The impact of image-guided radiation therapy on treatment of cervical cancer / 中华放射肿瘤学杂志

Objective:To evaluate the effect of radical image-guided radiotherapy (IGRT) on the target dose in cervical cancer and investigate the appropriate application mode.Methods:Twenty patients with cervical cancer treated with helical tomotherapy (HT) in Seventh Medical Center of PLA General Hospital from 2012 to 2016 were selected. A megavoltage CT (MVCT) scan was performed before each treatment. The obtained MVCT images were used for dose parameter in the adaptive module of HT to obtain the actual dose (Plan 1) and the non-image-guided dose parameter was simulated (Plan 2). Each single dose distribution and the corresponding fused CT images were transferred to the software Mimvista 6.5 to obtain the total radiation dose parameter by dose superposition.Results:The motion of CTV, uterus and GTV in Plan 2 was significantly larger than that of Plan 1(all P<0.05), and the largest changes were seen in the ventrodorsal and uterine direction. The V 45Gy, V 50Gy, D 98% and D mean of CTV and uterus and V 50Gy of GTV in Plan 2 were significantly decreased compared with those in Plan 1(all P<0.05). The left-right motion of Plan 1 was negatively correlated with D 2% and D 98% of CTV and uterus (both P<0.05). The head-foot motion was negatively associated with V 45Gy and V 50Gy of GTV (both P<0.05). The ventrodorsal motion was negatively correlated with D 98% of uterus ( P<0.05). The left-right motion of Plan 2 was negatively correlated with D 2% of CTV and V 50Gy of uterus (both P<0.05). The head-foot motion was negatively associated with D 98% of CTV, and D 98%, D mean, V 45Gy and V 50Gy of uterus (all P<0.05). The ventrodorsal motion was negatively correlated with D 98% of CTV, D 98%, D mean, V 45Gy and V 50Gy of uterus, and D mean and V 45Gy of GTV (all P<0.05). Conclusions:In intensity-modulated radiotherapy for cervical cancer, the uterine body displacement is large and the low CTV area is mainly located in the uterine body. IGRT can significantly reduce the dosimetric deviation induced by organ movement.

Dosimetry study of fourtypes of radiotherapy plan optimization methods in the hypofractionated radiotherapy for lung cancer / 中华放射肿瘤学杂志

Objective To discuss the dosimetric differences in the planning methods between physical and biological optimization during thehypofractionated radiotherapy for lung cancer.MethodsTen cases of non-small cell lung cancer (NSCLC) receiving radiotherapy were selected in this retrospective study.The VMAT plans for all patients were re-designed by physical functions (DV group),biological combined with physical functions (DV+EUD group and EUD+DV group) and biological functions (EUD group).The constrained functions were different,whereas the constrained conditions and optimized parameters were identical among four groups.The dosimetric differences among four optimization methods during thehypofractionated radiotherapy for lung cancer were evaluated through calculating and analyzing each dosimetry parameter.Results For the target area,the equivalent uniform dose was approximate between the EUD and EUD+DV groups.The EUD in these two groups was approximately 2.8％-3.6％ and 3.2％-3.7％ higher than those in the DV and DV+EUD groups.The average tumor control probability (TCP) in the EUD and EUD +DV groupswas considerably higher than those in the other two groups (both P＜0.05).The homogeneity index (HI) significantly differed (all P＜0.05),whereas the conformity index (CI) did not differ (all P＞0.05).For the organ at risk (OAR) area,the differences of EUD,V5,V1o,V20,V30 of normal lung tissues and the difference of dosimetry parameters in heart and spinal cord were not statistically significant (all P＞0.05).The mean dose of all lungs in the EUD and EUD+DV groupswas slightly lower than those in the other two groups.ConclusionsBiological optimization method has certain advantages in increasing EUD and TCP in the target area and decreasing the irradiation dose of normal lung tissues,which provides references for selecting the optimization method with biological functions in clinical practice.

