Analysis of the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy

Objective:To explore the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy.Methods: A total of 84 patients who were admitted in our hospital after modified radical mastectomy were included in the study and divided into the conventional radiotherapy group (n=42) and the three-dimensional conformal radiotherapy group (n=42) according to different radiotherapy methods. The patients in the conventional radiotherapy group were given conventional radiotherapy of chest wall and clavicular field, while the patients in the three-dimensional conformal radiotherapy group were given three-dimensional conformal radiotherapy. The serum tumor markers and peripheral blood T lymphocyte subsets 6-8 weeks after treatment in the two groups were detected. The clinical efficacy, and toxic and side effects in the two groups were evaluated.Results: The serum CA15-3, CA125, CEA, and CK19 levels after treatment in the two groups were significantly reduced when compared with before treatment, CD3+,CD4+, and CD4+/CD8+ were significantly elevated, while CD8+ was significantly reduced when compared with before treatment, but the comparison of the above indicators between the two groups was not statistically significant. The occurrence rate of radioactive skin damage and pneumonia after treatment in the conventional radiotherapy group was significantly higher than that in the three-dimensional conformal radiotherapy group. Conclusions:The two kinds of radiotherapy schemes have an equal efficacy, but the toxic and side effects of three-dimensional conformal radiotherapy are significantly lower than those by the conventional radiotherapy, with a certain advantage.

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.

Clinical Research on Three-Dimensional Conformal Radiotherapy of Non-Small Cell Lung Cancer

OBJECTIVE To investigate the clinical efficacy and toxic effect of the 3-dimensional conformal radiation therapy （3DCRT） for non- small cell lung cancer （NSCLC）. METHODS Fifty-two patients with the Stage-I and IV NSCLC were treated with 3DCRT. Cross analysis of the clinical data was conducted in the comparison between the 52 cases with 3DCRT and the other 50 cases with the conventional radiation therapy （CRT）. In the 3DCRT group, only the primary tumor and positive lymph-node draining area were included in the clinical target area, setting 4 to 6 coplanar or non-coplanar irradiation fields, with 2 Gy or 3 Gy/fraction, 1 fraction a day and 5 fractions per week. The total dose ranged from a test dose （DT） of 66 Gy to 72 Gy. In the CRT group, the field area contained the primary tumor plus the homolateral hilum of the lung, the mediastinum superior or hol-mediastinum, and opposed anteroposterior irradiation. When the dosage reached DT 36-40 Gy, an oblique portal administered radiation was conducted in order to avoid injuring the spinal cord. The DT was 1.8-2.0 Gy/fraction, 1 fraction a day, 5 fractions per week, with a total dose of 60 Gy to 70 Gy. RESULTS The therapeutic effect （CR ＋ PR） was 90.4% in the 3DCRT group, and was 72% in the CRT group. There was statistically significant difference between the two groups, P 〈 0.01. There was a clinical symptom improvement attained by 96.5% and 86.4% respectively in the two groups, and there was a statistically significant difference between the groups, P 〈 0.01. The 6-month, 1 and 2-year overall survival rates were 92.3%, 75.0% and 42.3% in the 3DCRT group, and 76%, 60% and 30% in the CRT group, respectively. There was a significant difference in the 6-month overall survival rate between the groups, P 〈 0.05. There was no obvious significant difference in the 1 and 2-year overall survival rates between the two groups, P 〉 0.05. The toxic reaction was 12.5% and 23.7% respectively in the 3DCRT and CRT groups. Acute radioactive esophagitis and leucopenia were markedly lower in the 3DCRT group than in the CRT group. There was a statistically significant difference between the groups, P 〈 0.05. No toxic reaction of Stage-III and over was found in the 3DCRT group during radiation therapy. CONCLUSION The 3DCRT method has a satisfactory shortterm efficacy and improvement of clinical symptoms in treating NSCLC, with a mild toxic reaction and good tolerance in patients. It can be used for enhancing the tumor-control rate and bettering the quality of life.

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.

