Preliminary analysis of a clinical trial for three-dimensional conformal radiation therapy after conservative surgery

Objective The aim of this study was to evaluate the efficacy, complications and cosmetic results of three-dimensional conformal radiation therapy for early breast cancer after conservative surgery.

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.

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.

The follow-up of 34 children with medulloblastoma who received 3-dimensional conformal radiation therapy

Objective:In our investigation,we studied the patients with medulloblastoma who received 3-dimensional conformal radiation therapy(3DCRT) and recorded their effects,side effects and failure reasons.Methods:From August 2001 to August 2007,34 children with medulloblastoma were treated in our hospital.The age at diagnosis was 3-16 years old,and the mean age at diagnosis was 9.5 years old.Among all the patients,16 cases were included in the high risk group and 18 cases were included in the low risk group.All the patients were performed total resection or subtotal resection and no patients received radiotherapy or chemotherapy before operation.All patients received 3DCRT within 3 weeks after resection.The dose of 30 Gy were given to the whole brain and whole spine,followed by 20-25 Gy boosted to the posterior brain fossa.The median fraction dose was 180 cGy.Every patient received the chemotherapy scheme of the Lomustine,Cisplatinum and Vincristine.Nobody received intrathecal chemotherapy.The tests of the complete blood count,blood biochemistry,hepatic and renal functions were required before every cycle of chemotherapy.Results:5-year overall survival(OS) and 5-year disease free survival(DFS) were 71% and 62% respectively.The median follow-up time was 36.5 months.The 5-year OS of the high risk group was 71% compared to 62% of the low risk group.There were significant difference between the two groups(P = 0.01).There were 13 failure cases in all the patients.Of these 13 patients,10 were dead and the other 3 were alive with tumor.The complete remission(CR) rate was 70.5% and the partial remission(PR) rate was 14%.Among the failure patients,there were 3 patients(8.8%) with the recurrences located in the brain of cribriform region.The 5-year OS of the patients with preoperative metastases was 12.5%(1/8),and which of the patients with residual tumor volume > 1.5 cm3 was 0%(0/5).Through the statistic analysis,it was found that both whether or not the metastases were found before surgery and residual tumor volume have the significant impacts on the prognosis of the children with medulloblastoma(P < 0.05).The major adverse reactions were hematological toxicity(7/34,20.6%) and gastrointestinal reaction(4/34,11.8%).Conclusion:Through the using of 3DCRT for the children with medulloblastoma,the severe side effects rate was not high.The prognosis of the patients in low risk group was satisfied which was opposite to that of the patients in high risk group.And the patients with residual tumor volume > 1.5 cm3 and preoperative metastases also had poor prognosis.It is needed to pay attention to the possible low dose of the brain of cribriform region.

A dosimetric comparative study between conformal and intensity modulated radiation therapy in the treatment of primary nasopharyngeal carcinomas: the Egyptian experience

Objective: The study is a comparative study, the aim of which is to compare 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) in treating nasopharyngeal carcinomas; dosimetrically evaluating and comparing both techniques as regard target coverage and doses to organs at risk (OAR). Methods: Twenty patients with nasopharyngeal carcinoma were treated by 3D-CRT technique and another 20 patients were treated by IMRT. A dosimetric comparison was done by performing two plans for the same patient using Eclipse planning system (version 8.6). Results: IMRT had a better tumor coverage and conformity index compared to 3D-CRT plans (P value of 0.001 and 0.004), respectively. As for the dose homogeneity it was also better in the IMRT plans and the reason for this was attributed to the dose inhomogeneity at the photon/electron junction in the 3D-CRT plans (P value 0.032). Also, doses received by the risk structures, particularly parotids, was significantly less in the IMRT plans than those of 3D-CRT (P value 0.001). Conclusion: IMRT technique was clearly able to increase the dose delivery to the target volume, improve conformity and homogeneity index and spare the parotid glands in comparison to 3D-CRT technique.

Evaluation of 3D-CRT and VMAT Radiotherapy Plans for Left Breast Cancer with Regional Lymph Nodes Irradiation

