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Objective:To investigate the clinical effect of stereotactic radiation therapy combined with sorafenib in the treatment of primary hepatic cancer (PHC).Methods:Ninety-two PHC patients admitted to Cancer Hospital of China Medical University from January 2017 to May 2018 were selected and divided into the observation group and the control group according to the random number table method, with 46 cases in each group. The control group was treated with stereotactic radiation therapy, and the observation group was treated with sorafenib on the basis of the control group. Clinical efficacy and incidence of adverse reactions in the two groups were compared; the scores of Karnofsky performance scale (KPS) and the levels of serum vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), hypoxia-inducing factor (HIF-1α), soluble interleukin-2 receptor (sIL-2R), transforming growth factor (TGF-β1) and alpha-fetoprotein (AFP) before and after the treatment between the two groups were compared. The overall survival (OS) of patients in both groups was recorded after 36 months of follow-up.Results:The total effective rate in the observation group was higher than that in the control group: 84.78%(39/46) vs. 65.22%(30/46), there was statistical difference ( χ2 = 4.70, P<0.05). After the treatment, the score of KPS in the observation group was higher than that in the control group: (85.06 ± 7.19) scores vs. (71.16 ± 7.08) scores; the levels of VEGF, bFGF, HIF-1α, AFP, TGF-β1, sIL-2R in the observation group were lower than those in the control group: (189.52 ± 31.47) ng/L vs. (235.81 ± 35.45) ng/L, (3.89 ± 0.97) ng/L vs. (6.74 ± 1.85) ng/L, (50.17 ± 6.09) ng/L vs. (53.07 ± 6.28) ng/L, (85.76 ± 14.09) μg/L vs. (131.51 ± 18.74) μg/L, (81.07 ± 12.96) μg/L vs. (106.58 ± 15.07) μg/L, (311.58 ± 74.81) kU/L vs. (405.97 ± 85.74) kU/L, there were statistical differences ( P<0.05). The results of 36 months follow-up showed that the 1-year and 3-year OS in the observation group were higher than those in the control group: 69.57% (32/46) vs. 58.70% (27/46), 43.47% (20/46) vs. 28.26 %(13/46), there were significant differences ( χ2 = 4.78, 3.94, P<0.05). Conclusions:Stereotactic radiation therapy combined with sorafenib can effectively improve the efficacy of PHC patients, reduce the expression of VEGF and bFGF, effectively inhibit tumor growth, but also prolong the survival time of patients, with both safety and high effectiveness, and good use value.
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Objective:To explore the efficacy of elective nodal irradiation (ENI) and involved field irradiation (IFI) combined with chemotherapy in treatment of esophageal cancer.Methods:A total of 104 patients with esophageal cancer in Affiliated Hospital of Jiangnan University from May 2018 to May 2020 were selected as subjects for prospective study. All patients were randomly divided into observation group and control group by lottery method with 52 cases in each group. The target volume of observation group was delineated with IFI, and the control group was delineated with ENI. The curative effects, the levels of serum tumor markers [carbohydrate antigen 50 (CA50), squamous cell carcinoma (SCC) and carcinoembryonic antigen (CEA)] before and after treatment, the 1-year overall survival (OS) rate, the incidence of adverse reactions and the scores of various dimensions of health survey summary (SF-36) after treatment were compared between the two groups.Results:The total effective rate in the observation group was 90.38% (47/52), the total effective rate in the control group was 84.62% (44/52), and the difference was not statistically significant ( χ2 = 0.79, P =0.374). There was no statistical difference in CA50, CEA, SCC levels between the two groups before and after treatment (all P > 0.05). After treatment, the CA50, CEA and SCC levels in the two groups were lower than those before treatment, and the differences were statistically significant (all P < 0.05). The 1-year OS rate of the observation group was 94.23%, the control group was 90.38%, and the difference in OS between the two groups was not statistically significant ( χ2 = 0.54, P = 0.462). The incidence of acute radiation esophagitis in the observation group was lower than that in the control group, and the difference was statistically significant ( P < 0.001). There was no statistical difference between the two groups in SF-36 scale scores of physical functioning, role-physical, bodily pain, mental health, vitality, social functioning, role-emotional, and general health after treatment (all P > 0.05). Conclusions:Both ENI and IFI are effective treatments for patients with esophageal cancer. There is no significant difference in the quality of life of patients between the two delineation methods, but the incidence of acute radiation esophagitis is lower in patients with IFI regimen.
