Dosimetric study of optimal beam number and arrangement for treatment of nasopharyngeal carcinoma with intensity‐modulated radiation therapy

The purpose of this dosimetric study was to evaluate the effect of beam number and arrangement on the dose distribution with intensity‐modulated radiation therapy in patients with nasopharyngeal cancer. Computed tomography data sets of seven patients who were treated for nasopharyngeal carcinoma at the Peter MacCallum Cancer Centre were used for the present dosimetric study. The dose planned was 70 Gy in 7 weeks for the gross nasopharyngeal and nodal disease and the biological equivalents of 60 Gy in 6 weeks for the high‐risk and 50 Gy in 5 weeks for the low‐risk nodal disease. A plan using seven fields was compared to that using nine fields in all patients. Plans were assessed on the dose to the planning target volume (PTV) and the degree of parotid sparing achieved by evaluating both dose?volume histograms (DVH) and axial slices. Seven fields (three anterior and four posterior) provide good PTV coverage and satisfactory parotid sparing in patients with localized nasopharyngeal lesions. Nine fields appear to be better for tumours with significant posterolateral parapharyngeal extension. Parotid sparing is consistently better with nine fields. Both DVH and axial slices need to be evaluated before accepting any plan.     

Intensity‐modulated radiation therapy: First reported treatment in Australasia

Intensity‐modulated radiation therapy (IMRT) is an exciting new advance in the practice of radiation oncology. It is the use of non‐uniform radiation beams to achieve conformal dose distributions. As a result of the high initial capital costs and the time and complexity of planning, IMRT is not yet a widely available clinical treatment option. We describe the process involved in applying this new technology to a case of locally advanced nasopharyngeal cancer.     

Cetuximab or nimotuzumab plus intensity‐modulated radiotherapy versus cisplatin plus intensity‐modulated radiotherapy for stage II‐IVb nasopharyngeal carcinoma

To compare intensity‐modulated radiotherapy (IMRT) with cisplatin (CDDP) versus cetuximab (CTX) and nimotuzumab (NTZ) for Stage II‐IVb Nasopharyngeal Carcinoma (NPC). A total of 1,837 patients with stage II – IV_b NPC who received IMRT plus CTX or NTZ, or CDDP between January 2009 and December 2013 were included in the current analysis. Using propensity scores to adjust for potential prognostic factors, a well‐balanced cohort of 715 patients was created by matching each patient who underwent IMRT plus concomitant NTZ/CTX with four patients who underwent IMRT plus concomitant CDDP (1:4). Efficacy and safety were compared between the CTX/NTZ and CDDP groups of this well‐balanced cohort. Furthermore, we conducted multivariate analysis and subgroup analysis based on all the 1,837 eligible cases. There was no significant difference between CTX/NTZ group and CDDP group in terms of DFS (3‐year, 86.7% vs. 86.2%, p > 0.05), LRRFS (96.2% vs. 96.3%, p > 0.05), DMFS (91.1% vs. 92.3%, p > 0.05) and OS (91.7% vs. 91.9%, p > 0.05). Subgroup analysis demonstrated a significant interaction effect between patients with IMRT plus CTX/NTZ and N3 node stage on LRRFS with the highest risk of loco‐regional relapse (HR 8.85, p = 0.001). Significantly increased hematologic toxicities, gastrointestinal reactions were observed in the CDDP group (p < 0.05). Patients of 3.4 – 4.7% experienced severe hematologic toxicities during the treatment with concomitant CTX and NTZ. Increased rate of CTX related‐skin reaction and mucositis was observed in the CTX group. CTX/NTZ used concurrently with IMRT may be comparable to those of the standard CDDP‐IMRT combination for maximizing survival for patients with stage II‐IVb NPC.     

连续加速分割逆向调强放疗治疗鼻咽癌的临床研究

目的比较鼻咽癌每周7次连续加速分割逆向调强放疗与常规逆向调强放疗的近期疗效及毒副作用。方法采用单双月分组方法将83例经病理学证实的初治鼻咽癌患者分至每周7次连续加速分割逆向调强放疗(continuous accelerated intensity modulated radiation therapy,CAIMRT)组及常规分割逆向调强放疗(intensity modulated radiation therapy,IMRT)组。总剂量70 Gy,分割剂量每次2 Gy。结果两组患者均顺利完成治疗,两组完全缓解率(complete response,CR)分别为86.8%及80%,统计学比较无明显差异(P0.05)。CAIMRT组与IMRT组比较,急性皮肤和黏膜反应出现时间提前,差异具有统计学意义(P0.05);总住院时间有所缩短,差异具有统计学意义(P0.01)。结论鼻咽癌患者采用每周7次连续加速分割逆向调强放疗,患者能够耐受,肿瘤近期局部控制率好。     

