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Objective To compare the dosimetric difference of stereotactic body radiation therapy (SBRT) plans for spine metastasis using 6 MV X-ray flattening filter free (FFF) and flattening filter (FF) modes.Methods A total of nine previously treated patients with a total of twelve spine metastasis were retrospectively included and replanned using FFF-SBRT and FF-SBRT, respectively.The dose-volume histograms (DVH), target conformity index (CI), monitor unites (MUs) and treatment time of target volume, organs at risk and normal tissues were compared between the plans.Results Both FFF-SBRT and FF-SBRT met the clinical objectives.Dose distribution of target volume, organs at risk and normal tissues were similar.MUs of the FFF-SBRT were significantly higher than that of FF-SBRT (t =-5.20, P ＜0.0l), while the treatment time was almost half of the latter (t =17.27, P ＜ 0.01).Conclusions Two plan modes are both clinically acceptable.FFF-SBRT plans are delivered in less time and with better efficiency.Trial registration Chinese clinical trial registry, ChiCTR-TRC-14004281.
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Objective To analyzed the effects of the positioning errors and weight variability of the head and neck cancer patients with intensity modulated radiation therapy (IMRT),or volumetric modulated arctherapy (VMAT) based on the kilovoltage cone-beam computed tomography (kV-CBCT).Methods CBCT images of 102 patients with head and neck cancer patients receiving IMRT or VMAT were screened by CBCT once a week for consecutively 6 weeks.The positioning errors were measured by comparing CBCT and planning CT in left-right (LR),anterior-posterior (AP) and cranio-caudal (CC) directions.Meanwhile,the weight of patients were measured every week.Results The positioning errors were (0.011 5±0.125 3) cm,(-0.017 6±0.123 3) cm and (-0.014 1±0.156 7) cm in LR,AP and CC directions,respectively.The mean systematic errors were all less than 0.02 cm in three axial directions,while the mean random errors were all within 0.2 cm.There was no statistically significant difference was observed among the setup errors in all three axial directions according to different week.Though the body weight of patients continued to drop during the radiation by with the mean weight loss of 3.5 kg and had a negative correlation with treatment course.Bivariate correlation analysis showed just the positioning errors in CC direction were significantly correlated with body weights loss.Conclusion There is no statistical relationship with in position errors of the patients with their treatment course,and the body weight loss seemed to influence the position errors in CC direction.
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Objective:To assess the safety and efficacy of induction chemotherapy with cisplatin and docetaxel followed by radia-tion concurrent with weekly cisplatin for unresectable, locally advanced esophageal cancer. Methods: Thirty-three patients with T3N0M0 to T4N2M0 thoracic esophageal squamous cell carcinoma without celiac lymph node metastasis were included in the study. They were treated with cisplatin (75 mg/m2 d1, d22) and docetaxel (75 mg/m2 d1, d22) neoadjuvant chemotherapy followed by three-dimensional conformal radiotherapy (60Gy/30F/6w) concurrent with cisplatin (30 mg/m2 d1, 8, 15, 22, 29, 36 from the beginning of radiation). Results:Grade 4 hematological toxicities were observed in 13.33%(4/33) of the patients after the neoadjuvant chemother-apy. No grade 3 or above hepatic or renal toxicities were found. During concurrent chemoradiation, the highest grade 3 hematological toxicities were observed in the erythrocyte, granulocyte, and macrophage at 21.21%(7/33), 15.15%(5/33), and 3.01%(1/33), respec-tively. No grade 2 or above hepatic or renal toxicities were observed. Grade 3 radiation esophagitis was observed in 9.1%(3/33) of the patients, whereas grade 3 and above radiation esophagitis or grade 1 and above acute radiation pneumonitis did not occur. The evalua-tion results after treatment completion were 84.85%(28/33), 12.12%(4/33), and 3.03%(1/33) for CR+PR, SD, and PD , respectively. Two months after treatment completion, the results changed to 75.76%(25/33), 9.10%(3/33), and 15.15%(5/33), respectively. Overall, 15 patients died. The one-year survival rate was 66.4%. Local failure was approximately 46.67%(7/15), whereas the local+distant fail-ure was approximately 26.67%(4/15). Therefore, local failure is the main pattern of failure in esophageal cancer. Conclusion:The re-sults indicate that neoadjuvant chemotherapy with cisplatin and docetaxel followed by radiotherapy concurrent with weekly cisplatin for locally advanced esophageal cancer is safe. Local failure remains the main pattern of failure in esophageal cancer.