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Objective:To investigate the efficacy and safety of camrelizumab combined with stereotactic body radiation therapy (SBRT) in the treatment of advanced oligometastaticnon-small cell lung cancer (NSCLC).Methods:Eighty-six patients with advanced oligometastatic NSCLC who met the inclusion and exclusion criteria from March 2020 to August 2021 in the Second People′s Hospital of Yibin were divided into the control group (43 cases) and the treatment group (43 cases) according to the random number table method, the control group was given camrelizumab combined with conventional radiotherapy, and the treatment group was given camrelizumab combined with SBRT. After 8 weeks of treatment, the efficacy of the two groups was evaluated, the occurrence of side effects in the two groups was counted, the serum tumor markers [carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC-Ag), cytokeratin 19 fragment anti-21-1 (CYFRA21-1)] levels were detected.Results:The objective effective rate of the treatment group was significantly higher than that of the control group:: 72.09% (31/43) vs. 51.16%(22/43), the difference was statistically significant ( P<0.05); the incidence of radiation pneumonia in the treatment group was significantly lower than that in the control group: 4.65% (2/43) vs. 18.60% (8/43), the difference was statistically significant ( P<0.05), and there was no significant difference in the incidences of other side effects such as cutaneous capillary endothelial proliferation (CCEP), liver damage, hypothyroidism, and radiation esophagitisbetween the treatment group and the control group ( P>0.05); the levels of serum CEA, SCC-Ag, CYFRA21-1after treatmentin the two groups were significantly lower than those before treatment, treatment group: treatmentgroup: (8.81 ± 4.82) ng/L vs. (81.67 ± 50.88) ng/L, (1.13 ± 0.55) ng/L vs. (1.56 ± 1.03) ng/L and (2.92 ± 0.99) ng/L vs. (4.63 ± 1.39) ng/L, controlgroup: (30.49 ± 19.44) ng/L vs. (89.91 ± 50.10) ng/L, (1.56 ± 1.23) ng/L vs. (1.86 ± 1.33) ng/L and (4.01 ± 2.10) ng/L vs. (5.03 ± 3.44) ng/L. and the levels after treatment in the treatment group were significantly lower than those in the control group, and there were statistical differences ( P<0.05). Conclusions:Camrelizumab combined with SBRT treatment for patients with advanced oligometastatic NSCLC can effectively reduce the levels of serum CEA, SCC-Ag, CYFRA21-1, and significantly improve the short-term efficacy, with relatively low incidence of toxic side effects.
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Objective To make a cost-effectiveness analysis for stereotactic radiotherapy and intensity-modulated radiotherapy using linear accelerators against malignant tumors, then to provide references for choosing a more cost-effective radiotherapy for the patient. Methods Basic information of patients subject to radiotherapy(gender, age, date of admission, days of hospital stay), hospitalization cost, admission diagnosis, clinical outcomes among others of 320 patients with malignant tumors(lung tumor, head and neck tumor, bone metastases, liver tumor) were collected from Hubei, Guangxi and Fujian provinces. The cost of hospitalized radiotherapy and treatment effect of these patients were compared to identify the more cost effective of the two methods. Results The effective rates of stereotactic radiotherapy and intensity-modulated radiotherapy were 99.1% (108/109) and 97.2% (205/211) respectively, and the difference was not significant( P>0.05). The average hospitalization cost of treatment of the two groups was 37 545.56 yuan and 48 159.05 yuan respectively; the cost-effectiveness ratio was 37 886.54 and 49 546.35 respectively. Conclusions The short-term effects of stereotactic and intensity-modulated radiotherapy are similar, but the cost of intensity-modulated radiotherapy is higher. The minimum cost analysis shows that stereotactic radiotherapy is more cost effective.
