Addition of insulin lispro protamine suspension or insulin glargine to oral type 2 diabetes regimens: a randomized trial

AIMS

The addition of basal insulin to existing oral therapy can help patients with type 2 diabetes (T2D) achieve glycaemic targets. This study compares the efficacy and safety of insulin lispro protamine suspension (ILPS) and insulin glargine in insulin-naive patients with T2D and inadequate control on oral antihyperglycaemic medication (OAM).

MATERIALS AND METHODS

An open-label, randomized, multicentre, multinational 24-week study of 471 patients receiving ≥2 OAMs for ≥3 months with a body mass index between 25 and 45 kg/m(2) and HbA1c 7.5-10.0% was conducted. ILPS was injected once or twice daily vs. glargine injected once daily plus prestudy OAMs. Primary objective compared the HbA1c change from baseline.

RESULTS

HbA1c change from baseline to endpoint was similar in both groups [-1.46% (ILPS) and -1.41% (glargine)]. Least-squares mean difference (95% CI) for HbA1c (-0.05 [-0.21, 0.11]%), glycaemic variability (0.06 [-0.06, 0.19] mmol/l) and weight change (-0.01 [-0.61, 0.59] kg) showed non-inferiority (margins of 0.4%, 0.8 mmol/l and 1.5 kg, respectively). Percentages of patients achieving HbA1c <7.0% were 43.8% ILPS and 41.2% glargine. Mean daily insulin dose was 0.39 vs. 0.35 U/kg (p = 0.02) and weight gain was 1.04 vs. 1.07 kg for ILPS vs. glargine (p = 0.98). Overall hypoglycaemia (episodes/patient/year) was similar for ILPS and glargine (24.2 ± 28.8 vs. 23.0 ± 30.9); nocturnal (6.1 ± 10.6 vs. 4.1 ± 9.4, p < 0.001) rates were higher for ILPS. Severe hypoglycaemia was higher for ILPS vs. glargine (n = 9 vs. n = 2; p = 0.04).

CONCLUSIONS

At endpoint, ILPS was non-inferior to glargine in HbA1c change from baseline, but associated with increased risk of hypoglycaemia.

A practical method to detect target failure of a helical tomotherapy unit

PURPOSE

Helical tomotherapy has been in clinical use for several years. One of the issues with a helical tomotherapy unit is the failure of detection of the x-ray target. In this study, we are proposing a method to detect potential failure of the x-ray target.

METHODS

Currently, on-board detector data from a helical tomotherapy unit are collected and sent to TomoTherapy Inc. for comparison with the so-called gold standard for the unit. However, this is sometimes time-consuming. Furthermore, the clinical medical physicists have no access to this comparison procedure. In this study, we developed a practical method to detect target failure based on one of the monthly quality assurance (QA) procedures. The commissioning cross-plane profiles were used as the comparison baseline. Larger EDR2 film (35×43 cm) were set at source-axis distance (SAD) (85 cm) and shot with 1.5 cm solid water as build-up material and 10 cm solid water as backscattering material. Cross-plane profiles obtained from the EDR2 film were compared with the commissioning profiles.

RESULTS

When the cross-plane profiles from monthly QA have 1° degree difference from the commissioning profiles, it is time that the target be changed.

CONCLUSION

This method enables the clinical medical physicists to easily evaluate the target status and to help improving the quality assurance of a helical tomotherapy unit.

Tradeoffs for assuming rigid target motion in Mlc-based real time target tracking radiotherapy: a dosimetric and radiobiological analysis

We report on our assessment of two types of real time target tracking modalities for lung cancer radiotherapy namely (1) single phase propagation (SPP) where motion compensation assumes a rigid target and (2) multi-phase propagation (MPP) where motion compensation considers a deformable target. In a retrospective study involving 4DCT volumes from six (n=6) previously treated lung cancer patients, four-dimensional treatment plans representative of the delivery scenarios were generated per modality and the corresponding dose distributions were derived. The modalities were then evaluated (a) Dosimetrically for target coverage adequacy and normal tissue sparing by computing the mean GTV dose, relative conformity gradient index (CGI), mean lung dose (MLD) and lung V(2)0; (b) Radiobiologically by calculating the biological effective uniform dose (D) for the target and organs at risk (OAR) and the complication free tumor control probability (P(+)). As a reference for the comparative study, we included a 4D Static modality, which was a conventional approach to account for organ motion and involved the use of individualized motion margins. With reference to the 4D Static modality, the average percent decrease in lung V(20) and MLD were respectively (13.1-/+6.9) % and (11.4-/+ 5.6)% for the MPP modality, whereas for the SPP modality they were (9.4-/+6.2) % and (7.2-/+4.7) %. On the other hand, the CGI was observed to improve by 15.3-/+13.2 and 9.6-/+10.0 points for the MPP and SPP modalities, respectively while the mean GTV dose agreed to better than 3% difference across all the modalities. A similar trend was observed in the radiobiological analysis where the P(+) improved on average by (6.7-/+4.9) % and (4.1-/+3.6) % for the MPP and SPP modalities, respectively while the D computed for the OAR decreased on average by (6.2-/+3.6) % and (3.8-/+3.5) % for the MPP and SPP tracking modalities, respectively. The D calculated for the GTV for all the modalities was in agreement to better than 2% difference. In general, respiratory motion induces target displacement and deformation and therefore the complex MPP real time target tracking modality is the preferred. On the other hand, the SPP approach affords simplicity in implementation at the expense of failing to account for target deformation. Radiobiological and dosimetric analyses enabled us to investigate the consequences of failing to compensate for deformation and assess the impact if any on the clinical outcome. While it is not possible to draw any general conclusions on a small patient cohort, our study suggests that the two tracking modalities can lead to comparable clinical outcomes and as expected are advantageous when compared with the static conventional modality.