Accelerated treatment using intensity‐modulated radiation therapy plus concurrent capecitabine for unresectable hepatocellular carcinoma

BACKGROUND:

Patients with unresectable hepatocellular carcinoma (HCC) have limited treatment options. In this study, the authors investigated the feasibility, toxicity, and efficacy associated with intensity‐modulated radiation therapy (IMRT) and concurrent, chronomodulated capecitabine in the treatment of unresectable HCC.

METHODS:

Twenty patients underwent treatment planning for HCC confined to the liver with helical tomotherapy‐based IMRT. Fifty‐five percent of patients had Child‐Pugh Class A disease, and 45% of patients had Class B disease. Ninety‐five percent of patients were prescribed 50 gray (Gy) of radiotherapy to the planning target volume delivered in 20 fractions with concurrent, chronomodulated capecitabine. Transcatheter arterial chemoembolization preceded radiotherapy in 11 patients, and 9 patients received IMRT alone because of portal vein thrombosis, esophageal varices, or tumor size.

RESULTS:

The mean greatest tumor dimension was 9 cm (range, 1.3‐17.4 cm), the mean dose to normal liver was 22.6 Gy (range, 10‐29.2 Gy), and the average volume of liver that received >30 Gy (V30) was 27.2% (range, 12%‐43%). Eighteen patients (90%) completed the prescribed treatment of 50 Gy. There was no increase from baseline in acute or late toxicity greater than 2 grades. Partial response or disease stability was achieved at 3 months to 6 months after treatment in 15 of 16 patients (94%). The median survival (±standard deviation) for patients who had Child‐Pugh Class A and B disease was 22.5 ± 5.1 months and 8 ± 3.3 months, respectively.

CONCLUSIONS:

In this initial experience with accelerated IMRT plus capecitabine for patients who had large HCC lesions, the results demonstrated acceptable toxicity with promising local control. The relatively low acute and late toxicity observed with this program suggested that dose intensification can be incorporated into the treatment regimen if needed. Cancer 2009. © 2009 American Cancer Society.     

靶区及危及器官剂量学改变与鼻咽癌自适应放疗计划优化时机

目的 在调强放疗期间,鼻咽癌患者存在不同程度的靶区及危及器官的解剖学及剂量学改变,通过评估这些解剖学及剂量学改变,研究自适应放疗的最佳干预时机.方法 收集2012 08 2013 12广西壮族自治区人民医院入组19例鼻咽癌患者,在调强放疗过程中进行每周CT扫描,通过形变配准方法将计划CT与新CT进行融合,自动勾画靶区及危及器官,评估解剖学改变.将原始放疗计划通过剂量映射传递到新CT图像上,形成合成计划,分别与原始计划对比DVH.结果 GTVnx、GTVnd和腮腺的体积在放疗过程中逐渐缩小.与原始计划相比,各周合成计划中所有靶区的HI差异均无统计学意义.与原计划相比,PTVnx和PTV1的部分剂量学参数显著改善,特别是在第10次放疗后,这些参数包括PTVnx的Dmean、D95、V95和CI,以及PTV1的Dmean、D95和CI;PTVnd的剂量学参数只有D95和V95在某些时间点上有显著改善;对于PTV2,其D95和V95在某些时间点上显著变劣.部分器官如脑干、脊髓、腮腺、声门、右侧眼球和左侧晶体的剂量在某些时点上显著增加.结论 鼻咽癌调强放疗过程中发生显著的靶区及危及器官的解剖学和剂量学改变.将PTV2的D95、V95及CI、脑干Dmax、脊髓Dmax、腮腺Dmean、声门喉Dmean、右侧眼球Dmax和左侧晶体Dmax作为预测自适应放疗时机的参数,经过分析建议在鼻咽癌调强放疗至第5次后和第15次后分别进行自适应计划优化.     

