Comparison of intensity-modulated radiotherapy with the 5-field technique,helical tomotherapy and volumetric modulated arc therapy for localized prostate cancer

The outcomes of three methods of intensity-modulated radiation therapy (IMRT) for localized prostate cancer were evaluated. Between 2010 and 2018, 308 D’Amico intermediate- or high-risk patients were treated with 2.2 Gy daily fractions to a total dose of 74.8 Gy in combination with hormonal therapy. Overall, 165 patients were treated with 5-field IMRT using a sliding window technique, 66 were then treated with helical tomotherapy and 77 were treated with volumetric modulated arc therapy (VMAT). The median age of patients was 71 years. The median follow-up period was 75 months. Five-year overall survival (OS) and biochemical or clinical failure-free survival (FFS) rates were 95.5 and 91.6% in the 5-field IMRT group, 95.1 and 90.3% in the tomotherapy group and 93.0 and 88.6% in the VMAT group, respectively, with no significant differences among the three groups. The 5-year cumulative incidence of late grade ≥2 genitourinary and gastrointestinal toxicities were 7.3 and 6.2%, respectively, for all patients. Late grade ≥2 gastrointestinal toxicities were less frequent in patients undergoing VMAT (0%) than in patients undergoing 5-field IMRT (7.3%) and those undergoing tomotherapy (11%) (P = 0.025), and this finding appeared to be correlated with the better rectal DVH parameters in patients undergoing VMAT. Other toxicities did not differ significantly among the three groups, although bladder dose-volume parameters were slightly worse in the tomotherapy group than in the other groups. Despite differences in the IMRT delivery methods, X-ray energies and daily registration methods, all modalities may be used as IMRT for localized prostate cancer.     

乳腺癌保乳术后动态调强放疗与常规放疗的剂量学比较

目的 比较早期乳腺癌保乳术后动态调强放疗(intensity modulated radiotherapy,IMRT)与常规放疗(conventional radiotherapy,CRT)的剂量学分布,为IMRT在乳腺癌保乳术后放疗中的应用提供依据。方法 选取12例保乳术后乳腺癌患者,针对每个患者分别设计IMRT计划和CRT计划,处方剂量均为50 Gy/25次,利用剂量体积直方图(DVH图)比较两种计划的靶区和危及器官的剂量学差异。结果 两种计划中95%等剂量曲线包绕计划靶区的体积相似,分别为98.22%和98.76%(P > 0.05);IMRT计划计划靶区的V_105%、V_110%分别为12.86%、1.02%低于CRT计划的44.56%、6.37%(P < 0.05);IMRT计划计划靶区的CI值由0.55提高至0.68,HI值由1.15降至1.09(P < 0.05)。与CRT计划相比,IMRT计划患侧肺V₃₀、V₂₀分别降低了3.68%和5.75%,同时肺平均剂量(MLD)由9.24 Gy下降至7.12 Gy(P < 0.05);IMRT计划将左侧乳腺癌患者心脏V₃₀、V₄₀和V₅₀分别降低了5.99%、5.68%和1.68%(P < 0.05)。结论 IMRT相比CRT在保证靶区覆盖率的同时,减少了高剂量的照射,改善了靶区剂量分布的均匀性,同时降低了周围正常器官的照射剂量。     

Current status and future direction of Japan's clinical trial for malignant pleural mesothelioma

The feasibility and efficacy of trimodality therapy for malignant pleural mesothelioma (MPM) are still controversial mainly due to the lack of clinical evidence. Although three major clinical trials on this therapy have been recently reported from North America and Europe, it remains unclear whether results in Caucasian populations may be directly applicable to Asian populations. In this context, as a project of the "Comprehensive approach on asbestos-related diseases" supported by the "Special Coordination Fund for Promoting Science and Technology of MEXT, Japan", a prospective multi-institutional study has been planned to evaluate the feasibility of induction chemotherapy using pemetrexed plus cisplatin, followed by extrapleural pneumonectomy (EPP) and postoperative hemithoracic radiation in patients with resectable MPM. Primary endpoints are macroscopic complete resection rate by EPP and treatment-related mortality for trimodality therapy. The study was initiated in May 2008 and patient enrollment was finished in November 2010.     