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ObjectiveThe study is to investigate the predictive values of dosimetric parameters and patient related factors in severe acute radiation pneumonitis (SARP) after concurrent chemoradiotherapy in non-small cell lung cancer (NSCLC).Methods In all,147 NSCLC patients treated with concurrent chemotherapy and 3DCRT between 2006 and 2010 was collected.Independent sample t test was used to compare parameter values between patients with SARP and those without SARP.Logistic regression was used to identify significant determined factor.Predictive value of each parameter was tested by ROC analysis.Pearson correlation was used to analyze correlations between parameters.Represent factors were identified by factor analysis.ResultsThe incidence of SARP was 9.5％ ( 14/147 ).The means lung dose (MLD),V20,V30,V40,and V50 ( x2 =4.87 -6.84,P =0.009 -0.025,respectively ) were determining factors for SARP.Our datasets shows that for SARP ＜5％,MLD,V20,V30,V40 and V50 should be ≤16.77 Gy,V20≤34.15％,.V30 ≤23.62％,.V40 ≤ 18.57％,V50 ≤ 13.02％.ROC analysis show that areas under MLD,V20,V30,V40 and V50 curves was corresponding to 0.678,0.661,0.667,0.677,and 0.651,respectively.In addition,the sensitivity and specificity of each parameter at cutoff values are:78.0％ and 48.1％ for MLD;42.9％ and 82.0％ for V2o ;78.6％ and 52.9％ for V30 ;71.4％ and 61.7％ for V40,and 57.1％ and 67.7％ for V50.Factor analysis suggest that we can choose 1 or 2 parameters from MLD,V20,or V30,and another from V40 or V50 for predicting.The incidence of SARP was greater in patients with tumorsin right lower lung than other locations ( 22.2％ vs 6.7％,x2 =6.19,P =0.0 2 3 ).Conclusions The MLD,V20,V30,V40 and V50 are determining factors for SARP.As predictive value of each parameter alone is relatively week,using two or more parameters to predict SARP is recommended.
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ObjectiveTo evaluate the local failure and the impact on survival by prospectively comparing involved field radiotherapy (IFRT) and elective nodal irradiation (ENI) in combination with concurrent chemotherapy for locally advanced non-small cell lung cancer ( LA-NSCLC ).Methods LANSCLC patients were treated with 2 cycles of carboplatin ( AUC =5 - 6,d1 ) combined with paclitaxel ( 175mg/m2 ),followed assessment without distant metastasis,then randomized into IFRT (45 patients) or ENI (54 patients) arm.IFRT included primary tumor,ipsilateral hilar and positive mediastinal lymph nodes;ENI included the primary lesion,ipsilateral hilar,hilateral mediastinal lymph node drainage and bilateral supraclavicular area.The prescription dose was given as high as possible with V20 ≤35％ and spinal cord dose ≤50 Gy,combined weekly paclitaxel 40 mg/m2 concurrent chemotherapy.The Kaplan-Meier method was used to estimate survival data and the log-rank method was used to test distribution of survival time between arms.ResultsThe follow-up rate was 99％.49,29 and 17 patients were followed-up for 1-,2-and 3-year,respectively.More patients from group IFRT received ＞60 Gy than ENI (49％ vs.26％,x2 =5.59,P =0.018 ).The local failure rates were 29％ and 36％,respectively ( x2 =0.46,P =0.497 ).The 1-,2-and 3-year local tumor progression-free survival rates were 76％,69％,65％ and 80％,53％,49％ ( x2 =0.74,P =0.389),respectively; the 1-,3-and 5-year overall survival rates were 80％,41％,33％ and 69％,32％,13％ (x2 =3.97,P =0.046),respectively.There were no significant differences in acute and late toxicities between the arms ( x2 =3.910 - 0.155,P =0.142 - 0.925 ).ConclusionsIFRT improved radiation dose and survival rate and did not increase the failure of elective lymph node region compared with ENI.The toxicities were no differences between IFRT and ENL Further investigation with big size sample is warranted.
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Objective To analyze the incidence and related factors of acute radiation pneumonitis (RP) in patients with non-small cell lung cancer (NSCLC) who underwent three-dimensional conformal ra-diotherapy with concurrent chemotherapy. Methods From January 2006 to October 2008, 90 NSCLC pa-tients treated with concurrent chemoradiotherapy were retrospectively reviewed. The clinical characteristics and treatment plan parameters from dose-volume histogram (DVH) were analyzed. Results Grade 1, 2,3, 4 and 5 RP was found in 32.2%, 30.0%, 5.6%, 0% and 1.1% of the patients. Primary tumor loca-tion was the only significant clinical factor in univariate analysis. And significant differences were found when the groups was divided by the mean lung dose (MLD) of 17 Gy, V_(5) of 47% ,V_(10) of 36% ,V_(20) of 24%,V_(30) of 23% and V_(40) of 22%, respectively. Multivariate analysis showed the MLD was the only independent predictive factor of RP. Conclusions Some factors may contribute to the RP. MLD should be set below 17 Gy in three-dimensional conformal radiation, especially when the tumor locates in the lower lobe.