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Objective: To evaluate the potential dose influence to organs at risk (OARs) and targets of adaptive radiotherapy (ART) for non-small cell lung cancer (NSCLC). Methods:Twice positional CT images of 12 patients with locally advanced NSCLC were captured during radio-(n=3) or radio-chemotherapy (n=9) for ART simulation. The twice positional scanningplan was fused using MIM software. The variation of irradiation doses for the lung, heart, and spinal cord was evaluated, and the prescription doses for the targets were escalated. Results:Adaptive radiation enabled dose reduction by an average of 3.53%for lung V20 and by 2.55%for V30. The mean dose for the lung decreased by 2.11 Gy. The dose was reduced by an average of 4.17%for heart V30 and by 3.37%for V40. Meanwhile, the maximum dose for the spinal cord was reduced by 3.52 Gy on average. Lung sparing with ART enabled an iso-mean lung dose escalation of the Planning gross tumor target volume dose, which improved by an average of 1.25 Gy. Conclusion:The adap-tation of radiotherapy for continuous tumor shrinkage during the treatment course for NSCLC reduces doses to OARs, enables signifi-cant dose escalation, and has the potential to increase local control.
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Objective To explore the prognosis and related factors of brain glioma .Methods 133 patients who have been con-firmed pathology with brain glioma from Jan .2001 to Dec .2010 were retrospectively analyzed .The factors such as sex ,age ,func-tional status ,histological character ,the longest diameter of tumor ,surgical excision of part or all of the tumor ,whether or not being radiotherapy after surgical excision were selected to evaluate by single factor and multiple factors analysis .Results The median fol-low-up time was 36 months ,The follow-up rate was 93% .73 cases were followed up for 3 years ,the 1- ,2- and 3- year survival rate was 93% ,82% and 70% ,respectively ,the median survival time was 62 .7 months .Multiple factors regression analysis showed that histological character ,the longest diameter of tumor and whether or not being radiotherapy after surgical excision were related to prognosis .Conclusion High-grade of histological character ,the longest diameter of tumor≥6 cm predict poor prognosis ,postop-erative radiotherapy can improve the survival of glioma .
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10.3969/j.issn.1000-8179.2013.12.010
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Objective To compare the accuracy and feasibility among CT, MR, and CT-MR image fusion technology in the delineation of gross target volume (GTV) for nasopharyngeal carcinoma (NPC). Methods Thirty-six consecutive patients with newly diagnosed or recurrent NPC were enrolled. Each pa-tient underwent both CT and MR scanning in the same treatment position. Several lead marks were made at the exactly same locations of the body surface before CT and MR scanning. The two sets of images were then transferred to the Tomcon workstation for image fusion. CT-MR image registration was performed using Land-Mark methods. GTV of each patient was contoured on CT (GTV_(CT)), MR (GTV_(MR)) and CT-MR (GTV_(CT-MR)) images. Results The mean GTV_(CT), GTV_(MR) and GTV_(CT-MR) were 27.60 cm~3, 30.99 cm~3 and 31.71 cm~3, respectively (F = 7.48, P = 0.001). Significant difference was found between GTV_(CT) and GTV_(MR) (q =2.54,P=0.016), GTV_(CT) and GTV_(CT-MR) (q =3.10,P =0.004), but not GTV_(MR) and GTV_(CT-MR) (q = 1.31 ,P = 0. 199). Significant difference among GTV_(CT), GTV_(MR) and GTV_(CT-MR) was found in patients with skull base invasion (35.65, 42.70 and 44.22 cm~3 ; F = 14. 13, P = 0. 000), but not in those without skull base invasion (20.79 cm~3, 20.46 cm~3 and 21.18 cm~3 ; F = 0.18, P = 0.832). Significant difference between GTV_(CT) and GTV_(CT-MR) was found in patients with T_3 and T_4 tumor (t = -2.17,P =0. 036), but not in those with T_1 and T_2 (t = -0.66 ,P = 0.514). Conclusions CT-MR image fusion is helpful in GTV de-lineation for NPC, particularly for patients with skull base invasion.
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Objective To study 18F-deoxyglueose positron emission tomography computed tomo graphy(18 FDG PET-CT) in the diagnosis of cervical lymph node(LN) metastasis from rabbit nasopharyngeal VX2 carcinoma.Methods Nasopharyngeal VX2 carcinoma model using 30 rabbits was established. 18 FDG PET-CT,MRI and pathological diagnosis were performed and compared.ResultsFifty-three cervi cal LNs were picked up from resected specimens of 30 rabbits with nasopharyngeal VX2 carcinoma.There were 42 pathologically confirmed positive LNs.Positivity rate was significantly correlated with the volume and the shortest diameter of the LNs (r = 9.18,P =0.007 ; r = 2.77,P = 0.008).The diagnostic sensitivity of PET-CT was 96% (24/25) and 29% (5/17) for LNs with volume >0.5 cm3 and ≤0.5 cm3 ,83% (25/30) and 33% (4/12) for LNs with the shortest diameter ≥0.5 cm and < 0.5 cm,respectively.The diagnostic sensitivity,specificity and accuracy of PET-CT was 69% (29/42) ,100% (11/11) and 95% (40/42) ,com paring with 60% (25/42) ,91% (10/11) and 83% (35/42) of MRl,respectively.The volume measured by PET-CT images was not significantly different from the pathologically measured volume (t =-1.23,P = 0.233) ,while the volume measured by MRI was significantly different from the pathologically measured vol ume (t =-3.99,P = 0.001).Conclusions The sensitivity,specificity and accuracy of PET-CT are better than those of MRl,especially for the cervical lymph nodes with volume >0.5 cm3 or the shortest diameter ≤ 0.5 cm.PET-CT also can be used to detect the smaller metastatic lymph nodes,though the false negative rate is higher.