食管癌术后纵隔淋巴结转移的后程调强适形放射治疗

目的评价食管癌根治术后纵隔淋巴结转移行后程调强适形放疗的价值。方法46例食管癌根治术后发生纵隔淋巴结转移患者,25例采用6MV—X射线常规放疗,T型野Dt36Gy／18次后改为斜野照射避脊髓至Dt56～60Gy／28～30次,21例采用先常规放疗,T型野Dt30Gy／15次后改为调强适形IMRT放疗,总Dt达66～70Gy／33～35次。结果食管癌根治术后纵隔淋巴结转移行后程IMRT治疗组和常规放疗组的有效率分别为90％和72％,结果比较有显著差异（P〈0．05）,后程IMRT组症状改善更理想。放射性肺部症状发生率,后程IMRT治疗和常规放疗分别为67％和72％,结果无差异（P〉0．05）。1年、2年、3年生存率后程IMRT治疗和常规放疗分别为69．4％、35．3％、13．2％和50．1％、20．1％、10．3％,远期生存率无明显改善（P〉0．05）。结论食管癌根治术后纵隔淋巴结转移行后程IMRT能明显提高对病灶的局部控制率,且放疗副作用无明履增高,患者均可耐受。     

肺癌患者三维适形放疗前后肺功能的动态变化及与放射性肺炎发生的关系研究

目的探讨非小细胞肺癌三维适形放疗前后肺功能的动态变化及其与放射性肺炎发生率的关系。方法68例未手术的肺癌患者,男42例,女26例,中位年龄52岁,KPS评分≥80分,均行三维适形放疗,放疗前及放疗后1、3个月检查肺功能主要参数用力肺活量（FVC）、1S用力呼气量（FEV1）、肺一氧化碳弥散量（CLCO）,同时观察放射性肺炎的发生率及程度。结果所有患者均完成放疗,剂量为60～70Gy。24例患者发生不同程度放射性肺炎,其中I级11例,Ⅱ级7例,Ⅲ级3例,Ⅳ级3例,无V级病例。FVC放疗前与放疗后3个月0级（n=44）和I＋Ⅱ＋Ⅲ＋Ⅳ级（n：24）放射性肺炎者比较,差异无统计学意义（P〉0．05）,而FEVl．0和DLCO放疗前与放疗后3个月的0级（n=44）和I＋Ⅱ＋Ⅲ级＋Ⅳ级（n=24）放射性肺炎者比较,差异有统计学意义（P〈0．05）。V20,V30及MLD平均值越大,放射性肺炎程度越高：结论非小细胞肺癌放疗后DLCO水平显著降低,放射性肺炎患者FEVl和DLCO放疗后显著降低。V20,V30,及MLD可预测放射性肺炎发生。     

螺旋断层放射治疗机房的防护设计与分析

目的掌握螺旋断层放射治疗机房的辐射水平,制订合理可行的辐射屏蔽与防护设计方案,为TOMO装置临床应用的辐射安全提供保障。方法以某医院的1台Tomotherapy Hi-Art螺旋断层放射治疗装置为研究对象,依据设备的性能参数,参照NCRP No.151报告和GBZ/T 201.2等技术标准以及AAPM No.148中相应的质量控制细则,确定TOMO机房的屏蔽与安全防护设计规划,并评估其防护效果。结果 TOMO机房屏蔽方案为:东、西防护墙和室顶为95cm重晶石;南墙为70cm重晶石;迷路内外墙分别为(70～30)cm重晶石和(30～70)cm重晶石;防护门为8mm铅。机房外围辐射水平估算结果表明,南墙外设备夹层通道的辐射剂量率最高为8.89μGy/h,其次为机房地下电缆沟处(3.25μGy/h);防护门外最高为1.6μGy/h。推算出机房外围放射工作人员所受年剂量最高为0.27mSv,公众可能受到的最高剂量均不高于0.03mSv/a。结论 TOMO装置治疗机房可主要考虑对泄漏辐射的屏蔽设计,同时应根据装置实际的照射参数、工作负荷和治疗机房的场所条件进行相应的防护效果分析。     

