[Measurement of docetaxel concentration in blood and ascites after drip infusion into each vessel and intraperitoneal cavity of gastric cancer].

We measured docetaxel (TXT) concentrations in the blood and ascites after drip infusion into each vessel and intraperitoneal cavity of a patient with advanced gastric cancer. The peak concentration was reached immediately (first time 244 ng/ml, second time 215 ng/ml) after the infusion of TXT (25 mg/m2) into the vessels. The concentration of TXT for ascites peaked after 30 min of drip infusion (first time 26 ng/ml, second time 30 ng/ml). AUC ascites/AUC blood was 27.2% and 35.8% respectively. This is the first report demonstrating the concentration of TXT in ascites after drip infusion into vessels. When TXT was administered into the peritoneal cavity, the peak concentration of ascites was reached immediately (54,200 ng/ml). After 240 min, the TXT concentration in the peritoneal cavity was still high (14,200 ng/ml). In blood, the level peaked (64 ng/ml) at 120 min. After 240 min, the TXT level in the blood remained 44 ng/ml. AUC blood/AUC ascites was only 0.25%. These results suggested that the transition rate of TXT from blood to intraperitoneal cavity was excellent, and that TXT was suitable for the treatment of peritoneal dissemination of gastric cancer. Furthermore, infusion of TXT (25 mg/m2) into the peritoneal cavity may directly and systemically provide its antitumor effect. If we prefer the antitumor effect directly, a much lower dose infusion of TXT may be recommended.