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Objective To explore the clinical effect of concurrent radiotherapy and chemotherapy in the treatment of advanced cervical cancer.Methods From January 2010 to January 2011,sixty patients with cervical cancer in Taizhou Cancer Hospital were randomly divided into two groups ,with 30 cases in each group.The control group was given radiotherapy alone ,the observation group was given concurrent radiotherapy and chemotherapy .The adverse reaction,curative effect,long -term effect of 5 -year follow -up were compared between the two groups. Results The total effective rate of the observation group was 93.33%,which was significantly higher than 73.33%of the control group,the difference was statistically significant (χ2＝14.397,P＜0.05).The 5-year survival rate of the observation group was 76.67%,which was significantly higher than 53.33% of the control group,the difference was statistically significant ( χ2＝11.922,P ＜0.05).The local recurrence rate and distant metastasis rate of the observation group were 16.67%,13.33%,respectively,which were significantly lower than those of the control group , the differences were statistically significant (χ2＝7.401,5.115,all P＜0.05).The incidence rate of adverse reaction of the control group was 13.33%,which of in the observation group was 23.33%,the difference was not statistically significant(χ2＝3.340,P ＞0.05).Conclusion The efficacy of concurrent radiotherapy and chemotherapy for patients with advanced cervical cancer is better ,and the survival rate of patients with advanced cervical cancer is better.
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Objective To investigate the safety and efficacy of re-irradiation with stereotactic body radiotherapy(SBRT) for treating locally recurrent advanced pancreatic cancer.Methods From 2014 to 2017,7 patients with stage Ⅲ pancreatic cancer were treated by re-irradiated with SBRT at Shanghai Changhai Hospital.SBRT was delivered via the G4 type cyberknife robotic stereotactic radiosurgery system in all the patients.The median dose of the first SBRT was 35Gy/5-7 fx,and the median dose of re-irradiation with SBRT was 31 Gy/5-8 fx.6 patients had undergone sequential chemotherapy either with gemcitabine or S-1 based therapy except one patient who refused the chemotherapy.Results There were 5 male and 2 female patients.The median overall survival (OS) of 7 patients was 30 months.Patients were re-irradiated with SBRT after a median interval of 10 months after the first SBRT.Median OS and locally relapse-free survival (LFRS) from re-irradiation were 13 months and 11 months,respectively.Three months after re-irradiation,3(42.9％) patients had partial remission and 4 patients had stable disease.Pain disappeared in 4 patients at the end of reirradiation and significant pain was alleviated in 2 patients 1 month after re-irradiation.There were no toxicities of grade 3 or higher grade during two courses of SBRT.Conclusions For patient with locally recurrent advanced pancreatic cancer,SBRT re irradiation regimen was associated with acceptable toxicity,which can effectively alleviate the pain,prolong the survival and improve the life quality.
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Objective To analyze the setup errors by cone-beam computed tomography (CBCT) for breast cancer patients who were immobilized with neck and breast thermoplastic mask and received intensity modulated radiation therapy (IMRT), and to calculate the external margins from the clinical target volume (CTV) to the planning target volume (PTV) (MPTV) of tumors. Methods Twenty-five breast cancer patients who were immobilized with neck and breast thermoplastic mask and received IMRT in the Oncology Department of Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from November 2016 to June 2017 were enrolled. The position of the patients were verified by CBCT before treatment . The linear and rotation errors of the X, Y and Z axes were analyzed by online bone registration. The systematic errors (Σ) and random errors (σ) of the patients were also calculated, and then the margins from CTV to PTV margins were calculated based on MPTV=2.5Σ+0.7σ. 25 patients'height, weight, body mass index (BMI) and the maximum diameters of CTV in the lateral, longitudinal and vertical directions were recorded, and the relation between the setup errors and the above mentioned was analyzed by using Spearman method. Results A total of 174 CBCT scans for 25 breast cancer patients were completed. The group Σ were 1.40 mm, 1.50 mm and 1.20 mm, and rotation errors were 0.9°, 0.7° and 0.8° at the X, Y and Z axes, respectively. The group σ were 2.20 mm, 3.00 mm and 1.40 mm, and rotation errors were 0.7°, 0.6° and 0.7° at the X, Y and Z axes, respectively. MPTVwas recommended as 4.90 mm, 6.00 mm and 3.90 mm at the X, Y and Z axes, respectively. There was no correlation between the height, weight, BMI of the patients and the setup errors (all P ＞ 0.05). However, there was a significant correlation between the maximum lateral, longitudinal diameters of the CTV and the setup errors (rs= 0.406, P= 0.044; rs= 0.512, P= 0.009). Conclusions The neck and breast thermoplastic mask can improve the diagnostic accuracy of radiotherapy in breast cancer patients. The data of setup errors verified by CBCT can provide meaningful references for the setting of MPTV.
