽癌放疗后112例患者的观察,探讨其发病因素,为尽量减少或预防鼻咽癌放疗后遗症寻求可能的途径。方法随访放疗后生存5年的鼻咽癌患者112例,全部病例均经病理证实。以6 MV直线加速器外照射。鼻咽部原发灶双耳前野照射共64例,部分辅以鼻前野照射48例,颈部淋巴结转移灶均先以X线切线野照射40 Gy后,再垂直电子线照射20 Gy左右。结果颈部纤维化、口干、后组颅神经损伤与耳前野放射剂量无明显相关性。张口受限、听力损伤随放射剂量增加而增多。颈部纤维化的发生率随放射剂量的增加而升高。后遗症的发生与采用双耳前野,双耳前野 鼻前野两者无明显差异。结论临床放射治疗鼻咽癌的剂量应掌握在70 Gy左右为宜。如仍有鼻咽部的残留肿物,以腔内后装加量,或三维适形缩野推量为妥。在颈部剂量已达65 Gy而淋巴结消退不理想时,应考虑多学科综合治疗为好,或设野中野,以小野推量放疗。

Etiological analysis of the sequelae of radiotherapy for nasopharyngeal carcinoma: a follow-up study of 112 cases

Objective To explore the etiology of the sequelae of radiotherapy for nasopharyngeal carcinoma (NPC) so as to find the possible means for reducing or preventing its occurrence. Methods A total of 112 pathologically confirmed patients with nasopharyngeal carcinoma, who had survived for 5 years following the radiotherapy, were included in this study. Sixty-four patients with the primary carcinoma in the nasopharyngeal region received radiotherapy with the radiation field covering the bilateral anterior ear regions, and in the other 48 patients, adjuvent exposure of the anterior nasal region was administered. The metastases in the cervical lymph nodes were exposed to tangential radiation by 40 Gy X-ray followed by approximately 20 Gy vertical electron beam exposure. Results Limited mouth-opening and dry mouth occurred mostly during the first 2 years after radiotherapy, and hearing loss in the first year. Neck fibrosis tended to increase with the time elapse after the therapy, and posterior cranial nerve damages showed no signs of time-related occurrence. It was found that the occurrence of neck fibrosis, dry mouth and the nerve injuries did not obviously correlate with the dosage of X-ray exposure in the anterior ear regions, while limited mouth-opening and the hearing loss increased with the radiation dosage. The sequelae did not arise from different radiation field selection as adopted in this study. Conclusion The radiation dose should be controlled at around 70 Gy for NPC treatment, and for carcinoma remnant in the nasopharyngeal region, additional dose in the cavity would be appropriate. When the X-ray dose of 65 Gy in the neck region fails to result in satisfactory recession of lymph node metastasis, comprehensive treatment involving multiple modalities should be considered.