Emerging clinical evidence revealed that postoperative adjuvant chemoradiotherapy (CRT) could improve the clinical outcome for resected head and neck squamous cell carcinoma in high-risk patients. The irradiation targets and doses should be determined by the primary tumor site, clinical stage, pathology reports, and the evaluation of postoperative imaging. Adjuvant concurrent CRT with cisplatin is the current standard treatment for high-risk postoperative head and neck squamous cell carcinoma patients. However, the effect of concurrent CRT with other chemotherapeutic agents and (or) epidermal growth factor receptor (EGFR) monoclonal antibody in these patients is inconclusive. Human papillomavirus (HPV)-positive oropharyngeal cancer has the unique biological characteristics, and the indications and treatment models of postoperative adjuvant CRT for these patients are still unclear. Further study is needed.

Microenviroment hypoxia is one of the common phenomenon in cancer,studies have indiacat-ed that hypoxia induces genetic instability via activating many DNA danlage-repair signal pathways,which asso-ciates with tumor invasion and resistance and chemi-radiotherapy resistivity.Here,we overview three main DNA damage-repair pathways:mismatch repair,homologous recombination and non-homologous end joining,and how hypoxia influences their mechanisms.

(0.05)). Multivariate analysis revealed that adjuvant radiotherapy and histology of tumor significantly affected the prognosis(P=(0.045) and P=(0.009), respectively). Whereas loco-regional control was only significantly affected by adjuvant radiotherapy(P=(0.000)). CONCLUSION: Adjuvant radiotherapy and histology of tumor are the important prognostic factors in the rectal cancer patients after treatment with multimodality therapy based on surgery.

Objective To investigate whether chromosome induced aberrations scored with fluorescence in situ hybridization (FISH) predict the radiosensitivity of human tumor cell lines. Methods Three human cell lines with different radiosensitivities(nasopharyngeal cell line CNE, lung adenocarcinoma cell line SPC, and breast adenocarcinoma cell line MCF 7) were used for clonogenic assay. Cells were irradiated with a dose of 1～8?Gy. Radiation induced aberration in a single chromosome (number 8) was measured at 24?h after irradiation of 2, 4 and 6?Gy.Results Radiation induced aberration in chromosome 8 reflected the radiosensitivity in CNE, SPC and MCF 7 cells 24 h after irradiation. It was associated with survival fraction at 2?Gy (r=0.96). Conclusion These results suggest that the radiation induced chromosome aberrations in interphase measured by FISH be a considerable promise for prediction of radiosensitivity in tumor cells.

Objective To evaluate the prognosis for patients with squamous cell carcinoma of cervical lymph node metastases from an unknown primary site who had different clinical stages and were irradiated to different fields. Methods The clinical date of 60 patients with cervical lymph node metastatic squamous cell carcinoma from an unknown primary site(no including patients with supraclavicular node metastases) were retrospectively analyzed. Results The overall 5-year survival rates(OSR) was 68.5%, the OSR of patients with N 1,N 2 and N 3 stage were 100%, 68.0% and 40.9% respectively(? 2=7.29,P=0.026). The OSR of patients with one lateral neck, whole neck and large fields irradiation were 66.5%, 74.5% and 54.6% respectively(? 2=1.38,P =0.501). The Cox proportional hazard model showed that clinical stages of cervical lymph node had an significant effect in patients survival(P=0.032). The 5-year local control rates(LCR) 65.6%, the LCR of patients with N 1,N 2 and N 3 stage were 100%, 63.2% and 34.6% respectively(? 2=5.51, P=0.064). The LCR of patients with one lateral neck, whole neck and large fields irradiation were 87.6%, 51.0% and 72.7% respectively(? 2=2.55, P =0.279). The 5-year subsequent appearance rates of occult primary cancer(SAR) was 21.2%, the SAR of patients irradiated by small(one lateral neck or whole neck) and large fields were 23.3% and 12.5% respectively(? 2=0.52, P =0.469). Conclusions The clinical stages of cervical lymph node is an important prognostic factor for survival and the local control rates has a decreasing trend as the stage increases. The subsequent appearance rates of occult primary cancer of patients irradiated by small fields has a higher trend than its of patients irradiated by large fields, but the control rates and survival rates have no significant difference in different fields irradiated.