Introduction: Radiation therapy after breast surgery is an integral part of the treatment of early breast cancer. The goal of radiation therapy is to achieve the best possible coverage of the planning target volume (PTV), while reducing the dose to organs at risk (OARs) which are normal tissues whose sensitivity to irradiation could cause damage that can lead to modification of the treatment plan. In the last decade, radiation oncologist started to use the Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) for irradiating the breast, in order to achieve better dose distribution and target dose to the PTV and OAR. The aim of this study is to compare 2 external radiotherapy techniques (VMAT vs 3D) for patients with node-positive left breast cancer. Patients and Methods: We randomly selected 10 cases of postoperative radiotherapy for breast cancer in our hospital. The patients are all female, the average age was 45.4 years old, and the primary lesions are left breast. The ANOVA test was used to compare the mean difference between subgroups, and the p value Results: Dose volume histogram (DVH) was used to analyze each evaluation dose of clinical target volume (CTV) and organs at risk (OARs). Compared to 3DCRT plans, VMAT provided more uniform coverage to the breast and regional lymph nodes. The max point dose for tVMAT was lower on average (106.4% for VMAT versus 109% for 3DCRT). OAR sparing was improved with tVMAT, with a lower average V17Gy for the left lung (27.91% for VMAT versus 30.04% for 3DCRT, p and lower for V28Gy (13.75% for VMAT versus 22.34% for 3DCRT, p = 0.01). We also found a lower V35Gy for the heart on VMAT plan (p = 0.02). On the contrary, dose of contralateral breast was lower in 3DCRT than VMAT (0.59 Gy vs 3.65 Gy, p = 0.00). Conclusion: The both types of plans can meet the clinical dosimetry demands of postoperative radiotherapy for left breast cancer. The VMAT plan has a better conformity, but 3CDRT can provide a lower dose to the contralateral organs (breast and lung) to avoid the risk of secondary cancers.

Role of radiation therapy in gastric adenocarcinoma

Outcomes in patients with gastric cancer in the United States remain disappointing, with a five-year overall survival rate of approximately 23%. Given high rates of local-regional control following surgery, a strong rationale exists for the use of adjuvant radiation therapy. Randomized trials have shown superior local control with adjuvant radiotherapy and improved overall survival with adjuvant chemoradiation. The benefit of adjuvant chemoradiation in patients who have undergone D2 lymph node dissection by an experienced surgeon is not known, and the benefit of adjuvant radiation therapy in addition to adjuvant chemotherapy continues to be defined. In unresectable disease, chemoradiation allows long-term survival in a small number of patients and provides effective palliation. Most trials show a benefit to combined modality therapy compared to chemotherapy or radiation therapy alone. The use of pre-operative, intra-operative, 3D conformal, and intensity modulated radiation therapy in gastric cancer is promising but requires further study. The current article reviews the role of radiation therapy in the treatment of resectable and unresectable gastric carcinoma, focusing on current recommendations in the United States.

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.

Evaluation of endocrine therapy combined with intensity modulated radiation therapy in patients with advanced prostate cancer

Objective The aim of this study was to study the effect of endocrine therapy combined with intensity-modulated radiation therapy in patients with advanced prostate cancer.Methods The clinical data of 231 patients with advanced prostate cancer treated with radiotherapy in our hospital from May 2010 to March 2018 were collected.A total of 135 patients were treated with endocrine therapy combined with intensity-modulated radiotherapy,and 96 patients were treated with intensity-modulated radiotherapy only because of drug allergy,serious adverse reactions,and economic reasons.Two months after the end of the treatment,the short-term curative effect was evaluated using imaging reexamination.The total prostate-specific antigen(TPSA)and free prostate-specific antigen(FPSA)were detected before and 2 months after the end of the treatment.All patients were followed up for at least 3 years,and the metastasis-free survival rate and cumulative survival rate of the two groups were calculated.Results The remission rates(RRs)of the observation and control groups were 64.45%and 46.87%,respectively;the difference was not statistically significant(P>0.05);however,the efficacy distribution of the endocrine therapy combined with intensity-modulated radiotherapy group was significantly better than that of the intensity-modulated radiotherapy group(P<0.05).There was no significant difference in clinical efficacy between the two groups in different TNM stages and Gleason grades.After treatment,the levels of TPSA and FPSA were significantly decreased compared with those before treatment;however,the decrease in the endocrine therapy combined with the intensity-modulated radiation therapy(IMRT)group was significantly higher than that in the IMRT group(P<0.05).Although there were no significant differences in the 1-year and 3-year cumulative survival rates between the two groups,the 1-year and 3-year metastasis-free survival rates of the endocrine therapy combined with the IMRT group were 60%and 38.17%,respectively,which were significantly higher than those of the IMRT group(37.5%and 20.83%,P<0.05).Conclusion Endocrine therapy combined with IMRT significantly improved the clinical efficacy of advanced prostate cancer,reduced PSA(prostate specific antigen)levels,and improved the metastasis-free survival rates.

