Objective To analyze the differences between calculated and actual volumes of regions of interest ( ROIs) in three treatment planning systems ( TPSs):PrecisePlan, Xio, and Oncentra, to transfer different ROIs and compare their calculated volume between the three TPSs, and to provide a basis for clinical application. Methods Different sizes of ROIs were delineated on 5 sets of computed tomography ( CT) images with different slice thickness. Square and round regions with different slice numbers were contoured in a homogeneous phantom. Three groups of patients ( n=5) with head and neck tumor, chest and abdomen tumor, and pelvic tumor, respectively, were enrolled as subjects. All the ROIs were independently transferred back and forth between three TPSs and different workstations with the same system in DICOM RT format. The changes in actual and calculated ROI volumes were evaluated after back and forth transfer. Results There was a significant positive linear correlation between the calculated volume, slice thickness, slice number, and actual volume of ROI in each TPS ( PrecisePlan:R2=0. 994, P<0. 01;Xio:R2=0. 997, P<0. 01;Oncentra:R2=0. 995, P<0. 01) . There were significant differences in all calculated ROI volumes of the head, chest and abdomen between the three TPS ( P<0. 05) except for the calculated ROI volumes of the chest and abdomen between Oncentra and Xio ( P=0. 114 ) . Conclusions The variations in volume calculation algorithm and slice thickness are the main causes of differences in calculated ROI volume. Particularly, small?volume ROIs have the greatest variation in calculated volume. To avoid a secondary reconstruction of ROI volume, it is recommended to transfer ROI back and forth between dose calculation workstations with the same TPS.

Objective To investigate the clinical significance and difference in the expression of endostatin and vascular endothelial growth factor (VEGF) in non-small cell lung cancer (NSCLC) patients with different response to recombinant human endostatin (rh-endostatin) combined with chemotherapy.Methods Serum levels of endostatin and VEGF in peripheral blood of 30 patients with stage Ⅳ NSCLC (NSCLC group) and 30 healthy controls (control group) were determined by enzyme-linked immunosorbent assay.Two cycles of chemotherapy combined with rh-endostatin were provided to NSCLC patients to evaluate the efficacy of the regimen.Simultaneously,serum levels of endostatin and VEGF were measured before and after treatment.Results The level of serum endostatin was (37.96 ± 9.01) ng/ml and (40.12 ± 12.11)ng/ml in NSCLC patients and healthy controls,respectively,which was lower in the former than that of the latter,without statistical difference (P ＞ 0.05).Furthermore,the level of serum VEGF was (127.98 ± 33.88) pg/ml and (36.33 ± 15.43) pg/ml in NSCLC patients and healthy controls,respectively,which was higher in the former than that of the latter,with statistical difference (t =13.48,P ＜ 0.05).Besides,levels of endostatin and VEGF in serum were not correlated with the sex,age,tumor pathological type and differentiation of NSCLC patients (P ＞ 0.05).After two cycles of chemotherapy combined with rh-endostatin treatment,the level of serum endostatin in partial response (PR) or stable disease (SD) patients was (76.22 ± 20.41) ng/ml,higher than that of progressive disease (PD) patients,which was (31.24 ± 13.09) ng/ml (t =7.143,P ＜ 0.05).In addition,the level of serum VEGF in PR or SD patients was (93.28 ± 21.33) pg/ml,which was lower than (155.81 ± 48.38) pg/ml of the PD patients (t =3.503,P ＜ 0.05).Conclusions The levels of endostatin and VEGF are associated with the efficacy of anti-angiogenesis combined with chemotherapy in NSCLC patients.