调强放疗模式下局部晚期鼻咽癌诱导化疗后同期化疗与单纯放疗疗效比较

目的:探讨调强放疗模式下局部晚期鼻咽癌诱导化疗后同期化疗与单纯放疗临床疗效的比较。方法:回顾性分析2010年-2012年期间在本院采用调强放疗技术治疗的局部晚期鼻咽癌,分期为Ⅲ-Ⅳ期的鼻咽癌患者共120例。所有患者都进行过诱导化疗。放疗范围及剂量为鼻咽原发灶、阳性淋巴结的大体肿瘤体积处方剂量为T1、T2期69.96Gy,T3、T4期72~74Gy;亚临床高危区靶体积处方剂量为60~64Gy;淋巴结阴性引流区处方剂量为50~54Gy。分为单纯放疗组60例,同期化疗组60例。同期化疗方案为单药顺铂为基础的方案。主要观察两组的近期疗效、3年无瘤生存率(DFS)、3年无局部区域复发生存率（LRFS）、3年无远处转移生存率（MFS）、3年总生存率（OS）及治疗的毒副反应情况。结果:两组性别、年龄、病理类型及临床分期的构成比均有可比性。两组患者中位随访36个月。治疗结束3个月两组患者的完全缓解率分别为83.3％、80.0％,3年无瘤生存率分别为78.3％、75.0％,3年的无局部区域复发生存率分别为93.3％、90.0％,3年无远处转移生存分别为81.7％、83.3％,3年总生存率分别为88.3％、86.7％,两组统计学无明显差异。同期化疗组急性毒副反应高于单纯放疗组。结论:在调强放疗治疗模式下,局部晚期鼻咽癌同期化疗与单纯放疗相比,患者的3年总生存率及无瘤生存率未能进一步提高,而急性毒副反应增加,同期化疗在调强放疗模式下治疗策略需要行进一步的临床研究。     

鼻咽癌容积调强旋转放疗和固定野适形调强放疗的剂量学对比

目的：对比旋转容积调强技术（RapidArc ）和固定野适形调强放疗（intensity modulated radiation therapy ,IMRT）治疗鼻咽癌剂量学方面的差异,探索不同T 分期从何种技术获益最大。方法：选取60例无远处转移鼻咽癌患者,按鼻咽癌2008分期T 1～2期20例,T 3 期20例,T 4 期20例。使用瓦里安公司Eclipse 系统,每例患者分别制定RapidArc 和固定野IMRT 计划,比较两者靶区覆盖、危机器官剂量、跳数和治疗时间的差别。结果：IMRT 和RapidArc 均能满足临床要求,靶区剂量分布差异无统计学意义（P >0.05）,均匀性和适形性相当。按T 分期分层比较,T 4 期患者RapidArc 组PGTV、PTV 1、PTV 2 的靶区剂量较高（P < 0.05）,PGTV 均匀指数较好（P = 0.059）。 RapidArc 组视神经、晶体、颞叶、腮腺V 20、喉、颞颌关节受照剂量均较低（P < 0.05）。 按T 分期分层比较,脑干剂量T 1～2 期、T 3 期两组比较差异无统计学意义（P > 0.05）,T 4 期患者脑干D 1% 、Dmax剂量RapidArc 组较IMRT 组低（P < 0.05）。RapidArc 和IMRT 相比,治疗跳数节省65% ,治疗时间节省63% 。结论：RapidArc 和9 野IMRT 治疗鼻咽癌均可满足临床要求,Rap?idArc 可明显降低正常器官剂量,缩短治疗时间,减少治疗跳数。对局部早、中期（T 1～3 期）患者,两者有相似的靶区剂量分布,但对局部晚期（T 4 期）患者,RapidArc 更具有将高剂量区集中在靶区而减少正常器官受照剂量的优势。     

Constrained‐beam inverse planning for intensity‐modulated radiation therapy of prostate cancer patients with bilateral hip prostheses

Hip prostheses present a technical challenge in the planning of curative external beam radiation treatment for patients with prostate cancer. Bilateral prostheses compel planners to compromise between target coverage and avoidance of beam entry through the prostheses. Inverse planning systems given objectives to avoid dose to prostheses are overly restricted from allowing exit dose to them. We report a novel inverse planning technique for intensity‐modulated radiation therapy of patients with prostate cancer and bilateral hip prostheses, by constraining beam characteristics rather than dose in the inverse planning process.     

