鼻咽癌调强放疗对腮腺功能的影响

目的 评价调强放疗对鼻咽癌患者腮腺功能的影响.方法 搜集2003年前2年内83例初治患者放疗前、放疗结束时、放疗后6个月和1、2、3、4、5年的口干变化情况的资料,通过分析其与腮腺受照剂量关系来评价调强放疗对腮腺功能影响.结果 共入组83例,其中Ⅰ期4例,Ⅱ期31例,Ⅲ期31例,ⅣA期17例;16例接受放化综合治疗.中位随访时间65个月,5年局部和区域控制率为96%和95%,总生存率为80%.放疗后7个时间段轻和中度口干发生率分别为42%、51%、71%、77%、58%、38%、26%和52%、53%、21%、8%、3%、2%、2%,无重度口干.双侧腮腺受照射平均剂量为34.34 Gy.放疗后6个月口干分级与腮腺平均受照剂量呈正相关,双侧腮腺50%体积受照剂量是放疗后6个月时口干分级的独立影响因素.当腮腺平均剂量≤33 Gy和D50≤29 Gy时,腮腺功能可得到较好地保护.结论 调强放疗在提高鼻咽癌局部和区域控制率的同时,降低了腮腺的受照剂量,减少了腮腺功能的损伤.     

鼻咽癌适形调强放疗中涎腺功能的全面保护

  目的  探讨鼻咽癌适形调强放疗(intensity modulate radiation therapy, IMRT)患者各涎腺功能的保护方法。  方法  选取2010年3月至2012年11月101例连续于中山大学肿瘤医院接受IMRT鼻咽癌患者, 勾画危及器官, 包括腮腺、颌下腺、口腔, 于3、6、12、18、24个月复查时采用面对面访谈式问卷调查评分口干程度情况, 并结合剂量体积直方图(dose-volume histograms, DVH)进行分析。  结果  腮腺平均剂量(MD)为37.4 Gy (患侧), 33.8 Gy (健侧); 颌下腺MD为51.6 Gy (患侧), 45.7 Gy (健侧); 口腔MD为38.2 Gy。77.2%(78/101)患者放疗结束后6个月口干症状明显改善, 1年后中度(G3)以上口干患者 < 5.0%(5/101)。  结论  随着时间的推移, 放疗后口干燥症明显改善; 限定至少一侧腮腺V30~35≤50.0%, 至少一侧颌下腺V40~45≤66.7%~50.0%, 口腔MD < 40 Gy可有效保护唾液腺功能。      

鼻咽癌调强放疗腮腺功能恢复与剂量-体积关系的探讨

目的:初步探讨应用调强放疗的鼻咽癌患者中,腮腺功能的恢复与剂量体积之间的关系.方法: 初程接受调强适形放射治疗(IMRT)的鼻咽癌患者34例,处方剂量70.6～76.6 Gy.根据DVH图得出双侧腮腺的平均剂量,30%和60%体积的受照射剂量;在治疗前、治疗后6个月及12个月用99mTcO4-检测腮腺功能,测定其分泌指数(EI);放疗结束时、放疗后6个月、12个月分别评价患者的口干程度.结果:左侧腮腺的平均受照射剂量为(27.5±2.67) Gy,≤26 Gy者占35.3%(12例)、≤30 Gy者占82.4%(28例)、30%体积的平均受照射剂量为(31.1±3.48) Gy、60%体积的为(20.7±2.68) Gy;右侧腮腺的平均受照射剂量为(28.3±2.95) Gy,≤26 Gy的患者占23.5%(8例)、≤30 Gy的患者占73.5%(25例)、30%体积的平均受照射剂量为(31.4±3.80) Gy、60%体积的为(20.8±3.91) Gy.EI值放疗前平均为0.62±0.11,放疗后6个月为0.28±0.06,12个月为0.48±0.07,放疗后6个月与放疗前及放疗后12个月比较差异有统计学意义,t值分别为2.71和2.17,P值分别为0.009和0.03;放疗后12个月与放疗前比较EI差异无统计学意义,t=1.07,P=0.29.放疗后6个月、12个月患者的中重度口干的发生率分别为64.7%(22例)、11.8%(4例).结论:鼻咽癌调强放疗中腮腺的平均受照射剂量控制在≤30 Gy,放疗后12个月患者口干可明显好转.     