Patients with ataxia-telangiectasia ( A-T) syndrome were charachaterized by profound hypersensitivity to ionizing radiation in clinic. Many studies have shown that this hypersensitivity possibly attributed to ATM gene whose critical compartment was ATM kinase. So inhibitors of the ATM kinase such as caffeine, pentoxifylline, methyl xanthines and 7-hydroxystaurosporine (UCN-01) were developed and have achieved a few encouraging results in basic and clinical stuides.

Objective To study the appropriate neck irradiation volume for neck lymph nodenegative nasopharyngeal carcinoma patients by Meta-analysis.Methods The related references published from Jan 1990 to Jun 2013 were searched in Pubmed,Embase,Cochrane and Wangfang Databases.The qualified references for enrollment criteria were screened and the relative data were collected.The OR (Odds ratio) value by fixed effect model was used to evaluate the data for patients who received radiotherapy between the upper neck and whole neck irradiation.The endpoints including 5-year neck local control rate (LCR),neck-in-irradiation LCR,and neck-outsides-irradiation LCR.Results Five qualified references were screened and belonged to respective research.There enrolled 1 333 patients,including 970 patients who received the upper neck irradiation and 363 patients who received the whole neck irradiation,respectively.The forest plots revealed that there were no significant differences for 5-year neck LCR,neckin-irradiation LCR,and neck-outsides-irradiation LCR for patients received radiotherapy between the upper neck and whole neck irradiation.These OR values were 0.89 (95％ CI:0.41-1.94),1.29 (95％ CI:0.58-2.88) and 0.42 (95％ CI:0.07-2.36),respectively.Conclusions The Meta-analysis results suggest that irradiation to the upper neck for neck lymph node-negative nasopharyngeal carcinoma can be appropriate.

Objective To assess the differences in delineation of organs at risk (OAR) and dosimetry between junior and senior physicians during intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC) and to evaluate the role of specific training in reducing the differences.Methods Sixteen patients newly diagnosed with NPC were selected in the study.The OAR was delineated separately by three junior physicians and three senior physicians,and the geometric and dosimetric differences were assessed relative to the reference OAR.Delineation was performed again for the two OARs with the biggest difference after specific training in the two groups of physicians,and the differences were evaluated again.The difference was determined by paired t test.Results The maximum dose differences (Dmax) of OAR in the junior and senior physicians were (2.33 ± 12.06) ％ (-48.06％-137.82％) and (0.09 ± 4.72) ％ (-49.54％-42.96％),respectively (P =0.039),and the difference in the optic chiasm was the greatest ((5.85 ± 19.63) ％ ∶ (1.36 ± 4.64) ％,P =0.042).The mean dose differences (Dmean) of OAR in the junior and senior physicians were (3.10 ± 8.07)％ (-46.76％-59.76％) and (-0.93 ± 2.03) ％ (-45.54％-35.69％),respectively (P =0.021),and the difference in the parotid gland was the greatest ((13.23 ± 13.39) ％ ∶ (3.20 ± 6.71) ％,P =0.002).In the secondary delineation after training,the Dmax of the optic chiasm in the junior and senior physicians was (1.68 ± 3.34)％ and (1.50 ± 1.87) ％,respectively (P =0.841),and the difference in junior physicians was reduced significantly compared with before training ((1.68 ± 3.34) ％ ∶ (5.85 ± 19.63) ％,P =0.048) ; the Dmean of the parotid gland in the junior and senior physicians was (2.46 ± 3.06) ％ and (1.35 ± 3.00) ％,respectively (P =0.2 7 4),significantly reduced compared with before training ((2.46 ± 3.0 6) ％ ∶ (13.23 ± 13.39)％,P=0.002; (1.35 ± 3.00)％ ∶ (3.20 ± 6.71) ％,P =0.033).Conclusions The differences in delineation of OAR lead to dose uncertainties during IMRT for NPC,and specific training can improve the accuracy of delineation.

