同时推量加速调强放疗治疗头颈部恶性肿瘤的临床研究

应用同时推量加速调强放疗技术（SIB－IMART）治疗15例头颈部恶性肿瘤，肉眼靶区（GTV）的平均剂量为70Gy，临床靶区（CTV）的平均剂量为54Gy，脑干、脊髓及腮腺等正常组织的受量均在允许范围之内。结果 13例38天内完成治疗，2例因副作用而中断放疗；皮肤反应I级12例、Ⅱ级3例；粘膜反应Ⅱ级9例、Ⅲ级4例、Ⅳ级2例，咽部及食管I级10例、Ⅱ级3例、Ⅲ级2例；唾液腺副作用明显较传统放疗技术轻，15例中0级3例、I级10例、Ⅱ级2例；口干0级3例、I级9例、Ⅱ级3例，无重度或完全口干病例。放疗结束后疗效达CR者13例，PR者2例，无一例出现病情进展。认为SIB－IMART治疗头颈部恶性肿瘤安全可行，特别是肋腺可受到较好保护，且不同的靶区可以同时实现不同的剂量水平，缩短了治疗时间。

Simultaneous integrated boost with intensity modulated accelerated radiation therapy on patients with head and neck cancer

To evaluate the feasibility of head and neck cancer treated with simultaneous integrated boost with intensity modulated accelerated radiation therapy(SIB IMART).15 patients with primary head and neck cancers were treated with SIB IMART technique.The treatment fields encompassed two simultaneous targets.The gross tumor volume (GTV) included palpable and visible disease.The clinical tumor volume (CTV) included sites at risk for microscopic disease.Total dose of 67.2 Gy in daily fraction of 2.4 Gy and 5 days weekly was prescribed to the GTV whilst total dose of 50.4 Gy in fraction size of 1.8 Gy to the CTV.Acute toxicity was evaluated by RTOG toxicity grading criteria.Initial tumor response was assessed by clinical and radiographical examinations.The mean doses to the GTV and CTV were 70 Gy and 54Gy.The doses to brainstem,spinal cord,and parotids were below their dose limits.All of the patients except for 2 ones completed their treatment within 38 days without any split.12 patients had RTOG grade 1 skin toxicity and the other had grade 2.Grade 2 mucositis occurred in 9 patients,grade 3 in 4 patients,and grade 4 in the other 2 patients.10 patients had grade 1 pharyngitis and esophagitis,3 patients had grade 2,and 2 patients had grade 3.87% patients had grade 1 or less toxicity with the salivary gland and no patients had higher than grade 2 toxicity.12 of 15 patients reported grade 1 or less mouth dryness.3 patients had grade 2 symptoms but none experienced severe or complete xerostomia.13 of 15 patients had complete response (CR) while the other patients had partial response (PR).These suggest that the patients with head and neck carcinomas treated with SIB IMART technique are clinically feasible.Though the mucositis toxicity is somewhat severe,the parotids are spared satisfactorily.Initial tumor response has been encouraging.Furthermore,the technique has the advantages of delivering different doses to different targets simultaneously and shortening the treatment course.