Impact of pulse forming network and injection current parameters on output and energy variations of helical tomotherapy

PURPOSE

In this study, an experiment was devised to establish the dependency of the impact of pulse forming network (PFN) and injection current (IC) parameters on output and energy variations of helical tomotherapy (HT) on the radiation beam output and energy.

METHODS

HT has unique radiation beam characteristics due to the absence of a flattening filter. As with conventional linear accelerators, the machine output and energy should be within a + or - 2% tolerance according to published studies. However, because a dose servo is not utilized in a HT unit, these parameters may drift out of the + or - 2% tolerance due to various reasons such as high machine temperatures. With this in mind, physicists and engineers must adjust certain machine parameters to reset the output and energy to within the tolerance of the commissioned baseline. Two parameters commonly adjusted are: PFN voltage (V(PFN)) and IC voltage (V(IC)).

RESULTS

Results showed that the HT unit possesses different working zones defined by the V(PFN) and V(IC) parameter settings. The working zones were classified into 5 zones: 1) low dose rate zone - radiation dose rate much lower than nominal dose rate and machine cannot run due to low dose rate fault; 2) normal dose rate zone - dose rate is within tolerance of nominal dose rate and machine can run without dose rate fault; 3) dose rate failure during treatment zone - dose rate within the tolerance of the nominal dose rate however machine interrupts during treatment due to dose rate fault; 4) high dose rate zone - dose rate is higher than nominal dose rate and machine cannot run due to high dose rate fault; and 5) inoperable dose rate zone - dose rate is much higher than the nominal dose rate and machine cannot run.

CONCLUSION

The results of this study may provide a quick guide for physicists to adjust their HT unit V(PFN) and V(IC) values in order to reset the radiation beam output and energy back to within the tolerance of the commissioned baseline.

TLRs antiviral effect on hepatitis B virus in HepG2 cells

AIMS

A hepatoma cell line, HepG2, was used as a model system to detect Toll-like receptor (TLR) expression in hepatocytes and examine the antiviral effect on hepatitis B virus (HBV).

METHODS AND RESULTS

Toll-like receptor expression was detected in HepG2 cells by RT-PCR. The TLRs, which were strongly expressed in HepG2 cells, were stimulated with specific ligands. Interferon (IFN) response was evaluated poststimulation with Western blotting for signal transduction and activators of transcription-1. Furthermore, HepG2 cells were transiently transfected with wild-type HBV 1.3-fold over-length plasmid and treated with specific ligands at indicated times. Replication of HBV DNA, transcription of HBV RNA intermediate and expression of HBV antigens were respectively detected by Southern blotting, real time PCR, ELISA and Western blotting. Activation of different TLRs induced antiviral effects on HBV to varying degrees.

CONCLUSIONS

The TLRs, which were strongly expressed in HepG2 cells, could be stimulated with specific ligands. Activation of TLRs induced apparent production of antiviral cytokines such as IFN-alpha/beta and inhibited HBV lifecycle in the hepatocyte cell model.

SIGNIFICANCE AND IMPACT OF THE STUDY

Expression of TLRs in hepatocytes may be related to local immunity of liver and participate in the outcome of viral hepatitis.

Electrodeposition and capacitive behavior of films for electrodes of electrochemical supercapacitors

Polypyrrole films were deposited by anodic electropolymerization on stainless steel substrates from aqueous pyrrole solutions containing sodium salicylate and tiron additives. The deposition yield was studied under galvanostatic conditions. The amount of the deposited material was varied by the variation of deposition time at a constant current density. SEM studies showed the formation of porous films with thicknesses in the range of 0-3 μm. Cyclic voltammetry data for the films tested in 0.5 M Na2SO4 solutions showed capacitive behavior and high specific capacitance (SC) in a voltage window of 0.9 V. The films prepared from pyrrole solutions containing tiron showed better capacitive behavior compared to the films prepared from the solutions containing sodium salicylate. A highest SC of 254 F g-1 was observed for the sample with a specific mass of 89 μg cm-2 at a scan rate of 2 mV s-1. The SC decreased with an increasing film thickness and scan rate. The results indicated that the polypyrrole films deposited on the stainless steel substrates by anodic electropolymerization can be used as electrodes for electrochemical supercapacitors (ES).