介绍吞咽困难常见于接受放化疗后的头颈部癌症患者,并且经常报道不足,也没有引起临床重视。如果达到对吞咽困难吸入相关结构(DARS)的所需剂量限制,则可以显着改善患者的生活质量。进行本研究是为了确定在标准调强放疗(st-IMRT)臂和吞咽困难优化的IMRT(do-IMRT)臂之间实现DARS剂量限制的可行性。材料和方法60例头颈部癌患者被随机分为两组:一组称为st-IMRT,没有约束DARS,在另一个叫做do-IMRT的小组中,限制被赋予了DARS。通过IMRT技术以35个部分的70Gy剂量的放化疗形式给予治疗,超过七周,两组中每分2Gy,每周同时使用顺铂(35mg/m2)。步进和拍摄IMRT设置用于计划,用于计划的系统是Eclipse13.6(瓦里安医疗系统,Inc.,帕洛阿尔托,CA,美国);采用渐进分辨率优化器算法进行优化,并采用各向异性分析算法进行剂量计算。Truebeam用于治疗递送。评估的DARS剂量测定参数为Dmean,V30、V50、V60、V70、D50和D80。辐射对皮肤的毒性,粘膜,喉部,唾液腺,根据5.0版的不良反应通用术语标准,在放疗期间和放疗后6个月内评估两组之间的吞咽困难和血液毒性。使用非配对T检验计算p值。结果在60例头颈癌患者中,95%是男性。比较了计划目标体积(PTV)的剂量学参数,但未发现显着。在危险器官的剂量学中,一些结构的p值被发现是显著的,尽管在两组中接受的剂量都在可耐受的限度内.发现下缩肌的DARS剂量测定V60和V70具有统计学意义(分别为p=0.01和0.008)。喉的V60和V70也具有统计学意义(分别为p=0.009和0.000)。发现ciricopharyngeus的V70和D50具有统计学意义(分别为p=0.01和0.03),合并咽缩肌的V30和V60被发现具有统计学意义(p=0.02和0.01),最后,组合DARS的V60也是显著的(p=0.004)。治疗后,在ST-IMRT组中,有33.3%的患者需要放置Ryle管。两组均未见4级血液学毒性,急性或慢性辐射引起的毒性。在剂量的定点比较中,p值在口咽和口腔癌患者中没有发现显着,但在喉和下咽亚部位发现有统计学意义。结论在喉癌和下咽癌的情况下,可以看到实现DARS剂量限制的可行性,其中收缩肌与PTV相距一定距离。Further,在较低剂量的处方中,无论是在术后病例中还是在低风险的临床目标体积淋巴结体积中,都可以看到实现剂量限制的可行性.
Introduction Dysphagia is commonly seen in patients with head and neck cancers after undergoing chemoradiotherapy and is often under-reported and also not given clinical importance. The quality of life of the patients can be significantly improved if the required dose constraints to the dysphagia aspiration-related structures (DARS) are achieved. The present study was conducted in order to determine the feasibility of achieving the dose constraints to DARS between the standard intensity-modulated radiotherapy (st-IMRT) arm and the dysphagia-optimized IMRT (do-IMRT) arm. Material and methods Sixty patients with head and neck cancer were recruited and randomized into two groups: In one group called the st-IMRT, constraints were not given to DARS, and in the other group called the do-IMRT, constraints were given to DARS. Treatment was given in the form of chemoradiation with a dose of 70 Gy in 35 fractions by IMRT technique, over seven weeks, 2 Gy per fraction along with weekly concurrent Cisplatin (35 mg/m2) in both the groups. Step and shoot IMRT setup was used for planning, and the system used for planning was Eclipse 13.6 (Varian Medical System, Inc., Palo Alto, CA, US); progressive resolution optimizer algorithm was used for optimization, and Anisotropic Analytical Algorithm algorithm was used for dose calculation. Truebeam was used for treatment delivery. DARS dosimetric parameters assessed were Dmean, V30, V50, V60, V70, D50, and D80. Radiation-induced toxicities to the skin, mucosa, larynx, salivary gland, and dysphagia and hematological toxicities were assessed in between both the groups during and after radiotherapy up to six months based on Common Terminology Criteria for Adverse Effects v5.0. p-values were calculated using the unpaired T-test. Results In the cohort of 60 patients with head and neck cancers, 95% were males. Dosimetric parameters of the planning target volume (PTV) were compared but were not found to be significant. In the dosimetry of the organs at risk, a p-value of some structures was found to be significant although the doses received were well within the tolerable limits in both arms. DARS dosimetry V60 and V70 of the inferior constrictor muscle was found to be statistically significant (p=0.01 and 0.008, respectively). V60 and V70 of larynx were also statistically significant (p=0.009 and 0.000, respectively). V70 and D50 of cricopharyngeus were found to be statistically significant (p=0.01 and 0.03, respectively), V30 and V60 for combined pharyngeal constrictor muscles were found to be statistically significant (p=0.02 and 0.01), and lastly, V60 for combined DARS was also significant (p=0.004). Post-treatment 33.3% of patients in the st-IMRT arm required Ryle\'s tube placement. No grade 4 toxicities were seen in either arm regarding hematological toxicities, acute or chronic radiation-induced toxicities. In site-wise comparison of doses, the p-value was not found to be significant in patients with oropharyngeal and oral cavity carcinomas but was found to be statistically significant in the larynx and hypopharynx subsites. Conclusion The feasibility of achieving dose constraints to the DARS was seen in cases of laryngeal and hypopharyngeal cancers where the constrictor muscles were at a distance from the PTV. Further, the feasibility of achieving dose constraints may be seen in lower-dose prescriptions either in postoperative cases or in low-risk clinical target volume nodal volumes.