目前放射治疗虽仍为鼻咽癌首选治疗手段，且疗效令人满意，但仍有部分患者经积极治疗后难免出现鼻咽和/或颈部淋巴结复发，对这些患者有时诊断和治疗有一定困难。本文对近年来国内外文献进行归纳分析，介绍局部复发鼻咽癌的复发因素、临床特征、现代诊断技术以及现代放射治疗、化疗和手术治疗等挽救治疗的方法。

To report our initial experience on the feasibility, toxicity, and tumor control using intensity-modulated radiotherapy (IMRT) for retreatment of recurrent nasopharyngeal carcinoma (NPC). Methods and Materials: A total of 49 patients with locoregional recurrent carcinoma in the nasopharynx were treated with IMRT between January 2001 and February 2002 at the Sun Yat-Sen University Cancer Center, Guangzhou, China. The average time to the nasopharyngeal recurrence was 30.2 months after initial conventional RT. The median isocenter dose to the nasopharynx was 70 Gy (range 60.9-78.0) for the initial conventional RT. All patients were restaged at the time of recurrence according to the 1992 Fuzhou, China staging system on NPC. The number of patients with Stage I, II, III and IV disease was 4, 9, 10, and 26, respectively. T1, T2, T3, and T4 disease was found in 4, 9, 11, and 25 patients, respectively. N0, N1, N2, and N3 disease was found in 46, 2, 0, and 1 patient, respectively. Invasion of the nasal cavity, maxillary sinus, ethmoid sinus, sphenoid sinus, and cavernous sinus and erosion of the base of the skull was found in 8, 1, 3, 8, 15, and 20 patients, respectively. The gross tumor volume (GTV) was contoured according to the International Commission on Radiation Units and Measurements (ICRU) Report 62 guidelines. The critical structures were contoured, and the doses to critical structures were constrained according to ICRU 50 guidelines. The GTV in the nasopharynx and positive lymph nodes in the neck received a prescription dose of 68-70 Gy and 60 Gy, respectively. All patients received full-course IMRT. Three patients who had positive lymph nodes were treated with five to six courses of chemotherapy (cisplatin+5-fluorouracil) after IMRT. The treatment plans showed that the percentage of GTV receiving 95% of the prescribed dose (V95-GTV) was 98.5%, and the dose encompassing 95% of GTV (D95-GTV) was 68.1 Gy in the nasopharynx. The mean dose to the GTV was 71.4 Gy. The average doses of the surrounding critical structures were much lower than the tolerable thresholds. At a median follow-up of 9 months (range 3-13), the locoregional control rate was 100%. Three cases (6.1%) of locoregional residual disease were seen at the completion of IMRT, but had achieved a complete response at follow-up. Three patients developed metastases at a distant site: two in the bone and one in the liver and lung at 13 months follow-up. Acute toxicity (skin, mucosa, and xerostomia) was acceptable according to the Radiation Therapy Oncology Group criteria. Tumor necrosis was seen toward the end of IMRT in 14 patients (28.6%). Conclusion: The improvement in tumor target coverage and ignificant sparing of adjacent critical structures allow the feasibility of IMRT as a retreatment option for recurrent NPC after initial conventional RT. This is the first large series using IMRT to reirradiate local recurrent NPC after initial RT failed. The treatment-related toxicity profile was acceptable. The initial tumor response/local control was also very encouraging. In contrast to primary NPC, recurrent NPC reirradiated with high-dose IMRT led to the shedding of tumor necrotic tissue toward the end of RT. More patients and longer term follow-up are warranted to evaluate late toxicity and treatment outcome.

目的评价调强适形放射治疗（IMRT）对复发性鼻咽癌的疗效、放射反应以及对肿瘤的控制。方法49例鼻咽局部复发的鼻咽癌患者（KPS≥80）均采用全程IMRT，其中伴有颈淋巴结转移的3例患者（N12例，N31例） 在IMRT后，给予PDD+52Fu方案5～6个疗程化疗。结果治疗计划结果显示，覆盖鼻咽GTVD95的平均剂量 68.09Gy，GTVV95的平均体积为98.46%，靶区内GTV、CTV1和CTV2 的平均剂量分别为71.40Gy、63.63Gy 59.81Gy。49例患者的中位随访时间为9个月（3～16个月）。局部无进展生存率100%，IMRT结束时有3例（6.1 %） 出现局部残留，14例（28.6%）出现鼻咽腔黏膜坏死。结论IMRT能有利覆盖肿瘤靶区而使邻近敏感器官获得有效分隔，对复发性鼻咽癌的再程放疗不失为一种有效方法。值得注意的是高剂量的鼻咽局部IMRT治疗对于复发性鼻咽癌容易导致鼻咽黏膜坏死，故应适当减少GTV的处方剂量以60～65Gy为宜。

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.