鼻咽癌调强放疗临床靶区中ⅡB区的优化对腮腺剂量的影响研究

[目的]评估优化鼻咽癌调强放疗临床靶区中ⅡB区后对腮腺剂量的影响,为鼻咽癌调强放疗靶区的优化提供依据。[方法]81例鼻咽癌调强放疗患者,以Kaplan-Meier法进行生存分析。对治疗计划保存完整的76例病例测算腮腺的放疗剂量参数,评估优化ⅡB区后对腮腺剂量的影响,并比较不同临床期别、T分期和N分期间腮腺放疗剂量参数。[结果]缩减临床靶区中C1横突或C2椎体以上水平ⅡB区可显著降低同侧腮腺的平均剂量及体积百分剂量V26（P〈0.05）;将该区处方剂量降为50Gy亦可显著降低同侧腮腺的平均剂量及V26（P〈0.05）。Ⅳ期和T4期患者的腮腺平均剂量与V26显著高于相应的其它各期别,而N0期患者的腮腺平均剂量与V26则显著低于淋巴结阳性者。[结论]对早期患者尤其是N0患者可以更合理地设计靶区,优化临床靶区中C1横突或C2椎体以上水平ⅡB区,更好地保护腮腺。     

鼻咽癌同期加速调强适形放射治疗疗效分析

目的 观察鼻咽癌同期加速调强适形放疗(SMART)可行性和近期疗效.方法 对42例病理确诊鼻咽癌初治患者实施SMART,局部晚期患者予辅助化疗.鼻咽大体肿瘤体积(GTVnx)和颈部转移淋巴结(GTVnd)70 Gy分30次完成;鼻咽区域及舌骨以上颈部临床靶区(CTVI)处方剂量为66 Gy分30次完成,下颈部锁骨上区域(CTV2)剂量为54 Gy或60 Gy分30次完成.采用Kaplan-Meier法计算总生存率、局部无进展率、无远处转移生存率;用RTOG/EORTC标准评价急性放射反应和晚期损伤;利用剂量体积直方图评价靶体积和敏感器官受照剂量.结果 放疗结束肿瘤完全缓解(CR)83.3%(35/42),部分缓解(PR)16.7%(7/42).总有效率100%.中位随访时间29个月(7～49个月),1、2、3年总生存率分别为97.6%、97.6%和93.2%;无复发生存率分别为97.3%、94.2%和94.2%;无远处转移生存率分别为97.4%、93.7%和78.7%.多数患者为2～3级急性反应和晚期损伤.GTVnx和GTVnd≥95%处方剂量的体积比分别为99.8%和99.6%.重要器官的平均受量均低于其耐受剂量,与肿瘤病灶对侧的腮腺(健侧)50%体积平均受量≤30.7 Gy,与肿瘤病灶同侧(患侧)≤38.5 Gy,健侧腮腺获得更好的保护.结论 鼻咽癌同期加速调强适形放疗靶区适形程度高,均匀度好,急性反应多数患者可耐受;减轻了放疗引发的口干;获理想的局部区域控制和总生存率.     

