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Objective To compare the therapeutic effects between three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) in patients with stage Ⅱ/Ⅲ esophageal cancer and investigate the prognostic factors.Methods Medical record of 2 132 patients with stage Ⅱ/Ⅲ esophageal cancer who underwent definitive radiotherapy with/without chemotherapy in 10 hospitals from January 2002 to December 2016 from were retrospectively analyzed.Among these patients,37.9％ of them were aged ≥ 70 years,33.9％ with neck and upper esophageal tumors and 66.1％ with middle and lower esophageal and borderline tumors.The median gross tumor volume (GTV) and lymph node gross tumor volume (GTVnd) was 41.6 cm3.Among them,32％ were stage Ⅱ] and 68％ were stage Ⅲ.A total of 723 patients received 3DCRT and 1 409 cases received IMRT.Patients received an equivalent dose in 2 Gy (EQD2) ≥ 60 Gy accounted for 86.1％,and 41.1％ of them received concurrent chemoradiotherapy.Results The median follow-up time was 60.8 months.The 1-,3-and 5-year overall survival (OS) of all patients was 73.9％,41.7％ and 32.6％,and the 1-,3-and 5-year progression-free survival (PFS) was 62.2％,37.3％ and 32％,respectively.Multivariate analysis demonstrated that age,primary tumor location,clinical stage,tumor target volume,EQD2 and concurrent chemoradiotherapy were the independent prognostic factors for OS.Age,primary tumor location,clinical stage,tumor target volume and EQD2 were the independent prognostic factors for PFS.The OS and PFS did not significantly differ among the low-risk,low-/moderate-risk,moderate-/high-risk and high-risk groups according to age≥70 years,tumor diameter＞5 cm,tumor volume ≥41.6 cm3 and stage Ⅲ (P＜0.001).After the propensity score matching (PSM) method,neither 3DCRT nor IMRT yielded significant advantages in OS or PFS (P=0.971;P=0.658).However,IMRT tended to yield survival benefits in low-risk patients (P=0.125).Conclusions Both 3DCRT and IMRT yield relatively high OS rate in patients with stage Ⅱ/Ⅲ esophageal cancer.The prognosis model established in this investigation can properly predict the survival of patients.Low-risk patients tend to obtain survival benefits from IMRT.
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Objective To evaluate the clinical efficacy and adverse events of intensity-modulated radiotherapy ( IMRT ) in the treatment of intermediate risk localized prostate cancer, and analyze the significance of prostate-specific antigen ( PSA) level changes. Methods Clinical data of 66 patients with intermediate risk localized prostate cancer admitted to our hospital between 2007 and 2018 were retrospectively analyzed. Sixty patients were treated with endocrine therapy before radiotherapy. The radiation field covered the pelvic lymph node drainage area in 6 cases. Forty-seven patients received image-guided radiotherapy ( IGRT) . The median dose in the prostate and seminal vesicle was 78 Gy and 48 Gy in the pelvic lymph node drainage area. The survival rate was calculated using the Kaplan-Meier method. Results The median age was 77 years. The median follow-up time was 71. 3 months. The 5-year sample size was 47. The 3-and 5-year overall survival (OS) was 98％ and 90％.The 3-and 5-year cancer-specific survival (CSS) was 100％ and 93％.The 3-and 5-year biochemical relapse-free survival was 97％ and 86％. The mean time of PSA declining to the nadir was 5. 83 months. The median level of PSA nadir was 0. 06 ng/ml after IMRT. The incidence of grade I andⅡearly adverse events in the urinary system was 38％ and 6％. The incidence of grade I andⅡearly adverse events in the gastrointestinal system was 21％ and 3％. The incidence of grade I andⅡadvanced-stage adverse events in the urinary system was 9％ and 2％. The incidence of grade I advanced-stage adverse events in the gastrointestinal system was 5％. Conclusions IMRT yields high clinical efficacy in the treatment of intermediate risk localized prostate cancer with a low risk of adverse events in the early and advanced stage. The monitoring of PSA after IMRT contributes to the assessment of clinical prognosis.
