[767] Correlation of Gleason Score and Tumor Size with Magnetic Reasonance Image-Detected Prostate Cancer
EM Genega, NB Bloch, W Dewolf, R Elliot, Y Fu, M Sanda, J Tomaszewski, N Rofsky. Beth Israel Deaconess Medical Center, Boston, MA; University of Pennsylvania, Philadelphia, PA
Background: Endorectal coil (ERC) magnetic resonance imaging (MR) has become important in the care of patients with prostate cancer (PC). In this study, we histologically characterized foci of PC with whole mount prepared radical prostatectomy specimens and correlated the findings with MR.
Design: Twenty-one patients with biopsy proven PC voluntarily enrolled in an IRB-approved study assessing 3T ERCMR prior to surgery. The prostate gland (PG) slices were kept intact and sections prepared on 2
x3 slides. On each slide, GS, size (greatest 2-dimensional), and pattern of tumor growth (A= < 10% benign glands; B= 
10-50% benign glands; C=small cluster of glands 
alone
; D=<10 glands infiltrating between benign glands) of each tumor focus was recorded. The genitourinary (GU) pathologist was blinded to the MR results. Two GU radiologists, blinded to pathology results, independently reviewed the ERCMR of each patient. Possible foci of carcinoma were graded on a 1-5 scale (1=no cancer; 5=positive). A score of 4 or 5 by at least one radiologist was considered a positive result. Each PG slice was spatially mapped to the corresponding MR slice for each case.
Results: Twenty-one cases were available for review and 81 separate foci of PC were identified histologically. Of these, 43 foci were seen by MR (MR+) and 38 were not (MR-).
| GS | # of foci | Tumor size | Growth pattern | ||||
 7mm | >7mm | A | B | C | D | ||
| 6(3+3) | 15 | 6 | 9 | 6 | 8 | 1 | |
| 7(3+4) | 23 | 3 | 20 | 10 | 13 | ||
| 7(4+3) | 3 | 1 | 2 | 2 | 1 | ||
| 7(4+3)5 | 1 | 1 | 1 | ||||
| 8(4+4) | 1 | 1 | 1 | ||||
| GS | # of foci | Tumor size | Growth pattern | ||||
| 7mm | >7mm | A | B | C | D | ||
| 6(3+3) | 33 | 33 | 7 | 7 | 2 | 17 | |
| 7(3+4) | 5 | 4 | 1 | 1 | 1 | 3 | |
Of the
7mm MR+ cases, the tumors ranged from 4-7mm and of the >7mm MR+ cases, 4 foci were 8-9mm, 22 were 1-2cm and 7 were >2cm. Of the MR- cases, 10 foci were 1mm, 25 were 2-5mm and 2 were 6-7mm. No histologic reason for a 1.6cm MR- focus of PC was found. MR reported 15 additional foci of PC lacking pathology concordance. Most MR+ PC foci were GS 7 (65%), 1cm (67%) and present as a dominant tumor nodule. Thirty-three of 34 (97%) foci > 7mm were MR+; all GS 4+3 were MR+. Most MR- PC foci are GS 6 (87%) and 7mm (97%), and more than half are present as a few glands infiltrating between benign glands.Conclusions: The PC foci identified by MR tend to be larger and higher grade and may prove to be more clinically relevant. ERCMR may be useful for guiding patient management, including
watchful-waiting protocols.Category: Genitourinary (including renal tumors)
Wednesday, March 11, 2009 9:30 AM
Poster Session V # 124, Wednesday Morning