鼻咽癌调强放射治疗的剂量学特点

[目的]分析鼻咽癌调强放疗各个靶区和周围正常器官的剂量学特点.[方法]2004年7月至10月入院的10例初治鼻咽癌调强放疗病人,用前7野方案,每野的照射范围从颅底到锁骨上淋巴预防区.剂量处方是:GTV1为2.18Gy/次,32次,GTV2为2.03Gy/次,32次,CTV1为1.88Gy/次,32次,CTV2为1.80Gy/次,28次.研究GTV的最大、最小和平均剂量,CTV的最小剂量,脊髓、脑干和晶状体的最大剂量,腮腺的50%体积受照剂量.[结果]10例病人GTV1的最大、最小和平均剂量(均值)分别是72.01Gy、68.65Gy、70.48Gy,GTV2的最大、最小和平均剂量(均值)分别是68.66y、65.50Gy、66.98Gy,CTV1的最小剂量为60.10Gy,CTV2的最小剂量为51.18Gy,脊髓、脑干和晶体状的最大剂量分别为44.7Gy、51.7Gy和6.8Gy,高剂量侧和低剂量侧,腮腺的50%体积的受照剂量分别为44.39Gy和39.36Gy.[结论]调强放疗可以使各个靶区得到足够的、均匀的剂量分布,周围的正常组织受到比较好的保护,腮腺50%体积受照剂量控制在40Gy～45Gy,显示已有较好的保护作用.     

腮腺分区勾画对伴有双侧颈部Ⅱ区淋巴结转移鼻咽癌调强放射治疗计划优化的影响

[目的]探讨腮腺分区勾画对伴有双颈部Ⅱ区淋巴结转移鼻咽癌调强放射治疗计划优化的影响。[方法]选择接受调强放疗的双颈部Ⅱ区淋巴结转移的鼻咽癌患者20例,利用Corvus6．3调强治疗计划系统设计3种治疗计划：既未进行腮腺分区勾画的常规计划（Pian01：将腮腺沿下颌后静脉前外缘作与腮腺后界的平行线,将腮腺分成前外与后内两部分,分别予剂量限制,重新计划优化,得到将腮腺分区勾画的计划（Planl）;将腮腺分区勾画的CT序列定义为模体,由常规计划（Plan0）进行正向运算得到计划2（Plan2）。比较Planl与Plan2在靶区和正常组织的剂量分布。『结果]两套计划均符合RTOG0615靶区及正常组织剂量限制要求。采用该腮腺分区勾画方法能够降低整个腺体的平均辐射剂量、V15以及〈20Gy体积,这主要归功于降低了腮腺前外侧区约20％的平均辐射剂量、30％～40％的V。[结论]在伴有双颈部Ⅱ区淋巴结转移鼻咽癌IMRT中,腮腺分区勾画在理论上和剂量学上具有可行性,尤其降低了干细胞集中部位（腮腺前外侧区）的辐射剂量．具有一定推广应用价值,对腮腺分泌功能的影响有待前瞻性随机试验证实。     

非小细胞肺癌三维适形放疗剂量体积直方图参数与放射性肺损伤CT分级的关系

目的 探讨剂量体积直方图(DVH)参数与非小细胞肺癌(NSCLC)三维适形放疗(3D-CRT)后放射性肺损伤CT分级的关系.方法 将3D-CRT治疗后CT随访6个月以上的169例Ⅰ～Ⅲ期NSCLC患者,按随访CT放射性肺损伤的表现分级(0～4级),并分为CT阳性组(2～4级)和CT阴性组(0～1级).从放疗计划中获取患者的DVH参数,分析DVH参数与放射性肺损伤CT分级的关系,评价DVH参数对放射性肺损伤的预测价值.结果 不同CT分级的全肺及患侧肺正常组织并发症概率(NTCP)值差异有统计学意义,随着CT分级的增加,NTCP相应增大.不同CT分级的全肺及患侧肺平均肺受照剂量(MLD)差异有统计学意义,随着CT分级的增加,全肺及患侧肺MLD相应增大.不同CT分级的全肺及患侧肺V20、V30和V40差异均有统计学意义,随着CT分级的增加,全肺及患侧肺V20、V30、V40相应增大.不同CT分级患者健侧肺的DVH参数差异无统计学意义.全肺、患侧肺DVH参数与患侧肺CT分级联系紧密,其中患侧肺NTCP与CT分级关联度最强(η=0.522).结论 NTCP、MID、V20、V30、V40等DVH参数与NSCLC 3D-CRT后放射性肺损伤的CT分级密切相关,可以作为评价及优化放疗计划的指标,以减少放疗后放射性肺损伤的发生.     