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Objective To compare the application values and setup errors between vacuum bag plus body mask and customized alpha cradle duringproton and carbon therapy using Siemens 6D robotic couch in prostate cancer patients.Methods Nineteen patients received vacuum bag plus body mask setup were allocated into the vacuum bag group andl9 patients with alpha cradle were assigned into the alpha cradle group.Orthogonal X-ray portals were performed to verify the treatment position before beam delivery in every fraction.The couch correction between the portal and reference DRR through manual image registration was recorded as setup errors in 6 directions including the lateral,supine-inferior,anterior-posterior,yaws,roll and pitch,respectively.Two-tail t-test was used to analyze the setup error data from each direction between two groups.Results In total,452 and 436 sets of data errors were collected from the vacuum bag and alpha cradle groups.The average setup errors and standard deviation in the vacuum bag and alpha cradle groups in the lateral,supine-inferior,anterior-posterior,yaws,roll and pitch directions were (0.63±0.48) cm vs.(0.33±0.24) cm (P=0.000),(0.40±0.3) cm vs.(0.31±0.25) cm (P=0.000),(0.69±0.61) cm vs.(0.82±0.69) cm (P=0.006),0.65°±0.47°vs 0.32°±0.25°(P=0.000),1.05°±0.95°vs 1.16°±0.94° (P=0.100) and 0.67°±0.56°vs 0.40°±0.36° (P=0.000),respectively.The maximum setup errors were detected in the pitch direction for both groups.Conclusions During the proton and carbon therapy using Siemens 6D robotic couch,two setup methods using vacuum bag plus body mask and customized alpha cradle should be selected according to the individual conditions of patients.A customized foot fixer should be utilized to reduce the uncertainty in the femoral head region.
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Objective To evaluate the clinical application of Catalyst system in patient positioning during breast cancer radiotherapy,and to analyze its correlation with age and body mass index (BMI).Methods Twenty-four patients with breast cancer who were admitted to our hospital from May to August,2016 were enrolled as subjects.For all patients,auxiliary positioning was made by the optical surface imaging system (CRad Catalyst) before each treatment.The kV-kV imaging was executed weekly to verify positioning.Age,BMI,and setup errors of the two systems in the anterior-posterior (AP),superior-inferior (SI),and left-fight (LR) directions were recorded and analyzed by independent samples t-test and Pearson correlation analysis.Results The C-Rad Catalyst system had a significantly larger setup error in the AP direction than the kV-kV imaging (0.22±0.17 vs.0.18±0.13 cm,P＜0.05).There were no significant differences in setup errors in the SI or LR direction between the two systems (0.23±0.18 vs.0.19±0.15 cm,P＞0.05;0.28±0.28 vs.0.20±0.15 cm,P＞ 0.05).Age and BMI of patients had significant impacts on the C-Rad Catalyst system but the kV-kV imaging (P＞0.05):there were significant differences in setup errors in the AP and SI directions between patients ≤44 years of age and those 45-59 years of age (all P＜0.05);there were significant differences in setup errors in the AP and LR directions between patients ≤44 years of age and those ≥60 years of age (all P＜0.05);there was a significant difference in setup error in the LR direction between patients 45-59 years of age and those ≥ 60 years of age (P＜0.05);there was a significant difference in setup error in the SI direction between patients with BMIs of＜ 25 and ≥ 25 kg/m2 (P＜ 0.05).For patients ≥ 60 years of age,setup error of the C-Rad Catalyst system in the SI direction was correlated with age (r=-0.496,P＜0.05).For patients with BMI of＜25 kg/m2,setup error of the C-Rad Catalyst system in the AP direction was correlated with BMI (r=-0.445,P＜ 0.05).For patients with a BMI of ≥ 25 kg/m2,setup error of the C-Rad Catalyst system in the SI direction was correlated with BMI (r=-0.252,P＜0.05).Conclusions There is significant difference in setup error in the AP direction between the C-Rad Catalyst system and the kV-kV imaging.Age and BMI have impacts on patient positioning by the C-Rad Catalyst system.