Survey of malignant pleural mesothelioma treatment in Japan: Patterns of practice and clinical outcomes in tomotherapy facilities

We conducted a nationwide survey of tomotherapy for malignant pleural mesothelioma (MPM) in Japan. Fifty-six facilities were surveyed and data on 31 patients treated curatively between 2008 and 2017 were collected from 14 facilities. Twenty patients received hemithorax irradiation after extrapleural pneumonectomy (EPP) (first group). Five patients received irradiation without EPP (second group), while six received salvage radiotherapy for local recurrence (salvage group). Among the seven patients not undergoing EPP, five (four in the second group and one in the salvage group) were treated with lung sparing pleural irradiation (LSPI) and two with irradiation to visible tumors. Two-year overall survival (OS) rates in the first and second groups were 33% and 60%, respectively (median, 13 vs 30 months, P = 0.82). In the first and second groups, 2-year local control (LC) rates were 53 and 67%, respectively (P = 0.54) and 2-year progression-free survival (PFS) rates were 16% and 60%, respectively (P = 0.07). Distant metastases occurred in 15 patients in the first group and three in the second group. In the salvage group, the median OS was 18 months. Recurrence was observed in the irradiated volume in four patients. The contralateral lung dose was higher in LSPI than in hemithorax irradiation plans (mean, 11.0 ± 2.2 vs 6.1 ± 3.1 Gy, P = 0.002). Grade 3 or 5 lung toxicity was observed in two patients receiving EPP and hemithorax irradiation, but not in those undergoing LSPI. In conclusion, outcomes of EPP and hemithorax irradiation were not satisfactory, whereas LSPI appeared promising and encouraging.     

Clinical outcomes of helical tomotherapy for super-elderly patients with localized and locally advanced prostate cancer: comparison with patients under 80 years of age

We investigated the clinical outcomes of helical tomotherapy in 23 patients aged ≥80 years with localized and locally advanced prostate cancer and compared the results with data from 171 patients under 80 years. All patients received helical tomotherapy in our hospital between September 2009 and October 2012. The median follow-up periods were 35 months in the aged group and 34 months in the younger group. The median prescribed dose in helical tomotherapy was 78 Gy in 39 fractions (range, 72–78 Gy). The 3-year overall survival and biochemical relapse-free rates were 92% and 96% in the aged group and 99.4% and 97.3% in the younger group, respectively. There was no significant difference between the two groups in the biochemical relapse-free rates. The 3-year cumulative incidences of late Grade 2 or higher rectal toxicity and urinary toxicity were 13% and 4.8% in the aged group and 7.0% and 1.2% in the younger group, respectively. There was no significant difference between the aged group and the younger group in the cumulative incidence rates of rectal toxicity or urinary toxicity. No patients exhibited Grade 4 or higher toxicity, and all patients improved with conservative therapy. Helical tomotherapy in super-elderly patients with localized and locally advanced prostate cancer had good biochemical control rates without severe late toxicity. Definitive helical tomotherapy may be the treatment of choice for patients with localized and locally advanced prostate cancer, even in those older than 80 years of age.     

螺旋断层放疗系统多叶准直器叶片的性能分析

目的：研究螺旋断层放疗系统的气动二元MLC叶片的设计和机械特性。方法：分析了气动二元多叶准直器叶片的重要参数,如叶片宽度、叶片速度、漏射和透射以及叶片运动产生的延迟效应。结果：气动二元MLC叶片的机械结构是为螺旋断层调强放疗的实施专门设计的。MLC叶片的延迟的准确建模保证了剂量计算的准确性。结论：气动二元多叶准直器是实现螺旋断层调强放疗理想的部件。     

