title: Toward prediction of efficacy of chemotherapy: a proof of concept study in lung cancer patients using [¹¹C]docetaxel and positron emission tomography.
abstract: OBJECTIVE
  Pharmacokinetics of docetaxel can be measured in vivo using positron emission tomography (PET) and a microdose of radiolabeled docetaxel ([(11)C]docetaxel). The objective of this study was to investigate whether a [(11)C]docetaxel PET microdosing study could predict tumor uptake of therapeutic doses of docetaxel.
  
  
  METHODS
  Docetaxel-naïve lung cancer patients underwent 2 [(11)C]docetaxel PET scans; one after bolus injection of [(11)C]docetaxel and another during combined infusion of [(11)C]docetaxel and a therapeutic dose of docetaxel (75 mg·m(-2)). Compartmental and spectral analyses were used to quantify [(11)C]docetaxel tumor kinetics. [(11)C]docetaxel PET measurements were used to estimate the area under the curve (AUC) of docetaxel in tumors. Tumor response was evaluated using computed tomography scans.
  
  
  RESULTS
  Net rates of influx (Ki) of [(11)C]docetaxel in tumors were comparable during microdosing and therapeutic scans. [(11)C]docetaxel AUCTumor during the therapeutic scan could be predicted reliably using an impulse response function derived from the microdosing scan together with the plasma curve of [(11)C]docetaxel during the therapeutic scan. At 90 minutes, the accumulated amount of docetaxel in tumors was less than 1% of the total infused dose of docetaxel. [(11)C]docetaxel Ki derived from the microdosing scan correlated with AUCTumor of docetaxel (Spearman ρ = 0.715; P = 0.004) during the therapeutic scan and with tumor response to docetaxel therapy (Spearman ρ = -0.800; P = 0.010).
  
  
  CONCLUSIONS
  Microdosing data of [(11)C]docetaxel PET can be used to predict tumor uptake of docetaxel during chemotherapy. The present study provides a framework for investigating the PET microdosing concept for radiolabeled anticancer drugs in patients.
authors.affiliation: Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands. aam.vanderveldt@vumc.nl
authors.forename: Astrid A M
authors.initials: AA
authors.lastname: van der Veldt
authors.forename: Mark
authors.initials: M
authors.lastname: Lubberink
authors.forename: Ron H J
authors.initials: RH
authors.lastname: Mathijssen
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Loos
authors.forename: Gerarda J M
authors.initials: GJ
authors.lastname: Herder
authors.forename: Henri N
authors.initials: HN
authors.lastname: Greuter
authors.forename: Emile F I
authors.initials: EF
authors.lastname: Comans
authors.forename: Hugo B
authors.initials: HB
authors.lastname: Rutten
authors.forename: Jonas
authors.initials: J
authors.lastname: Eriksson
authors.forename: Albert D
authors.initials: AD
authors.lastname: Windhorst
authors.forename: N Harry
authors.initials: NH
authors.lastname: Hendrikse
authors.forename: Pieter E
authors.initials: PE
authors.lastname: Postmus
authors.forename: Egbert F
authors.initials: EF
authors.lastname: Smit
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D002247:Carbon Isotopes / Q000008:administration & dosage; D000077143:Docetaxel; D004358:Drug Therapy; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D008875:Middle Aged; D049268:Positron-Emission Tomography; D043823:Taxoids / Q000008:administration & dosage* / Q000097:blood* / Q000493:pharmacokinetics; D047368:Tumor Burden
chemical_list: D000970:Antineoplastic Agents; D002247:Carbon Isotopes; D043823:Taxoids; D000077143:Docetaxel