Currently,resectable esophageal cancer is commonly initially treated with surgery in China,but the optimal postoperative treatment remains unclear.Postoperative concurrent chemoradiotherapy can improve local control and reduce distant metastasis and may become the preferred treatment for patients after surgery for esophageal cancer.By summarizing the studies on concurrent chemoradiotherapy after surgery for esophageal cancer,this review points out that postoperative concurrent chemoradiotherapy can improve the overall survival of patients with positive lymph nodes and has tolerable adverse effects,but the populations who can benefit from this treatment,the optimal radiotherapy dosage,target volume,and chemotherapy regimen of postoperative concurrent chemoradiotherapy await further investigation.

Combined small cell lung cancer (C-SCLC) is a special subtype of small cell lung cancer (SCLC),which has a low incidence and diagnostic rate.However,the incidence and diagnostic rate appear an increasing tendency recently.The clinical features of C-SCLC are similar to the pure SCLC,while it has a relatively limited stage.The main treatment pattern of C-SCLC is multimodality therapy,though the response to chemotherapy in C-SCLC is relatively poor.Survival between patients with C-SCLC versus SCLC is similar.KPS,stage,composite components,tumor location and diameter,surgery margin are prognostic factors.Radiotherapy can benefit for the patients with ⅢA/ⅢB disease,positive lymph nodes,or with more metastatic lymph nodes after surgery.

Radiation therapy is one of the main treatment methods for cancer. Machine learning can be used in all aspects of clinical practice in radiation therapy, including clinical decision support, automatic segmentation of target volumes, prediction of treatment efficacy and side effects. Despite the challenges of lacking structured data and poor interpretability of models, the application of machine learning in radiotherapy will become increasingly profound and extensive. This review contains three aspects: introduction of machine learning, the clinical application of machine learning in radiotherapy, challenges and solutions.

Objective Renal papillary cell carcinoma(RPCC) has been historically regarded as a radio-resistant malignancy. However, the molecular mechanism underlying its radio-resistance is not well understood. Recently,STAT1, a transcription factor downstream of the IFN-signalling pathway, has been implicated in radioresistance. This study is to investigate the role of STAT1 in "radio-resistant RPCC". Methods The expression of STAT, in 137 human RPCC samples compared with 15 normal kidney tissues was examined by micrearray expression profiling using the Affymetrix HGU133 Plus 2.0 GeneChip oligonucleotide arrays. For in-vltro experiments, human RPCC cell line(SKRC-39), human fibroblast(CCL-116) and human Wiim's tumor cell line(CRL-1441) were used. Western blotting was performed to evaluate total and phosporylated STAT1 expression. RPCC cells were irradiated and compared to controls in clonogenic assays. STAT1 inhibition either with fludarabine or siRNA was done and their effects on radiation-induced cell survival were investigated. Results The STAT1 expression data shows that there was a significant increase in human RPCC when compared to normal kidney tissues (t=44.38,P=0.000). Similarly, the expression of STAT1 was higher in the RPCC cell line when compared to firbroblast and Wilm's tumor cell lines. STAT1 expression was inhibited by beth fludarabine and siRNA. Radiosensitivity in RPCC cell lines was enhanced by both fludarabine and siRNA induced STAT1 inhibition. Conclusions This is the first study reporting the over-expression of STAT1 in human RPCC tissues and human RPCC cell line. Radiesensitization of RPCC is observed via inhibition of STAT1 signaling by fludarabine and siRNA techniques. Our data suggests that STAT1, through IFN-signalling pathway , may play a key role in RPCC radioresistance and manipulation of this pathway may enhance the efficacy of radiotherapy.

Objective To study the expression of signal transducer and activator of transcription 1 (STAT1) in human renal clear cell carcinoma (RCC) and the effect of STATI inhibition on the radiosensi-tivity of RCC. Methods The expression of STAT1 in 34 human RCC samples compared with 12 normal kid-ney tissues was examined by immunohistochemistry method. For in vitro experiments, a human RCC cell line, CRL-1932, was used. Western blotting was performed to evaluate the expression of total and phospory-lated STAT1. Fludarabine and siRNA were respectively used to inhibit the expression of STAT1 in CRL-1932 cells. Clonogenic assay and trypan blue staining assay were used to evaluate the radiosensitivity of CRL-1932 cells. Results The expression of both total and phospborylated STAT1 in human RCC samples was signifi-cantly higher when compared to normal kidney tissues. Similarly, the expression of STAT1 was higher in CRL-1932 cells when compared to fibroblast and Wilm's tumor cell lines. STAT1 expression was inhibited by both fludarabine and siRNA. Radiosensitivity of CRL-1932 cells was enhanced by both fludarabine and siRNA induced STAT1 inhibition. Conclusions STAT1 is over-expressed in both human RCC tissue and cell line. Inhibition of STAT1 can enhance the radiosensitivity of RCC cells.

