Objective To investigate the relationship between dose-volume histogram (DVH) parameters and the late side effects (LSE) of the rectum in external-beam radiotherapy combined with computed tomography (CT)-based brachytherapy for locally advanced cervical cancer.Methods From 2008 to 2011,18 patients with stage ⅡB-ⅢB cervical cancer received external-beam radiotherapy and CTbased brachytherapy.The DVH parameters of high-risk clinical target volume (HR CTV) D90,point A dose,and D1 cm3 and D2 cm3 of the rectum and bladder were calculated by Oncentra HDR treatment planning system.Survival outcomes were followed up and rectal LSE were evaluated by RTOG/EORTC grades.Results The point A dose and HR CTV D90 were (93.0 ± 5.5) Gy and (73.6 ± 11.9) Gy,respectively.The median follow-up was 26 months.No recurrence was found during follow-up.Eight patients had mild and moderate rectal LSE,and their rectum D2 cm3 and D1 cm3 were significantly higher than those of patients without mild and moderate rectal LSE (D2 cm3:(87.4 ± 3.8) Gy vs.(75.8 ± 7.4) Gy,P =0.004 ; D1 cm3:(96.4±6.6) Gy vs.(80.5± 7.1) Gy,P=0.001).Conclusions HR CTV D90 in CT-based brachytherapy for locally advanced cervical cancer might be lower than that in the MRI-based plan.Rectum D2 cm3 is recommended to be less than 75 Gy.

Objective To evaluate the role of thoracic three-dimensional conformal radiotherapy (3DCRT) in patients with extensive-stage small cell lung cancer (ES-SCLC).Methods A total of 171 patients with ES-SCLC admitted from 2004 to 2009 were included in the study.Eighty-six patients received thoracic 3DCRT and systemic chemotherapy (CT),while 85 patients received systemic CT alone.3DCRT was delivered at 1.5 Gy/fraction twice daily or 2.0 Gy/fraction once daily,with a total dose ranging from 40 to 62 Gy.The CT regimen consisted of carboplatin/cisplatin and etoposide.The survival time and survival rate were calculated by the Kaplan-Meier method,and the log-rank test was used for univariate prognostic analysis;the Cox model was used for multivariate prognostic analysis.Results The follow-up rate was 100％.The median overall survival (OS) time and the 2-and 5-year OS rates were 15 months,31.5％,and 2.4％,respectively,for all patients;they were 18 months,35.3％,and 2.4％,respectively,for the CT/3DCRT group,versus 12 months,14.5％,and 2.4％ for the CT group (P =0.023).The median progression-free survival (PFS) time and the 1-and 2-year PFS rates were 8 months,27.5％,and 2.4％,respectively,for all patients;they were 9 months,35.4％,and 6.0％,respectively,for the CT/3DCRT group,versus 6 months,20.5％,and 6.0％ for the CT group (P =0.004).In the CT/3DCRT group,the 22 patients who received 45 Gy at 1.5 Gy/fraction twice daily had a median PFS time of 11 months,versus 9 months for the 26 patients who received 60 Gy at 2.0 Gy/fraction once daily (P =0.037).Multivariate analysis revealed that receiving ≥ 4 cycles of CT (P =0.001) and 3DCRT (P =0.008) were favorable prognostic factors for OS.Conclusions Thoracic 3DCRT can improve the OS and PFS in patients with EDSCLC,and it has good efficacy when delivered with a total dose of 45 Gy at 1.5 Gy/fraction twice daily.Thoracic 3DCRT and receiving ≥4 cycles of CT are independent favorable prognostic factors for OS.

Objective To investigate the clinical features and survival status of mucosal melanoma of the nasal cavity and paranasal sinuses and to analyze the prognostic factors.Methods A retrospective analysis was performed on the clinical data of 94 patients with mucosal melanoma of the nasal cavity and paranasal sinuses treated from January 2000 to December 2012.Of the 94 patients,50 were male,and 44 were female.The median age of onset was 60 years (range,26-85 years).The primary sites were nasal cavity (86 patients),maxillary sinus (7 patients),and nasopharynx (1 patient).Cervical lymph node metastasis was observed in 10 patients (7 patients before treatment,2 patients during treatment,and 1 patient after treatment).No patient had distant metastasis.Patients were treated with surgery ± radiotherapy.The Kaplan-Meier method was used to calculate survival rates,and the logrank test was used for univariate prognostic analysis;the Cox regression model was used for multivariate prognostic analysis.Results The 1-,3-,and 5-year sample sizes were 80,54,and 50,respectively.The 1-,3-,and 5-year disease-related survival rates were 71％,33％,and 22％,respectively.Univariate analysis showed that the prognostic factors were age over 55 years (P =0.034),involvement of the posterior naris (P =0.011),involvement of the maxillary sinus (P =0.009),involvement of the hard palate (P =0.003),cervical lymph node metastasis (P =0.001),and therapeutic method (P =0.038).Multivariate analysis showed that the prognostic factors were involvement of the posterior naris (P =0.027),involvement of the orbit (P =0.005),and involvement of the hard palate (P =0.003).Conclusions The distant metastasis and local recurrence rates are high among patients with mucosal melanoma of the nasal cavity and paranasal sinuses,so combination therapy is imperative.Cervical lymph node metastasis rate is low.Rational clinical staging needs to be further explored.