乳腺癌保乳术后三种放疗技术剂量学评价

目的:比较乳腺癌保乳术后常规放疗(CR)、三维适形(3D-CRT)放疗、调强适形(IMRT)放疗靶区剂量均匀性、危及器官受照体积等方面的差异。方法:随机选择10例乳腺癌患者,为每例患者设计上述三种照射技术的治疗计划。处方剂量为50Gy/25次。所有计划都使95%靶区体积达到处方剂量要求。根据积分剂量体积直方图(DVH)比较靶区受量和相关正常器官受量的差异和剂量分布。结果:CR、3D-CRT、IMRT靶区均匀性指数分别为1.16±0.03、1.15±0.03和1.14±0.02(P=0.279),适形度指数分别为0.61±0.05、0.65±0.06和0.69±0.06(P=0.025);三种放疗技术中患侧肺V30分别为19.39±3.09、15.53.±3.98、15.68±4.38(P=0.057),V20分别为22.26±3.52、18.87±4.24、20.68±4.52(P=0.202),V10分别为26.68±3.72、23.96±4.76、34.27±14.02(P=0.039),V5分别为33.71±3.70、31.66±5.49、49.81±24.25(P=0.018);对侧乳腺V3分别为3.31±3.74、2.37±3.11、14.24±3.81(P=0.007);心脏V5分别为19.99±17.22、13.77±11.10、38.42±29.95(P=0.037)。结论:与CR相比,3D-CRT和IMRT能够改善靶区均匀性和适形度,并降低患侧肺的高剂量受照体积,但IMRT同时增加了患侧肺、对侧乳腺、心脏低剂量受照体积。

乳腺癌保乳术后常规、三维适形和直接子野优化调强放疗技术剂量学评估

目的:比较乳腺癌保乳术后常规放疗(CR)、三维适形(3D-CRT)放疗、直接子野优化调强适形(DMPO-IMRT)放疗靶区剂量分布及危及器官受照体积等方面的差异。方法:随机选择10位乳腺癌患者,为每位患者设计上述三种照射技术的治疗计划。处方剂量为50 Gy/2 Gy/25次。所有计划都使95%靶区体积达到处方剂量要求。根据积分剂量体积直方图(DVH)比较靶区受量和相关正常器官受量的差异和剂量分布。结果:三种技术靶区均匀性指数(HI)和适形度指数(CI)差异均有显著性意义(P=0.049,P=0.001),其中尤以DMPO-IMRT的指标最佳。与CR相比,3DCRT降低了患侧肺、对侧乳腺和心脏在各个剂量区的受照体积,而DMPO-IMRT增大了患侧肺(V20、V30除外)、对侧乳腺和心脏的受照体积。与3DCRT相比,DMPO-IMRT增大了患侧肺(V30除外)、对侧乳腺和心脏的受照体积。结论:与CR相比,3D-CRT和DMPO-IMRT改善了靶区的均匀性和适形度。与此同时,3DCRT降低了本研究中各个剂量区危及器官的受照体积,DMPO-IMRT在降低患侧肺高剂量受照体积的同时,增大了患侧肺、对侧乳腺、心脏的低剂量受照体积。

食管癌3种放疗方式的疗效比较

目的探讨常规放疗、三维适形放疗(3DCRT)、调强放疗(IMRT)治疗食管癌的疗效差异。方法 117例食管癌中,38例采用常规放疗,32例采用3DCRT,47例采用IMRT。并对疗效和毒副反应进行比较分析。结果常规放疗组、3DCRT组和IMRT组的有效率分别为92.1%、96.9%、91.5%,差异无统计学意义(P=0.617)。3组1年生存率分别为77.9%、87.5%、86.7%(P=0.193);2年生存率分别为38.6%、55.1%、57.7%(P=0.211)。3DCRT组+IMRT组总疼痛缓解率为90.9%,常规放疗组为84.6%,差异无统计学意义(P=0.642)。放射性食管炎发生率3DCRT组+IMRT组较常规放疗组高(P=0.012),放射性肺炎发生率常规放疗组较3DCRT组+IMRT组高(P<0.001),放射性气管炎常规放疗组较3DCRT组+IMRT组高(P=0.028),骨髓抑制常规放疗组较3DCRT组+IMRT组高(P=0.010)。结论 3DCRT和IMRT能提高食管癌的临床疗效,并减轻患者的放射性损伤。

