Assessment of tumor blood flow distribution by dynamic contrast-enhanced CT.

A distinct feature of the tumor vasculature is its tortuosity and irregular branching of vessels, which can translate to a wider dispersion and higher variability of blood flow in the tumor. To enable tumor blood flow variability to be assessed in vivo by imaging, a tracer kinetic model that accounts for flow dispersion is developed for use with dynamic contrast-enhanced (DCE) CT. The proposed model adopts a multiple-pathway approach and allows for the quantification of relative dispersion in the blood flow distribution, which reflects flow variability in the tumor vasculature. Monte Carlo simulation experiments were performed to study the possibility of reducing the number of model parameters based on the Akaike information criterion approach and to explore possible noise and tissue conditions in which the model might be applicable. The model was used for region-of-interest analysis and to generate perfusion parameter maps for three patient DCE CT cases with cerebral tumors, to illustrate clinical applicability.

Economic analysis of celecoxib versus diclofenac plus omeprazole for the treatment of arthritis in patients at risk of ulcer disease.

AIM: To evaluate the economic impact of celecoxib therapy vs. diclofenac plus omeprazole therapy for the treatment of arthritis in Chinese patients with a high risk of bleeding, from the perspective of a public health organization in Hong Kong. METHODS: The medical records of 287 Chinese arthritic patients with a history of bleeding ulcers who had previously participated in a randomised study of celecoxib 200 mg twice daily and extended-release diclofenac 75 mg twice daily plus 20 mg of omeprazole daily for 6 months were reviewed. RESULTS: Compared to the diclofenac plus omeprazole group, the average total direct cost per patient in the celecoxib group showed a significant reduction of 11%, from HK 10,915 (range HK dollars 10,915-57,899) to HK dollars 9714 (range HK dollars 9714-89,770) (P<0.0001) (1 US dollars=7.8 HK dollars). The median direct medical cost for routine management in the celecoxib group was significantly lower (11%) than that for the diclofenac plus omeprazole group [HK dollars 10,915 (range 10,915-28,048) vs. HK dollars 9714 (range HK dollars 6946-26,179) (P<0.0001)]. In patients who experienced recurrent bleeding, the celecoxib group showed a significantly higher median cost of management of recurrent bleeding than the diclofenac plus omeprazole group [HK dollars 8466 (range 572-29,851) vs. HK dollars 23,210 (range HK dollars 12,318-65,823)] (P=0.036). CONCLUSIONS: Celecoxib therapy appears to cost less compared with diclofenac plus omeprazole for treatment of arthritis in Chinese patients with a high risk of bleeding.