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Objective To assess the dosimetric benefit,prognosis and toxicity of intensitymodulated radiation therapy (IMRT) for stage Ⅲ esophageal squamous cell cancer.Methods This was a retrospective analysis of 28 patients,aged between 45 and 83 years,with stage Ⅲ esophageal squamous cell cancer who had received radical IMRT.Of these patients,six received concurrent chemotherapy and eight received targeted therapy.The median radiotherapy dose was 67.1 Gy.Dosimetric parameters for the target volume and critical normal structures were evaluated by dose volume histogram.The Kaplan-Meier method was used to calculate overall survival (OS),progress free survival (PFS) and locoregional control (LRC).Results The mean conformity index (CI) and homogeneity index (HI) scores of the planning target volume (PTV) were 0.82 and 0.92,respectively,indicating very good coverage of the target volume.Three-year OS,PFS,and LRC were 48.0 ％,31.2％,and 62.0％,respectively.Acute toxicities were mild,only two patients developed acute esophagitis (grade ≥3),and three had acute pneumonitis (grade ≥2).Conclusions IMRT can provide excellent dose conformity and achieve favorable LRC and survival with only mild toxicities in patients with stage Ⅲ esophageal squamous cancer.
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Objective To assess the dosimetric benefit,prognosis and toxicity of intensitymodulated radiation therapy (IMRT) for stage Ⅲ esophageal squamous cell cancer.Methods This was a retrospective analysis of 28 patients,aged between 45 and 83 years,with stage Ⅲ esophageal squamous cell cancer who had received radical IMRT.Of these patients,six received concurrent chemotherapy and eight received targeted therapy.The median radiotherapy dose was 67.1 Gy.Dosimetric parameters for the target volume and critical normal structures were evaluated by dose volume histogram.The Kaplan-Meier method was used to calculate overall survival (OS),progress free survival (PFS) and locoregional control (LRC).Results The mean conformity index (CI) and homogeneity index (HI) scores of the planning target volume (PTV) were 0.82 and 0.92,respectively,indicating very good coverage of the target volume.Three-year OS,PFS,and LRC were 48.0 ％,31.2％,and 62.0％,respectively.Acute toxicities were mild,only two patients developed acute esophagitis (grade ≥3),and three had acute pneumonitis (grade ≥2).Conclusions IMRT can provide excellent dose conformity and achieve favorable LRC and survival with only mild toxicities in patients with stage Ⅲ esophageal squamous cancer.
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Objective To analyze the clinical efficacy of daily online cone-beam computed tomography (CBCT)-guided stereotactic body radiation therapy (SBRT) for primary and metastatic lung cancer and its related factors.Methods From May 2009 to May 2013,36 patients with lung cancer were treated with SBRT,including 24 patients with primary lung cancer and 12 patients with metastatic lung cancer.The biologically effective dose at 10 Gy was ≥ 100 Gy in 85.7％ of 42 lesions.Before each delivery,CBCT was acquired,and online automatic or manual registration was performed to make the tumors on CBCT within the planning target volume/primary gross tumor volume;the setup threshold was not set,and the couch was moved for correction.Results The 1-,2-,and 3-year sample sizes were 36,29,and 26,respectively.The 1-,2-,and 3-year local control (LC) rates were 96％,89％,and 72％,respectively.The 1-,2-,and 3-year cancer-specific survival (CCS) rates were 82％,74％,and 64％,respectively.The 1-,2-,and 3-year overall survival (OS) rates were 78％,64％,and 53％,respectively.Univariate analysis found no factors associated with LC.Multivariate analysis revealed no factors associated with OS.Both univariate and multivariate analyses showed that only tumor location (central type or peripheral type) was associated with CCS;the mean values (95％ confidence intervals) of CCS in patients with central-type and peripheral-type lesions were 21.4 months (13.2-29.6 months) and 42.3 months (35.7-49.0months),respectively (P=0.024).Conclusions Daily online image-guided SBRT for primary or metastatic lung cancer can lead to a satisfactory LC.
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Objective To study a series of tests to the IMRT planning system RayStation,and verify the feasibility of this Standard.Referring to the standard Performance and test methods for intensity modulated radiation therapy (IMRT) treatment planning system (Standard).Methods Referring to the Standard,the tests include:dose goals used for planning,point dose calculation accuracy and dose distribution calculation accuracy.And test phantoms include:AAPM TG119 report's test cases and solid water phantom for verification,and IMRT test cases include:multitarget,mock prostate,head/neck and CTshape (easier version and harder version) and so on.Referring to the Standard,we optimize and calculate doses of interest in RayStation,and use the common measurement equipments and tools,such as an ionization chamber,films,a detector array,and etc,to measure the doses on the accelerator,then calculate and analyze the errors between them.Results The results of dose goals for five different mock plans meet the requirements of the Standard.And the point dose ionization chamber measurements are in line with the requirements of the Standard,and the total error of the mock plans was (0.83 ± 1.65) ％.The γpass rates of per-field measurements using detector array are all greater than 99.0％,and the γpass rates of composite film measurements are all greater than 92.5％.Conclusions The results of three trials to IMRT performance of RayStation are in full compliance with the requirements of the Standard.And also it is an evidence for the feasibility of this Standard.