三维适形放疗治疗原发性肝癌患者疗效及发生放射性肝损伤影响因素分析

目的分析采用三维适形放疗(3DCRT)治疗原发性肝癌(PLC)患者的疗效和放射性肝损伤(RILI)发生的影响因素。方法2019年4月~2022年4月我院诊治的PLC患者85例,均接受3DCRT治疗。按照实体瘤疗效评价标准考核疗效,根据报道的标准诊断RILI。应用Logistic回归模型分析影响PLC患者接受3D-CRT治疗疗效和RILI发生的因素。结果经3D-CRT治疗,本组获得客观缓解50例(58.8%);客观缓解组TNMⅣ期和Child-Pugh B级占比分别为36.0%和14.0%,均显著低于非客观缓解组的60.0%和48.6%(P<0.05),而单次剂量为3~4 Gy和总剂量为50~60 Gy占比分别为52.0%和68.0%,均显著高于非客观缓解组的28.6%和45.7%(P<0.05);本组发生RILI者15例(17.7%);RILI组TNMⅣ期和Child-Pugh B级、单次剂量为3~4 Gy和总剂量50~60 Gy占比分别为80.0%、93.0%、73.3%和86.7%,均显著高于无RILI组(分别为38.6%、14.3%、35.7%和52.9%,P<0.05);多因素Logistic回归分析发现,TNM分期、Child-Pugh分级、单次剂量和总剂量均为影响3DCRT治疗的疗效和发生RILI的因素(OR=5.078、4.988、4.600、4.850、4.963、5.043、5.150、4.740,P<0.05)。结论PLC患者接受3DCRT治疗的疗效和RILI的发生受TNM分期、Child-Pugh分级、单次剂量和总剂量的影响,临床在制定放疗计划时,要充分考虑以上敏感因素,以保证提高疗效并显著降低RILI的发生。

BMS-IMRT与三维适形放疗在宫颈癌术后放疗中的剂量学优势及对危及器官的影响

目的 比较骨髓单独限量调强适形放疗(BM S-IM RT)与三维适形放疗(3D-CRT)在宫颈癌术后全盆腔放疗中的剂量学差异,并探讨对危及器官(OARs)的影响。方法 回顾性分析2018年8月至2020年8月本院收治的40例宫颈癌术后行全盆腔放疗患者的临床病例资料,根据术后放疗方式不同分为BMS-I MRT组(n=16)与3D-CRT组(n=24),BMS-IMRT组接受BMS-IMRT计划,3D-CRT组接受3D-CRT计划。比较2组靶区剂量分布,OARs的剂量学差异以及骨髓抑制情况。结果 BMS-IMRT组和3D-CRT组的D_(95)[(44.78±0.42) vs (44.61±0.57)]、V_(95)[(99.40±2.73) Vs(99.07±5.26)]比较,均无统计学差异(P>0.05);BMS-IMRT组的均匀指数(HI)[(1.07±0.04) vs (1.11±0.02)]/适形指数(CI)[(0.67±0.10) vs (048±0.07)]均优于3D-CRT组,差异有统计学意义(P<0.06);3D-CRT组直肠、膀胱、小肠的V_(40),小肠V_(35),骨髓V_(20)和骨髓V_(10)均明显高于BMS-IMRT组(P<0.05);BMS-IMRT组Ⅱ级及以上骨髓抑制的比例明显低于3D-CRT组[66.67%vs 31.25%](P<0.05)。结论 宫颈癌术后全盆腔放疗中,BMS-IMRT计划在保证靶区剂量前提下,更有助于保护危及器官,改善骨髓抑制情况。

卡瑞利珠单抗联合调强适形放疗用于非小细胞肺癌患者的效果

目的:观察卡瑞利珠单抗联合调强适形放疗用于非小细胞肺癌(NSCLC)患者的效果。方法:选取2021年1月至2023年2月该院收治的80例NSCLC患者进行前瞻性研究,按照随机数字表法将其分为对照组和观察组各40例。对照组采用调强适形放疗,观察组在对照组基础上联合卡瑞利珠单抗治疗。比较两组临床疗效,治疗前后肿瘤标志物[糖类抗原125(CA125)、蛋白激酶B(PKB)、脂肪酸合成酶(FAS)]水平、血清学指标[肿瘤特异性生长因子(TSGF)、血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(b-FGF)]水平,以及不良反应发生率。结果:观察组客观缓解率(ORR)为72.50%(29/40),高于对照组的50.00%(20/40),差异有统计学意义(P<0.05);治疗后,观察组CA125、PKB、FAS水平均低于对照组,差异有统计学意义(P<0.05);治疗后,观察组TSGF、VEGF、b-FGF水平均低于对照组,差异有统计学意义(P<0.05);两组白细胞减少、贫血、血小板减少、放射性肺炎、恶心呕吐等不良反应发生率比较,差异均无统计学意义(P>0.05)。结论:卡瑞利珠单抗联合调强适形放疗用于NSCLC患者可提高ORR,降低肿瘤标志物、血清学指标水平,效果优于单纯调强适形放疗。

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.

