OBJECTIVES: To determine if endo-rectal multiparametric MRI (MpMRI) at 1.5T could predict a tumor target-volume in the perspective of focal therapy of prostate cancer (PCa).
PATIENTS AND METHODS: Eighty-four consecutive patients underwent MpMRI before radical prostatectomy. Volume of each suspicious area detected on MRI and of all surgical histological foci was determined by planimetry using first each MRI sequence (T2, Diffusion-Weighted and Dynamic Contrast Enhanced-MRI) and then the MRI sequence showing the largest tumor area ("multiparametric volume", MPV). Finally, the largest area of any MRI sequence was used to calculate a "target volume" (TV), assimilated to that of a cylinder. Agreement between MRI and pathological findings was assessed by linear regression and residuals analysis.
RESULTS: Histology showed 99 significant tumors (volume greater than 0.2cc and/or Gleason score greater than 6). Of them, 16 (16.2%) were undetected by mp-MRI. Linear regression analysis showed that tumor volume estimated with T2 or DW-MRI were significantly correlated to pathological volume (r²= 0.82 and 0.83, respectively). Residuals from DW-MRI estimation of volumes were non-significant from 0. Nevertheless, DW-MRI underestimated pathological volume in 43/87 (49%) cases (mean underestimation of 0.56 cm3 [0.005-2.84]). MPV and TV significantly overestimated pathological volume (mean: 16% and 44%, respectively). Underestimated rate was 28 (32%) and 15 (17%) cases, respectively. Volume underestimation was significantly higher for tumor foci < 0.5 cm3. Percentage of Gleason grade 4 did not influence tumor volume estimation.
CONCLUSIONS: MRI can detect most significant tumors. MRI delineation of a target volume may require further adjustment before planning MRI-targeted focal treatments.
Written by:
Cornud F, Khoury G, Bouazza N, Beuvon F, Peyromaure M, Flam T, Zerbib M, Legmann P, Delongchamps NB. Are you the author?
Department of Radiology, Hôpital Cochin, Paris Descartes University, France; Department of Radiology, Hôpital Cochin, Paris Descartes University, France; Department of Clinical Research, AP-HP, Tarnier Hospital, Paris Descartes University, Sorbonne Paris Cité, France; Department of Pathology, HôpitalCochin, Paris Descartes University, France; Department of Urology, HôpitalCochin, Paris Descartes University, France.
Reference: J Urol. 2013 Dec 11. pii: S0022-5347(13)06088-6.
doi: 10.1016/j.juro.2013.12.006
PubMed Abstract
PMID: 24333516
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