Objective To investigate the effect of human lung cancer-associated fibroblasts (CAF) on the radiosensitivity of lung cancer cells when CAF is placed in direct contact co-culture with lung cancer cells.Methods Human lung CAF was obtained from fresh human lung adenocarcinoma tissue specimens by primary culture and subculture and was then identified by immunofluorescence staining.The CAF was placed in direct contact co-culture with lung cancer A549 and H1299 cells,and the effects of CAF on the radiosensitivity of A549 and H1299 cells were evaluated by colony-forming assay.Results The human lung CAF obtained by adherent culture could stably grow and proliferate,and it had specific expression of α-smooth muscle actin,vimentin,and fibroblast activation protein,but without expression of cytokeratin-18.The plating efficiency (PE,％) of A549 cells at 0 Gy irradiation was (20.0 ± 3.9) ％ when cultured alone versus (32.3 ± 5.5) ％ when co-cultured with CAF (t =3.16,P ＜ 0.05),and the PE of H1299 cells at 0 Gy irradiation was (20.6 ± 3.1) ％ when cultured alone versus (35.2 ± 2.3) ％ when co-cultured with CAF (t =6.55,P ＜0.05).The cell survival rate at 2 Gy irradiation (SF2) of A549 cells was 0.727 ±0.061 when cultured alone versus 0.782 ± 0.089 when co-cultured with CAF (t =0.88,P ＞ 0.05),and the SF2 of H1299 cells was 0.692 ±0.065 when cultured alone versus 0.782 ± 0.037 when co-cultured with CAF (t =2.08,P ＞0.05).The protection enhancement ratios of human lung CAF for A549 cells and H1299 cells were 1.29 and 1.25,respectively.Conclusions Human lung CAF reduces the radiosensitivity of lung cancer cells when placed in direct contact co-culture with them,and the radioprotective effect may be attributed to CAF promoting the proliferation of lung cancer cells.

Objective To investigate the dosimetric difference of organ at risk (OAR) for planning and actual estimated during intensity-modulated radiotherapy (IMRT) for patients with nasopharyngeal carcinoma.Methods Thirteen patients were enrolled to accept full course of IMRT.CT scans were acquired in the 10th,20th,and 30th fractions during radiotherapy,respectively.OAR,including brain stem,spinal cord,parotid gland and submandibular gland,were delineated on repeated CT scans.The volume change of OAR were investigated.After that,the plans were copied to the new CT image to calculate the escalated average dose of OAR during radiotherapy (Actual estimated receiving dose minus planning dose).Results The change trend of volume was decreasing gradually for parotid gland and submandibular gland during the 10th,20th,and 30th times radiotherapy (all P =0.000).The maximum dose (Dmax) of brain stem and spinal cord and the 50％ volume receiving dose (D50) of parotid gland increased significantly in the 10th,20th,and 30th times during radiotherapy,respectively.The escalated average dose were 3.76 and 3.68 Gy for Dmax of brain stem and spinal cord (P =0.000,0.000),5.11 and 3.54 Gy for D50 of left and right parotid (P =0.001,0.023),and 0.49 and 0.75 Gy for D50 of left and right submandibular gland (P =0.220,0.230),respectively.Conclusions The volume of parotid gland and submandibular gland significantly decreased after radiotherapy The actual receiving dose of brain stem,spinal cord,and parotid gland increased significantly during radiotherapy.However,there was no significant change for the actual receiving dose of submandibular gland.