唾液腺显像对鼻咽癌放疗后腮腺功能的评价

目的探讨唾液腺显像对鼻咽癌放疗后腮腺功能的评价。方法对40例鼻咽癌行适形调强放疗(30例)及常规放疗(10例)的患者,分别于放疗前、放疗结束时及放疗后5个月作口干程度的比较及唾液腺功能显像检查。结果放疗结束时患者出现不同程度口干症状,放疗后5个月,部分患者口干症状有明显改善。唾液腺受损后腮腺显像图像征象及时间放射性曲线均有变化。放疗结束时腮腺定量分析摄取指数(UI)及分泌指数(EI)均比放疗前低(P<0.05),但适形调强放疗组的UI及EI均比常规放疗组高(P<0.05)。结论适形调强放疗可以有效保护腮腺功能,唾液腺显像可用于监测鼻咽癌放疗后腮腺功能变化。     

鼻咽癌调强放疗等效均匀剂量优化方法对腮腺的保护作用

目的 探索等效均匀剂量（EUD）优化方法在鼻咽癌调强放疗中对腮腺的保护作用。方法 从已接受调强放疗的鼻咽癌患者中，随机抽取12例。这些患者的治疗计划均是采用物理约束条件优化设计的。以这些计划为基础，将腮腺的物理约束条件改为EUD约束，而保持其他危及器官和靶区的约束条件不变，为每位患者设计一个新的计划，并比较新旧治疗计划。结果 在保证靶区和其他危及器官受照剂量不变情况下，EUD优化能够使腮腺的平均剂量和V30显著降低，经T检验，P值都〈0．05。结论 EUD优化能够降低腮腺的受照剂量，这对降低腮腺放疗并发症具有重要意义，也为靶区加量提供了空间。     

B超检测腮腺血流在评价鼻咽癌放疗患者口干程度中的应用

目的 探讨B超检测在IMRT过程中评价鼻咽癌患者口干程度的有效性。方法 收集2013—2014年间本院收治的鼻咽癌患者30例,根据RTOG“涎腺急性放疗损伤评估表”对患者自觉口干程度进行评分,采用彩色多普勒超声技术检测鼻咽癌患者IMRT前、中、后的腮腺小血管收缩期峰值血流速度、颌下腺血管收缩期峰值血流速度和腮腺血管内径变化情况,对各项指标与患者口干程度间相关性采用方差分析等。结果 28例鼻咽癌患者IMRT过程中患者口干程度较IMRT前明显加重(P=0.024),IMRT后3个月较IMRT中明显降低(P=0.035);IMRT中腮腺小血管收缩期峰值血流速度、颌下腺血管收缩期峰值血流速度和腮腺血管内径出现缩小比例较IMRT前明显升高(P=0.001、0.003;P=0.001);IMRT停止3个月后的上述指标较IMRT中均明显下降(P=0.008、0.012;P=0.001);IMRT中和IMRT后腮腺小血管收缩期峰值血流速度与患者口干程度相关性更大(r=0.563、0.409,P=0.026、0.031)。结论 腮腺血流B超检测可以无创检测腮腺血流动力学的变化,对于评价鼻咽癌患者IMRT中和IMRT后口干严重程度具有一定的临床参考价值。     

Importance of the initial volume of parotid glands in xerostomia for patients with head and neck cancers treated with IMRT