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Objective@#To investigate the potential dosimetric benefits of four-dimensional computed tomography (4DCT) compared to three-dimensional CT (3DCT) in the planning of radiotherapy for external-beam partial breast irradiation (EB-PBI).@*Methods@#Three-DCT and 4DCT scan sets were acquired for 20 patients who underwent EB-PBI. For each patient a conventional 3D conformal plan (3D-CRT) was generated based on end-inhalation phase (EI). The treatment plan based on the 4DCT EI phase images was copied and applied to the end-exhalation phase (EE) and 3DCT images (defined as EB-PBIEI, EB-PBIEE, EB-PBI3D, respectively).@*Results@#The median volumes of the tumour bed based on 3DCT, EI and EE were 20.99 cm3, 19.28 cm3, and 18.78 cm3, respectively. The tumour bed volume based on 3DCT was significantly greater than that of EI and EE volumes (P<0.05). The planning target volumes (PTV) coverage of EB-PBI3D, EB-PBIEI and EB-PBIEE were 96.85%, 97.51%, 97.03%, respectively. The planning target volume (PTV) coverage of EB-PBI3D was significantly less than that of EB-PBIEI and EB-PBIEE (P<0.05). The median homogeneity indexs (HI) based on 3DCT, EI and EE were 0.13, 0.13, 0.13, respectively. The median conformal indexs (CI) based on 3DCT, EI and EE were 0.68, 0.69, 0.68, respectively. The median mean doses (Dmean) based on 3DCT, EI and EE were 36.20 Gy, 36.20 Gy, 36.22 Gy, respectively. However there were no significant differences in the homogeneity index, conformity index and the mean dose of PTV between the three treatment plans (P>0.05). The EB-PBI3D plan resulted in the largest organs at risk dose (P<0.05).@*Conclusion@#There was a significant benefit when using 4DCT to plan 3D-CRT for EB-PBI with regard to reduced non-target organ exposure, and might result in poor dose coverage when the PTV is determined using 3DCT.
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Objective To evaluate the performance of progressive optimization algorithm-based Auto-Planning module in automated volumetric-modulated arc therapy(VMAT)planning for nasopharyngeal carcinoma. Methods Thirteen treated VMAT plans of nasopharyngeal carcinoma were re-planed with Auto-Planning module. Only one cycle of automated optimization of the Auto-Planning module was performed for each plan without any manual intervention. The dosimetric parameters of the automated treatment plans were compared with those of the manual plans. Paired t-test was used for statistical analysis. The time required for automated planning using the Auto-Planning module was also measured. Results All plans generated with the Auto-Planning module met the routine dosimetric requirements and were acceptable for clinical use. The homogeneity index of targets was superior in the automated plans than in manual plans(P= 0.000).In addition,the automated plans had significantly improved protection for some organs at risk than the manual plans. The mean dose to the left and right parotids were reduced by 7.75 Gy(P=0.000)and 5.79 Gy(P=0.000)in the automated plans,respectively. Furthermore,the V60(0.58% vs. 3.12%,P=0.000)and Dmean(34.11 Gy vs. 40.78 Gy,P= 0.000)of the mandible were also significantly lower with Auto-Planning than with manual planning. Conclusions Auto-Planning module can improve the overall quality and consistency of treatment plans,and reduce the workload and time of treatment planning,resulting in substantially enhanced treatment planning efficiency.
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Objective To explore a desirable therapeutic regimen,which is effective,reasonable and practicable for locally advanced nasopharyngeal cancer (LA-NPC) patients in the era of IMRT,with a potential of translating into survival improvement of these patients.Methods Patients presented with stage Ⅲ-Ⅳ B,WHO type Ⅱ or Ⅲ NPC were randomly assigned to receive concurrent chemoradiotherapy (CCRT group) (45 cases) or induction chemotherapy plus radiotherapy alone (IC + RT group) (43 cases),with random number table.IMRT and rapid arc planning were generated in the same treatment planning system for all patients.These two arms received docetaxel plus cisplatin for first cycle of chemotherapy,and cisplatin only for the second cycle.Results Forty-five patients received CCRT and 43 received IC + RT.All the patients completed two cycles chemotherapy.Compared to the CCRT group,the incidence rate of grade 2-4 leukopenia was lower in IC + RT group[67.4 ％ (29/43) vs.86.7 ％ (39/45),x2 =4.628,P =0.031],while the incidence rate of dermatitis,mucositis,neutropenia and fungal infection of oral cavity had no significant differences (all P ＞ 0.05).The tumor response rate (95.3 ％ vs.100.0 ％,P =0.236),2-year overall survival rate (95.5 ％ vs.94.2 ％,P =0.627),2-year progression free survival rate (94.6 ％ vs.88.6 ％,P =0.303),2-year local recurrent free survival rate (97.3 ％ vs.95.5 ％,P =0.951),2-year regional recurrent free survival rate (94.7 ％ vs.96.2 ％,P =0.949),and 2-years distant metastasis free survival rate (93.7 ％ vs.91.5 ％,P =0.454) of the two groups were similar while comparing CCRT to IC + RT group.Conclusion Combined IMRT with TP/DDP regimen,the efficacy of IC + RT is similar to CCRT for LA-NPC.The IC + RT group has less severe leukopenia than CCRT group,which is worth further study.