非小细胞肺癌三维适形放疗所致重度放射性肺炎与剂量体积直方图分析

目的 探讨非小细胞肺癌三维适形放疗所致重度(≥3级)放射性肺炎(RP)与剂量体积直方图(DVH)参数之间的关系.方法 94例非小细胞肺癌患者予以三维适形放疗,对临床参数及DVH参数与重度RP发生的关系进行单因素、多因素Logistic分析.结果 年龄、性别、KPS评分、第1秒用力呼气容积、体重减轻、肺基础疾病、外科手术史和化疗史与重度RP的发生差异无统计学意义(P>0.05).单因素Logistic回归分析结果显示,除了总剂量以外,受到20、30或加Gy以上剂量照射的肺体积占全肺总体积的百分数(V20、V30、V40)、平均剂量(MLD)和正常组织并发症概率(NTCP)与重度RP的发生差异均有统计学意义(P<0.01);在多因素Logistic回归分析中,MLD、V30与重度RP的发生差异有统计学意义(P<0.01);当MLD<10 Gy、10～20 Gy、>20 Gy时,重度RP的发生率分别为0、21%(8/39)、35%(7/20),当V30<25%、25%～35%、>35%时,重度RP的发生率分别为0、12%(4/33)、38%(11/29).结论 MLD和V30是重度RP发生的重要预测因素,应该分别被限制到≤20 Gy和≤35%,以减少重度RP的发生.     

Dose–volume histogram comparison between static 5-field IMRT with 18-MV X-rays and helical tomotherapy with 6-MV X-rays

We treated prostate cancer patients with static 5-field intensity-modulated radiation therapy (IMRT) using linac 18-MV X-rays or tomotherapy with 6-MV X-rays. As X-ray energies differ, we hypothesized that 18-MV photon IMRT may be better for large patients and tomotherapy may be more suitable for small patients. Thus, we compared dose–volume parameters for the planning target volume (PTV) and organs at risk (OARs) in 59 patients with T1–3 N0M0 prostate cancer who had been treated using 5-field IMRT. For these same patients, tomotherapy plans were also prepared for comparison. In addition, plans of 18 patients who were actually treated with tomotherapy were analyzed. The evaluated parameters were homogeneity indicies and a conformity index for the PTVs, and D2 (dose received by 2% of the PTV in Gy), D98, Dmean and V_{10–70 Gy} (%) for OARs. To evaluate differences by body size, patients with a known body mass index were grouped by that index ( <21; 21–25; and >25 kg/m²). For the PTV, all parameters were higher in the tomotherapy plans compared with the 5-field IMRT plans. For the rectum, V_{10 Gy} and V_{60 Gy} were higher, whereas V_{20 Gy} and V_{30 Gy} were lower in the tomotherapy plans. For the bladder, all parameters were higher in the tomotherapy plans. However, both plans were considered clinically acceptable. Similar trends were observed in 18 patients treated with tomotherapy. Obvious trends were not observed for body size. Tomotherapy provides equivalent dose distributions for PTVs and OARs compared with 18-MV 5-field IMRT. Tomotherapy could be used as a substitute for high-energy photon IMRT for prostate cancer regardless of body size.     

乳腺癌改良根治术后放疗诱发放射性肺炎的危险因素分析

目的探讨乳腺癌改良根治术后放疗诱发放射性肺炎(RP)的相关因素。方法选取2017年12月至2019年12月在温州市中心医院就诊的120乳腺癌患者作为研究对象,所有病例均行乳腺癌改良根治术并实施术后放射治疗。采用单因素及多因素Logistic回归分析年龄、绝经状态、肿瘤位置、临床分期、放疗前化疗、放疗总剂量、双肺V5、V20及平均耐受剂量(MLD)对放射性肺炎的影响。结果120例乳腺癌改良根治术后放疗后患者中23例出现急性或慢性放射性肺损伤,17例发生RP,RP发生率为14.17%。单因素分析显示血红蛋白正常的乳腺癌患者RP的发生率显著低于贫血患者(χ²=8.038,P<0.05),放疗前接受过化疗的乳腺癌患者RP发生率显著高于未接受过化疗的患者(χ²=6.397,P<0.05),而不同年龄、绝经状态、分期、放疗前内分泌治疗与否、放疗模式、放疗技术之间比较差异均无统计学意义(χ²值为0.003~0.473,均P>0.05)。发生RP的乳腺癌患者的PTV1肿瘤体积、PTV2肿瘤体积、V5、V10、V20、全肺MLD的照射剂量显著高于未发生PR的患者,差异有统计学差异(t值分别为4.678、3.907、2.576、3.754、2.903、3.115,均P<0.05),而发生RP乳腺癌患者的V30、V40、V50与未发生RP乳腺癌患者之间比较,差异均无统计学意义(t值分别为0.325、0.216、0.307,均P>0.05)。Logistic多因素分析结果显示V5是乳腺癌改良根治术放疗后发生RP的独立预后因素(RR=1.343,P<0.05)。结论乳腺癌改良术后接受放射治疗的患者应该考虑双肺的放疗剂量,设定合理的放疗计划参数,可能可以降低放射性肺炎的发生率。     

