title: Metabolic monitoring of breast cancer chemohormonotherapy using positron emission tomography: initial evaluation.
abstract: OBJECTIVE
  We assessed the feasibility of noninvasive metabolic monitoring of cancer chemohormonotherapy using sequential quantitative positron emission tomographic (PET) scans of tumor glucose metabolism with the glucose analog 2-[18F]-fluoro-2-deoxy-D-glucose (FDG).
  
  
  METHODS
  Eleven women with newly diagnosed primary breast cancers larger than 3 cm in diameter beginning a chemohormonotherapy program underwent a baseline and four follow-up quantitative PET scans during the first three cycles of treatment (days 0 to 63). Tumor response was sequentially determined clinically, radiographically, and then pathologically after nine treatment cycles.
  
  
  RESULTS
  Eight patients had partial or complete pathologic responses. Their maximal tumor uptake of FDG assessed by PET decreased promptly with treatment to the following: day 8, 78 +/- 9.2% (P < .03); day 21, 68.1 +/- 7.5% (P < .025); day 42, 60 +/- 5.1% (P < .001); day 63, 52.4 +/- 4.4% (P < .0001) of the basal values. Tumor diameter did not decrease significantly during this period through 63 days. Prompt decreases in the FDG influx rate (K) from basal levels (from .019 to .014 mL/cm3/min) after 8 days of treatment (P < .02) and in the estimated rate of FDG phosphorylation to FDG-6-phosphate (k3) from .055 to .038 min-1 after 8 days of treatment (P < .02) to .029 +/- .004 min-1 at 21 days) (P < .02) were observed. Three nonresponding patients had no significant decrease in tumor uptake of FDG (81 +/- 18% of basal value), influx rate (.015 to .012 mL/cm3/min), or tumor size (81 +/- 12% of basal diameter) comparing basal versus 63-day posttreatment values.
  
  
  CONCLUSIONS
  Quantitative FDG PET scans of primary breast cancers showed a rapid and significant decrease in tumor glucose metabolism after effective treatment was initiated, with the reduction in metabolism antedating any decrement in tumor size. No significant decrease in FDG uptake (SUV) after three cycles of treatment was observed in the nonresponding patients. FDG PET scanning has substantial promise as an early noninvasive metabolic marker of the efficacy of cancer treatment.
authors.affiliation: Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109-0028.
authors.forename: R L
authors.initials: RL
authors.lastname: Wahl
authors.forename: K
authors.initials: K
authors.lastname: Zasadny
authors.forename: M
authors.initials: M
authors.lastname: Helvie
authors.forename: G D
authors.initials: GD
authors.lastname: Hutchins
authors.forename: B
authors.initials: B
authors.lastname: Weber
authors.forename: R
authors.initials: R
authors.lastname: Cody
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005240:Feasibility Studies; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008327:Mammography; D008875:Middle Aged; D014055:Tomography, Emission-Computed
chemical_list: D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose