Three-dimensional intensity-modulated radiotherapy in the treatment of nasopharyngeal carcinoma: The University of California-San Francisco experience
Three-dimensional intensity-modulated radiotherapy in the treatment of nasopharyngeal carcinoma: The University of California-San Francisco experience
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DOI：
10.1016/s0360-3016(00)00702-1
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发表时间：
2000-10-01
影响因子：
7
通讯作者：
Fu, KK
中科院分区：
文献类型：
--
作者：
Sultanem, K;Shu, HK;Fu, KK
目的：总结三维调强放疗（IMRT）治疗鼻咽癌的经验。方法和材料：我们回顾了1995年4月至1998年3月期间在加州大学旧金山分校接受鼻咽癌3D IR IRT治疗的35例患者的记录。根据1997年美国癌症分期联合委员会的数据，4名（12%）患者为I期疾病，6名（17%）为II期疾病，11名（32%）为III期疾病，14名（40%）为IV期疾病。原发肿瘤的IMRT使用以下三种技术之一进行：(I)手动切割部分传输块，(2)计算机控制的自动测序静态多叶准直器（MLC）和(3)孔雀系统使用动态多叶片强度调制准直器（MIMiC）。前两种方法采用正向三维治疗计划系统，第三种方法采用逆向治疗计划系统。颈部采用常规技术照射，采用上颈部外侧相对场和下颈部及锁骨上窝前场照射。规定剂量为肿瘤总体积（GTV）和阳性颈部淋巴结65 ~ 70 Gy，临床靶体积（CTV） 60 Gy，临床阴性颈部50 ~ 60 Gy。11例（32%）患者在体外放射治疗后1-2周对原发肿瘤进行了分次高剂量率腔内近距离治疗。32例（91%）患者在放疗期间接受顺铂治疗，放疗后接受顺铂和5-氟尿嘧啶治疗。根据放射治疗肿瘤组（RTOG）放射发病率评分标准对急性和晚期正常组织的影响进行分级。使用Kaplan-Meier方法估计局部-区域无进展、无远处转移生存期和总生存期。结果：中位随访21.8个月（范围5-49个月），局部-区域无进展率为100%。4年总生存率为94%，无远处转移率为57%。最严重的急性毒性为2级16例（46%），3级18例（51%），4级1例（3%）。最严重的晚期毒性为1级15例（43%），2级13例（37%）；5例（14%）患者为3级。只有1例患者出现短暂的4级软组织坏死。在治疗后24个月，50%的评估患者为0级，50%为1级，没有2级口干症。剂量-体积直方图（DVHs）分析显示，GTV的平均最大、平均和最小剂量分别为79.5 Gy、75.8 Gy和56.5 Gy， CTV的平均最大、平均和最小剂量分别为78.9 Gy、71.2 Gy和45.4 Gy。平均只有3%的GTV和2%的CTV接受的剂量低于规定剂量的95%。脑干、视交叉、左右视神经5%的平均剂量分别为48.3 Gy、23.9 Gy、15.0 Gy、14.9 Gy。每毫升颈脊髓的平均剂量为41.7戈瑞。所给剂量在这些关键正常结构的耐受范围内。左右腮腺、垂体、左右T-M关节及耳部50%部位的平均剂量分别为43.2 Gy、41.0 Gy、46.3 Gy、60.5 Gy、58.3 Gy、52.0 Gy、52.2 Gy。结论：三维调强放疗提高了大体肿瘤的靶体积覆盖范围和剂量，显著保留了唾液腺和其他关键正常结构。局部区域控制率与联合IMRT和化疗是优秀的，虽然远处转移仍然没有减少。(C) 2000 Elsevier Science Inc.；
Purpose: To review our experience with three-dimensional intensity-modulated radiotherapy (IMRT) in the treatment of nasopharyngeal carcinoma.Methods and Materials: We reviewed the records of 35 patients who underwent 3D IR IRT for nasopharyngeal carcinoma at the University of California-San Francisco between April 1995 and March 1998. According to the 1997 American Joint Committee on Cancer staging classification, 4 (12%) patients had Stage I disease, 6 (17%) had Stage II, 11 (32%) had Stage III, and 14 (40%) had Stage IV disease. IMRT of the primary tumor was delivered using one of the following three techniques: (I) manually cut partial transmission blocks, (2) computer-controlled autosequencing static multileaf collimator (MLC), and (3) Peacock system using a dynamic multivane intensity-modulating collimator (MIMiC). A forward 3D treatment-planning system was used for the first two methods, and an inverse treatment planning system was used for the third method. The neck was irradiated with a conventional technique using lateral opposed fields to the upper neck and an anterior field to the lower neck and supraclavicular fossae. The prescribed dose was 65-70 Gy to the gross tumor volume (GTV) and positive neck nodes, 60 Gy to the clinical target volume (CTV), and 50-60 Gy to the clinically negative neck. Eleven (32%) patients had fractionated high-dose-rate intracavitary brachytherapy boost to the primary tumor 1-2 weeks following external beam radiotherapy. Thirty-two (91%) patients also received cisplatin during, and cisplatin and 5-fluorouracil after, radiotherapy. Acute and late normal tissue effects were graded according to the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. Local-regional progression-free, distant metastasis-free survival and overall survival were estimated using the Kaplan-Meier method.Results: With a median follow-up of 21.8 months (range, 5-49 months), the local-regional progression-free rate was 100%. The 4-year overall survival was 94%, and the distant metastasis-free rate was 57%. The worst acute toxicity was Grade 2 in 16 (46%) patients, Grade 3 in 18 (51%) patients and Grade 4 in 1 (3%) patient. The worst late toxicity was Grade 1 in 15 (43 %), Grade 2 in 13 (37%); and Grade 3 in 5 (14%) patients. Only 1 patient had a transient Grade 4 soft-tissue necrosis. At 24 months after treatment, 50% of the evaluated patients had Grade 0, 50% had Grade 1, and none had Grade 2 xerostomia. Analysis of the dose-volume histograms (DVHs) showed that the average maximum, mean, and minimum dose delivered were 79.5 Gy, 75.8 Gy, and 56.5 Gy to the GTV, and 78.9 Gy, 71.2 Gy, and 45.4 Gy to the CTV, respectively. An average of only 3% of the GTV and 2% of the CTV received less than 95% of the prescribed dose. The average dose to 5% of the brain stem, optic chiasm, and right and left optic nerves was 48.3 Gy, 23.9 Gy, 15.0 Gy, and 14.9 Gy, respectively. The average dose to 1 cc of the cervical spinal cord was 41.7 Gy. The doses delivered were within the tolerance of these critical normal structures. The average dose to 50% of the right and left parotids, pituitary, right and left T-M joints, and ears was 43.2 Gy, 41.0 Gy, 46.3 Gy, 60.5 Gy, 58.3 Gy, 52.0 Gy, and 52.2 Gy, respectively.Conclusion: 3D intensity-modulated radiotherapy provided improved target volume coverage and increased dose to the gross tumor with significant sparing of the salivary glands and other critical normal structures. Local-regional control rate with combined IMRT and chemotherapy was excellent, although distant metastasis remained unabated. (C) 2000 Elsevier Science Inc.