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-percentile were 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-percentile achieved 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.
Abdominal radiology (New York). 2017 Apr 10 [Epub ahead of print]
Tsutomu Tamada, Hasan Dani, Samir S Taneja, Andrew B Rosenkrantz
Department of Radiology, NYU Langone Medical Center, 550 First Ave, New York, NY, 10016, USA. ., Division of Urologic Oncology, Department of Urology, NYU Langone Medical Center, 550 First Ave, New York, NY, 10016, USA., Department of Radiology, NYU Langone Medical Center, 550 First Ave, New York, NY, 10016, USA.