30例早期鼻咽癌调强放射治疗疗效分析

目的：探讨调强放射治疗（IMRT）对早期鼻咽癌的近期疗效和不良反应。方法：回顾分析30例早期鼻咽癌患者,鼻咽部和上颈部淋巴引流区采用IMRT技术照射,下颈部淋巴引流区采用颈前野常规照射。鼻咽大体肿瘤体积（GTVnx）处方剂量68Gy-74Gy,颈部淋巴结（GTVnd）处方剂量64Gy-70Gy,临床靶体积（CTV1）处方剂量60Gy-64Gy,临床靶体积（CTV2）处方剂量50Gy-54Gy,分30-34次进行照射。对于淋巴结分期为N1的患者,结合淋巴结的情况行诱导化疗和（或）同期化疗2-4周期,N0患者行单纯调强放射治疗。结果：鼻咽大体肿瘤体积（GTVnx）D95平均剂量为74.5Gy,GTVnx V95平均体积99.6%,脊髓D1cc平均剂量41.5Gy,脑干D3平均剂量50.3Gy,左腮腺D50平均剂量32.8Gy,右腮腺D50平均剂量31.4Gy,左颞叶D10平均剂量45.5Gy,右颞叶D10平均剂量45.2Gy,均低于限制剂量。中位随访时间33.5个月（4-45个月）。1年、2年、3年的总生存率、无局部复发生存率和无远处转移生存率均为100%。最严重的急性反应是放射性黏膜炎,1-3级分别有63.3%,30%,和6.7%,晚期不良反应主要表现为口干（Ⅰ度33.3%,Ⅱ度3.7%）。结论：IMRT对初治早期鼻咽癌可获得理想的剂量分布,取得较好的近期疗效,正常组织得到很好的保护。     

30例早期鼻咽癌调强放射治疗疗效分析

目的:探讨调强放射治疗(IMRT)对早期鼻咽癌的近期疗效和不良反应.方法:回顾分析30例早期鼻咽癌患者,鼻咽部和上颈部淋巴引流区采用IMRT技术照射,下颈部淋巴引流区采用颈前野常规照射.鼻咽大体肿瘤体积(GTVnx)处方剂量68Gy-74Gy,颈部淋巴结(GTVnd)处方剂量64Gy-70Gy,临床靶体积(CTV1)处方剂量 60Gy-64Gy,临床靶体积(CTV2)处方剂量 50Gy-54Gy,分30-34次进行照射.对于淋巴结分期为N1的患者,结合淋巴结的情况行诱导化疗和(或)同期化疗2-4周期,N0患者行单纯调强放射治疗.结果:鼻咽大体肿瘤体积(GTVnx)D95平均剂量为74.5Gy,GTVnx V95平均体积99.6%,脊髓D1cc平均剂量41.5Gy,脑干D3平均剂量50.3Gy,左腮腺D50平均剂量32.8Gy,右腮腺D50平均剂量31.4Gy,左颞叶D10平均剂量45.5Gy,右颞叶D10平均剂量45.2Gy,均低于限制剂量.中位随访时间33.5个月(4-45个月).1年、2年、3年的总生存率、无局部复发生存率和无远处转移生存率均为100%.最严重的急性反应是放射性黏膜炎,1-3级分别有 63.3%,30%,和6.7%,晚期不良反应主要表现为口干(Ⅰ度33.3%,Ⅱ度3.7%).结论:IMRT对初治早期鼻咽癌可获得理想的剂量分布,取得较好的近期疗效,正常组织得到很好的保护.     

鼻咽癌调强放疗的剂量学研究

 【摘要】目的 分析鼻咽癌调强放疗各个靶区和周围正常组织器官的剂量学特点。方法 2005年1月-2006年6月住院的30例初治鼻咽癌进行调强放疗，将鼻咽和颈部的靶体积勾画为鼻咽大体肿瘤体积（GTVnx）、颈部大体肿瘤体积(GTVnd)、临床靶体积1（CTV1）和临床靶体积2(CTV2)，处方剂量分别为70、66、60、60Gy/30F，鼻咽和上颈部靶体积采用IMRT技术照射、下颈部靶体积采用下颈前野常规照射。研究GTV、CTV的最大、最小、平均剂量和颞叶、脑干、脊髓、视神经、晶体、眼球的最大受照剂量及腮腺、颞下颌关节的50%体积受照剂量。结果 GTVnx的最大、最小、平均剂量（均值）分别为79.2、59.5、71.9Gy, GTVnd的最大、最小、平均剂量分别为77.1、63.6、72.1Gy，CTV1、CTV2的最小剂量分别为47.6、49.7Gy，颞叶、脑干、脊髓、视神经、晶体、眼球的最大受照剂量及腮腺、颞下颌关节的50%体积受照剂量63.2、48.6、44.7、59.3、6.9、25.9Gy和34.0、36.3Gy。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，周围正常组织器官得到较好的保护，但是要注意CTV的低剂量区。鼻咽癌调强放疗剂量分布优于常规放疗。     

