Clinical observation of gemcitabine and concomitant three-dimensional conformal radiotherapy in the treatment of locally advanced non-small cell lung cancer

Objective： To evaluate the clinical effect of gemcitabine and concurrent three-dimensional conformal radiation therapy （3D-CRT） for locally advanced non-small cell lung cancer （NSCLC）. Methods： From April 2002 to June 2005, 38 patients with inoperable stage Ⅲ NSCLC were treated with gemcitabine and 3D-CRT simultaneously. Chemotherapy consisted of intravenously gemcitabine 350 mg/m^2 on days 1, 8, 15, 22, 29, 36.3D-CRT was delivered up to a total dose of 60-64 Gy with a 2.0 Gy dose fraction per day, 5 days per week. Results： The overall response rates of primary tumor and mediastinum metastatic node were 86.8% （33/38） and 90.6% （29/32） respectively, and 91.7% （22/24） and 78.6% （11/14） for squamous cell carcinoma and adenocarcinoma respectively. The acute side effects of patients were mostly myelosuppression, nausea, vomiting, radiation-induced esophagitis and pneumonitis （RTOG 1/11）, however, all of them were cured. Conclusion： Concurrent application of gemcitabine and 3D-CRT can improve the overall response rate for locally advanced NSCLC without aggravating the side effects.

Influences of Motion Artifacts on Three-Dimensional Reconstruction Volume and Conformal Radiotherapy Planning

Objective ：To investigate the influences of motion artifacts on three-dimensional （3D） reconstruction volume and conformal radiotherapy planning. Methods： A phantom which can mimic the clip motion of lung tumor along the cranial-caudal direction is constructed by step motor, small ball of polyethylene and potato. Ten different scan protocols were set and CT data of the phantom were acquired by using a commercial GE LightSpeedl6 CT scanner. The 3D reconstruction of the CT data was implemented by adopting volume-rendering technology of GE AdvantageSim 6.0 system. The reconstructed volumes of each target in different scan protocols were measured through 3D measuring tools. Thus, relative deviations of the reconstruction volumes between moving targets and static ones were determined. The three-dimensional conformal radiation therapy （3D- CRT） plans and conformal fields were created and compared for a static/moving target with the WiMRT treatment planning system （TPS）. Results：For a static target, there was no obvious difference among the 3D reconstruction volumes when the CT data were acquired with different pitches and slices. The appearance of 3D reconstruction volume and 3D conformal field of a moving target was quite different from that of static one. The maximum relative deviation is nearly 90% for a moving target scanned with different scan protocols. The relative deviations are variable among the different targets, about from -39.8% to 89.5% for a smaller target and from - 18.4% to 20.5% for a larger one. Conclusion ：The motion artifacts have great effects on 3 D-CRT planning and reconstruction volume, which will greatly induce distorted conformal radiation fields and false DVHs for a moving target.

Simultaneous modulated accelerated radiation therapy for esophageal cancer:A feasibility study

AIM: To establish the feasibility of simultaneous modulated accelerated radiation therapy (SMART) in esophageal cancer (EC).

Study of the impact of CT/CT image fusion radiotherapy on V_(20) and radiation pneumonitis of non-small cell lung cancer

Objective:The aim of our study was to investigate the value of CT/CT image fusion radiation treatment planning in non-small cell lung cancer(NSCLC) and the impact on V20 and radiation pneumonitis(RP).Methods:Patients who were pathologically or cytologically diagnosed of stage IIIA and IIIB NSCLC were treated with three-dimensional conformal radiation therapy(4000 cGy).Forty patients got at least 25% tumor reduction were randomly divided into two groups:group A of regular shrink field radiotherapy(20 cases) and group B of CT/CT image fused shrink field radiotherapy(20 cases).Dosage reached 6600 cGy.Clinical data,V20 and RP were observed within 3 months after radiotherapy.Statistical analysis was conducted for the NSCLC patients.Results:22.5%(9/40) patients got RP during follow-up.Group A accounted for 6 cases(30%),and group B had 3 cases(15%).There was no marked difference between the two groups(P = 0.256),univariate analysis revealed that the IV20 of A and B groups,and IV20 and CV20 of all patients were statistically related to the incidence of RP(P < 0.05).With Wilcoxon method assay,the ipsilateral lung V20 and contralateral lung V20 had statistical significance between the two groups(P < 0.05).Conclusion:The CT/CT image infusion treatment planning could increase the radical dosage with better tumor control probability but won't increase adverse reaction.

