RESUMO
Objective:To analyze the differences in dosimetric quality and plan complexity of volumetric modulated arc therapy (VMAT) plans based on Halcyon 2.0 and Truebeam for different treatment sites of the patients.Methods:Halcyon 2.0 VMAT plans in head & neck, chest, abdomen, and pelvis treatment sites of 49 cases were retrospectively selected and the VMAT plans were re-designed based on Truebeam with the same optimization parameters. The differences in dosimetric metrics and plan complexity between the two types of plans were compared and analyzed. P<0.05 was considered as statistically significant. Results:In terms of PTV, Halcyon 2.0 plans showed better homogeneity index (HI), conformal index (CI) in the head & neck and chest. Besides, Halcyon 2.0 plans yielded better D 98% and CI in the abdomen and better D 2% in the pelvis. For organs at risk (OAR), the D 20% and D mean of bilateral lungs, and D meanof heart for Halcyon 2.0 plans in the chest were lower than those for Truebeam plans (all P<0.05). For the complexity metrics, the median average aperture area variability (AAV) of Halcyon 2.0 plans in the head & neck, abdomen and pelvis were 0.414, 0.425 and 0.432, which were better than 0.385, 0.368 and 0.361 of Truebeam plans in the corresponding sites, respectively. In the abdomen and pelvis, Halcyon 2.0 plans showed better median modulation complexity score (MCS) than Truebeam plans (0.320 vs. 0.268, 0.303 vs. 0.282; both P<0.05). The median small aperture score (SAS) for all plans of Halcyon 2.0 were better than that of Truebeam plans (all P<0.05), and the median plan average beam area (PA) of all plans of Halcyon 2.0 were larger than that of Truebeam plans (all P<0.05). Conclusions:Compared with conventional fractionated VMAT plans based on Halcyon 2.0 and Truebeam, Halcyon 2.0 plans have similar or even better dosimetric quality. However, Halcyon 2.0 plans have lower plan complexity, which makes it an advantage in clinical application.
RESUMO
AIM: To establish a simple, rapid and accurate high performance liquid chromatographic method (HPLC) for the determination of cyclosporin A (CsA) in human whole blood, and to study the influence of nicotinylmethylamide (Nic) on the pharmacokinetic parameters of cyclosporin A (CsA). METHODS: Whole blood CsA concentrations were measured by HPLC in 18 healthy volunteers administrated single CsA or co administrated Nic. The data of time blood concentrations of CsA were analyzed by 3p97 Program. The analysis of variance and two one sided t test were used to compare the main pharmacokinetic parameters of CsA in the two administrations. RESULTS: C max and AUC 0～∞ of CsA had statistically significance between the single CsA group and co administration of Nic group (P0.05). CONCLUSION: This HPLC method is simple, sensitive and accurate, and is suitable for routine determination of blood CsA levels in human. Nic can improve the absorption of CsA and increase the C max and AUC of CsA, but has no influence on the metabolism of CsA.