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Based on the assumption that apparent diffusion coefficients (ADCs) define high-risk clinical target volume (aCTVHR) in high-grade glioma in a cellularity-dependent manner, the dosimetric effects of aCTVHR-targeted dose optimization were evaluated in two intensity-modulated radiation therapy (IMRT) plans. Diffusion-weighted magnetic resonance (MR) images and ADC maps were analyzed qualitatively and quantitatively to determine aCTVHR in a high-grade glioma with high cellularity. After confirming tumor malignancy using the average and minimum ADCs and ADC ratios, the aCTVHR with double- or triple-restricted water diffusion was defined on computed tomography images through image registration. Doses to the aCTVHR and CTV defined on T1-weighted MR images were optimized using a simultaneous integrated boost technique. The dosimetric benefits for CTVs and organs at risk (OARs) were compared using dose volume histograms and various biophysical indices in an ADC map-based IMRT (IMRTADC) plan and a conventional IMRT (IMRTconv) plan. The IMRTADC plan improved dose conformity up to 15 times, compared to the IMRTconv plan. It reduced the equivalent uniform doses in the visual system and brain stem by more than 10% and 16%, respectively. The ADC-based target differentiation and dose optimization may facilitate conformal dose distribution to the aCTVHR and OAR sparing in an IMRT plan.
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Humans , Contrast Media , Gadolinium , Glioma/radiotherapy , Magnetic Resonance Imaging/methods , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Intensity-Modulated/methods , Tumor BurdenABSTRACT
PurposeTo perform a quality assurance program for Truebeam imaging system using MIMI phantom, and to evaluate the accuracy of the imaging system center with the radiation isocenter and the accuracy of couch shift.Materials and Methods The reference images of MIMI phantom were acquired using CT scanner. The reference images were imported into the treatment planning system and a simple plan was created. The MIMI phantom was placed on the treatment couch. The images were acquired using the MV/KV imaging system, and a match registration was performed with the reference images from the TPS.Results Measured over six months, the precision of the imager and linac's isocenter was <1 mm, and the couch shift accuracy was <1 mm. The measurements over six months demonstrate that isocenters of the MV/KV imaging systems on Truebeam system are stable.Conclusion The accuracy of the Truebeam imaging system center and couch shift is safe and reliable. The error of Truebeam imaging system center and couch shift can be tested on a monthly base.
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Intensity modulated radiation therapy(IMRT)has become the mainstay of treatment modal-ity for nasopharyngeal carcinoma(NPC). The whole treatment course generally continues 7 to 8 weeks. With the radiotherapy proceeding,the patients exhibit oropharyngeal reaction aggravating,weight losing and tumor shrinking,resulting in the changes of tumor target and surrounding tissue. Those changes may influence the dose distribution of tumor and organ at risk. It is necessary to modulate target volume during radiotherapy of NPC.
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Objective To evaluate the effect of an equivalent uiform dose optimization (EUD) based optimization algorithm in sparing the organ at risk (OAR) of tumor treated with intensity-modulated radiation therapy (IMRT).Methods 10 patients of nasopharyngeal carcinoma (NPC),10 patients of esophagus cancer,6 patients of rectum cancer were randomly selected from all patients received IMRT treatment.Then physical optimization constraints (dose/dose-volume constraints) were designed as EUD optimization,while the physical objectives for targets and other OAR were unchanged.Results There was statistically significant difference in protecting OAR in 8 NPC patients of PLANED group compared with those of PLANNO_EuD group (t values were 2.590,2.352,3.656,2.148,2.283,3.683,2.192,2.353,2.146,2.276,2.126,P ＜ 0.05).There was no statistically significant difference in protecting OAR in 10 cases of esophageal cancer between PLANEUD group and PLANNO_EUD group (t value were 0.408,0.427,0.920,P ＞ 0.05).There was statistically significant difference in protecting OAR in 6 cases of rectum cancer of PLANED group compared with those of PLANNO_EUD group (t values were 2.332,2.693,2.279,2.244,P ＜ 0.05).Conclusion EUD optimization can reduce the doses to OAR which may be quite helpful to reduce the occurrence rate of OAR complications.