Preliminary analysis of risk factors for late rectal toxicity after helical tomotherapy for prostate cancer

The purpose of this study is to examine risk factors for late rectal toxicity for localized prostate cancer patients treated with helical tomotherapy (HT). The patient cohort of this retrospective study was composed of 241 patients treated with HT and followed up regularly. Toxicity levels were scored according to the Radiation Therapy Oncology Group grading scale. The clinical and dosimetric potential factors increasing the risk of late rectal toxicity, such as age, diabetes, anticoagulants, prior abdominal surgery, prescribed dose, maximum dose of the rectum, and the percentage of the rectum covered by 70 Gy (V70), 60 Gy (V60), 40 Gy (V40) and 20 Gy (V20) were compared between ≤ Grade 1 and ≥ Grade 2 toxicity groups using the Student''s t-test. Multivariable logistic regression analysis of the factors that appeared to be associated with the risk of late rectal toxicity (as determined by the Student''s t-test) was performed. The median follow-up time was 35 months. Late Grade 2–3 rectal toxicity was observed in 18 patients (7.4%). Age, the maximum dose of the rectum, V70 and V60 of the ≥ Grade 2 toxicity group were significantly higher than in those of the ≤ Grade 1 toxicity group (P = 0.00093, 0.048, 0.0030 and 0.0021, respectively). No factor was significant in the multivariable analysis. The result of this study indicates that the risk of late rectal toxicity correlates with the rectal volume exposed to high doses of HT for localized prostate cancer. Further follow-up and data accumulation may establish dose–volume modeling to predict rectal complications after HT.     

直肠癌术后不同体位调强放疗的研究

目的比较直肠癌术后俯卧位和仰卧位调强放疗（IMRT）照射,靶N（CTV、PTV）,小肠、膀胱、股骨头的体积一剂量关系,探讨直肠癌术后IMRT放疗的合适体位。方法统一规定直肠癌术后辅助性放疗的临床肿瘤体积（CTV）范围,设定计划靶体积（PTV）为CTV~I＂扩0．5～1．0cm。对14例直肠癌术后俯卧位和仰卧位IMRT计划进行剂量学评估,比较2种体位IMRT~术下靶区．小肠,膀胱,股骨头受照射剂量一体积关系。结果直肠癌术后放疗采~IMRT技术时,仰卧位和俯卧位时的靶N（CTV45,CTV50．PTV45、PTV50）、小肠（平均剂量Dmean、V20,V30、V40、V45、V50）、膀胱（平均剂量Dmean．V30、V40,V50）及股骨头（平均剂量Dmean．V40,V50）均无统计学差异炒0．05。结论直肠癌术后IMRT时,无有孔腹板条件下,仰卧位放疗,较之俯卧位,不会导致靶区剂量分布变劣及小肠、膀胱、股骨头等正常结构受照射的剂量、体积增加,并有较好的重复性和舒适度,值得采用。     