Objective To compare the effect of set-up errors to two different body positions that are putting arms on the side of the body (A group) or placing arms folded across the elbow on forehead (B group) in esophageal cancer' fraction radiotherapy.Methods By using case-control study,all supine patients were divided into the A group and the B group.After patients were fixed by thermoplastic membrane,they were located by spiral CT and treated by using IGRT.During treatmwnt,there were three cone-beam CT scans in the first week and then at least one scan weekly.We obtained the linear set-up errors data by using bone registration with manual proofreading in 3 directions that were left and right (x),head and feet (y),abdomen and back (z) by using CBCT.Means were compared by using independent sample t-test,and ratios were compared by chi-square test.Results Every group had 11 cases that the A group had 92 people times and the B group had 87 people times.Absolute set-up errors of two different positions:only x-axis,the mean of the A group was (2.46 ± 1.79) mm.But the mean of the B group was (1.91 ± 1.71)mm,which was significantly less than the A group (P =0.036).Relative set-up errors of two groups:only y-axis,the mean of the B group was (1.91 ± 4.12) mm.The A group was (0.09 ± 3.90) mm,which was significantly less than the B group (P =0.003).There was no significant difference of three-dimensional set-up errors (P=0.751).And there was no significant difference in absolute weekly set-up errors or weekly three-dimensional set-up errors in radiotherapy (P ＞ 0.05).Conclusions The each of two body positions in esophageal cancer' fraction radiotherapy has advantage and disadvantage for set-up errors,but they were in control and didn't affect the radiotherapy planning.We can choose appropriate treatment position according to clinical practice.

Objective To investigate the impact of anatomical landmarks on registration in image?guided radiotherapy (IGRT) for central and peripheral lung cancer. Methods Twenty?five patients with central or peripheral lung cancer for IGRT were enrolled in this study. Kilo?voltage cone?beam CT ( kV?CBCT) scanning was acquired before irradiotion. Tumor coverage on CBCT was assessed using gross tumor volume (GTV), clinical target volume (CTV), and planning target volume (PTV) contours according to tumor alignment, carina registration, and spine registration, respectively. The grading analysiswas based on visual tumor assessment as follows:grade 0, tumor within GTV;grade 1, tumor outside GTV but inside CTV;grade 2, tumor outside CTV but inside PTV;and grade 3, tumor outside PTV. Results Totally 177 sets of kV?CBCT of 25 patients was collected. According to the registration landmarks of the tumor, carina and spine for central lung cancer, the percentages were 57?55%, 53?77% and 16?04% in grade 0, 39?62%, 45?28%and 58?49% in grade 1, and 1?89%, 0?94% and 25?47% in grade 2, respectively. For peripheral lung cancer, the percentages were 47?89%, 14?08% and 2?82% in grade 0, 43?66%, 29?58% and 45?07% in grade 1, and 8?45%, 40?85% and 35?21% in grade 2, respectively. Conclusions For central lung cancer,the tumor was recommended as the best registration landmark, and the carina was recommended as well, while the spine was not recommended. For peripheral lung cancer, the tumor was recommended as the best registration landmark, while the spine and the carina were not recommended.

Objective To investigate the efficacy and toxicity of postmastectomy hypofractionation radiotherapy in patients with high-risk breast cancer. Methods Postmastectomy radiation of 43.5 Gy in 15 fractions of 2.9 Gy over 3 weeks was delivered to 38 patients with breast cancer. The incidence of acute radi-ation toxicity and lecoregional recurrence was evaluated. Results With a median follow up of 13 months, all patients were alive. No patient had locoregional recurrence within radiation field. Five (13%) had dis-tant metastases. Five (13%) developed grade 3 radiation dermatitis at 2 to 3 weeks after the course of radia-tion. Three (8%) had grade 2 radiation pneumonitis. Conclusions Hypofractionation radiation of 43.5 Gy in 15 fractions of 2.9 Gy over 3 weeks is effective in the near time for patients with high-risk breast cancer after mastectomy, and the acute toxicities are tolerable.

