Objective To investigate the differences in clinical features and prognosis between patients with stage Ⅰ E-Ⅱ E nasal cavity natural killer (NK)/T-cell lymphoma (NC-NKTL) and Waldeyer's ring NK/T-cell lymphoma (WR-NKTL).Methods A retrospective analysis was performed on 273patients with NK/T lymphoma who were initially treated in our hospital from January 1991 to December 2011.Of these patients,184 had Ann Arbor stage Ⅰ E disease,and 89 had stage Ⅱ E disease;209 had NCNKTL,and 64 had WR-NKTL.A total of 258 patients (94.5％) were first treated with chemotherapy.The majority of patients received CHOP or CHOP-like chemotherapy.The median dose of radiotherapy was 54Gy.Results Compared with NC-NKTL patients,WR-NKTL patients had significantly higher percentages of individuals in stage Ⅱ E and individuals with B symptoms (P ＜0.05 for both).The overall response rates of the two groups after treatment were similar (88.7％ vs 87.9％,P =0.869).The follow-up rate was 96.3％.196 patients were followed up for at least 5 years.The 5-year overall survival (OS) and progression-free survival (PFS) were 52.6％ and 41.4％,respectively.The 5-year OS of NC-NKTL patients was nonsignificantly higher than that of WR-NKTL patients (57.0％ vs 39.0％,P =0.062),while the 5-year PFS of NC-NKTL patients was significantly higher than that of WR-NKTL patients (46.7％ vs 25.8％,P =0.019).Conclusions Patients with early-stage WR-NKTL are more prone to systemic symptoms and cervical lymph node metastasis and have poorer prognosis,as compared with patients with early-stage NC-NKTL,so radiotherapy and prophylactic irradiation should be considered in early stage.

Objective To investigate the role of three-dimensional (3D) radiotherapy to the thoracic primary tumor in non-small cell lung cancer (NSCLC) patients with bone metastases during chemotherapy with concurrent 3D radiotherapy.Methods From 2003 to 2010,the clinical data of 95 stage Ⅳ NSCLC patients with bone metastases were collected.All patients received 3D radiotherapy to the thoracic primary tumor and at least 2 cycles of chemotherapy.Of the 95 patients,47 had only bone metastases,and 48 had metastases to bones and other organs.The Kaplan-Meier method was used to calculate overall survival (OS) 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 95％.The 1-,2-,and 3-year OS rates were 44％,17％,and 9％,respectively.The univariate analysis showed that radiation dose to the planning target volume (PTV) of primary tumor of ≥ 63 Gy,response to treatment of primary tumor,and at least 4 cycles of chemotherapy were favorable prognostic factors for OS in all patients (P =0.001,0.037,and 0.009).Radiation dose to the PTV of primary tumor of ≥ 63 Gy remained the favorable prognostic factor for OS in patients with only bone metastases and those with metastases to bones and other organs (P =0.045 and 0.012).Among patients with only bone metastases,those with T1 + T2 primary tumors had longer OS than those with T3 + T4 primary tumors (P =0.048).The multivariate analysis showed that radiation dose to the PTV of primary tumor of ≥ 63 Gy and metastases to bones only were independent favorable prognostic factors for OS in all patients (P =0.036 and 0.035).Conclusions For NSCLC patients with bone metastases,3D radiotherapy to the thoracic primary tumor and its dose play an important role in improving OS during chemotherapy with concurrent 3D radiotherapy.

Objective To analyze the difference of prescription dose between ICRU report 83 and Chinese recommendation in the nasopharyngeal carcinoma (NPC) for intensity modulated radiation therapy (IMRT).Methods Eighty-four NPC were treated using IMRT technology from Jan 1,2010 to Apr 1,2012.All dose volume histogram of the 84 IMRT plan were analyzed retrospectively.The target volumes of planning gross tumor volume of nasopharynx (PGTVnx) or planning clinical target volume and high risk lymphatic drainage (PCTV1) and doses of D100,D98,D95,D50,D2 and D0 were recorded.The mean,standard error,medial,range,coefficient of variation (CV) of PGTVnx,PCTV1,and D100,D98,D95,D50,D2and D0 were calculated,respectively.The homogeneity index (HI) and deviation between D95 and D50 of PGTVnx and PCTV1 were calculated,respectively.The differentiation of grouping results were analyzed with grouped t-test method.Results The HI of PGTVnx and PCTV1 were 0.118 ± 0.045 and 0.272 ± 0.037,respectively.It is the bigger target volume,the worse HI;and the advanced T stage,the worse HI.Either PGTVnx or PCTV1,D95 were less than D50.The average deviation was-5.15％ and-10.97％,and the actual difference value was (382± 180) cGy (P=0.000) and (741± 140) cGy (P=0.000).Conclusions D550,which is the recommendation prescription dose of PTV in ICRU report 83,could evaluate accurately the IMRT plan with combining D98 and D2· When D50 is used to instand of D95,the prescription dose of PGTVnx and PCTV1 should increase 5％ and 11％,respectively.

