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Objective:To investigate the effect and mechanism of circular RNA (cirRNA) on the radiosensitivity of rectal cancer.Methods:The differential circRNAs in radiosensitive and radioresistant rectal cancer tissues (biopsy tissue before radiotherapy and chemotherapy) were detected by gene sequencing, and the effect of circRNAs on the radiosensitivity of colorectal cancer cells was further confirmed in vitro. Results:Through gene sequencing of rectal cancer tissue samples, 64 circRNAs were found to be highly expressed in radiosensitive rectal cancer tissues, and 36 circRNAs were lowly expressed in radiosensitive tissues. Ten differential circRNAs were selected and verified by qRT-PCR, and it was found that circATL2 was highly expressed in radiosensitive rectal cancer tissues. In vitro cell experiment indicated that up-regulation of circATL2 expression could significantly improve the radiosensitivity of rectal cancer. Subsequently, 8 miRNAs lowly expressed in radiosensitive rectal cancer tissues were analyzed. The direct binding relationship between miR-205 and circATL2 was confirmed by dual luciferase reporter assay. The rescue experiment confirmed that circATL2 in rectal cancer regulated the radiosensitivity of rectal cancer through miR-205. Conclusion:circATL2 regulates the radiosensitivity of rectal cancer by binding to miR-205.
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Objective To investigate the effects of hippocampal?sparing intensity?modulated radiotherapy ( IMRT) on dose distribution of target volume and organs at risk ( OARs) in locally advanced nasopharyngeal carcinoma. Methods A retrospective dosimetric analysis was performed among 11 patients with locally advanced nasopharyngeal carcinoma. The MONACO ? v5. 10 Treatment Planning System was used to design three treatment plans:routine volumetric modulated arc therapy ( VMAT ) , hippocampal?sparing VMAT, and nine fixed?fields IMRT. The D98%, D50%, D2%, Dmean , conformity index ( CI ) , and homogeneity index (HI) of planning target volume (PTV) and PTVnx as well as dose distribution of the hippocampus and OARs were evaluated. Using single factor analysis of variance,two group comparative was LSD or paired t?test. Results For the above three plans,the D2% values of PTVnx were ,7 513,and 7 462 cGy,respectively (P=0. 016);the D98% values of PTV were 5837,5812,and 5914 cGy,respectively (P=0. 029);the average D2% values of PTV were 7 399,7 380,and 7 333 cGy,respectively ( P=0. 047);the HI values of PTV were 0. 239,0. 241,and 0. 220,respectively (P=0. 016);the V10 values of the brain stem were 97. 2%,88. 1%,and 90. 3%,respectively ( P=0. 001);the V20 values of the brain stem were 74. 2%, 62. 3%,and 67. 1%,respectively ( P=0. 032);the V30 values of the brain stem were 50. 9%,35. 8%,and 45. 5%, respectively ( P= 0. 020 );the V40 values of brain stem were 24. 4%, 14. 4%, and 23. 3%, respectively ( P=0. 018);the Dmean values of hippocampus were 1 518,899,and 896 cGy,respectively ( P=0. 000);the D40% values of hippocampus were 1 379,642,and 639 cGy,respectively ( P=0. 000);the V10 values of the hippocampus were 54. 1%,25. 1%,and 3. 8%,respectively ( P=0. 000);the V20 values of the hippocampus were 26. 2%, 12. 6%, and 12. 0%, respectively ( P=0. 001 ) . Conclusions Hippocampal?sparing VMAT and nine fixed?fields IMRT can significantly reduce the dose to the hippocampus without affecting dose distribution of target volume and OARs. VMAT may be superior to IMRT because VMAT can simultaneously reduce the dose to the brain stem.
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Objective To compare the differences in setup error ( SE) assessment and correction between three-dimensional cone-beam computed tomography ( 3DCBCT ) and four-dimensional CBCT ( 4 DCBCT ) in breast irradiation patients during free breathing after breast-conserving surgery . Methods Twenty patients with breast cancer after breast-conserving surgery were recruited for external beam breast irradiation and 4DCBCT and 3DCBCT simulation. The target volumes were delineated. Volumetric modulated arc therapy plans were designed using the MONACO v510 treatment planning system. 3DCBCT and 4DCBCT images were collected alternately five times each before breast irradiation. The CT images were matched, and the interfraction SEs were acquired. After online setup correction, the residual errors were calculated, and the SEs, systematic errors, and random errors were compared. The paired t test was used for comparison between groups. Results The SEs acquired by 4DCBCT were significantly larger than those acquired by 3DCBCT in three directions ( P=0035, 0018, 0040 ) . After online setup correction, the random errors based on 3DCBCT were significantly smaller than those based on 4DCBCT in left-right and anterior-posterior ( AP ) directions ( 0.5± 039 mm vs. 0.7± 030 mm, P=0005;0.9± 109 mm vs. 1.2± 048 mm, P=0000) , and the residual errors based on 3DCBCT were also significantly smaller than those based on 4DCBCT in AP direction (0.2±033 mm vs. 0.6±063 mm, P=0000). The setup margins based on 4DCBCT was significantly larger than those based on 3DCBCT in AP direction both before and after online setup correction (P=0002). Conclusions Compared with 3DCBCT, 4DCBCT has more advantages in monitoring the SEs in three directions. Both 3DCBCT and 4DCBCT have similar efficacy in random error correction. The satisfying position repeatability and minimized target volume margins will be achieved by online setup correction.