局部晚期非小细胞肺癌常规放疗与三维立体放疗疗效比较

目的:通过回顾分析比较未手术的Ⅲa期和Ⅲb期非小细胞肺癌(NSCLC)三维立体适形放疗(3DCRT)与常规二维放射治疗(2DRT)的治疗效果。方法:选择133例患者进行分析。其中64例接受三维放疗,69例接受普通放疗。结果:三维放疗组的1、3、5年总生存率分别是69.7%、22.7%、10.4%,中位生存时间为18.6个月,普通常规放疗组分别为57.3%、12.4%、6.6%和13个月(P=0.043)。三维放疗组1、3、5年的肿瘤专项生存率依次为73.8%、29.7%和15.8%,常规放疗组是60.8%、15.5%和12.4%(P=0.020)。Cox多因素回归分析结果表明:三维立体适形放疗较普通放疗显著提高患者总生存率和肿瘤专项生存率。结论:采用三维放射治疗可以改善不能手术的Ⅲa期和Ⅲb期非小细胞肺癌患者的生存率。

鼻咽癌三维适形放射治疗与常规放射治疗剂量对比研究

目的对比研究鼻咽癌三维适形放射治疗与常规放射治疗剂量情况。方法在60例鼻咽癌三维适形放射治疗(3D-CRT)(3D组)的治疗计划中,按三维计划要求,进行靶区勾画、照射野设计、剂量计算、剂量优化等,同时在同样患者、同样的照射野下再按常规放射治疗(CFRT)(2D组)的方法计算剂量(没有剂量优化)。对比三维适形放射治疗与常规二维放射治疗的剂量差别。结果 60例鼻咽癌患者中,3D组的处方剂量平均比2D组高7.2%(加15度楔形板)和5.0%(不加楔形板),95%等剂量曲线包含的靶体积3D组CFRT高50.2%(98.2%vs65.4%)。在3D-CRT计划中加用楔形板剂量分布比不加楔形板更合理。结论 3D-CRT的剂量分布明显比CFRT更符合临床放射剂量学的要求。加用楔板能进一步优化鼻咽癌的剂量分布。

紫杉醇加顺铂同步放化疗治疗局部晚期非小细胞肺癌的临床观察

目的:探讨紫杉醇加顺铂同步放化疗治疗局部晚期非小细胞肺癌(NSCLC)的疗效和毒副反应。方法:32例患者行常规分割放疗40Gy,针对局部病灶行三维适形放疗(3DCRT)加量至中位总剂量达70Gy/35次。化疗方案为紫杉醇135mg/m2静脉滴注第1天,顺铂20mg/m2静脉滴注,第1天～4天。结果:全组32例均可评价疗效,总有效率(CR+PR)为71.9%。中位缓解期为8.6个月,中位生存期为15.2个月,1年、2年的生存率分别为68.8%和46.9%。主要毒性反应为白细胞减少,Ⅲ度16例(50.0%),Ⅳ度3例(9.7%)。急性放射性肺炎1级～2级13例(40.6%);急性放射性食管炎1级～2级17例(53.1%),3级2例(6.3%)。结论:紫杉醇加顺铂同步放化疗治疗局部晚期NSCLC局控率较高,骨髓毒副反应较明显,急性放射性损伤在大多数患者尚可耐受。

上段食管癌累及野照射CRT、3D-CRT与IMRT计划的剂量学对比研究

目的比较颈段、胸上段食管癌常规放疗(CRT)、三维适形放疗(3D-CRT)、调强放疗(IMRT)累及野放疗中靶区和危及器官(OAR)的剂量学差异,进而为临床治疗选择最优放射治疗方案;比较不同大小肿瘤(直径<3 cm及>5 cm)不同放疗计划对危及器官的影响,进而选择较优的放疗计划。方法选择12例颈段及胸上段食管癌患者,应用三维治疗计划系统(TPS)分别为每位患者设计三种治疗计划(A.常规放疗;B三维适形放疗;C调强适形放疗),在规定CTV至少达到95%处方剂量前提下根据剂量体积直方图(DVH)、等剂量曲线比较三种计划靶区剂量分布及脊髓、气管、肺正常组织受量的差异;同时比较不同大小的肿瘤三种放疗计划对脊髓的剂量学影响。结果三种计划的靶区的平均剂量以IMRT计划为好,IMRT同时减少了脊髓及气管的剂量,差异有统计学意义(P<0.05);不管肿瘤直径大小,以IMRT计划最好。结论颈段及胸上段食管癌采用调强适形放疗,能在提高靶区剂量的同时更好的保护周围正常组织及器官,较三维适形放疗有剂量学优势,是目前较好的一种放疗方法。