Impacts of bladder and rectum filling status on their dosimetric parameters in helical tomotherapy for cervical cancer / 中华放射肿瘤学杂志

Objective To analyze the changes in volume and the planning volume of the bladder and rectum during helical tomotherapy (HT) treatment for cervical cancer,and to evaluate the impacts of bladder and rectum filling on their dosimetric parameters.Methods Twenty patients with cervical cancer who received HT in our hospital from 2012 to 2016 were enrolled as subjects.Before treatment,megavolt computed tomography (MVCT) and registration of planning CT images were preformed to recalculate the dose distribution,delineate the target volume,and measure the volume and position of the bladder and the rectum.Each MVCT image and the corresponding single dose were obtained by dose reconstruction using the Planned Adaptive module in HT planning workstation.The fused MVCT images and the corresponding single dose for each MVCT were loaded to MIM Maestro software 6.0 for dose stacking.The obtained total radiation dose was compared with that obtained by kilovolt CT.Between-group comparison was made by paired t-test or analysis of variance.Results If the volume change in the bladder was more than 400 ml or the rate of volume change was higher than 60％,the displacements of the bladder centroid toward the foot and dorsal sides were significantly increased;the Dmean and V50 were significantly increased (P＜0.05).If the volume change in the rectum was more than 30 ml or the rate of volume change was higher than 30％,the displacements of the rectum centroid toward the head and ventral sides were significantly increased;the V45 and V50 for the rectum were significantly increased (P＜0.05).Conclusions Although the bladder filling status has little effect on the radiation dose to the bladder,the volume change or the rate of volume change should be no more than 400 ml or 60％,respectively.Moderately filled bladder is recommended for positioning and treatment,which achieves satisfactory repeatability of the treatment.A volume change of more than 30 ml or a rate of volume change of higher than 30％ can result in an increase in the dose to the rectum.Empty rectum can effectively reduce the dose to the rectum.

Effect of image guidance on doses to the rectum and bladder in radiotherapy for cervical cancer / 中华放射肿瘤学杂志

Objective To analyze the effect of image guidance on the doses to the rectum and bladder in radical external beam radiotherapy for cervical cancer, and to investigate the reasonable application mode of image-guided radiotherapy (IGRT) in the treatment of cervical cancer. Methods A total of 20 patients with cervical cancer who underwent helical tomotherapy(HT) in PLA Army General Hospital from 2012 to 2016 were enrolled in this study. A megavoltage computed tomography(MVCT) scan was performed before each treatment. The obtained MVCT images were used for dose reconstruction in the adaptive module of HT to obtain the actual dose (Plan-1) and the non-image-guided dose was simulated (Plan-2). Each single dose distribution and the corresponding fused CT image were sent to the software MIM 6.0 to obtain the total radiation dose by dose superposition. The radiation doses and volumes of the rectum and bladder were compared between the two therapeutic plans. Results The radiation doses to the rectum and bladder in Plan-2 were significantly higher than those in Plan-1. There were significant differences in Dmaxand V50of the rectum and V50of the bladder between Plan-1 and Plan-2(P=0.040;P=0.000;P=0.047). Compared with Plan-1, there were statistical differences in inter-fractional Dmaxand V50during the initial treatment (P=0.047,0.037), and V50of the rectum within the 13thto 21stradiotherapy, respectively (P=0.009, 0.017, 0.028). Besides, differences regarding Vmaxand V50in the initial treatment and the 21stto 23rdradiotherapy were close to the statistical significance when compared to those in Plan-1, respectively (P= 0.061,0.053; P= 0.072,0.058). Conclusions IGRT can reduce the radiation doses and volumes of the rectum and bladder, especially the rectum. The therapeutic plan should be rescheduled when tumor retraction is evident at half of the total radiation dose (around 13thfraction) in external beam radiotherapy. If it is difficult to achieve image guidance in each treatment,selective image guidance could be performed to effectively reduce the injuries of the rectum and bladder.

Margins of planning target volume in cervix cancer with tomotherapy / 中华放射医学与防护杂志

Objective To determine the margins of planning target volume (MPTV) in primary cervical cancer patients with tomotherapy and evaluate the importance of automatic registration(AR) plus manual registration.Methods The setup errors of 29 primary cervical cancer patients receiving external radiation from June 2012 to Dec 2014 were measured by megavoltage computed tomography (MVCT),which were performed at least two times weekly before treatment and were registered with the planning CT.The setup errors between automatic registration and total shift (TS) including both AR and manual registration were compared MPTV was calculated.Results Setup errors were collecte from 443 sets of MVCT in 29 patients.AR and total shift (TS) values in the x,y,z directions and rotation angle were (-0.9±2.3),(0.0±3.1),(1.0±2.6) mm,0.2° ±0.8° and (-0.8±1.8),(-0.4±3.4),(l.4 ± 2.5) mm,0.1° ± 0.5°,respectively.There were statistically significant differences between the two groups in all directions except for the x axis (t =5.1,-5.2,3.2,P ＜ 0.05).MPTV were 4.6,5.7,3.3 mm in the x,y,z directions,respectively.Conclusions Manual registration is necessary after automatic registration in cervical cancer patients with tomotherapy.For patients with cervical cancer treated by tomotherapy,planning target volume MPTV parameters are suggested to be 5,6,4 mm in the x,y,z directions.