Objective To investigate the value of DWI using 3.0 T MRI to predict response to radiotherapy(RT) and concurrent chemoradiotherapy(CCRT) in patients with advanced non-small cell lung cancer (NSCLC).Methods From January 2014 to May 2015, 40 patients with stageⅢ(Ⅲa orⅢb) NSCLC underwent DWI using 3.0 T MRI before RT/CCRT were enrolled. The imaging quality of diffusion-weighted images were evaluated on 3-level grades as good, moderate and non-diagnostic.The patients with good or moderate image quality were underwent DWI at 2 weeks after starting therapy(total dose of 20 Gy), and at the end of therapy (total dose of 60 Gy). Apparent diffusion coefficient(ADC) of lung cancer with good and moderate image quality were calculated by Funtool. The following quantitative parameters were recorded and calculated: the mean pretreatment ADC value(ADCpre), the mean mid-treatment ADC value (ADCmid), the mean post-treatment ADC value(ADCpost), the rate of changes inmean ADC value at 2 weeks post therapy (ΔADCmid) and the rate of changes inmean ADC value at the end of therapy(ΔADCpost). The patients were classified into response group and non-response group according to the tumor response, which was assessed with revised response evaluation criteria in solid tumors (RECIST1.1) after CCRT. The Mann-Whitney U test was used to compare parameters between the two groups.The relationship between these obtained parameters and tumor response was evaluated by Spearman correlation analysis. The value of parameters on predicting tumor response was calculated by receiver operating characteristic curve.Results 96.4%(80/83) DW images were graded as good or moderate image quality. The responders had lower median ADCpre[1.32 (0.77—1.96) × 10- 3 mm2/s] than non-responders[1.60(1.12—2.33) × 10- 3 mm2/s], which had statistically significant difference (Z=-2.934,P=0.003).Tumor regression rate after treatment had negative correlation with ADCpre(r=-0.386, P=0.018).The responders had increased ADC [ΔADCmid: 38.9%(12.8%—139.0%),ΔADCpost: 48.3% (25.6%—148.1%)] than non-responders [ΔADCmid: -2.5% (-15%—29.4%), ΔADCpost:14.2% (- 28.1% —71.3% )], which had statistically significant difference (Z=- 2.847, - 2.221, respectively;P<0.05). Tumor regression rate after treatment had positive correlation with ΔADCmid(r=0.637, P=0.001) and ΔADCpost(r=0.631, P=0.005).From ROC analysis,when setting threshold on pretreatment ADCpre=1.38 × 10-3 mm2/s, ΔADCmid=21.6%, ΔADCpost=38.8%, the area under curve was 0.782, 0.838 and 0.813.Conclusion The mean ADC value before RT/CCRT and its changes during treatment is likely to be a valuabletool for predicting the response after RT/CCRT in advanced NSCLC, which may be helpful to clinical decision on individualized therapy.

ObjectiveTo evaluate the current practice of breast-conserving radiotherapy (BCR) in mainland China.MethodsA questionnaire on the details of treatment pattern of BCR for early breast cancer was mailed twice to all radiotherapy centers in mainland China in 2009.The responding data were collected and analyzed.ResultsOf the 952 surveyed centers,396 responded (41.6％) and 328 performed BCR.The median interval between surgery and radiotherapy was 9 weeks.Of the 328 centers with BCR,whole breast was the most common irradiation target (319 centers,97.3％ ),followed by supraclavicular region (273 centers,83.2％ ),axilla (138 centers,43.3％ ),and internal mammary chain (85 centers,26.8％ ).In 97.5％ of centers (310/319),whole breast was irradiated in all candidates.Supraclavicular region and axilla irradiation was performed for lymph-node positive patients in 41.8％ (114/273) and 26.8％(37/138) centers,and for ≥4 positive lymph-nodes in 31.5％ (86/273) and 29.0％ (/138)centers,respectively. Internal mammary chain was irradiated for tumors located in the center or inner quadrant in 72.9％ ( 56/85 ) centers.Conformal radiotherapy for the whole breast was used in 51.8％centers.The median total dose was 50 Gy,all using conventional fractionations.ConclusionsA consensus has been reached that radiotherapy is needed for patients receiving breast-conserving surgery and that irradiation to whole breast is necessary.However,establishment and widespread use of guidelines for BCR should be strengthened.