100 patients who underwent RRP for biopsy-confirmed prostatic malignancy and MRI for preoperative staging.

Transcription

1 Is T2WI with dynamic contrast-enhanced MRI of neurovascular bundles effective for postoperative erectile function after nerve-sparing radical retropubic prostatectomy? Poster No.: C-1352 Congress: ECR 2011 Type: Scientific Paper Authors: Y. E. Bahn, S. H. Kim, Y. H. Kim; Daegu/KR Keywords: Genital / Reproductive system male, MR, Complications, Tissue characterisation DOI: /ecr2011/C-1352 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 15

2 Purpose To assess the impact of T2 - weighted images with additional dynamic contrast enhanced (DCE) MRI for preoperative detection of neurovascular bundle (NVB) regarding postoperative erectile function after following nerve-sparing radical retropubic prostatectomy (NS-RRP). Methods and Materials Patients From January 2005 to June patients who underwent RRP for biopsy-confirmed prostatic malignancy and MRI for preoperative staging. All patients had comparatively satisfactory erectile function (EF) for their age. Exclusion criteria : patients with a history of uncontrolled diabetes mellitus, prior pelvic surgery, preoperative treatment of erectile dysfunction or penile deformity, preoperative or postoperative radiotherapy or hormonal therapy. The patients' clinical and pathologic characteristics are summarized in Table 1. Table 1. Patient's clinical and pathologic characteristics Mean Age (years): 65.3; range, Mean serum prostate-specific antigen (ng/dl): 9.1 (range ) Serum prostate-specific antigen (ng/dl) < (25) (60) > (15) Page 2 of 15

3 Median Gleason score: 6 (range 6-8) 6 28 (28) 7 70 (70) 8 2 (2) Pathologic stage T2a 37 (35) T2b 5 (5) T2c 48 (44) T3 10 (8) Median preoperative IIEF-5 score 19 Median postoperative IIEF-5 score 16 Mean follow-up duration (months) 12 Data presented as number of patients Data in parentheses are percentages IIEF-5 = International Index of Erectile Function, 5-items questionnaire One experienced attending urologist performed or supervised RRP. The medical records of 100 patients who underwent postoperative follow-up for at least 12 months were retrospectively reviewed. No early penile rehabilitation regimen after RP was routinely used. Before and after surgery, patients' erectile potency status was generally assessed by the International Index of Erectile Function 5-item (IIEF-5) questionnaire as evaluated by the urologist MR protocols Patients performed MRI at least 4 weeks after prostate biopsy to minimize hemorrhagic effects of biopsy on imaging. MRI was performed at 3.0 T and 1.5 T MR scanners (GE Signa; General Electric, Milwakee, WI, USA. Avanto; Siemens Medical Systems, Erlargen, Germany) equipped with a maximal gradient strength of 23 mt/m, and a maximal rise time 120 mtm/msec, using surface body coil without an endorectal coil. Page 3 of 15

4 First, Fast spin-echo (FSE) T2-weighted images (TR = 3500 msec, TE = 90 msec, flip angle =90, field of view = 220 mm, slice thickness = 4 mm, interslice gap = 0.2 mm, matrix size = 512 x 224) from the bladder dome to the anus were acquired in the transverse, coronal and sagittal orientations to provide anatomical details of the prostate gland. Thereafter, transverse dynamic contrast enhanced (DCE) - MRI images were performed using a three-dimensional (3D) multi-slice fast gradient echoes sequence (TR = 5.3 msec, TE =1.4 m/sec, flip angle = 20, field of view = 220 mm, slice thickness = 4 mm, no interslice gap, matrix size = 128 x 128; 25 slices). A series of T2-weighted images were acquired prior to DCE-MRI images. After the initial images sets were obtained, a rapid bolus intravenous injection of gadopentetate dimeglumine (Magnevisit; Schering, Berlin, Germany, dose: 0.1 mmol/kg) were administered via a mechanical injector. The time resolution of each dynamic set was 30 seconds, and sequences were attained for 300 seconds. Contrast injection began concurrently with the start of the third imaging session. The dosage of injected contrast material was 15mL, and the injected rate was 3 ml/sec. Data Analyses The images were interpreted by two experienced radiologist with consensus. Nerve-sparing (NS) procedure was considered with the convention that NVB is localized mostly in the retrolateral regions (4-5 and 7-8 o'clock directions) of the prostate, and the surgeon did not made efforts to dissect the NVB more widely or anteriorly than is traditionally performed. In addition, the NS procedure was not considered if the tumor extended outside the capsule in the retrolateral region as assessed by MRI. NVB was defined as round or ellipsoid structures with signal void near the retrolateral region on T2 - weight MRI, and early (From 7 to 30 seconds) strong enhanced vascular structures than enhancement in the normal peripheral and central tissues as reference on DCE - MRI. T2 - weighted images and T2 - weighted images with additional DCE - MRI were categorized into three groups on each side of the prostate according to presence of definite formation of a NVB Group 1: no definite observed structure Group 2: probable observed structures Page 4 of 15