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Objective To investigate the range of inter-fraction and intra-fraction motion of crystalline lens in radiotherapy. Methods The CT and MRI images of 17 patients were registered, and the profile of crystalline lens was delineated to determine the respective center coordinates, thus simulating and analyzing inter-fraction and intra-fraction motion of lens in radiotherapy. Results Both left and right lens moved in different degree during both interor intra-fraction phase. The range of lens movement was larger in inter-fraction than in intra-fraction phase in all directions. Conclusion When radiotherapy is given in the free state, considering the distance of lens movement alone in inter- and intra-fraction and without considering the setup error, the lens planning organs at risk should increase l.5mm outside the lens boundary.
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Objective To study the effect of labeling esophageal carcinoma with sliver clips on two sides by esophagoscopy in mapping the target for conformal radiotherapy (CRT). Methods Eighty patients with esophageal carcinoma (28 patients in early stage, 52 patients in late stage), who were eligible for CRT, were collected and the tumor volume was detected by three methods: CT (A),CT combined with X-ray (B) and CT combined with sliver clip labeling by esophagoscopy (C). The differences of the tumor length and position in head-foot site (Y-axsis) among three methods were compared. Results The comparison of average length of tumor in early stage patients showed significant difference among three methods in all types of tumor (F= 4.07 ～ 7.43, P＜0.05 ) except papillary type (F= 1. 71, P＞0. 05). There was difference (ranged from 0. 5 cm to 2. 0 cm) in detection of position in head-foot site between A and B methods and C method. Significant difference was found in determining the displacement on head-foot site among three methods (F = 34. 36 ～193.50,P ＜0.01). The comparison of average length of tumor in middle or terminal stage patients showed significant difference among three methods in all types of tumor (F=4. 07～30.10 ,P＜0.05) except mushroom type (F = 2.44, P＞ 0. 05). Significant difference was found in determining the displacement on head-foot site among three methods (F= 12.00 ～ 21.16, P ＜ 0. 01 ). Conclusion These findings indicate that C method is more sensitive and correct in mapping the target for CRT in comparison with other two methods.
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Objective To study the spatial distribution of set-up errors for cervical cancer with intensity modulated radiation therapy (IMRT) and to provide referential safety margin out of clinical tumor volume (CTV) during treatment plan design. Methods Six patients with cervical cancer were treated with IMRT in prone position, belly board and thermoplastic cast was used for immobilization. Measurement were made on a daily basis setup under five consecutive treatments with electron portal images device (EPID).Portal films from two projection (one anter-posterior and one opposite lateral)were taken. Sixty portal films were analyzed. The translational and rotational deviations were analyzed by registering and comparing the bony structures of EPID and digitally reconstructed radiographs (DRR). Results The translational deviations were (3.1 ±1.8) mm, (3.9 ±3.3) mm, (4.2 ±2.6) mm in medi-lateral, cranio-caudal and anterior-posterior directions, the rotational deviations were in coronal plane (0.8±0.9)° and sagittal plane (1.2±1)°. Conclusion For the patients with cervical cancer undergoing IMRT, the margins between the CTV and PTV should be 7.1 mm in lateral direction, 10.4 mm in cranio-caudal and 10.8 mm in anterior-posterior directions. The sign on patients body can help to reduce the setup errors.
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The intensity-modulated radiation therapy (IMRT) planning strategies for nasopharyngeal cancer among Korean radiation oncology facilities were investigated. Five institutions with IMRT planning capacity using the same planning system were invited to participate in this study. The institutions were requested to produce the best plan possible for 2 cases that would deliver 70 Gy to the planning target volume of gross tumor (PTV1), 59.4 Gy to the PTV2, and 51.5 Gy to the PTV3 in which elective irradiation was required. The advised fractionation number was 33. The planning parameters, resultant dose distributions, and biological indices were compared. We found 2-3-fold variations in the volume of treatment targets. Similar degree of variation was found in the delineation of normal tissue. The physician-related factors in IMRT planning had more influence on the plan quality. The inhomogeneity index of PTV dose ranged from 4 to 49% in Case 1, and from 5 to 46% in Case 2. Variation in tumor control probabilities for the primary lesion and involved LNs was less marked. Normal tissue complication probabilities for parotid glands and skin showed marked variation. Results from this study suggest that greater efforts in providing training and continuing education in terms of IMRT planning parameters usually set by physician are necessary for the successful implementation of IMRT.