利用DVH图分析鼻咽癌调强放疗中正常器官体积剂量的变化

目的：应用剂量体积直方图（DVH）,研究鼻咽癌患者在放疗过程中正常器官体积及剂量的变化。方法：接受全程调强放疗（IMRT）的20例初治鼻咽癌患者,在治疗20次时,按原固定体位和参考坐标重新CT扫描,设计计划,与原计划进行比较DVH图中正常器官（眼球、晶状体、视神经、腮腺、脊髓及脑干）体积剂量的变化。结果：DVH2上左右腮腺体积明显小于DVH1（P〈0.05）,左右腮腺和脊髓的最大剂量和平均剂量明显增加,脑干最大剂量变化有统计学意义（P=0.011）,其中腮腺的剂量增加与放疗所致的腮腺缩小程度有一定相关性,其余无统计意义。结论：鼻咽癌IMRT过程中正常器官（特别是腮腺）体积剂量会发生一些变化,建议放疗中后期有必要重新勾画靶区,重新计划,减小正常器官的受照量,减少放疗反应。     

Intensity-modulated radiation therapy reduces radiation-induced trismus in patients with nasopharyngeal carcinoma: a prospective study with >5 years of follow-up

BACKGROUND:

Intensity‐modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC) provides better temporomandibular joint (TMJ) sparing and, thus, may reduce the incidence of radiation‐induced trismus after radiotherapy. The objectives of this study were to evaluate radiation‐induced trismus in patients with NPC who had received IMRT and to assess the pretreatment factors, relevant treatment factors, and dosimetry parameters associated with trismus.

METHODS:

A prospective, single‐arm measurement study with more than 5 years of follow‐up was designed. Patients with newly diagnosed stage I through IVB NPC who received treatment with IMRT were eligible. Patients received 66 to 70 grays (Gy) to the gross tumor volume. The maximal interincisal distance (MID) was measured at baseline and 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years after they completed IMRT.

RESULTS:

The trial enrolled 211 consecutive patients from 2001 to 2004. The mean dose to the TMJ ranged from 6.18 Gy to 51.36 Gy (median dose, 29.88 Gy). Compared with baseline MID levels, normalized MID levels at 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years after IMRT were 94.6% ± 9.9%, 92.5% ± 10.5%, 92% ± 10.6%, 92.2% ± 10.5%, 92.1% ± 10.2%, and 90.3% ± 11.4%, respectively (P < .001). According to a revised subjective‐objective management‐analytical (SOMA) scale, grade 1/2 trismus was identified in 12 of 211 patients (5.7%), and no grade 3/4 trismus was observed. There was an increasing risk of trismus after IMRT when the MID was <40.5 mm at baseline compared with an MID >40.5 mm (P = .007). No dosimetric parameter was associated with trismus.

CONCLUSIONS:

IMRT was able to reduce the radiation dose to the TMJ and likely reduced the incidence and severity of radiation‐induced trismus after radiotherapy. Cancer 2011. © 2011 American Cancer Society.     

调强放疗同期化疗治疗局部中晚期鼻咽癌

目的:探讨调强放疗联合同期化疗治疗局部晚期鼻咽癌的疗效。方法:选择2009年1月至2010年12月我院收治的107例鼻咽癌患者,按照随机数字表法将其分为观察组和对照组,其中观察组55例、对照组52例。两组患者均采取相同的化疗方案,观察组患者联合调强放疗,对照组则采取常规放疗,比较两组患者临床疗效及不良反应。结果:观察组治疗总有效率为94.54%（52/55）,对照组治疗总有效率为75.00%（39/52）,P＜0.05。观察组急性毒性反应发生率为41.82%（23/55）,对照组急性毒性反应发生率为71.15%（37/52）,P＜0.05。观察组患者远期不良反应发生率为20.00%（11/55）,对照组患者远期不良反应发生率为38.46%（20/52）,P＜0.05。观察组患者3年生存率为76.36%,对照组患者3年生存率为71.54%（P＞0.05）。观察组患者5年生存率为65.45%,对照组患者5年生存率为40.38%（P＜0.05）。观察组患者5年累积复发率为10.91%,对照组患者5年累积复发率为26.92%（P＜0.05）。观察组患者5年无远处转移生存率为85.45%,对照组患者5年无远处转移生存率为67.31%（P＜0.05）。结论:调强放疗同期化疗治疗局部中晚期鼻咽癌能够显著提高患者临床疗效、减少不良反应发生率,值得临床进一步观察研究。