The Effect of Absorbed Dose to Organs at Risk Following Craniospinal Irradiation Using Different Radiotherapy Techniques

Introduction: In medulloblastoma patients craniospinal irradiation is an important element the treatment. Our study aimed to evaluate the effect of absorbed dose to organs at risk using the hybrid intensity-modulated radiation therapy (IMRT) versus three-dimensional conformal radiotherapy (3DCRT) for craniospinal irradiation (CSI) in average risk medulloblastoma patients. Materials and Methods: In this study, thirteen medulloblastoma patients were included. The prescribed total dose to the planning target volume (PTV) was 23, 40 Gy in 13 fractions. Two radiotherapy techniques, three dimensional conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (IMRT) were used to treat these patients. The coverage of the Target was evaluated using the D mean, D95%, D2%, D98% and V95%. Other parameters were also compared such as Integral dose (ID), Homogeneity index (HI) and doses to the organs at risk (OARs). Results: There was no significant difference in the mean dose received by the PTV-Brain or the dose received by 95% and 98% of PTV volume using the two techniques. For PTV-Spine, the percentage volume receiving 95% of the total dose increased significantly in the hybrid IMRT technique compared to the conformal technique. So, hybrid IMRT plan achieved the best coverage for PTV spine. Lower dose for OAR was delivered by 3DCRT, except the heart and thyroid, hybrid IMRT achieved better sparing. All plans resulted in the same dose homogeneity index (DHI) for PTV-Brain. For PTV-Spine, hybrid IMRT technique achieved better dose homogeneity compared to 3DCRT technique (1.09 vs. 1.12;p > 0.05). Conclusions: hybrid IMRT technique can be realized on conformal technique because it achieved better dose coverage for the (PTV) and organ at risk (OAR). 3DCRT reduced mean dose to most OARS, except the heart and thyroid. Therefore, the hybrid IMRT technique may be a CSI treatment alternative to 3DCRT.

Helical tomotherapy and volumetric modulated arc therapy:New therapeutic arms in the breast cancer radiotherapy

AIM To analyse clinical and dosimetric results of helical tomotherapy(HT) and volumetric modulated arc therapy(VMAT) in complex adjuvant breast and nodes irradiation.METHODS Seventy-three patients were included(31 HT and 42 VMAT). Dose were 63.8 Gy(HT) and 63.2 Gy(VMAT) in the tumour bed, 52.2 Gy in the breast, 50.4 Gy in supraclavicular nodes(SCN) and internal mammary chain(IMC) with HT and 52.2 Gy and 49.3 Gy in IMC and SCN with VMAT in 29 fractions. Margins to particle tracking velocimetry were greater in the VMAT cohort(7 mm vs 5 mm).RESULTS For the HT cohort, the coverage of clinical target volumes was as follows: Tumour bed: 99.4% ± 2.4%; breast: 98.4% ± 4.3%; SCN: 99.5% ± 1.2%; IMC:96.5% ± 13.9%. For the VMAT cohort, the coverage was as follows: Tumour bed: 99.7% ± 0.5%, breast: 99.3% ± 0.7%; SCN: 99.6% ± 1.4%; IMC: 99.3% ± 3%. For ipsilateral lung, Dmean and V20 were 13.6 ± 1.2 Gy, 21.1% ± 5%(HT) and 13.6 ± 1.4 Gy, 20.1% ± 3.2%(VMAT). Dmean and V30 of the heart were 7.4 ± 1.4 Gy, 1% ± 1%(HT) and 10.3 ± 4.2 Gy, 2.5% ± 3.9%(VMAT). For controlateral breast Dmean was 3.6 ± 0.2 Gy(HT) and 4.6 ± 0.9 Gy(VMAT). Acute skin toxicity grade 3 was 5% in the two cohorts.CONCLUSION HT and VMAT in complex adjuvant breast irradiation allow a good coverage of target volumes with an acceptable acute tolerance. A longer follow-up is needed to assess the impact of low doses to healthy tissues.