Objective To evaluate the feasibility and significance of CT image-based threedimensional (3D) brachytherapy for cervical cancer.Methods Three-dimensional (3D) plan and twodimensional (2D) plan were designed for 55 CT images of brachytherapy from 12 cervical cancer patients who received radical radiotherapy in 2013.Dosimetric comparison was performed between the 3D plan and 2D plan,and paired t-test,Wilcoxon signed rank test,Pearson correlation analysis,and Spearman correlation analysis were performed.Results A point dose,D90,V100,CI,and CI' in 3D plan were higher than those in 2D plan (P=0.015,0.016,0.000,0.000,0.000).Bladder point dose,rectal point dose,and rectal D2 cm3 in 3D plan were slightly higher than those in 2D plan,but hot spot dose was significantly reduced in 3D plan (P =0.140,0.123,0.214).Bladder D2cm3 was significantly higher than bladder point dose (P =0.000).Sigmoid colon D2cm3 was more correlated with the average doses of the three highest rectal points than rectal D2 cm3 (r =0.314,0.630,P =0.000,0.000).V100 showed a linear relationship with high-risk CTV (r =0.981,P =0.000).Bladder D2cm3 was higher than 430 cGy when the bladder volume was more than 80 cm3 ;small intestinal D2 cm3 did not change significantly when the bladder volume was less than 115 cm3,but decreased significantly once the volume exceeded the value.Conclusions Compared with the traditional 2D plan,the 3D plan for CT image-based cervical cancer brachytherapy significantly increases the target coverage and conformity index,but does not significantly increase the doses to organs at risk.Point dose evaluation is confirmed to be inaccurate.The doses to the bladder,rectum,and small intestine can be adjusted by controlling the bladder volume.

Objective To study the impacts of bladder filling status on the dosimetric parameters of the target volume and organs at risk (OAR) in intensity-modulated radiotherapy (IMRT) for prostate cancer.Methods Ten localized prostate cancer patients without serious complications treated with IMRT were selected for this study.These patients underwent CT scans of the whole pelvic cavity three times in different bladder filling status (empty and injected with 150 ml and 300 ml of normal saline) to obtain three series of pelvic CT images.The three sets of CT images were transferred to the treatment planning system.The target volume and OAR such as the rectum,bladder,and femoral heads were contoured by the same doctor.The treatment planning was performed and optimized by the physicist.The dosimetric parameters of the target volume and OAR in three bladder filling status were subjected to analysis by paired t-test.Results If the bladder filling status was consistent in orientation and radiation,the bladder filling status was not associated with the dosimetric parameters of the target volume and femoral heads (P =0.077-0.998 ; P =0.219-0.969) ;it had significant impacts on the dosimetric parameters of the bladder (P =0.000-0.562) and some dosimetric parameters of the rectum (P =0.000-0.645),and bladder filling was favorable for the protection of the bladder and rectum.If the bladder filling status was not consistent in orientation and actual radiation,the calculated planning target volume,the dosimetric parameters of the bladder,and some dosimetric parameters of the rectum were different from those in actual treatment (P =0.000-0.913).Conclusions For the prostate cancer patients treated with IMRT,it is recommended to keep the bladder well and consistently filled.

