title: The role of whole-lesion apparent diffusion coefficient analysis for predicting outcomes of prostate cancer patients on active surveillance.
abstract: To explore the role of whole-lesion apparent diffusion coefficient (ADC) analysis for predicting outcomes in prostate cancer patients on active surveillance.
  
  
  
  This study included 72 prostate cancer patients who underwent MRI-ultrasound fusion-targeted biopsy at the initiation of active surveillance, had a visible MRI lesion in the region of tumor on biopsy, and underwent 3T baseline and follow-up MRI examinations separated by at least one year. Thirty of the patients also underwent an additional MRI-ultrasound fusion-targeted biopsy after the follow-up MRI. Whole-lesion ADC metrics and lesion volumes were computed from 3D whole-lesion volumes-of-interest placed on lesions on the baseline and follow-up ADC maps. The percent change in lesion volume on the ADC map between the serial examinations was computed. Statistical analysis included unpaired t tests, ROC analysis, and Fisher's exact test.
  
  
  
  Baseline mean ADC, ADC0-10th-percentile, ADC10-25th-percentile, and ADC25-50th-percentilewere all significantly lower in lesions exhibiting ≥50% growth on the ADC map compared with remaining lesions (all P ≤ 0.007), with strongest difference between lesions with and without ≥50% growth observed for ADC0-10th-percentile(585 ± 308 vs. 911 ± 336; P = 0.001). ADC0-10th-percentileachieved highest performance for predicting ≥50% growth (AUC = 0.754). Mean percent change in tumor volume on the ADC map was 62.3% ± 26.9% in patients with GS ≥ 3 + 4 on follow-up biopsy compared with 3.6% ± 64.6% in remaining patients (P = 0.050).
  
  
  
  Our preliminary results suggest a role for 3D whole-lesion ADC analysis in prostate cancer active surveillance.
authors.affiliation: Department of Radiology, NYU Langone Medical Center, 550 First Ave, New York, NY, 10016, USA. ttamada@med.kawasaki-m.ac.jp.|Department of Radiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan. ttamada@med.kawasaki-m.ac.jp.
authors.forename: Tsutomu
authors.identifier: 0000-0003-2521-9570
authors.initials: T
authors.lastname: Tamada
authors.affiliation: Division of Urologic Oncology, Department of Urology, NYU Langone Medical Center, 550 First Ave, New York, NY, 10016, USA.
authors.forename: Hasan
authors.initials: H
authors.lastname: Dani
authors.affiliation: Division of Urologic Oncology, Department of Urology, NYU Langone Medical Center, 550 First Ave, New York, NY, 10016, USA.
authors.forename: Samir S
authors.initials: SS
authors.lastname: Taneja
authors.affiliation: Department of Radiology, NYU Langone Medical Center, 550 First Ave, New York, NY, 10016, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Rosenkrantz
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D061705:Image-Guided Biopsy; D021621:Imaging, Three-Dimensional; D053783:Magnetic Resonance Imaging, Interventional; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D011237:Predictive Value of Tests; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D012189:Retrospective Studies; D018084:Ultrasonography, Interventional
keywords: Active surveillance; Apparent diffusion coefficient; DWI; MRI; Prostate cancer