Objective　To investigate the systemic stress responses of laparoscopic cholecystectomy(LC). Methods　Seventy patients with cholecystolithiasis were randomly divided into two groups: LC and open cholecystectomy(OC). Peripheral blood samples were obtained during the preoperative day and 1, 3, 5, 7 day after operation. Serum cytokines levels (TNF-α, IL-1β and IL-6) and C-reactive protein(CRP) were measured. Results　Changes of TNF-α and IL-1β before or after surgery in both groups showed no significant difference(P>0.05). Serum concentrations of IL-6 and CRP after surgery in both groups were significantly higher than those before surgery(P<0.05); but there were no significant difference between the two groups(P>0.05). Conclusions　The systemic stress responses of LC have no significant difference comparing with OC.

Objective To quantify the correlations between Elekta XVI cone beam CT dose and various scanning protocols,providing mathematical models to assess the protocol-dependency of imaging dose during imnage guided radiotherapy.Methods Based on standard protocols and various combinations of kVp and mA on an XVI mounted on an Elekta Versa HD accelerator,the air KERMA was measured at various positions in a standard PTW CTDI body phantom using calibrated PTW 30009 kV chamber and UNIDOS webline electrometer.Weighted CT dose index (CTDIw) was computed thereafter.SigmaPlot 10.0 was used to fit the measurements against mA and/or kVp yielding empirical functions.Results Under standard protocols,the CTDIw of Varian OBI was only 11.23％ (chest) and 9.15％ (pelvis) of Elekta XVI.Using the default and other 4 investigated kVp values,the central and peripheral KERMA were both proportional to mA,and vet the slope value a varied dramatically from 0.479 to 6.679.Major affecting factors included kVp settings,measurement locations,and dosimetric mnetrics,etc.None linear regressions were used to fit kVp against KERMA at various locations and CTDIw (R2 ＞ 0.997).The differences between all coefficients were statistically significant (P ＜ 0.05).The impact of changing both mA and kVp on the dose to phantom center can be described as mGy =(5.917-0.197 ×kVp+0.002 × kVp2-5.063 × 10-6 × kVp3) × mA.Conclusions Imaging dose of Elekta XVI is strongly dependent on scanning paraneters.The proposed mathematical models can be used as efficient and robust indicators of such dependency.