The impact of intensity modulated radiotherapy on the skin dose for deep seated tumors

Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate the skin dose calculation accuracy of the XIO 4.04 treatment planning system. Methods: More investigations for the influences of IMRT on skin doses would increase its applications for many treatment sites. Measuring skin doses in real treatment situations would reduce the uncertainty of skin dose prediction. In this work a pediatric human phantom was covered by a layer of 1 mm bolus at three treatment sites and thermoluminescent dosimeter (TLD) chips were inserted into the bolus at each treatment site before CT scan. Two different treatment plans [three-dimensional conformal radiation therapy (3DCRT) and IMRT] for each treatment sites were performed on XIO 4.04 treatment planning system using superposition algorism. Results: The results showed that the surface doses for 3DCRT were higher than the surface doses in IMRT by 1.6%, 2.5% and 3.2% for brain, abdomen and pelvis sites respectively. There was good agreement between measured and calculated surface doses, where the calculated surface dose was 15.5% for brain tumor calculated with 3DCRT whereas the measured surface dose was 12.1%. For abdomen site the calculated surface dose for IMRT treatment plan was 16.5% whereas the measured surface dose was 12.6%. Conclusion: The skin dose in IMRT for deep seated tumors is lower than that in 3DCRT which is another advantage for the IMRT. The TLD readings showed that the difference between the calculated and measured point dose is negligible. The superposition calculation algorism of the XIO 4.04 treatment planning system modeled the superficial dose well.

大分割三维适形放疗在非小细胞肺癌治疗中的应用

背景与目的：采用常规分割放射治疗治疗非小细胞肺癌其局部控制率较低，在适形放疔技术下可以采用大分割放疗，有望提高其局部控制率，但合适的分割剂量和毒性还需要深入研究。本研究前瞻性评估采用大分割三维适形放疗治疗非小细胞肺癌的安全性和有效性。方法：根据剂量体积直方图V20（受到20Gy以上照射的肺的体积占全肺体积的比例）水平将患者分成3组治疗：①低V20组（V20≤20％组），②中V20组（20％〈V20〈30％组），③高V20组（V20≥30％组），每5例患者为一组依次进入上述3个V20水平进行试验，放疗方法为三维适形放疔，每次3Gy，总剂量57～66Gy，4～5周完成。最大耐受剂量定义为10例患者中有至少有8例患者能耐受剂量限制毒性（≥Ⅲ级的放射性损伤）。放射毒性分级采用美国肿瘤放射治疗协作组（RTOG）早期和晚期损伤标准。所有患者不进行同期放化疔。结果：低V20组，共10例患者完成试验，无≥HI级的放射性肺炎发生；中V20组，先5例患者中有1例发生Ⅲ级放射性肺炎，再增加5例患者后无发生≥Ⅲ级的放射性肺炎；高V20组，5例患者中有2例发生Ⅲ级放射性肺炎，1例发生Ⅳ级放射性肺炎而死亡。没有≥Ⅲ级的放射性食管炎：25例患者中有8例达到完全缓解（32％），13例达到部分缓解（52％）．3例稳定（12％），1例进展（4％）。结论：进行大分割三维适形放疗时，把V20控制在30％以下是可行的，当V20≥30％时应改为姑息性放疗。其有效性需要进一步研究。

