Lapeyre M, Marchesi V, Mege A, Aletti P, Graff P, Racadot S, Noel A, Marchal C
Unité de radiothérapie externe, centre Alexis-Vautrin, département de radiothérapie, avenue de Bourgogne, 54511 Vandoeuvre-les-Nancy, France.
Cancer Radiother. 2004 Jun;8(3):134-47. doi: 10.1016/j.canrad.2004.03.001.
To report preliminary results of a prospective study of intensity-modulated radiotherapy (IMRT) for head and neck squamous cell carcinoma (HNC) with bilateral irradiation of the neck.
At the Alexis Vautrin Cancer Center, 23 patients have been treated with IMRT for HNC since January 2002-August 2003. The first 10 patients with a minimum follow-up of 3 months were analyzed. All tumors were oropharyngeal. There were four females and six males, with a mean age of 50 years (range 39-66). Stages were I-II in eight and III-IV in two. CTV1 was microscopic disease and N0 neck (prescribed dose : 50 Gy) and CTV2 was macroscopic disease and the volume at risk (prescribed dose: 66-70 Gy). PTV were CTV + 5 mm. Patient's immobilization consisted of a five-point head neck shoulder thermoplastic mask. Set-up verifications were done by semi-automatically matching portal images and digitized reconstructed radiographs. IMRT used dynamic multileaf collimation. Five patients (group A) received 50 Gy IMRT (two post-operative and three with a brachytherapy boost with a mean dose: 27.5 Gy), and five patients (group B) received 66-70 Gy IMRT (four post-operative). Acute and late normal tissue effects were graded according to the RTOG-EORTC radiation morbidity scoring criteria.
With a median follow-up of 7.4 months (range 3-18.5), no patient died or had loco-regional relapse. The displacements were <4 mm in 98% cases. CTV1 and 2 received 95% of the prescribed dose in 100% of the volume. On average the mean dose to the contralateral parotid was 25.5 Gy for group A vs. 31 Gy for group B (P = 0.09). Mean doses <26 Gy were obtained in three of five patients in group A vs. zero of five patients in group B (P = 0.04). Acute skin toxicities were grade 1 in five patients, grade 2 in four and grade 3 in one. Acute mucositis cases were grade 1 in three patients, grade 2 in five and localized grade 3 in two. At 3 months, 50% of the patients had a grade 0-1 late xerostomia.
The 26 Gy dose limit constraint to the contralateral parotid was easier to satisfy when IMRT was prescribed at a maximum dose of 50 Gy. Acute toxicity is low. The displacements in the mask indicate that it is possible to define the PTV as CTV + 4 mm. This reduction should decrease the mean dose to the parotids. At 3 months, a 50% rate of grade 0-1 late xerostomia encourages the hope of a very low rate at 2 years.
报告一项关于对头颈部鳞状细胞癌（HNC）进行双侧颈部照射的调强放射治疗（IMRT）前瞻性研究的初步结果。
自2002年1月至2003年8月，在亚历克西斯·沃特兰癌症中心，23例患者接受了IMRT治疗HNC。对最初10例随访至少3个月的患者进行分析。所有肿瘤均为口咽癌。其中女性4例，男性6例，平均年龄50岁（范围39 - 66岁）。分期为I - II期的有8例，III - IV期的有2例。临床靶体积1（CTV1）为显微镜下可见病灶且颈部N0（处方剂量：50 Gy），临床靶体积2（CTV2）为肉眼可见病灶及危险体积（处方剂量：66 - 70 Gy）。计划靶体积（PTV）为CTV + 5 mm。患者固定采用五点式头颈肩热塑面罩。通过半自动匹配射野图像和数字化重建影像进行摆位验证。IMRT采用动态多叶准直器。5例患者（A组）接受50 Gy的IMRT（2例术后患者，3例接受近距离放疗增敏，平均剂量：27.5 Gy），5例患者（B组）接受66 - 70 Gy的IMRT（4例术后患者）。根据美国放射肿瘤学会（RTOG）-欧洲癌症研究与治疗组织（EORTC）放射损伤评分标准对急性和晚期正常组织效应进行分级。
中位随访时间为7.4个月（范围3 - 18.5个月），无患者死亡或局部区域复发。98%的病例位移<4 mm。CTV1和CTV2在100%的体积内接受了95%的处方剂量。平均而言，A组对侧腮腺的平均剂量为25.5 Gy，B组为31 Gy（P = 0.09）。A组5例患者中有3例平均剂量<26 Gy，B组5例患者中无一例（P = 0.04）。急性皮肤毒性反应，5例患者为1级，4例为2级，1例为3级。急性口腔黏膜炎病例，3例患者为1级，5例为2级，2例为局限性3级。3个月时，50%的患者有0 - 1级晚期口干。
当IMRT的处方最大剂量为50 Gy时，更容易满足对侧腮腺26 Gy的剂量限制约束。急性毒性较低。面罩中的位移表明将PTV定义为CTV + 4 mm是可行的。这种减少应会降低腮腺的平均剂量。3个月时，0 - 1级晚期口干发生率为50%，让人期望2年时发生率会非常低。