调强放射治疗未分化型鼻咽癌的疗效及治疗前后血清sE-cad与PDGF水平变化探讨

目的探究调强放射治疗(IMRT)未分化型鼻咽癌(NPC)的临床疗效及患者治疗前后血清上皮型钙黏蛋白(sE-cad)、血小板源性生长因子(PDGF)水平变化。方法选取2019年6月—2021年6月收治的84例未分化型NPC患者作为研究对象,按照随机数字表法按1∶1比例分为观察组和对照组,每组各42例,对照组采用三维适形放射治疗(3DCRT),观察组采用IMRT治疗。治疗7周后比较两组患者临床疗效,治疗前与治疗7周后肿瘤标志物水平[癌胚抗原(CEA)、鳞状细胞癌相关抗原(SCC-Ag)、角蛋白19片段21-1(CYFRA21-1)],生活质量核心量表(QLQ-C30)评分,纤维化指标[透明质酸(HA)、层黏连蛋白(LN)、Ⅲ型前胶原(PCⅢ)],血清sE-cad、PDGF水平及治疗期间并发症发生率。结果治疗7周后,观察组疾病控制率95.24%,显著高于对照组的80.95%(P<0.05);观察组血清CEA、SCC-Ag、CYFRA21-1水平较对照组低(P<0.05);观察组QLQ-C30评分较对照组低(P<0.05);观察组血清HA、LN、PCⅢ水平较对照组低(P<0.05);观察组血清sE-cad、PDGF水平较对照组低(P<0.05);观察组并发症发生率较对照组低(P<0.05)。结论与3DCRT相比,采用IMRT治疗未分化型NPC可有效降低肿瘤标志物及血清sE-cad、PDGF水平,提高生活质量,疗效显著,且对正常组织影响更小,安全性高。

术前三维适形放射治疗对结肠癌的疗效及其对血小板参数的影响

目的:分析术前三维适形放射治疗(3DCRT)对结肠癌的疗效及对血小板(PLT)参数的影响。方法:选取医院收治的110例结肠癌患者,根据治疗方式不同将其分为对照组(62例)和观察组(58例),对照组给予常规放射治疗,观察组给予术前3DCRT治疗,对比两组放射治疗前后PLT参数指标,统计随访放射治疗后1~3年的局部控制率、生存率及治疗期间并发症发生率。结果:放射治疗后,两组患者PLT及其平均体积(MPV)均低于治疗前,差异有统计学意义(t观察组=7.407,t=5.733;t对照组=4.977,t=2.589;P<0.05)。放射治疗后,观察组PLT、MPV及降钙素原(PCT)值低于对照组,差异有统计学意义(t=2.256,t=4.165,t=2.737;P<0.05)。观察组随访1年、2年及3年的局部控制率及生存率均高于对照组,差异均有统计学意义(χ^(2)局部控制率=4.359,χ^(2)=3.944,χ^(2)=3.910;χ^(2)生存率=3.986,χ^(2)=4.270,χ^(2)=0.011;P<0.05)。两组患者治疗期间白细胞减少率、晚期并发症发生率及全身反应发生率比较,差异均无统计学意义(χ^(2)=0.187,χ^(2)=0.006,χ^(2)=0.011;P>0.05)。结论:术前3DCRT治疗结肠癌可获得更高的肿瘤切除率,可有效调节血小板参数,并明显改善局部控制率及生存率,放射治疗相关不良反应发生率较低,患者可耐受。

对比常规放疗与三维适形放射治疗(3D-CRT)乳腺癌的临床疗效、毒副作用

目的对比常规放疗与三维适形放射治疗(3D-CRT)乳腺癌的临床疗效、毒副作用。方法选定本院2018年1月至2021年1月住院的90例乳腺癌患者,以随机法将其分组(每组n=45),对比组给予常规放疗治疗,观察组给予3D-CRT治疗,对比两组局部复发率、血清肿瘤标志物、毒副反应总发生率,统计危及器官照射剂量。结果观察组局部复发率(2.22%)低于对比组(22.22%),P<0.05(差异有统计学意义)。观察组治疗后血清糖类抗原199(CA199)、糖类抗原125(CA125)、癌胚抗原(CEA)均低于对比组,P<0.05(差异均具有统计学意义)。观察组毒副反应总发生率(8.89%)低于对比组(28.89%),P<0.05(差异具有统计学意义)。患侧肺V20、患侧肺V30、患侧肺V40、患侧肺V50、左侧心脏V30、左侧心脏V40、左侧心脏V50、分别是(15.28±2.62)cm^(3)、(10.15±3.96)cm^(3)、(1.85±0.62)cm^(3)、(0.54±0.26)cm^(3)、(2.52±1.25)cm^(3)、(2.24±0.99)cm^(3)、(0.45±0.13)cm^(3)。结论3D-CRT可有效抑制乳腺癌患者肿瘤病灶生长,降低局部复发率、血清肿瘤标志物浓度,同时可减少危及器官照射剂量,减轻毒副反应。