5 3. Group 3: clearly observed structure. Normal EF was defined as per IIEF-5 score, as recommended by Rosen et al mild (18 to 22) : 65% moderate (12 to 17) : 25% severe (6 to 11) : 10% Statistical Analyses All statistical analyses were performed with SPSS software (SPSS version ,Chicago, Ill). Comparison in the presence of definite NVB formation between T2 weighted images and T2 - weighted with additional DCE - MRI were assessed with the Student t test. Correlations of EF between the two groups: T2 - weighted images and T2 - weighted images with additional DCE - MRI, were assessed using the Pearson correlation coefficient. To assess the predictive value of each EF found at univariate analysis to have a statistically significant role in comparison with T2 - weighted images and DCE - MRI, stepwise logistic regression analysis was performed. To assess intraobserver variation between radiologists interpreting MR images, the values of kappa were used. A P value of less than.05 was considered to be a statistically significant difference Results The results of distribution on NVB formation in terms of only T2 - weighted images, and T2 - weighted images with additional DCE - MRI on each side are summarized in Table 2. (Figures:1-A,1-B, 2-A, 2-B, 3-A,3-B). Table 2. The results of distribution in formation of a NVB in terms of T2 - weighted images and T2 - weighted images with additional DCE - MRI Distribution of T2 T2 + DCE P=value (age) Page 5 of 15

6 NVB Formation 1&1 Group 15 (65.5) 9 (64.8) NS 1&2 Group 23 (66.2) 15 (67.8) NS 1&3 Group 12 (67.1) 20 (64.7) NS 2&2 Group 21 (66.9) 12 (67.4) NS 2&3 Group 18 (68.2) 29 (66.9) NS (65.7) 15 (67.2) NS 3&3 Group 11 1: no definite observed structure 2: probably observed structures 3: clearly observed structure Data presented as number of patients Data in parentheses are mean age for respective groups NS = Nonsignificant ( > 0.05), &= and Patient age distribution was not significantly different between these groups (P > 0.05). Serum PSA level, pathologic stage, pathologic Gleason score, and preoperative erectile function by preoperative IIEF-5 score were not significantly different between these groups (P > 0.05). The results of EF correlation between the groups with only T2 - weighted images, and that of and T2 - weighted images with additional DCE - MRI are summarized in Table 3. Changes in IIEF-5 score following NS-RRP showed significantly larger increase in the combination of Group 3, In addition, when T2 - weighted images and DCE - MRI were compared, changes in IIEF-5 score after NS-RP showed significantly larger increase in T2 - weighted images with additional DCE than in T2 - weighted images alone (P = 0.04). Assessment made by the two radiologists showed relatively high concordance (kappa = 0.72; P < 0.001). Table 3.The results of correlation of erectile function between the groups with T2 weighted images and T2 - weighted images with additional DCE - MRI Page 6 of 15

7 T2 T2+DCE C Increase of IIEF-5 PreOp-IIEF-5 PostOp- IIEF-5 PreOp-IIEF-5 PostOp- IIEF-5 P=value (0.04) 1&1 Group NS 1&2 Group <0.05 1&3 Group <0.05 2&2 Group <0.05 2&3 Group <0.05 3&3 Group <0.05 3Group 1& 2 Group 3Group 1&2Group P=value P=value Increase of (9.8, 11.6, 12.8) (10.9, 12.7, 14.1) (7.5, 8.2, 9.0) 0.03 (7.4, 8.4, 10.0) 0.02 PostOP- IIEF-5 Data presented as score of IIEF-5 Data in parentheses are value of mean postop-iief-5 scores for comparison between combination 3 group and combination 1 and 2 group 3 Group = 1&3 group, 2&3 group, 3&3 group 1 & 2 Group = 1&1 group, 1&2 group, 2&2 group NS = Nonsignificant ( > 0.05), &= and Images for this section: Page 7 of 15

8 Fig. 1: Fig 1-A. A 65-year-old man with stage T2a prostate malignancy (PSA; 5.1 ng/dl, Gleason score; 6). The preoperative and postoperative IIEF - 5 score was 17 and 14, respectively. T2 - weighted image shows a ellipsoidal signal void structures with clear observation in both rectolateral regions.(arrow) Page 8 of 15