OBJECTIVE: Our aim was to evaluate predictors of xerostomia in patients with head and neck cancers treated with intensity-modulated radiation therapy (IMRT). METHODS: Thirty-three patients with pharyngeal cancer were evaluated for xerostomia after having been treated with IMRT. All patients were treated with whole-neck irradiation of 46-50 Gy by IMRT, followed by boost IMRT to the high-risk clinical target volume to a total dose of 56-70 Gy in 28-35 fractions (median, 68 Gy). For boost IMRT, a second computed tomography (CT-2) scan was done in the third to fourth week of IMRT. Xerostomia was scored 3-4 months after the start of IMRT. RESULTS: The mean doses to the contralateral and ipsilateral parotid glands were 24.0 +/- 6.2 and 30.3 +/- 6.6 Gy, respectively. Among the 33 patients, xerostomia of grades 0, 1, 2 and 3 was noted in one, 18, 12 and two patients, respectively. Although the mean dose to the parotid glands was not correlated with the grade of xerostomia, the initial volume of the parotid glands was correlated with the grade of xerostomia (P = 0.04). Of 17 patients with small parotid glands (< or =38.8 ml) on initial CT (CT-1), 11 (65%) showed grade 2 or grade 3 xerostomia, whereas only three (19%) of 16 patients with larger parotid glands showed grade 2 xerostomia (P < 0.05). The mean volume of the parotid glands on CT-1 was 43.1 +/- 15.2 ml, but decreased significantly to 32.0 +/- 11.4 ml (74%) on CT-2 (P < 0.0001). CONCLUSIONS: Initial volumes of the parotid glands are significantly correlated with the grade of xerostomia in patients treated with IMRT. The volume of the parotid glands decreased significantly during the course of IMRT.     

Level II lymph nodes and radiation-induced xerostomia

PURPOSE: To investigate the influence of the cranial border of electively irradiated Level II lymph nodes on xerostomia in patients with oropharyngeal cancer using three-dimensional conformal and intensity-modulated radiotherapy (3D-CRT and IMRT). METHODS AND MATERIALS: The target volumes and organs at risk were delineated on the planning CT scans of 12 patients. Two elective target volumes were delineated. The first had the transverse process of the C1 atlas and the second had the transverse process of the C2 axis as cranial border of the Level II lymph nodes. 3D-CRT and IMRT planning were performed for both elective volumes, resulting in two plans per patient and technique, called the C1 and C2 plans, respectively. Irradiation of the ipsilateral elective volume up to C1 and the contralateral up to C2 was also performed for IMRT. The normal tissue complication probability (NTCP) for xerostomia 1 year after RT was calculated using the parotid mean dose. RESULTS: The average mean dose +/- standard deviation (SD) to the contralateral parotid gland was reduced from 33 +/- 5 Gy for the IMRT C1 plans to 26 +/- 4 Gy for the IMRT C2 plans and from 51 +/- 6 Gy to 49 +/- 7 Gy for the 3D-CRT C1 and C2 plans, respectively. The associated NTCP +/- SD for xerostomia was 38% +/- 10% for IMRT C1 plans and 24% +/- 6% for IMRT up to C2 on the contralateral side, regardless of which cranial border was irradiated on the ipsilateral side. For the 3D-CRT C1 and C2 plans, an NTCP value of 74% +/- 12% and 71% +/- 15% was obtained, respectively. The NTCP for xerostomia of the ipsilateral parotid gland was 53% +/- 17% and 45% +/- 20% for the IMRT C1 and C2 plans and 89% +/- 11% and 87% +/- 12% for the 3D-CRT C1 and C2 plans, respectively. CONCLUSION: Lowering the cranial border of the Level II lymph nodes from C1 to C2, in the case of bilateral elective neck irradiation, could be considered on the contralateral side when the risk of metastasis on that side is very low. This is especially true when IMRT is used, because the relative reduction of NTCP for xerostomia 1 year after RT could be up to 68% compared with conventional conformal RT up to C1.     

Dose and volume impact on radiation-induced xerostomia

Radiation-induced xerostomia consists in the chronic dryness of the mouth caused by parotid gland irradiation. Parotid glands produce approximately 60% of saliva while the rest is secreted by submandibular and accessory salivary glands. Methods of measuring the salivary output are essentially represented by 99mTc-pertechnate scintigraphy or simpler albeit less accurate methods in stimulated or unstimulated saliva. There are subjective and objective criteria of classification and grading of the secretion of saliva. Radiation-induced xerostomia, namely the residual salivary gland function is evidently associated with the mean dose absorbed. The salivary output tends to decrease after the end of radiotherapy. The partial dose-volume is substantially correlated with the mean dose to the whole gland. As for ipsilateral irradiation for head and neck cancer, conformal RT or IMRT allow to spare the contralateral parotid gland without increasing the risk of contralateral nodal recurrences. The monitoring system of late toxicity used by the authors is presented.     