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Objective To explore a method of using a computer system for multi-media cases study in radiation oncology clinical work,in order to replace the traditional use of film images and paper.Methods We use a dedicated networked computer's Windows XP's Remote Desktop feature to remote access an Eclipse TPS and the radiation therapy information management system.Then we can online read the patient' s information of CT images,target volumes,treatment plans,plan application forms and electronic medical records,and use a projector to project it on the screen.Results There has been half a year since we successfully set up a radiation therapy case study multi-media system in the department.It's convenient and effective to achieve the department conducted a collective case discussion.Conclusions The equipment required is simple,and it's a safe and reliable technology,greatly improving the clinical efficiency and quality of medical care.
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Objective To evaluate the setup errors of image guided radiation therapy (IGRT) for head-and-neck cancer using kilovoltage cone beam CT( kV CBCT).Methods 256 patients with head-and-neck cancer were treated with intensity modulated radiation therapy (IMRT) from March 2009 to October 2011.All patients were immobilized with head-and-neck mask and localized with final isocenter marking method using the Philips PQS CT or Philips Brilliance CT Big Bore scanners,which were equipped with LAP movable laser systems.The CT images were transferred to a Varian Eclipse V8.6 workstation for contouring and planning.A kV cone-beam CT scans was acquired,and registered before the treatment for every patient on a Varian iX linear accelerator via OBI system.The setup errors in the right-left ( RL),superior-inferior (SI),and anterior-posterior (AP) directions were recorded.Results The setup errors for the 473 datasets followed a Gaussian distribution.The systematic errors ± random errors in the RL,SI and AP were(-0.6 ± 1.3 ),(0.5 ± 1.6) and (0.9 ± 1.7 ) mm,respectively.The planning target volume (PTV) margins were calculated respectively as 2.4,2.4 and 3.4 mm according to the formula of M =2.5∑ +0.7δ The margins of 288 sets of data using the Big Bore CT scanner were calculated as 2.0,2.1 and 1.7 mm,respectively.Conclusions The setup errors using final isocenter marking method are smaller than those using reference point marking method.The result derived from this retrospective study could be used to set the margin between CTV and PTV.
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Objective To meet the special needs of the department of radiation oncology, a radiation therapy information management system ( RTIMS) has been developed as a secondary database system to supplement the Varian Varis/Aria since 2007. Methods The RTIMS server was used to run a database and web service of Apache + PHP + MySQL. The RTIMS sever's web service could be visited with Internet Explorer (IE) to input, search, count, and print informations from about 30 workstations and 20 personal computers. As some workstations were installed with Windows and IE in English only, some functions had English version. Results In past five years, as the RTIMS was implemented in the department, some further needs were met and more practical functions were developed. And now the RTIMS almost covered the whole workflow of radiation therapy ( RT) . By September 2011 , recorded patients data in the RTIMS is as follows: 3900 patients, 2600 0utpatient RT records, 6800 progress notes, 1900 RT summaries, 6700 charge records, 83000 workload records, 3900 plan application forms, 1600 ICRT records. etc. Conclusions The RTIMS hased on the workflow of RT has been successfully developed and clinically implemented. And it was demonstrated to be user-friendly and was proven to significantly improve the efficiency of the department. Since it is an in-house developed system, more functions can be added or modified to further enhance its potentials in research and clinical practice.
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ObjectiveTo evaluate setup errors of image guided radiation therapy (IGRT) for body tumors immbilized with vacuum cushions and localized with final isocenter marked method using kilovoltage cone beam CT (KVCBCT).MethodsA retrospective study has been carried out for 223 patients from March 2009 to April 2011.All patients were immobilized with vacuum cushions and localized with final isocenter marked method in Philips PQS CT or Philips Brilliance CT Big Bore scanner,which were equipped with LAP movable laser systems. The CT images were transferred to a Varian Eclipse workstation for contouring and treatment planning.Before irradiation,a KVCBCT scan was performed and image registration was done on a Varian iX linear accelerator via OBI system.Each set of setup errors in right-left ( RL),superior-inferior (SI),and anterior-posterior (AP) directions were gathered.An independent-samples t-test statistical analysis was conducted with the 758 sets of data using SPSS 16.0.Results The statistical analysis showed that setup errors from the 758 datasets were depicted a Gaussian distribution.The system errors ± random errors in RL,SI and AP were ( -0.5 ±2.8) mm,(0.0±3.0) mm and (0.4±3.4)mm,respectively.Referring to the formula for planning target volume margin calculation,M =2.5Σ + 0.7δ,the margins were calculated as 3.2,2.1 and 3.4 mm,respectively.ConclusionsThe margins derived from this retrospective study have confirmed the premise that the treatment plans were executed in patients with high reliability,thereby created a high sense of confidence for the clinicians.