A dosimetric study of helical tomotherapy for nasopharyngeal carcinoma / 中华放射肿瘤学杂志

Objective To use helical tomotherapy ( HT ) for determining the difference between actual doses and planning doses to the target volume and organs at risk ( OARs ) in patients with nasopharyngeal carcinoma receiving radiotherapy, and to provide guidance for the clinical treatment. Methods Localization and delineation of the target volume and OARs were performed by computed tomography ( CT) in 21 patients with nasopharyngeal carcinoma receiving radical radiotherapy using HT. All patients underwent megavoltage CT ( MVCT) scan prior to treatment. The obtained MVCT images were used for dose reconstruction in the adaptive module of HT, in which the actual dose was obtained and the non?image?guided dose was simulated. Each single dose distribution and the corresponding CT image were sent to software MIM6. 0 for superimposition, and the overall dose was obtained. The initial plan, image?guided plan, and non?image?guided plan were named Plan?1, 2, and 3, respectively. The dose distribution in the target volume and OARs was compared between the three plans with t ? test or wilcoxon test . Results Compared with those in Plan?1, the D98 values for the planning gross tumor volume ( PGTV) and planning target volume ( PTV) in Plan?2 were significantly reduced by 1. 16% and 2. 3%, respectively ( P=0. 025;P=0. 043);the volumes of the left and right parotids in Plan?2 were significantly reduced by 46. 0% and 46. 5% on average, respectively ( P=0. 000);the distances between the midline and the center?of?mass for left and right parotids were significantly reduced by 6. 9% and 6. 5%, respectively ( P=0. 000);the V26 and Dmean for both parotid glands were significantly elevated by 32. 8% and 25. 2%, respectively ( P=0. 000) . Compared with those in Plan?1, the D98 values for PGTV, PTV?1, and PTV?2 in Plan?3 were significantly reduced by 2. 0%, 1. 9%, and 2. 4%, respectively ( P=0. 001;P=0. 007;P=0. 036);the V26 and Dmean for both parotid glands in Plan?3 were significantly elevated by 33. 6% and 25. 3%, respectively ( P=0. 000);Dmax to the spinal cord was significantly increased by 6. 9%( P=0. 005) . There was no significant difference in D2 to the spinal cord between Plan?2 and Plan?1( P=0. 392) . Conclusions The doses to both parotid glands increase during HT for nasopharyngeal carcinoma, which is closely associated with the shift of the parotid glands toward the midline. Image?guided radiotherapy does not enhance the dose to the target volume, but reduces the dose to the spinal cord.

The study on short-time therapeutic effect and adverse reaction observation of TOMOX regimen combined with three dimensional conformal radiotherapy for middle and advanced esophageal cancer / 中国医学装备

Objective:To explore the efficacy and adverse reaction of TOMOX regimen combined with three dimensional conformal radiotherapy in the treatment of middle and advanced esophageal cancer. Methods:51 cases of hospitalized patients with esophageal cancer were selected from January 2013 to December 2015 in our hospital who were divided into observation group (n=27) and control group (n=24) by random number table method. The control group was treated with three dimensional conformal radiotherapy, and the observation group was added with the TOMOX scheme based on the control group. Compare the efficacy of the two groups, the control period, the survival period, the toxicity and side effects.Results: The rate of complete response(CR)and partial response (PR) in the observation group was significantly higher than that in the control group, the difference was statistically significant (P0.05). The rate of acute esophagitis in the observation group group was higher than that in the control group, the difference was statistically significant (P<0.05).Conclusion: TOMOX combined with three-dimensional conformal radiation therapy can effectively improve the short-term efficacy and long-term survival rate, reduce adverse reactions.