Objective To evaluate the treatment outcome and prognostic factors in patients with grade Ⅲ/Ⅳ glioma following postoperative chemoradiotherapy.Methods A retrospective analysis was performed on the medical records of 119 patients with grade Ⅲ/Ⅳ glioma who received treatment in our hospital from January 2007 to April 2012.Of the 119 patients,49 received radiotherapy alone,21 received radiotherapy combined with nitrosoureas,and 49 received radiotherapy combined with temozolomide.The Kaplan-Meier method was used to calculate overall survival (OS) rates and recurrence rates.The Cox regression model was used for multivariate prognostic analysis.Results The follow-up rate was 94.1％.Fifty-three patients were followed up for at least 1 year,and 10 for at least 2 years.The overall recurrence rate was 69.7％.The 1-and 2-year OS rates were 44.5％ and 8.4％,respectively.The multivariate analysis showed that age,presence or absence of seizures before surgery,extent of tumor resection,and radiotherapy plus concurrent and adjuvant temozolomide were the main prognostic factors for tumor recurrence (P =0.002,0.005,0.000,and 0.000).The above factors and the pathological grade of tumor were the independent prognostic factors for patients' survival (P =0.006,0.010,0.000,0.000,and 0.001).Conclusions Postoperative radiotherapy plus concurrent and adjuvant temozolomide produce a good clinical effect in patients with grade Ⅲ/Ⅳ glioma.Age of ＜ 60 years,no seizures before surgery,total tumor resection,and pathological grade Ⅲ of tumor are the favorable prognostic factors for the long-term survival in patients with malignant glioma.

Objective To compare the errors of final isocenter marking method and reference point marking method for CT simulation positioning in intensity-modulated radiotherapy (IMRT).Methods From 2009 to 2012,327 patients with head and neck cancer for IMRT underwent CT simulation positioning using the Philips Brilliance CT Big Bore scanner and Philips Tumor LOC workstation and were divided into final isocenter marking group (n =208) and reference point marking group (n =119) according to positioning methods.Target volume delineation and treatment plan design were performed on the Varian Eclipse treatment planning system (TPS).Before treatment,kilovoltage cone-beam CT scans and registration were performed with the Varian EX on-board imager system to obtain beam position errors in the right-left (RL),superior-inferior (SI),and anterior-posterior (AP) directions,and then comparisons of errors between the two groups were made by independent-samples t test.Finally,the TPS was used to measure the changes in the doses to the organs at risk after moving isocenters in the RL,SI,and AP directions among 5 patients with nasopharyngeal carcinoma.Results The mean beam position errors in the three directions were less in the final isocenter marking group than in the reference point marking group (P =0.02,0.01,0.03).After moving isocenters in the three directions,the target dose was reduced and the dose to the normal tissue around the target tumor was increased significantly.The error in the AP direction had the maximum influence on the spinal cord and brainstem.Conclusions Final isocenter marking method leads to less beam position error than reference point marking method in CT simulation positioning.Small isocenter motion can cause large changes in the doses to the organs at risk.

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.

Objective To compare postoperative adjuvant chemoradiotherapy with adjuvant chemotherapy in patients with gastric cancer by a meta-analysis.Methods PubMed,EMbase,Cochrane Library,Wanfang,CNKI,VIP,and CBM databases were searched to identify the controlled clinical trials of postoperative adjuvant chemoradiotherapy versus adjuvant chemotherapy for gastric cancer.The obtained data were analyzed using RevMan 5.2.5 and Stata 12.0.The difference between two groups was estimated by calculating the odds ratio (OR) with 95％ confidence interval (CI).Results A total of 12 controlled clinical trials involving 1674 gastric cancer patients,which were selected according to inclusion and exclusion criteria,were included in this meta-analysis.The meta-analysis showed that the 3-and 5-year survival rates were significantly higher in the adjuvant chemoradiotherapy group than in the adjuvant chemotherapy group (OR=2.96,95％ CI=1.75-5.03,P=0.000; OR=1.45,95％ CI=1.06-1.99,P =0.020);the local recurrence rate was significantly lower in the adjuvant chemoradiotherapy group than in the adjuvant chemotherapy group (OR =0.50,95％ CI =0.34-0.72,P =0.000) ; there was no significant difference in distant metastasis rate between the two groups (OR =0.79,95％ CI =0.58 -1.07,P =0.130).Conclusions The meta-analysis of existing study results shows that compared with adjuvant chemotherapy alone,adjuvant chemoradiotherapy is a relatively safe and effective postoperative treatment for gastric cancer.