9 Fig. 2: Fig 1-B.T2 - weighted image with additional DCE - MRI (b) show strong enhancing vascular structures with clear observation in the same region (arrow). Page 9 of 15

10 Fig. 3: Fig 2-A. A 68-year-old man with stage T2b prostate malignancy (PSA; 8.5 ng/ dl, Gleason score; 7). Preoperative and postoperative IIEF - 5 score was 15 and 8, respectively. T2 - weighted image shows an ellipsoidal signal void structure with probable observation in the left rectolateral region (arrow) Page 10 of 15

11 Fig. 4: Fig 2-B.T2 - weighted image with additional DCE - MRI shows a strong enhancing vascular structure with clear observation in same region (arrow). No definite observation of NVB is noted in right region on T2 and T2 with additional DCE. Page 11 of 15

12 Fig. 5: Fig 3-A. A 68-year-old man with stage T2c prostate malignancy (PSA; 10.2 ng/dl, Gleason score; 7). Preoperative and postoperative IIEF - 5 score was 18 and 15, respectively. T2 - weighted image shows no definite observed signal void structure (arrow) Page 12 of 15

13 Fig. 6: Fig 3-B. T2 - weighted image with additional DCE - MRI shows a strong enhancing vascular structure with clear observation in the left rectolateral region (arrow). T2 weighted image shows an ellipsoidal signal void structure with probable observation in the right rectolateral region, and T2 - weighted image with additional DCE - MRI shows a strong enhancing vascular structure with clear observation in the same region. Page 13 of 15

14 Conclusion T2 - weighted images with additional DCE could be useful in the evaluation of preoperative NVB, which appear as enhanced bundle like structures, and be utilized as a supplementary prognostic factor to predict postoperative erectile function. References 1.Baader B, Herrmann M. Topography of the pelvic autonomic nervous system and its potential impact on surgical intervention in the pelvis. Clin Anat 2003;16: Walsh PC, Epstein JI, Lowe FC. Potency following radical prostatectomy with wide unilateral excision of the neurovascular bundle. J Urol 1987;138: Katz R, Salomon L, Hoznek A, et al. Patient reported sexual function following laparoscopic radical prostatectomy. J Urol 2002;168: Kiyoshima K, Yokomizo A, Yoshida T, Tomita K, Yonemasu H, Nakamura M, et al. Anatomical features of periprostatic tissue and its surroundings: a histological analysis of 79 radical retropubic prostatectomy specimens. Jpn J Clin Oncol 2004;34: Costello AJ, Brooks M, Cole OJ. Anatomical studies of the neurovascular bundle and cavernosal nerves. BJU Int 2004;94: Coakely FV, Hricak H. Radiologic anatomy of the prostate gland: a clinical approach. Radiol Clin North Am 2000:38: Lee SB, Hong SK, Choe GY, Lee SE Periprostatic Distribution of Nerves in Specimens From Non-nerve-sparing Radical Retropubic Prostatectomy. UROLOGY 2008;72: Rosen RC, Cappelleri JC, Smith MD, et al. Development and evaluation of an abridged, 5-item version of the International Index of Erectile Function (IIEF-5) as a diagnostic tool for erectile dysfunction. Int J Impot Res 11: , Graefen M, Walz J, Huland H. Open retropubic nervesparing radical prostatectomy. Eur Urol 2006;49: Hricak H, Wang L, Wei DC, et al. The role of preoperative endorectal magnetic resonance imaging in the decision regarding whether to preserve or resect neurovascular bundles during radical retropubic prostatectomy. Cancer 2004;100: Hricak H, Wang L, Wei DC, Coakley FV, Akin O, Reuter VE, et al. The role of preoperative endorectal magnetic resonance imaging in the decision regarding whether to preserve or resect neurovascular bundles during radical retropubic prostatectomy. Cancer 2004;/100:/ Geary ES, Dendinger TE, Freiha FS, Stamey TA. Nerve sparing radical prostatectomy: a different view. J Urol 1995;/154:/ Engelbrecht MR, Huisman HJ, Laheij RF, Jager GJ, Van Leenders GJLH Hulsbergen-Van De Kaa, CA, et al. Disrimination of prostate cancer from normal peripheral zone and central gland tissue by using dynamic contrast-enhanced MR Imaging1 Radiology 2003; 229: Steiner MS. Current results and patient selection for nerve-sparing radical retropubic prostatectomy. Semin Urol Oncol 1995;13: Ogura K, Maekawa S, Okubo K, Aoki Y, Okada T, Oda K, et al. Dynamic endorectal magnetic resonance imaging for local staging and detection of neurovascular bundle involvement of prostate cancer: correlation with histopathologic results. Urology Page 14 of 15

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