Chemoradiation effect of combined preoperative intensity-modulated radiotherapy with oral capecitabine in patients with locally advanced mid-low rectal cancer using a simultaneous integrated boost of tomotherapy / 中国综合临床

Objective To assess the safety and efficacy of preoperative intensity-modulated radiotherapy(IMRT) with oral capecitabine in patients with locally advanced mid-low rectal cancer using a simultaneous integrated boost (SIB) of tomotherapy.Methods Total 16 patients with resectable locally advanced mid-low rectal cancer (patients with T3 to T4 and/or N ± rectal cancer) were enroll in current study.Patients were received IMRT to 2 dose levels simultaneously (55 and 47.5 Gy in 25 fractions) with concurrent capecitabine 825 mg/m2 twice daily,5 days/week.Total mesorectal excision was performed at 8 to 9 week after the completion of chemoradiation.The primary end point included side effect,the rate of sphinctersparing,postoperative complication and pathological complete response rate (pCR) were observed.Side effects were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0.Results All patients were received chemoradiotion therapy without any break.Tomotherapy showed superiority with respect to target coverage,homogeneity and conformality.Two patients refused to perform radical surgery because of almost complete primary tumor regression and complete symptom relief after neoadjuvant therapy.Fourteen patients underwent surgical resection and 11 patients (78.6％) underwent sphincter-sparing lower anterior resection.Four patients(28.6％) had a pathological complete response.The incidence of grade 1-2 hematologic,gastro-intestinal toxicities were 62.5％ (10/16) and 18.8％ (3/16).The incidence of grade 3 skin toxicities were 68.8％(10/16).Grade Ⅳ side effect was not observed.Surgical complications (incisional infection on thirteen after surgery) were observed in 1 patient.Conclusion Preoperative simultaneous integrated boost of tomotherapy with concurrent oral capecitabine is safe and well tolerated in patients with a promising local control.However,a larger number of patients and a long follow-up are required to assess its potential superiority.

Variation of organ position and dose for cervical cancer patients treated with helical tomotherapy / 中华放射医学与防护杂志

Objective To observe the interfractional variation and actual dose for cervical cancer patients treated with tomotherapy.Methods Five patients who received tomotherapy were chosen from Aug 2013 to Feb 2014.A megavohage computed tomography (MVCT) scan was performed before treatment and then registered with the planning CT images.Dose distributions were recalculated and targets were contoured on the MVCT images.The differences between the actual radiation and planning were analyzed.Results In the patients received external radiotherapy, the decline in cervix volume and maximum diameter was 68.90％ and 26.91％ , respectively (t =5.21, 8.39, P ＜0.05).Cervix, uterus and CTV movement in left-right, anteroposterior, superoinferior were 1.43,-7.72, 0.02,-0.40,-1.24, -6.51,-0.43,-1.68and-0.22mm.The medianCTV V95％ was 99.40％ (95.96％-100％), and missing volume was 6.94 cm3 (0-32.30 cm3).Conclusions During radiotherapy for cervical cancer patients, the volume, position and doses are different between initial plan and actual radiation.Based on image guided radiation therapy (IGRT), missing targets are limited.

Position modification and actual radiation dose in parotids for head and neck cancers treated with TomoTherapy / 中华放射医学与防护杂志

Objective To analyze the impact of parotid's position and volume changing on radiation dose for head and neck cancer treated with TomoTherapy.Methods Totally 12 patients with head and neck cancer were treated with TomoTherapy.Before the treatment,the dose distribution was recalculated with MVCT images,which would obtain the parameters of position,volume and actual radiation dose for parotids.Results The volume of parotids in Plan2 was significantly lower than in Plan1,and the percentage reduction was 29.06％ and 31.78％ for left and right parotid,respectively (Z =6.77,3.06,P ＜ 0.05).Distance between the COM (center of mass) of parotids and the midline of body was significantly smaller in Plan2 than in Plan1,and the percentage reduction was 6.72％ and 6.19％ (t =5.14,5.80,P ＜ 0.05) at left and right side,respectively.Average dose and V26 for both parotids were higher than those in Plan1,increasing by an average of 37.74％,25.08％ (Z =-6.03,-5.31,P ＜ 0.05) for left parotid and 30.45％,19.33％ (Z =-5.43,-3.26,P ＜0.05) for right parotid,respectively.Conclusions The actual radiation dose to parotids was significantly increased during the radiation therapy for patients with head and neck cancer.There was a linear correlation between the decrease of distance between the COM of parotids and the midline of body and the percentage increase of parotids' radiation dose.No correlation between the reduction of parotids' volume and dose to parotids.In order to reduce the parotids' radiation dose,modification of treatment plan at the appropriate time is essential.