直肠癌术后不同体位调强放疗的研究

目的 比较直肠癌术后俯卧位和仰卧住调强放疗(IMRT)照射,靶区(CTV、PTV)、小肠、膀胱、股骨头的体积-剂量关系,探讨直肠癌术后IMRT放疗的合适体位.方法 统一规定直肠癌术后辅助性放疗的临床肿瘤体积(CTV)范围,设定计划靶体积(PTV)为CTV外扩0.5～1.0cm.对14例直肠癌术后俯卧位和仰卧住IMRT计划进行剂量学评估,比较2种体位-IMRT技术下靶区、小肠、膀胱、股骨头受照射剂量-体积关系.结果 直肠癌术后放疗采用IMRT技术时,仰卧位和俯卧位时的靶区(CTV45、CTV50、PTV45、PTV50)、小肠(平均剂量Dmean、V20、V30、V40、V45、V50)、膀胱(平均剂量Dmean、V30、V40、V50)及股骨头(平均剂量Dmean、V40、V50)均无统计学差异,＞0.05.结论 直肠癌术后IMRT时,无有孔腹板条件下,仰卧位放疗,较之俯卧住,不会导致靶区剂量分布变劣及小肠、膀胱、股骨头等正常结构受照射的剂量、体积增加,并有较好的重复性和舒适度,值得采用.     

三维适形调强放疗在乳腺癌根治术中的应用

目的 对三维适形调强放疗在乳腺癌患者改良根治术后的疗效和剂量学进行观察和研究。方法 选取2016年2月-2017年2月我院收治的行改良根治术的乳腺癌患者90例,随机分为两组,对照组应用三维适形放疗（3D-CRT）,研究组应用三维适形调强放疗（IMRT）,对比两组患者辐射剂量以及不良反应发生情况。结果 IMRT同3D-CRT靶区剂量百分比无明显区别（P>0.05）,IMRT的V105%、V110%、V115%显著低于3D-CRT （P<0.05）,同时IMRT的HI显著低于（P<0.05）;同3D-CRT比较而言,IMRT可以有效减少患侧肺、心脏、肝脏以及对侧乳腺射剂量（P<0.05）;IMRT治疗患者肝炎、放射性肺损伤、骨髓抑制、胸骨后疼痛以及消化障碍等不良反应发生情况显著低于3D-CRT计划（P<0.05）。结论 乳腺癌根治术患者应用IMRT以及3D-CRT的靶区覆盖率都较为理想,但是MIRT在剂量均匀性以及靶区适形度方面更为理想,同时能够降低患者不良反应发生风险,临床上应当进一步推广应用。     

简易调强计划设计方法在上段食管癌调强计划临床应，的可行性研究

目的探讨一种简易调强计划设计方法在上段食管癌中的应用。方法选取6例胸上段食管癌患者,分别制定传统9野调强计划和简易调强计划,统一处方剂量60Gy／30F,比较靶区、危及器官的剂量体积参数,加速器的总机器跳数（MU）。结果传统9野调强计划与简易调强计划的靶区剂量分布基本一致。对于高剂量区1％体积的脊髓受量和双肺20Gy和30Gy照射的肺体积百分比（V20,V30）,两种计划的结果无明显差异（P〉O．05）,但简易调强设计方法可以减少脊髓、肺两种重要器官的低剂量受照体积,同时减少投射跳数（P〈0．05）。结论简易调强设计方法可以在胸上段食管癌中应用。     

立体定向放疗序贯TP方案治疗不能手术的早期非小细胞肺癌临床研究

目的研究立体定向放射治疗序贯TP方案化疗治疗不能手术的早期非小细胞肺癌疗效和毒副作用。方法60例不能手术的早期非小细胞肺癌患者随机分成A组和B组进行临床研究,A组30例采用立体定向放射治疗,剂量（50％剂量线）4～5Gy／次．隔日1次,共8～10次,总剂量40～50Gy。B组30例采用立体定向放射治疗序贯TP方案化疗四个疗程。结果两组患者的总有效率分别为80．O％（24／30）和83．3％（25／30）,P〉0．05,患者1、2年总生存率分别为86．7％（26／30）VS83．3％（25／30）和73．3％（22／30）VS80．0％（24／30）,P〉0．05。2年无远处转移生存率分别为60．0％（18／30）和73．2％（22／30）,B组虽高于A组,但P〉0．05。两组患者早期放射反应主要为I～II级放射性肺炎和骨髓抑制,后期放射反应主要为I～II级放射性肺炎,发生率两组接近。结论立体定向放射治疗序贯TP方案化疗治疗不能手术的早期非小细胞肺癌疗效较好。