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Objective To compare the planning systems of the simplified manual intensity modulated (SMIM) irradiation and standard tangential (ST) irradiation,in order to explore the application of SMIM technique in clinic.Methods In 64 cases of breast cancers after breast conserving surgery,each underwent both SMIM and ST planning systems.SMIM planning was designed by copying additional fields for shielding the high dose areas from internal or lateral tangential field.The high dose areas were reduced by adjusting the size of the additional field and open tangential field.To optimize the SMIM planning,3 high dose areas (＞ 103% ,＞ 105% and ＞ 107%) were shielded and 3 protocols carried out.The wedges were also optimized in ST plan.The target coverage and dose homogeneity and dose of organ at risk were compared between SMIM and ST planning systems.Results When the dose was normalized to cover the volume of 95% CTV,85% of the shielded areas in optimal SMIM planning were that of ＞ 103% high dose area,and 94% of target area was covered.The study on the volume of breast CTV showed that,in the large breast group,SMIM could not only significantly reduce the high dose areas,and the maximum dose as well as the dose of organ at risk,but also enhance the dose homogeneity index.However,no such effect was not significant in the small breast group.Conclusions The simplified manual intensity modulated technique can improve target dose homogeneity in the large breast cases instead of the standard tangential technique.
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Objective To restrospectively investigate clinical outcomes and prognositic factors in localized prostate cancer treated with neoadjuvant endocrine therapy followed by intensity modulated radiotherapy (IMRT). Methods Between March 2003 and October 2008, 54 localized prostate cancer treated by IMRT were recruited. All patients had received endocrine therapy before IMRT. The endocrine therapy included surgical castration or medical castration in combination with antiandrogens. The target of IMRT was the prostate and seminal vesicles with or without pelvis. The biochemical failure was defined according to the phoenix definition. By using the risk grouping standard proposed by D'Amico, patients were divided into three groups: low-risk group (n = 5), intermediate-risk group (n = 12), and high-risk group (n = 37). Kaplan-Meier method was used to calculate the overall survival rate. Prognostic factors were analyzed by univariate and multiple Cox regression analysis. Results The follow-up rate was 98%. The number of patients under follow-up was 39 at 3 years and 25 at 5 years. Potential prognostic factors, including risk groups, mode of endocrine therapy, time of endocrine therapy, phoenix grouping before IMRT, the prostate specific antigen doubling time (PSADT) before radiotherapy, PSA value before IMRT, interval of endocrine therapy and IMRT, irradiation region, and irradiation dose were analyzed by survival analysis. In univariate analysis, time of endocrine therapy (75 % vs 95 %, χ~2= 6. 45, P = 0. 011), phoenix grouping before IMRT (87% vs 96%, χ~2 = 4. 36, P = 0. 037), interval of endocrine therapy and IMRT (80% vs 95% ,χ~2= 11.60,P= 0. 001) ,irradiationdose(75% vs 91% ,χ~2=5.92,P= 0. 015) were statisticallysignificant prognostic factors for3 - year overall survival , and risk groups (85 vs 53 vs 29 , χ~2= 6. 40,P =0. 041) and PSADT before IMRT (62 vs 120, U =24. 50,P =0. 003) were significant factors for the median survival time. In the multiple Cox regression model, only time of endocrine therapy and phoenix grouping before IMRT were significantly related to the overall survival. The 3-year overall survival rates in patients with endocrine therapy less than 3 months versus more than 3 months were 75% versus 95% (χ~2= 5.45, P= 0.020). The 5-year overall survival rates in patients with biochemical failure versus nobiochemieal failure was 71% versus 92% (χ~2= 8.83 , P= 0.003) Conclusions Neoadjuvant endocrine therapy should last at least three months. Intensity modulate radiotherapy should start before biochemical failure after the endocrine therapy.