Recent effects of radiotherapy combined with gastroscopic radiofrequency for advanced esophageal cancer / 中国医师杂志

Objective To evaluate the recent effects of radiotherapy plus gastroscopic radiofrequency for advanced esophageal cancer.Methods The date of 53 patients were retrospectively reviewed.The obstruction of the same period, endoscopic classifica-tion, pathology staging similar in 53 patients with advanced esophageal cancer were contrasted .All patients underwent conventional ra -diotherapy.The treatment group: the first day radiofrequency and afterwards within 8 hours the start of radiotherapy.Results The median time to appear the eat obstruction improvement for the combined group was the fourth day and the eighteenth day for the control group.The difference between two groups was statistically significant ( P 0.05).The objective alleviation rate after esophagus pathology radio -therapy, for the combined group, was 96.2% and 88.7% for the contrasted group.No difference in statistically significant ( P >0.05) was for both groups.1-year local control rate was respectively 69.8% and 56.6%.The survival rate was 75.5% and 62.3%. There was no difference in statistically significant ( P >0.05).Conclusions The treatment of radiofrequency in gastroscopy chamber can rapidly improve the patients'eating situation, enhance the patients'fitness, enable the smooth radiotherapy, and make a good foun-dation for the concurrent radiotherapy and chemotherapy to improve the effect on the treatment to esophageal cancer .

Evaluation of PTW Seven29 combining Octavius phantom for tomotherapy patient-specific quality assurance / 中华放射肿瘤学杂志

Objective To investigate the feasibility of dose verification of helical tomotherapy (HT) using the PTW Seven29 2D-ARRAY with Octavius phantom.Methods The 12 patients HT plan were verified with the PTW Seven29 2D-ARRAY combining Octavius phantom.The detector array was guided and registered by MVCT imaging,and measured dose distributions on the corresponding planes were compared with those calculated by the treatment planning system (TPS).Based on several different Gamma criteria,the Gamma analysis method was utilized to evaluate the dose verification.Results According to the different acceptance criteria combination of dose difference/distance to agreement at different threshold level including 3％/2 mm,3％/3 mm,3％/4 mm,3％/5 mm at TH5,TH10,TH20,TH30,the mean passing rates with γparameter ≤ 1 were all above 91.7％ and 93.9％ when PTW Seven29 2D-ARRAY was horizontal and vertical.The dose distribution measured by the 2D-ARRAY combining Octavius phantom was well consistent with that calculated by the TPS.Conclusions 2D-ARRAY with Octavius phantom can get satisfying results when used in HT plan dose verification and is a viable tool to replace traditional film dosimetry system in clinical quality assurance work.

Fabrication of lead eyeshade and its clinical use in radiation therapy / 中国医学装备

Objective:To introduce the fabrication of lead eyeshade and its use in the radiotherapy of both malignant and benign eye tumors and observe the preliminary clinical effect. Methods:To lead sheet with thickness of 2.5-3mm was fabricated into spherical eyeshade and erythromycin Eye Ointment was smeared onto it. Results:According to EORTC criteria, the first level side effect was occasional and mild pain and drying of the eye. The second level was intermittent and tolerable pain and drying of the eye. The third level was constant and intense pain and drying of the eye and the fourth level was incurable and intolerable and drying of the eye. Conclusion:It was shown that the use of lead eyeshade can not only ensure the efficacy of radiotherapy, but also reduce the incidence of radiation injury of surrounding normal tissues. The method used for making of lead eyeshade is effective and easy to grasp.

