Purpose: To evaluate the long-term outcome and prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after initial radiotherapy (RT). Methods and Materials: From January 1985 to December 1986, 100 patients (71 males, 29 females) with a diagnosis of nasopharyngeal carcinoma were found on computed tomography (CT) to have skull base erosion. The mean age was 41 years (range 16-66). Ninety-six patients had World Health Organization type III undifferentiated carcinoma, and 4 had type I. The metastatic workup, including chest radiography, liver ultrasound scanning, and liver function test was negative. All patients underwent external beam RT (EBRT) alone to 66-80 Gy during 6-8 weeks. A daily fraction size of 2 Gy was delivered using 60Co or a linear accelerator. No patient received chemotherapy. All patients were followed at regular intervals after irradiation. he median follow-up was 22.3 months (range 2-174). Survival of the cohort was computed by the Kaplan-Meier method. The potential prognostic factors of survival were examined. Multivariate analyses were performed using the Cox regression model. Results: The 1, 2, 5, and 10-year overall survival rate for the cohort was 79%, 41%, 27%, and 13%, respectively. However, the subgroup of patients with both anterior cranial nerve (I-VIII) and posterior cranial nerve (IX-XII) involvement had a 5-year survival of only 7.7%. A difference in the time course of local recurrence and distant metastasis was observed. Both local recurrence and distant metastasis often occurred within the first 2 years after RT. However, local relapse continued to occur after 5 years. In contrast, no additional distant metastases were found after 5 years. The causes of death included local recurrence (n=59), distant metastasis (n=21), both local recurrence and distant metastasis (n=1), and unrelated causes (n=5). After multivariate analysis, complete recovery of cranial nerve involvement, cranial nerve palsy, and headache after irradiation were found to be independent prognostic factors in this cohort. Conclusions: We present one of the longest follow-ups of patients with nasopharyngeal carcinoma invading the skull base. Our results demonstrate the importance of cranial nerve involvement, recovery of headache, and cranial nerve palsy. These factors should be carefully evaluated from the history, physical examination, and imaging studies. A subgroup of patients with skull base involvement had long-term survival after RT alone. The findings of this study are important as a yardstick against which more aggressive strategies, such as combined radiochemotherapy and altered fractionation RT can be compared.

目的：介绍适形调强放射治疗在头颈肿瘤中临床使用的方法和初步结果。方法：2001年1月至2月我院用适形调强放射治疗头颈肿瘤15例，其中初治鼻咽癌4例，未控或复发鼻咽癌8例，第@6颈椎神经鞘瘤，脑膜瘤，肺癌脑转移瘤各1例。照射靶区和敏感器官按ICRU50号文标准勾划。用孔雀系统的CORVUS做逆向治疗计划设计，用MIMiC作共面旋转照射。照射野每5变换一次，从105°～255°旋转照射。常规外照射+后IMRT6例，全程IMRT9例。全部病例按常规分割照射，200cCY/次，每周5次。常规外照射剂量20～70Gy。IMRT处方剂量：全程IMRT60～76Gy，后程IMRT30～50Gy。结果：尽管全部病例肿瘤体积的目标剂量是20～70Gy，但最后靶区的平均剂量可达到11.42～78.04G。敏感器官照射的平均剂量为，晶体3.26Gy（0.30c.）视神经19.07Gy（0.90c.c），颞颌关节20。55Gy，（5.54c.c），腮腺19.7Gy（13.32c.c），垂体21.98Gy（0.76c.c）， 脑干20.6Gy（21.21c.c），脊髓19.14Gy（9.28c.c），结论：孔雀系统对头颈肿瘤的适形调强放疗能较好地适形照射肿瘤体积和有效地保护邻近敏感器官。