局部晚期宫颈癌盆腔精确放疗剂量学研究

目的对局部晚期宫颈癌（LACC）的盆腔精确放疗与常规放疗（CRT）靶区和危及器官（OAR）的剂量分布以及放疗实施所需时间（MU）进行比较，探讨LACC的最佳放疗方式。方法对10例LACC患者进行盆腔CT扫描并勾画靶区和OAR。临床靶区（CTV）包括宫颈原发肿瘤（GTV）、子宫和宫旁组织、部分阴道及髂内外淋巴引流区、闭孔及骶前淋巴引流区。计划靶区（PTV）为CTV均匀外放10mM。给予6MVX线照射PTv45Gy／25次。对每一例患者盆腔放疗分别进行CRT及精确放疗计划设计，包括三维适形放疗（3DCRT）和调强放疗（IMRT）。其中，IMRT根据入射野数目的不同，设五野计划（IMRT计）、七野计划（IMRT7F）及九野计划（IMRT9F）。依据剂量体积直方图（DVH），对五种放疗方式PTv的均匀指数（HI）、靶区适形度（CI）和0AR剂量分布及Mu值进行比较。结果五种放疗方式PTV的H嗟异无统计学意义。IMRT的CI优于3DCRT，3DCRT优于CRT（P〈0．01）。IMRT7f与IMRT9f的CI及对OAR的保护相似，均明显优于其他放疗方式。IMRT7f的MU值为（1，185．1±135．42），明显低于IMRT9f的（1.414．20±198．66）（P=-0．003）。结论精确放疗优于CRT，具有更好的CI，可更好地保护OAR。精确放疗中，IMRT优于3DCRT，其中IMRT7f珂作为最佳的IMRT方式应用于LACC盆腔放疗。

肺癌常规放疗与适形放疗致急性放射性肺炎的比较

目的:比较肺癌适形放疗和常规放疗所致的急性放射性肺炎。方法:2008年11月～2009年3月,26例非小细胞肺癌,适形放疗组14例,普通放疗组12例。观察急性放射性肺炎。结果:26例患者均顺利完成治疗。常规放疗与适形放疗所致放射性肺炎总的发生率分别为16.7%(2/12)、21.4%(3/14)。结论:非小细胞肺癌,适形放疗比常规放疗所致急性放射性肺炎基本相同,差异无显著性。

三维适形放射治疗前列腺癌的疗效

目的:目的:评价三维适形放射治疗前列腺癌的疗效。方法:回顾分析本院放射治疗41例前列腺癌患者,其中3DCRT组18例,常规放疗组23例。所有患者均采用6/15MVX线,1.8-2.0Gy/次,每周5次。3DCRT组肿瘤剂量DT70-78Gy,常规放疗组肿瘤剂量DT65-72Gy。结果:3DCRT组与常规放疗组的3、5年生存率分别为83.3%、66.7%和69.6%、56.5%(P>0.05),两组2级以上急性胃肠道和泌尿系统反应发生率分别为27.8%和60.9%(P<0.05),2级以上慢性胃肠道和泌尿系统反应发生率分别为5.6%和21.7%(P>0.05)。结论:三维适形放射治疗前列腺癌有提高生存率的趋势,副反应可接受,未发生严重晚期副反应。

食管癌放射治疗胸部组织校正与否对剂量学影响的研究

目的:探讨不均匀胸部组织校正与否对食管癌癌患者的肿瘤靶区、正常组织及重要器官剂量分布的影响。方法:选择21例病理证实的食管癌癌,每个病例同时设计两组治疗计划,模拟常规放疗不校正不均匀胸部组织计划、三维适形放疗校正不均匀胸部组织计划。常规计划为照射60 Gy,通过调节剂量权重使处方剂量与常规放疗的相同;射野大小、及其他参数与常规放疗的相同,此时得到常规计划的剂量分布就是常规不校正不均匀肺组织在患者体内的实际分布。三维计划为三维适形放疗照射60 Gy。将常规计划与三维计划进行比较。结果:两组治疗计划临床靶区的最大值、平均值、95%体积剂量和100%体积剂量的均数有显著性差异(p<0.05);适形度指数值的均数有显著性差异(p<0.05);脊髓最大值,两肺V5、V20的均数有显著性差异(p<0.05);均匀性指数值和两肺平均值的均数无显著性差异(p>0.05)。结论:食管癌三维适形放疗,可使肿瘤获得比常规放疗更理想的剂量,更好地保护正常组织。