Delta three-dimensional semiconductor array verification for intensity modulated planning of helical tomotherapy / 中华放射肿瘤学杂志

Objective To investigate the feasibility of dose verification of intensity modulated planning of helical tomotherapy (HT) using three-dimensional semiconductor array (Delta4) and find a more time-consuming and accurate method to validate the delivery dose.Methods Delta4 detector array was used to verify the HT plan dose distribution of 10 patients.The precise setup of detector array was guided and registered by MVCT imaging.After the implementation of delivery,the measured dose distributions on the corresponding planes were compared with those calculated by the treatment planning system (TPS).According to the different acceptance criteria combination of dose difference or distance to agreement at different threshold level including 3％/2 mm,3％/3 mm,3％/4 mm,3％/5 mm at TH5,TH10,TH20,TH30,TH70,TH90,the γ analysis method was utilized to evaluate the dose verification.Results The dose distribution measured by the Delta4 was well consistent with that calculated by the TPS.The mean γpassing rates were all above 94.89％.Conclusions Delta4 detector array can get satisfying results when used in HT plan dose verification and is a viable tool to replace traditional film dosimetry system in clinical quality assurance work.

Establishment of a rabbit model of cardiopulmonary bypass in acute cerebral embolism phase / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a stable and feasible rabbit model of cardiopulmonary bypass (CPB) in acute cerebral embolism phase for studying the effects of CPB on brain tissues and the timing of surgical intervention of acute cerebral embolism.</p><p><b>METHODS</b>Fifty-four rabbits were randomized into group A (n=18) to receive CPB without middle cerebral artery occlusion (MCAO) and group B to undergo CPB at 24 h (group B1, n=18) or 1 week (group B2, n=18) after MCAO. Through a supraorbital margin approach, electrocoagulation was carried out to occlude the main stem of the left MCA under direct vision to establish MCAO. Magnetic resonance imaging (MRI) was performed at both 24 h and 1 week after MCAO, and the severity of cerebral embolization was evaluated. CPB was established by cannulation of the ascending aorta and the right atrium through a median sternotomy incision. MRI was performed at 2 h after CPB to observe the brain tissues.</p><p><b>RESULTS</b>MCAO was successfully established in groups B1 and B2, and all the rabbits survived after MCAO. In both groups A and B, MRI examination detected no cerebral hemorrhage or new embolism 2 h after CPB.</p><p><b>CONCLUSIONS</b>We have established a stable and feasible CPB model in rabbits with acute cerebral embolism to allow study of the mechanisms of CPB-related organ damage and its interventions.</p>

Para-recurrent lymph node metastasis was a significant predictor for cervical lymph nodes metastasis in thoracic esophageal carcinoma / 中华放射肿瘤学杂志

ObjectiveTo evaluate correlation factors of cervical lymph nodes metastasis in thoracic esophageal carcinoma.MethodsLocal-regional metastasis of lymph node for 126 cases with esophageal squamous cell cancer after surgery from 2004 to 2009 were reviewed.Risk factors of cervical lymph nodes metastasis were examined by multiple Logistic regression analysis.ResultsIn 126 cases,supraclavicular lymph node metastasis rate was 43.7％ (55/126).By logistic regression,none of the primary site,T stage,N stage,histological grade,lymph node metastasis rate,lymph node metastasis degree and number of lymph nodes metastatic field was not the high risk of cervical lymph nodes metastasis.In addition,multivariate analysis found that lymph node metastasis in mediastinum region 1 was high risk factor for lymph node metastasis of region 1 ( x2 =12.14,9.27,P =0.000,0.002),lymph node metastasis in region Ⅲ and region 2 were high risk factors for lymph node metastasis of region Ⅱa ( x2 =14.56,8.27,8.02,3.93,P =0.000,0.004,0.005,0.047 ).ConclusionMediastinal para-recurrent nerve lymph node metastasis is a significant predictor for cervical lymph nodes metastasis.

Dosimetric Comparison of Bone Marrow-Sparing Intensity-Modulated Radiotherapy Versus Conventional Intensity-Modulatedr Radiotherapy for Treatment of Cervical Cancer / 中国医学物理学杂志

