title: Translating response during therapy into ultimate treatment outcome: a personalized 4-dimensional MRI tumor volumetric regression approach in cervical cancer.
abstract: OBJECTIVE
  To assess individual volumetric tumor regression pattern in cervical cancer during therapy using serial four-dimensional MRI and to define the regression parameters' prognostic value validated with local control and survival correlation.
  
  
  METHODS
  One hundred and fifteen patients with Stage IB(2)-IVA cervical cancer treated with radiation therapy (RT) underwent serial MRI before (MRI 1) and during RT, at 2-2.5 weeks (MRI 2, at 20-25 Gy), and at 4-5 weeks (MRI 3, at 40-50 Gy). Eighty patients had a fourth MRI 1-2 months post-RT. Mean follow-up was 5.3 years. Tumor volume was measured by MRI-based three-dimensional volumetry, and plotted as dose(time)/volume regression curves. Volume regression parameters were correlated with local control, disease-specific, and overall survival.
  
  
  RESULTS
  Residual tumor volume, slope, and area under the regression curve correlated significantly with local control and survival. Residual volumes >or=20% at 40-50 Gy were independently associated with inferior 5-year local control (53% vs. 97%, p <0.001) and disease-specific survival rates (50% vs. 72%, p = 0.009) than smaller volumes. Patients with post-RT residual volumes >or=10% had 0% local control and 17% disease-specific survival, compared with 91% and 72% for <10% volume (p <0.001).
  
  
  CONCLUSIONS
  Using more accurate four-dimensional volumetric regression analysis, tumor response can now be directly translated into individual patients' outcome for clinical application. Our results define two temporal thresholds critically influencing local control and survival. In patients with >or=20% residual volume at 40-50 Gy and >or=10% post-RT, the risk for local failure and death are so high that aggressive intervention may be warranted.
authors.affiliation: Department of Radiation Medicine, Ohio State University, Columbus, OH 43210, USA. Nina.Mayr@osumc.edu
authors.forename: Nina A
authors.initials: NA
authors.lastname: Mayr
authors.forename: Jian Z
authors.initials: JZ
authors.lastname: Wang
authors.forename: Simon S
authors.initials: SS
authors.lastname: Lo
authors.forename: Dongqing
authors.initials: D
authors.lastname: Zhang
authors.forename: John C
authors.initials: JC
authors.lastname: Grecula
authors.forename: Lanchun
authors.initials: L
authors.lastname: Lu
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Montebello
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Fowler
authors.forename: William T C
authors.initials: WT
authors.lastname: Yuh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D012044:Regression Analysis; D012074:Remission Induction; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden; D002583:Uterine Cervical Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*