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Objective To evaluate the prognosis and side-effects of three-dimensional conformal radiotherapy (3 DCRT) and intensity modulated radiotherapy (IMRT) for prostate carcinoma. Methods From 2001 to 2009, 62 patients with prostate carcinoma treated with radiotherapy were included in the retrospective analysis. Among them, 60 patients received IMRT while the other two received 3DCRT. There were 56 patients receiving androgen deprivation therapy before radiotherapy. The median dose was 78 Gy to 95% planning target volume (PTV) of the prostate and seminal vesicles, and the median dose to 95% PTV of the pelvic lymph nodes was 48 Gy. Results The median follow-up was 15.4 months. The 3-and 5-year overall survival (OS) rates were 92% and 83%, with the corresponding biochemical disease-free survival rates of 87% and 69%, and the distant metastasis-free survival (DMFS) rate of 77% and 55%, respectively. Patients with a PSA nadir ≤ 2 ng/ml had a 3-year OS of 94% and DMFS of 88%, compared with 56% and 11% (χ~2 = 16. 39, P < 0.01 for OS ; χ~2 = 28. 87, P < 0. 01 for DMFS) for those with a PSA nadir > 2 ng/ml. The incidence of grade 1 and 2 urinary toxicity was 32% and 0% for acute damage, 10% and 0% for late damage, respectively. The incidence of grade 1 and 2 intestinal toxicity was 19% and 3%. for acute damage, 5% and 3% for late damage, respectively. Conclusions Radiation therapy for patients with prostate carcinoma shows satisfactory outcomes with a good toleration. Monitor of PSA after radiotherapy has benefit for prognosis evaluation.
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Objective To evaluate the clinical feasibility of quality assurance of intensity modulated radiation therapy(IMRT) through a series of clinical case studies. Methods Helios inverse planning system was used to provide optimized IMRT treatment plans for brain tumor, nasopharyngeal carcinoma, pancreatic cancer, spinal metastatic tumor and prostatic cancer. To verify the conformation between the fluence map of each beam predicted by the planning system and that actually delivered, a piece of film under a homogeneous polystyrene phantom was irradiated vertically with each of the beams to record the deposited dose. This measured fluence map was compared with that predicted by the planning. The dose distribution was recorded by irradiating the film in an anthropomorphic phantom using patients' treatment plan, then compared with that predicted by the planning. An ionization chamber in a water phantom was used to measure the central point dose and another eccentric point dose. Results The fluence map measured by the film was well consistent with that predicted by the planning. The error between the measured dose and predicted dose in the central point was less than 3%, whereas the error of the dose in another eccentric point varied greatly. The isodose distribution (on axial plane) measured by the film was consisent with the predicted one. Conclusions The procedures for quality assurance of IMRT are feasible in our experience.
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Objective To compare the dose to the contralateral breast, ipsilateral lung, and the whole lung in the tangential field radiotherapy for primary breast cancer using the dynamic wedge or physical wedge. Methods With thirteen breast cancer patients chosen, the dose distribution was computed for the plan used in practical treatment with the dynamic wedge and physical wedge. Plans were compared using dose volume histograms for the contralateral breast, ipsilateral lung and the whole lung. As for the contralateral breast, the dose distributions were not computed for the whole breast but computed for the two regions similar to a rectangular area in the axial slice and parts of the whole breast. The mean dose was used to evaluate CB1, CB2 and ipsilateral lung, and V_ 20 was used to evaluate the whole lung. The treatment planning system used was Varian CadPlan. An ionization chamber in a water phantom was used to measure some point doses to simulate the dose to the contralateral breast. Results When using the 30? dynamic wedge, the mean dose to CB1 and CB2 was 1.5%-3.9% and 1.1%- 2.6% , and the mean dose to the ipsilateral lung was 4.1%-14.7%. When using the 30? physical wedge, the mean dose to CB1 and CB2 were 1.5%-4.4% and 1.2%-3.0%, respectively, and the mean dose to the ipsilateral lung was 4.4%-15.2%. The values of V_ 20 were equal. When using the 15? dynamic wedge, the mean dose to CB1 and CB2 decreased compared to 15? physical wedge, but the value reduced was smaller than when using 30? wedge. Also, the measured results verified that the dose to the normal tissue is reduced using the dynamic wedge. Conclusions The mean dose to the contralateral breast was reduced by using the dynamic wedge instead of the physical wedge, and the mean dose to the ipsilateral lung or V_ 20 is reduced or equal to each other. So the probability of normal tissue complication such as a second breast malignancy or pneumonitis associated with radiotherapy are likely to be reduced.