Objective To investigate the safety of intraoperative electron radiation therapy (IOERT) for stage Ⅰ hepatocellular carcinoma (HCC) by a cohort study.Methods From November 2010 to May 2012,16 patients who were pathologically diagnosed with stage Ⅰ HCC underwent IOERT after radical resection.With a cohort study,87 patients with stage Ⅰ HCC who underwent radical resection alone during the same period were qualified,and according to tumor size (＞ 5 cm and ≤ 5 cm) and resection margin (close margin and negative margin),32 of 87 patients made up the control group.The intraoperative and postoperative adverse events,liver function parameters,coagulogram,and routine blood parameters,as well as IOERT-related adverse reactions,were evaluated.Independent-samples t test was used for analyzing the differences between groups.Results Compared with the control group,the IOERT group had a significantly longer operative time ((275.4 ± 71.55) min vs.(184.7 ± 64.74) min,P =0.000),a slightly higher incidence of intraoperative adverse events (18.75％ vs.6.25％,P=1.000),a slightly lower incidence of operative complications (12.50％ vs.28.12％,P =0.460),and a lower perioperative mortality (0 vs.6％,P =0.440).Liver function parameters showed no significant differences between the two groups (P ＞ 0.05).There were no significant differences between the two groups in postoperative time to grade 1 or normal liver function parameters,median length of postoperative hospital stay,length of hospital stay in the surgical department,time to incision healing,and level of incision healing (P ＞ 0.05).During follow-up,no radiation hepatitis was found in the IOERT group.Conclusions As an adjuvant therapy after radical resection for early HCC,IOERT has no significant side effects on postoperative recovery and liver function,and an intraoperative dose of 15-16 Gy is safe.

Objective To investigate the long-term survival of esophageal squamous cell carcinoma (ESCC) patients of different ages after three-dimensional conformal radiotherapy (3 DCRT).Methods From July 2003 to September 2008,769 patients with stage Ⅰ-Ⅲ ESCC were eligible for the analysis.All patients were treated with 3DCRT.The prescribed dose was 50-70 Gy (median,60 Gy),1.8-2.0 Gy per fraction,5 fractions per week.The Kaplan-Meier method was used to calculate overall survival (OS) and local control (LC) rates; the log-rank test was used for survival difference analysis and univariate prognostic analysis;the Cox regression model was used for multivariate prognostic analysis.Results The follow-up rate was 98.3％.For all patients,the 1-,3-,and 5-year LC rates were 76.3％,52.8％,and 48.5％,respectively,and the 1-,3-,and 5-year OS rates were 70.1％,36.2％,and 23.0％,respectively.The 1-,3-,and 5-year OS rates were 71.2％,38.8％,and 24.9％,respectively,for patients aged 45-74 years,versus 69.6％,26.6％,and 15.4％ for patients aged 75-89 years (P =0.008).Multivariate prognostic analysis showed that age was also a prognostic factor in ESCC patients after 3DCRT.A total of 620 patients died.Patients aged 45-74 years had a significantly higher proportion of individuals that died of distant metastasis (23.9％ vs.14.2％,P =0.009),while patients aged 75-89 years had a significantly higher proportion of individuals that died of non-cancer diseases (14.1％ vs.4.9％,P=0.000).Conclusions Survival varies between ESCC patients of different ages after 3DCRT.The survival of elderly ESCC patients is poor,and the relatively high mortality from non-cancer diseases may be an important reason for poor survival.

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.

Objective To investigate the accuracy and reliability of the image automatic matching using X-ray volumetric image (ⅩⅥ) system with the accelerator Elekta Synergy and to compare the matches with different methods and area.Methods A simulation plan using the head and neck phantom was designed and sent to ⅩⅥ system for CBCT scanning.During the scanning,the couch for certain distance was moved and the data of ⅩⅥ image automatic Matching in different matching methods and area was collected.Results The result of ⅩⅥ image automatic matching is consistent and correct to direction and distance which the couch had been moved (x:(0.11 ± 0.41) mm,y:(-0.04± 2.6) mm,z:(0.28 ± 0.74 mm)).There are not significant differences between the results that matching in different matching methods and different matching area.Conclusions The automatic image Matching of ⅩⅥ is accuracy and high reliability in recognition of offset error.But there are some significant differences on the automatic image Matching in different matching methods and different matching area.

Objective To investigate influence on dose distribution due to cavity and inhomogeneous structures using thermoluminescence dosimeters (TLD) and Chengdu phantoms.Methods A cavity 4 cm × 4 cm × 3 cm was made by a head and neck phantom and a lung phantom was cut into slices which were got a CT scanning and setup in a digital simulator.The TLD were pasted on edge and in the center of cavity structure and inhomogeneous structures.Treatment plans of different radiotherapy technologies were made generated and delivered on a linear accelerator.Then the TLD were read and analyzed.Results There were remarkable cavity effects of conventional single field,opposite fields and IMRT plans with 7 fields for head and neck phantom.There is similar effect in lung phantom.The more complexity the radiotherapy technology was the less cavity effect.Conclusions It is necessary to consider using more advanced radiotherapy technology or applying more fields to make treatment plans in order to decrease the cavity effect or similar effect when there are inhomogeneous structures.