Objective:To compare bone marrow-sparing intensity-modulated radiotherapy(BMS-IMRT)with conventional (four-field box[3DCRT]and anteroposterior-posteroanterior[CRT])techniques in the treatment of cervical cancer.Methods:For a cohort of 10 patients,BMS-IMRT,3DCRT and CRT planning were designed.The prescribed dose was 45Gy/1.8Gy/25f,95%of the planning target volume received this dose.Doses were computed with a commercially available TPS.Plans were compared according to dose-volume histogram (DVH)analysis in terms of PTV homogeneity and conformity indices(HI and CI)as well as OARs dose and volume parameters.Results:BMS-IMRT had an advantages over 3DCRT and CRT in terms of CI,but inferior to the latter two for HI.BMS-IMRT was superior to 3DCRT in reducing the dose to PBM,small bowel,bladder and rectum.Compared with CRT,BMS-IMRT reduced the volume irradiated to the doses from 30Gy to 40Gy,but increased the volume irradiated to the low doses from 5Gy to 20Gy.In addition,BMS-IMRT reduced the volume of small bowel,bladder,rectum at nearly all dose levels.Conclusion:BMS-IMRT reduced irradiation of PBM compared with 3DCRT technique.Compared with CRT technique,BMS-IMRT reduced the volume of PBM irradiated to high doses.Therefore,for patients with cervical cancer after hysterectomy,BMS-IMRT might reduce acute hematologic toxicity(HT)compared with conventional techniques.

Specific Study on VCG Diagnose of Canine Myocardial Infarction / 中国医学物理学杂志

Objective: Tracing the 15 leads electric signal of canine myocardial infarction by means of VCG and ECG ,compar-ing the diagnose standard of VCG and ECG ,confirm the difference of diagnose standard of canine myocardial infarction ,vali-date the diagnosing specificity of canine myocardial infarction. Methods: Make an operation of coronary artery ligation on 30 healthy dogs to make a myocardial infarction model, record the 15 leads information of ECG and VCG from body surface ,then contrast and analyse them. Results: The sensitivity diagnosing to canice myocardial infarction by VCG is much higher and more specific than that by ECG. Conclusions: Diagnosing early by means of VCG and ECG, VCG is more specific to diag-nose myocardial infarction than ECG.

Dosimetric Comparison of Inverse Three-Dimensional Conformal Radiotherapy and Intensity Modulated Radiotherapy for Non-Ssmall Cell Lung Cancer / 中国医学物理学杂志

Objective: To compare inverse three-dimensional conformal radiotherapy (Inv 3D-CRT) and intensity modulated ra-diotherapy (IMRT) for non-small cell lung cancer. Methods: For a cohort of 10 patients, Inv 3D-CRT and three groups of IMRT plannings were designed for per patient. The prescribed dose was 60 Gy/2 Gy/30f, 95% of the planning target volume received this dose. Dose was computed with a commercially available TPS using convolution/superposition (CS) algorithm. Plans were compared according to the PTV_(95)V_(20) ratio (PTV_(95)V_(20)) and D_(max)-D_(min). Results: Compared with Inv 3D-CRT, the PTV_(95)V_(20) ratio of three groups of IMRT increased by 1.08 (P = 0.014), 0.72 (P = 0.089) and 0.42 (P = 0.318), respectively. Conclusions: For NSCLC, IMRT can reduce the dose to the lungs compared with inverse 3D-CRT by improving the conformity of the plan and is worth spreading in clinical work.

Dosimetric comparison between bone marrow-sparing intensity-modulated radiotherapy and conventional intensity-modulated radiotherapy for cervical cancer / 中华放射肿瘤学杂志

Objective To compare bone marrow-sparing intensity-modulated radiotherapy (BMS-IMRT) with conventional intensity-modulated radiotherapy (IMRT) without considering pelvic bone marrow (PBM) as a planning constraint in the treatment of cervical cancer after hysterectomy. Methods BMS-IM-RT and IMRT planning were separately designed in a cohort of 10 patients with cervical cancer after hysterec-tomy. The prescribed dose was 95% planning target volume receiving 45 Gy/25 f. A commercially available TPS with convolution/superposition (CS) algorithm was used for dose calculation. Plans were compared ac-cording to dose-volume histogram (DVH) analysis in terms of PTV homogeneity (HI), conformity index (CI) as well as dose and volume parameters of organ at risks (OARs). Results BMS-IMRT was better than IMRT in terms of CI, but inferior to the latter for HI. When compared with IMRT, V_5, V_(10), V_(20), V_(30) and V_(40) of PBM in BMS-IMRT were reduced by 1.81% ,8.61% ,31.81% ,29.50% and 28.29%, respec-tively. No statistically significant differences were found between BMS-IMRT and IMRT for dose distritutions of the small bowel, bladder or rectum. Conclusions For patients with cervical cancer after hysterectomy, BMS-IMRT can reduce the PBM volume irradiated by low dose, which may reduce acute hematologic toxici-ties.