非小细胞肺癌后程大剂量分割三维适形放射治疗

目的对非小细胞肺癌行大剂量分割三维适形放射治疗,探索此分割方法治疗非小细胞肺癌的近期疗效和急性放射反应。方法2001年6月-2003年12月,11例非小细胞肺癌患者进入本研究,可以评价病例共9例。常规放射治疗40Gy后对原发灶行大剂量分割三维适形放射治疗,3Gy/次,1次/日,5次/周,7-10次。治疗1个月后评价肿瘤消退情况和放射性副反应。结果9例患者顺利完成治疗。原发灶完全缓解率(CR)占33%(3/9),部分缓解率56%(5/9),无变化(1/9),总有效率为89%(8/9)。急性放射性食道炎发生率Ⅰ、Ⅱ级22%(2/9),Ⅲ级11%(1/9)。急性放射性肺炎发生率0级22%(2/9),I、Ⅱ级44%(4/9),Ⅲ、Ⅳ级33%(3/9)。急性骨髓抑制均在I级以下。2例分别于治疗结束2.5个月和5个月死于放射性肺炎。单次剂量超过2Gy的同侧受照肺体积≥400cc时,急性放射性肺炎明显加重。结论利用三维适形技术对非小细胞肺癌行后程大剂量分割照射,抑制肿瘤干细胞的加速再增殖是可行的,有较好的近期疗效。单次剂量大于200cCy的同侧受照肺体积是很好的预测放射性肺炎的指标。远期疗效和晚期并发症还有待进一步的观察。

低分割三维适形调强放疗治疗局部进展期胰腺癌的临床观察

目的探讨氟尿嘧啶(5-FU)联合低分割影像引导的三维适形调强放疗治疗局部进展期胰腺癌的疗效和毒副反应。方法收集2011年6月至2014年12月间收治的37例经病理组织学证实的不可切除局部进展期胰腺癌,均采用CT引导下三维适形调强放疗技术,放疗采用大分割3.0~3.1 Gy/次,16次,DT 48~49.6 Gy;同步化疗方案:5-FU 350 mg/m^2,每日1次,一周5次,与放疗同步进行。观察疗效和毒副反应,并随访生存。结果所有患者均完成放疗。同步放化疗获CR 5例,PR 14例,SD 14例,PD 4例,有效率为51.4%(19/37);临床受益反应有效者21例,临床受益率为56.8%(21/37)。同步放化疗期间发生3级以上骨髓抑制7例,严重胆道梗阻1例,胃十二指肠溃疡2例。37例患者1、2年无远处转移生存率分别为36.0%、4.8%;1、2年生存率分别为51.3%、11.6%。至随访截止日期,13例患者出现局部复发,26例患者出现远处转移。结论氟尿嘧啶联合低分割影像引导的适形调强放疗治疗局部进展期胰腺癌疗效较好,毒副反应可耐受。

Dosimetric evaluation of CR, 3DCRT and two types of IMRT for breast cancer after conservative surgery

Objective: The purpose of this study was to compare the dose distribution and dose volume histogram (DVH) of the planning target volume (PTV) and organs at risk (OARs) among conventional radiation therapy (CR), three-dimensional conformal radiation therapy (3DCRT), two-step intensity-modulated radiation therapy (TS-IMRT) and direct machine parameter optimization intensity-modulated radiation therapy (DMPO-IMRT) after breast-conserving surgery. Methods: For each of 20 randomly chosen patients, 4 plans were designed using 4 irradiation techniques. The prescribed dose was 50 Gy/2 Gy/25 f, 95% of the planning target volume received this dose. The cumulated DVHs and 3D dose distributions of CR, 3DCRT, TS-IMRT and DMPO-IMRT plans were compared. Results: For the homogeneity indices, no statistically significant difference was observed among CR, 3DCRT, TS-IMRT and DMPO-IMRT while the difference of the conformality indices were statistically significant. With regard to the organs at risk, IMRT and 3DCRT showed a significantly fewer exposure dose to the ipsilateral lung than CR in the high-dose area while in the low-dose area, IMRT demonstrated a significant increase of exposure dose to ipsilateral lung, heart and contralateral breast compared with 3DCRT and CR. In addition, the monitor units (MUs) for DMPO-IMRT were approximately 26% more than those of TS-IMRT and the segments of the former were approximately 24% less than those of the latter. Conclusion: Compared with CR, 3DCRT and IMRT improved the homogeneity and conformity of PTV, reduced the irradiated volume of OARs in high dose area but IMRT increased the irradiated volume of OARs in low dose area. DMPO-IMRT plan has fewer delivery time but more MUs than TS-IMRT.