鼻咽癌IMRT后腮腺区域失败分析

目的 讨论鼻咽癌IMRT后腮腺复发的潜在原因。方法 回顾我院2005—2012年间鼻咽癌IMRT患者 1096例,其中腮腺复发 13例,可分析腮腺复发 12例。以腮腺复发侧为病例组、腮腺健侧为对照组进行病例对照研究。分析腮腺失败与肿瘤侵犯范围、IMRT剂量分布、局部复发等因素之间关系。组间比较行χ²检验或Fisher′s精确概率法检验。结果 11例患者原发鼻咽癌为Ⅲ—Ⅳ期,根治性IMRT后 9例有局部区域残留。腮腺复发中位时间为16(8~43)个月。腮腺复发患者中 8例位于腮腺浅叶、1例位于深叶,另外 3例累及腮腺深、浅叶。腮腺复发见于原发肿瘤中心同侧(P=0.000)。腮腺复发侧颈部穿刺和(或)手术史较健侧多见(P=0.025)。腮腺复发多合并同侧颈淋巴结复发(67%∶8%,P=0.003),并有合并同侧原发灶复发的趋势(42%∶8%,P=0.059)。结论 鼻咽癌IMRT后腮腺复发率很低。腮腺复发可能与鼻咽癌局部晚期、治疗后残留、颈部穿刺和(或)手术史,以及局部区域复发有关。IMRT导致腮腺区放疗低剂量可能是腮腺复发的重要原因。     

Evaluation of salivary gland function after treatment of head-and-neck tumors with intensity-modulated radiotherapy by quantitative pertechnetate scintigraphy

PURPOSE: To evaluate salivary gland function after inversely planned stereotactic intensity-modulated radiotherapy (IMRT) for tumors of the head-and-neck region using quantitative pertechnetate scintigraphy. METHODS AND MATERIALS: Since January 2000, 18 patients undergoing IMRT for cancer of the head and neck underwent pre- and posttherapeutic scintigraphy to examine salivary gland function. The mean dose to the primary planning target volume was 61.5 Gy (range 50.4-73.2), and the median follow-up was 23 months. In all cases, the parotid glands were directly adjacent to the planning target volume. The treatment planning goal was for at least one parotid gland to receive a mean dose of <26 Gy. Two quantitative parameters (change in maximal uptake and change in the relative excretion rate before and after IMRT) characterizing the change in salivary gland function after radiotherapy were determined. These parameters were compared with respect to the dose thresholds of 26 and 30 Gy for the mean dose. In addition, dose-response curves were calculated. RESULTS: Using IMRT, it was possible in 16 patients to reduce the dose for at least one parotid gland to < or =26 Gy. In 7 patients, protection of both parotid glands was possible. No recurrent disease adjacent to the protected parotid glands was observed. Using the Radiation Therapy Oncology Group/European Organization for the Research and Treatment of Cancer scoring system, only 3 patients had Grade 2 xerostomia. No greater toxicity was seen for the salivary glands. The change in the relative excretion rate was significantly greater, if the parotid glands received a mean dose of > or =26 Gy or > or =30 Gy. For the change in maximal uptake, a statistically significant difference was seen only for the parotid glands and a dose threshold of 30 Gy. For the end point of a reduction in the parotid excretion rate of >50% and 75%, the dose-response curves yielded a dose at 50% complication probability of 34.8 +/- 3.6 and 40.8 +/- 5.3 Gy, respectively. CONCLUSION: Using IMRT, it is possible to protect the parotid glands and reduce the incidence and severity of xerostomia in patients. Doses <26-30 Gy significantly preserve salivary gland function. The results support the hypothesis that application of IMRT does not lead to increased local failure rates.