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Objective To compare the differences in setup error ( SE) assessment and correction between three-dimensional cone-beam computed tomography ( 3DCBCT ) and four-dimensional CBCT ( 4 DCBCT ) in breast irradiation patients during free breathing after breast-conserving surgery . Methods Twenty patients with breast cancer after breast-conserving surgery were recruited for external beam breast irradiation and 4DCBCT and 3DCBCT simulation. The target volumes were delineated. Volumetric modulated arc therapy plans were designed using the MONACO v510 treatment planning system. 3DCBCT and 4DCBCT images were collected alternately five times each before breast irradiation. The CT images were matched, and the interfraction SEs were acquired. After online setup correction, the residual errors were calculated, and the SEs, systematic errors, and random errors were compared. The paired t test was used for comparison between groups. Results The SEs acquired by 4DCBCT were significantly larger than those acquired by 3DCBCT in three directions ( P=0035, 0018, 0040 ) . After online setup correction, the random errors based on 3DCBCT were significantly smaller than those based on 4DCBCT in left-right and anterior-posterior ( AP ) directions ( 0.5± 039 mm vs. 0.7± 030 mm, P=0005;0.9± 109 mm vs. 1.2± 048 mm, P=0000) , and the residual errors based on 3DCBCT were also significantly smaller than those based on 4DCBCT in AP direction (0.2±033 mm vs. 0.6±063 mm, P=0000). The setup margins based on 4DCBCT was significantly larger than those based on 3DCBCT in AP direction both before and after online setup correction (P=0002). Conclusions Compared with 3DCBCT, 4DCBCT has more advantages in monitoring the SEs in three directions. Both 3DCBCT and 4DCBCT have similar efficacy in random error correction. The satisfying position repeatability and minimized target volume margins will be achieved by online setup correction.
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Objective To investigate the feasibility of prophylactic cranial irradiation with hippocampal avoidance (HA-PCI) in non-small cell lung cancer (NSCLC).Methods The clinical data of 56 patients with brain metastases of NSCLC who were treated from 2011 to 2014 were collected.Brain metastases and the hippocampus were delineated on T1 W1 contrast-enhanced MRI,and the distance between brain metastases and the hippocampus was analyzed;an HA-PCI regimen was also developed,and the distribution of the metastases in planning target volume (PTV) low-dose regions around the hippocampus was analyzed.Results None of the 139 metastases involved the hippocampus.There were 6(4.3％) and 18 (12.9％) metastases within 5 mm and 10 mm,respectively,outside the hippocampus.In the HA-PCI regimen,the D50％ and D2％ of PTV were 25.6 Gy and 27.1 Gy,respectively.Dmean and D2％ for the hippocampus were 7.4 Gy and 9.9 Gy,respectively;D50％ within 0-5.0 mm,5.1-10.0 mm,and 10.1-15.0 mm outside the hippocampus was 10.3 Gy,15.1 Gy,and 20.5 Gy,respectively.Conclusions HA-PCI may be feasible theoretically,but this needs to be confirmed by the intracranial failure pattern in patients with long-term survival.
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Objective To investigate the impact of oral contrast agent for assisting in outlining the small bowel on pelvic volumetric modulated arc therapy (VMAT) dose in patients with cervical cancer.Methods Nine cervical cancer patients for postoperative radiotherapy underwent CT scans,and the target volumes and organs at risk including the small bowel were contoured.The VMAT plan was designed for each case.Then another plan was generated by re-calculating the radiation dose after changing the electron density of the small bowel.The first plan (plan A) was the conventional VMAT plan,and the second one (plan B) specified the electron density of the small bowel.Paired t-test was used to compare the dose distribution between the two plans.Results The Dg8,D5o,conformity index,and homogeneity index of plans A and B were 4 989.1 vs.5 000.1 cGy (P =0.026),5 208.6 vs.5 191.6 cGy (P =0.005),0.766 vs.0.765 (P =0.920),and 0.081 vs.0.074(P =0.055),respectively.The volumes of the small bowel receiving at least 30 Gy for plans A and B were 309.3 vs.314.3 cm3(P =0.207),while bladder V45 of the two plans was 52.4％ vs.51.1％ (P =0.168).To achieve the same prescribed dose,plan A and plan B needed 893.3 MU and 865.8 MU (P =0.093).Conclusions The contrast agent filling the small bowel does not lead to a significant increase in the pelvic VMAT dose in patients with cervical cancer after surgery.