Comparative study of IORT and 3D-CRT for hepato-cellular carcinoma

Objective: To investigate the feasibility of intra-operative radiation therapy (IORT) in hepato-cellular carcinoma (HCC). Methods: Based on the dosage distribution of tumor and adjacent sensitive organs, and dose-volume histogram (DVH), Topslane three-dimensional therapy plan was used to compare IORT and three-dimensional conformal radiation therapy (3D-CRT) in 12 cases of HCC. Results: Taking the center of tumors as the isodose center, the V90 (volume of 90% dose distribution) of IORT was significantly better than that of 3D-CRT, and median absorbed doses of normal organs in IORT was significantly lower than that in 3D-CRT. Conclusion: The V90 of IORT is better than that of 3D-CRT in HCC, and neighboring sensitive organs were effectively protected by IORT. The tumors absorbed dose and local control rate are improved in IORT.

介入联合大分割三维适形治疗晚期肺癌的疗效分析

目的探讨介入联合大分割三维适形对晚期肺癌的疗效。方法 75例患者接受此种治疗。介入法采用Seldinger法化疗药物灌注,每次灌注顺铂、5-Fu、紫杉醇、亚叶酸钙;3D-CRT采用6MV X线,Topslane ARTP系统,总剂量为40～42Gy/10次/2周。介入治疗、3D-CRT、再介入治疗,"夹心"进行。结果 75例病人总有效率(CR+PR)为93.4%,平均生存期为14.5个月。结论采用介入化疗与大分割三维适形相结合,可使肺癌的瘤体迅速缩小,生存期延长,生活质量提高,为晚期肺癌有效的治疗手段。

大分割三维适形放射治疗肺癌单发脑转移

目的探讨大分割三维适形(3D-CRT)方法治疗肺癌单发脑转移的疗效。方法 87例患者接受大分割3D-CRT治疗。方法 3～4Gy/次,1次/d,5次/周,共8～12次。整个治疗期间配合脱水治疗以降低颅压。结果有效率71.2%,87例患者中位生存期为11个月,生活质量提高。结论大分割3D-CRT治疗肺癌单发脑转移是一种行之有效的治疗方法。

用Lyman NTCP模型分析原发性肝癌三维适形放疗引起的放射性肝病

目的建立原发性肝癌三维大分割适形放疗Lyman NTCP模型的参数和探讨放射性肝病的影响因素。方法109例患者进行大分割三维适形放疗,其中93例患者肝硬化Child-Pugh分级A级,16例为B级。患者每星期治疗3次,每次间隔48h,(4．8±0．5)Gy/次,平均剂量(53．5±5．5)Gy。用最大拟然比方法分别得到Child-A和Child-B患者Lyman模型中的NTCP参数。结果共有17例发生放射性肝病,发生在Child-A组8例,Child-B组9例。多因数分析表明,肝硬化分级程度是与放射性肝病相关的独立因素(P=0．000)。所有患者的NTCP参数为n=1．1,m=0．35,TD_(50) (1)=38．5Gy；Child-A级为n=1．1,m=0．28,TD_(50)(1)=40．5Gy；Child-B级为n=0．7,m=0．43,TD_(50)(1)=23Gy。结论肝硬化分级是预测放射性肝病发生的危险因子。Child-B患者进行适形放疗易引起放射性肝病。

老年非小细胞肺癌大分割三维适形放疗长期随访结果

目的：评价70岁以上老年非小细胞肺癌患者大分割放疗的长期疗效和并发症。方法：对1997年8月至2003年2月收治的38例70岁以上非小细胞肺癌实施大分割三维适形放疗（3D-CRT）,年龄70～85岁,中位年龄74岁。全组卡氏评分均≥70。其中Ⅰ期8例,Ⅱ期20例,Ⅲ期8例,Ⅳ期2例。结果：全组有效率（CR＋PR）92.1%;1,2,3,5年生存率分别为94.7%、65.7%、38.9%和28.0%。1,2级急性放射性食管炎发生率47.4%（18/38）;未出现急性症状性放射性肺炎,未发现严重心脏、食管、脊髓放射性反应。晚期局部肺放射性纤维化表现（CT和/或胸片）为34.2%（13/38）.结论：不能手术的老年非小细胞肺癌患者大分割适形放射治疗,安全有效,副作用可以耐受。