BACKGROUND: Our aim was to determine the value of 99mTc-Sestamibi scanning as functional detection method of P-glycoprotein (Pgp) blockade by PSC 833 in solid tumour patients. PATIENTS AND METHODS: Day 1 and day 4 after 2,200 mg orally administered PSC 833 the tumour area was scanned after intravenous (i.v.) administration of 400 MBq 99mTc-Sestamibi. In tumours with net 99mTc-Sestamibi uptake and in the hepatic region K-efflux was determined. Whole blood was analyzed for 99mTc-Sestamibi, and PSC 833 levels. RESULTS: Fourteen patients were included. In the only Pgp-positive tumour with positive 99mTc-Sestamibi scanning K-efflux of 99mTc-Sestamibi decreased significantly after PSC 833 intake. A net inhibition of liver efflux of Sestamibi after PSC 833 intake was observed in all evaluable patients. PSC 833 blood levels were all above 2 mg/L during scanning; 99mTc-Sestamibi blood levels post versus pre PSC 833 were unchanged. CONCLUSIONS: PSC 833 induced modulation of K-efflux of 99mTc-Sestamibi in a Pgp positive tumour and in all patients in the liver.
BACKGROUND: Our aim was to determine the value of 99mTc-Sestamibi scanning as functional detection method of P-glycoprotein (Pgp) blockade by PSC 833 in solid tumourpatients. PATIENTS AND METHODS: Day 1 and day 4 after 2,200 mg orally administered PSC 833 the tumour area was scanned after intravenous (i.v.) administration of 400 MBq 99mTc-Sestamibi. In tumours with net 99mTc-Sestamibi uptake and in the hepatic region K-efflux was determined. Whole blood was analyzed for 99mTc-Sestamibi, and PSC 833 levels. RESULTS: Fourteen patients were included. In the only Pgp-positive tumour with positive 99mTc-Sestamibi scanning K-efflux of 99mTc-Sestamibi decreased significantly after PSC 833 intake. A net inhibition of liver efflux of Sestamibi after PSC 833 intake was observed in all evaluable patients. PSC 833 blood levels were all above 2 mg/L during scanning; 99mTc-Sestamibi blood levels post versus pre PSC 833 were unchanged. CONCLUSIONS: PSC 833 induced modulation of K-efflux of 99mTc-Sestamibi in a Pgp positive tumour and in all patients in the liver.
Authors: Ronan J Kelly; Deborah Draper; Clara C Chen; Robert W Robey; William D Figg; Richard L Piekarz; Xiaohong Chen; Erin R Gardner; Frank M Balis; Aradhana M Venkatesan; Seth M Steinberg; Tito Fojo; Susan E Bates Journal: Clin Cancer Res Date: 2010-11-16 Impact factor: 12.531
Authors: Zhonglin Liu; Gail D Stevenson; Harrison H Barrett; Lars R Furenlid; Donald W Wilson; George A Kastis; Michael Bettan; James M Woolfenden Journal: Nucl Med Biol Date: 2005-08 Impact factor: 2.408
Authors: Zhonglin Liu; Gail D Stevenson; Harrison H Barrett; George A Kastis; Michael Bettan; Lars R Furenlid; Donald W Wilson; James M Woolfenden Journal: Nucl Med Biol Date: 2004-01 Impact factor: 2.408