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Objective To study the accuracy of SentinelTM system for patient setup using rigid-body phantom.Methods A 002LFC IMRT phantom was placed on Elekta HexaPODTM 6-degree couch using tattoo and the laser in the treatment room.When a well-know shift (3 directions) and rotation (3 positions) was moved,CBCT and SentinelTM system were scanned respectively,and the measuring errors of six dimensions were recorded.The absolute differences between applied and measured errors were compared and paired t-test.Results Total 15 well-know shifts were investigated.The SentinelTM system was very good stability and the largest absolute difference only 0.9 mm (z direction) and 0.2° (arbitrary direction).At the same time,a good conformance between SentinelTM system and CBCT was displayed because the largest absolute difference between applied and measuring error was less than 0.9 mm (z direction) and 0.2° (arbitrary direction).Conclusions SentinelTM system is fast,simple,non-invasive and seems to be reliable in detecting patient setup errors.It maybe hold potential to ensure precise patient positioning with reduced CBCT frequency in tumor locations with fixed relation to surface structures.
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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.
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Objective To analyze the clinical characteristics, treatment and prognosis of primary parotid non-Hodgkin's lymphoma. Methods From March 1988 to February 2001, twenty-nine patients with primary parotid non-Hodgkin' s lymphoma treated in our hospital were retrospectively analyzed. The data were analyzed according to the following factors: sex, age, stage, pathologic classification, chemotherapy given or not, cycles of chemotherapy, radiotherapy given or not, and the dose at the parotid. Kaplan-Meier method and Log-rank method were used in the statistic analysis. Results The overall 5-year and 10-year survival rates were 73. 3% and 51.0% . Stage and pathologic classification were prognostic factors in our statistic analysis. The 5-year survival rates were 81.6% and 25.0% for early stage ( I E + IIE) and advanced stage ( III E + IVE) patients, with the difference significant ( P
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Objective To analyze the clinical feature, diagnosis, treatment a nd prognostic factors of primary lymphoma of the small bowel. Methods From Apr il 1989 to May 2002, 33 patients with non-Hodgkin's lymphoma of the small bowel were analyzed retrospectively. The Ann Arbor stages were: ⅠE 12, ⅡE 15 and Ⅳ E 6. The histological subtypes were: T-cell lymphoma 1 and B-cell lymphomas 32. A ll the patients received surgical treatment including radical or palliative rese ction. Twenty-six patients received postoperative radiotherapy including strip -f ield technique in 12 and opposed anterior-posterior fields in 14, with a median dose of 2543.5?cGy. Postoperative chemotherapy were applied to all patients inclu ding CHOP regimen in 17, COMP regimen in 6, COP regimen in 3, MINE regimen in 2, COPP regimen in 3 and BACOP regimen in 2. The median number of cycle was 4. Results The overall 5-year survival rate and disease-free survival rate were 48% and 39%. The 5-year survival rates were: ⅠE stage 42%, ⅡE stage 67% and ⅣE s tage 17%, respectively. Conclusions Most of the primary non-Hodgkin's lymphoma of the small intestine are in stage ⅠE and ⅡE, and the intermediate-grade and h igh-grade pathological subtypes are predominant. Surgery based combined treatme n t is effective and is advised. Radiotherapy and chemotherapy may improve the sur vival.
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Objective To analyze the results of neck dissection in patients who failed in cervical lymph nodes after radiotherapy for nasopharyngeal carcinoma.Methods Eighty-three patients who received neck dissection due to lymph node persistence or recurrence after definitive radiotherapy were analyzed retrospectively according to the following relevant factors: age, sex, the interval between completion of radiotherapy and surgery, rN stage, postoperative radiotherapy given or not, the adjacent tissues involved or not and the number of positive nodes. Kaplan-Meier method, Log-rank method and Cox method were used in the statistical analysis.Results The 1-, 3- and 5-year overall survival rates were 80.7%, 47.1% and 34.9%. The interval between completion of radiotherapy and surgery, postoperative radiotherapy given or not, the adjacent tissues involved or not were significantly prognostic factors in statistic analysis. Conclusions Neck dissection can be applied in the management of cervical lymph node failure in nasopharyngeal carcinoma after radiotherapy. Postoperative radiotherapy should be considered in patients with capsular invasion and/or adjacent tissue involvement.