title: FDG PET for the assessment of myometrial infiltration in clinical stage I uterine corpus cancer.
abstract: OBJECTIVE
  For surgical planning of uterine corpus cancer, prior knowledge of the depth of myometrial invasion is important. Curative tumour resection is possible in superficial invasion (stages IA and IB), while post-surgical chemotherapy or radiation therapy is required in deep invasion (stage IC). We evaluated the value of positron emission tomography with 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG PET) for estimating the myometrial invasion in uterine corpus cancer.
  
  
  METHODS
  We studied 22 patients with clinical stage I uterine corpus cancer, who underwent FDG PET prior to surgery. Standardized uptake value (SUV; tracer activity per injected dose normalized to body weight) was calculated on the PET image. PET findings were compared with magnetic resonance imaging (MRI) and the surgical staging.
  
  
  RESULTS
  The surgical stage was IA in five, IB in 11 and IC in six patients. SUVs in deep invasion (15.69+/-4.73, 8.83-21.84) were significantly higher than those in superficial invasion (9.09+/-3.29, 2.68-15.41) (P<0.005). Using 12.0 as a cut-off value of SUV for the differentiation of these two groups, PET results were correct in 19 patients but were incorrect in three patients. Although both PET and MRI provided correct staging in 14 patients, only MRI overestimated the myometrial invasion in four patients with stage IB and showed inconclusive findings in one patient with stage IC. Four of these five patients were post-menopausal.
  
  
  CONCLUSIONS
  The cut-off value of SUV (=12.0) may be a useful index for the differentiation of superficial invasion and deep invasion. FDG PET may be feasible for predicting the myometrial infiltration of uterine corpus cancer, especially when uterine atrophy makes it difficult at MRI in post-menopausal patients.
authors.affiliation: Positron Medical Center, Hamamatsu Medical Center, Japan. tatsuo@pmc.hmedc.or.jp
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Torizuka
authors.forename: Fumitoshi
authors.initials: F
authors.lastname: Nakamura
authors.forename: Munetaka
authors.initials: M
authors.lastname: Takekuma
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kanno
authors.forename: Tomomi
authors.initials: T
authors.lastname: Ogusu
authors.forename: Etsuji
authors.initials: E
authors.lastname: Yoshikawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okada
authors.forename: Makoto
authors.initials: M
authors.lastname: Maeda
authors.forename: Yasuomi
authors.initials: Y
authors.lastname: Ouchi
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D009215:Myometrium / Q000000981:diagnostic imaging* / Q000473:pathology*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014594:Uterine Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18