Objective To analyze the outcomes of radiotherapy for keloids by high energy electron beams and the factors influencing the treatment outcome.Methods From Jan 1998 to Jun 2012,846lesions in 578 patients received radiotherapy.The median age is 29 years old (range 5-80 years old).There are 841 lesions with postoperative radiotherapy and 39 lesions with skin-grafting.656 lesions treated within 1 day after operations.The max diameter of 348 keloids are ＞ 5 cm.We used 6 MeV and 7 MeV electron-beam radiation therapy.The total dose ranging from 16-18 Gy/2f (interval 1 week).Treatment fields including entire keloid scars,and any suture/puncture holes with a 1 cm-margin around the lesion were used.The skin grafting patients need radiotherapy after the flap survived (about 10-15 days after the operation).The median follow-up period was 36 months (range 8-185 months).Results There are 736 (87.0％) of 846 lesions with radiotherapy effective.Other 89 (10.5％) lesions relapse in 4-33 months (median 12 months).21 lesions were of no avail.The univarate analysis shows that keloids length,keloids location,skin-grafting,interval between operations and irradiations are the influencing factors of outcomes (P =0.007,0.000,0.000,0.001).The multivariate analysis shows that keloids location and skin-grafting remained statistically significant differences (P =0.001,0.001).Most of the recurrence cases are large and bent scars.Conclusions High-energy electron-beam radiotherapy for keloids can receive good outcomes.Treatment fields flat is very important for electron-beam radiotherapy.

ObjectiveTo compare the accuracy of enhanced dynamic wedge (EDW) models of adaptive convolution algorithm (ACA) in Pinnacle3 9.0 and anisotropic analytical algorithm (AAA),and pencil beam convolution (PBC) algorithms in Eclipse7.3 treatment planning systems (TPS).MethodsTo evaluate the accuracy of the three algorithm models,we compared actual measurement values with TPS calculation values of EDW wedge factors under for different fields in which Varian-21EX 6 MV X-ray was applied,and also compared the actual dose distribution profile with that of TPS.ResultsThe deviations of EDW wedge factors of symmetry fields and asymmetric fields are within 2.8％ and 19.4％ for ACA in Pinnacle3 9.0.Meanwhile,the deviations are 1.0％ and 2.0％ for AAA,1.2％ and 3.0％ for PBC in Eclipse7.3.The deviations between measurement and calculation of all fields profile for ACA is within 3％ and within 2.7％ for AAA within 4.0％ for PBC in wedge direction.For the dose distributions,we evaluated the pass rates of three algorithms using gamma analysis.The gamma pass rates among all the three algorithms in symmetry and asymmetric fields are above 87％ and 85％ respectively.After the removal of the penumbra zone,the pass rates among all the three algorithms are above 96％ in symmetry fields,and above 95％ in asymmetric fields,respectively.Conclusions AAA and PBC algorithms in symmetric and asymmetric fields can meet the need of clinical applications.While,wedge factor of ACA should not be used in clinical due to its greater error in asymmetric fields.

ObjectiveTo investigate the CT number linearity of the cone-beam CT (CBCT) images at the different spatial locations in the scanning area.MethodsThe CatphanS04 phantom at the different locations are scanned repeatcdly using the CBCT on the Varian 23EX linear accelerator.The phantom is located the isocenter point,eccentric 3 cm,eccentric 6 cm,and different points on the z-axis successively on the accelerator.The scanned mode is the standard head mode.The reconstructive thickness is 2.5 cm.The different densities inserts of CTP404 module on the different locations are measured via Eclips treatment planning system (TPS) and computed by Matlab 7.0 and the CT linear fitting are then processed.In order to understand better the linear distribution along with the value of CT in the spatial distribution the results are compared with the fan-beam CT.ResultsPhantom studies show that:CBCT has good linearity performance not only under the standard header (body) of the scanning conditions,but also on such locations including the cross-sectional,the sagittal,the coronal plane and the eccentric position ( R2 ＞ 0.953 ).Bowtie filtration device does not change the CT finearity but changes the value of CT.ConclusionsThe linearity of X-ray CBCT on the Varian linear accelerator is favorable.CBCT will be used in the TPS dose calculation via further correction of the CT value.