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355 Topographical risk stratification of undertreatment in focal therapy for prostate cancer: Mid-apical biopsy compensates for MRI underdiagnosis
355
Topographical risk stratification of undertreatment in focal therapy for prostate cancer: Midapical biopsy compensates for MRI underdiagnosis Eur Urol Suppl 2014;13;e355
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Matsuoka Y. 1 , Numao N.1 , Saito K. 1 , Tanaka H.2 , Kijima T.1 , Nakanishi Y. 1 , Yoshida S. 1 , Ishioka J. 1 , Fujii Y. 1 , Kihara K. 1 1 Tokyo
Medical and Dental University Graduate School, Dept. of Urology, Tokyo, Japan, 2 Ochanomizu Surugadai Clinic, Dept. of
Radiology, Tokyo, Japan INTRODUCTION & OBJECTIVES: Pretreatment assessment procedures with well-balanced diagnostic accuracy and versatility would encourage the dissemination of focal therapy (FT). In hemiablation, we have reported that MRI in combination with 14-core systematic biopsy (SBx) decreases undetectable significant cancer (SC) in untreated lobes with a negative predictive value (NPV) of 95% (Eur Urol. in press). There is a growing demand for MRI-guided lesion-targeted FT as a more selective treatment. However, invisible or vaguely-outlined lesions are not uncommon on MRI, and it remains to be clarified whether MRI performance varies with anatomical location. We investigated site-specific MRI diagnosis for SC in order to establish efficient biopsy strategy for FT based on SC distribution and MRI performance. MATERIAL & METHODS: Between 2007 and 2012, 162 men with clinically localized prostate cancer and PSA levels < 20 ng/ml were enrolled. These subjects underwent multiparametric MRI and 14-core SBx including ventral sampling, followed by radical prostatectomy (RP). MR images and RP specimens were divided into 12 segments (right/left; ventral/dorsal; basal/mid/apical thirds), and a total of 1944 segments were examined. SC was defined as a lesion with Gleason score ≥ 4+3 and/or tumour volume ≥ 0.5 cm3 and/or extraprostatic extension. When SC extended to the adjacent segment, both areas were assigned to harbor SC. We examined the predictive values of MRI for RP pathology in each segment, and then conducted simulated analyses on MRI performance in combination with SBx with various numbers of cores. RESULTS: The number of segments with positive MRI findings in the ventral-base (VB)/dorsal-base (DB)/ventral-mid (VM)/dorsal-mid (DM)/ventral-apex (VA)/dorsal-apex (DA) were 59/53/149/138/121/107 (18/16/46/43/37/33%), respectively. In VB/DB/VM/DM/VA/DA of RP specimens, cancer was found in 70/59/228/199/180/192 segments (22/18/70/61/56/59%), respectively, and SC was found in 58/53/153/146/134/140 segments (18/16/47/45/41/43%), respectively. In both the ventral and dorsal sides, the basal thirds had less MRI positivity and less SC than the other thirds (p < 0.001 for both). The positive predictive value, NPV, sensitivity, and specificity of MRI for SC in VB/DB/VM/DM/VA/DA were 85/83/85/84/80/92%, 97/97/84/84/82/81%, 86/83/82/79/72/70%, and 97/97/86/88/87/95%, respectively. There was no difference in the NPV between ventral and dorsal sides in each third. The basal thirds had superior NPV (97/97% in VB/DB) compared to the other thirds (84/84/82/81% in VM/DM/VA/DA) (p < 0.001 in both the ventral and dorsal sides). In cases where no cancer was found in the mid-apical region of each prostatic quadrant through 2-, 3-, and 4-core sampling (subsets of 8-, 12-, and 14-core SBx, respectively), the NPV of MRI for SC in VM/DM/VA/DA increased to 89/87/90/85%, 90/94/90/90%, and 93/95/90/93% (MRI alone vs. MRI with the regional 4-core biopsy, p < 0.05 in VM/DM/DA, p = 0.08 in VA), respectively. CONCLUSIONS: The basal prostate with negative MRI findings could be assigned as untreated area with the NPV of 97% for SC, even in the absence of biopsy information. In contrast, the NPV in the mid and apical prostate remained at 81 to 84%, suggesting that SBx sampling for the pretreatment assessment of FT should be focused on the mid and apical prostate to reduce the risk of undertreatment in untreated areas.
Topographical risk stratification of undertreatment in focal therapy for prostate cancer: Midapical biopsy compensates for MRI underdiagnosis Eur Urol Suppl 2014;13;e355
Print! Print!
Matsuoka Y. 1 , Numao N.1 , Saito K. 1 , Tanaka H.2 , Kijima T.1 , Nakanishi Y. 1 , Yoshida S. 1 , Ishioka J. 1 , Fujii Y. 1 , Kihara K. 1 1 Tokyo
Medical and Dental University Graduate School, Dept. of Urology, Tokyo, Japan, 2 Ochanomizu Surugadai Clinic, Dept. of
Radiology, Tokyo, Japan INTRODUCTION & OBJECTIVES: Pretreatment assessment procedures with well-balanced diagnostic accuracy and versatility would encourage the dissemination of focal therapy (FT). In hemiablation, we have reported that MRI in combination with 14-core systematic biopsy (SBx) decreases undetectable significant cancer (SC) in untreated lobes with a negative predictive value (NPV) of 95% (Eur Urol. in press). There is a growing demand for MRI-guided lesion-targeted FT as a more selective treatment. However, invisible or vaguely-outlined lesions are not uncommon on MRI, and it remains to be clarified whether MRI performance varies with anatomical location. We investigated site-specific MRI diagnosis for SC in order to establish efficient biopsy strategy for FT based on SC distribution and MRI performance. MATERIAL & METHODS: Between 2007 and 2012, 162 men with clinically localized prostate cancer and PSA levels < 20 ng/ml were enrolled. These subjects underwent multiparametric MRI and 14-core SBx including ventral sampling, followed by radical prostatectomy (RP). MR images and RP specimens were divided into 12 segments (right/left; ventral/dorsal; basal/mid/apical thirds), and a total of 1944 segments were examined. SC was defined as a lesion with Gleason score ≥ 4+3 and/or tumour volume ≥ 0.5 cm3 and/or extraprostatic extension. When SC extended to the adjacent segment, both areas were assigned to harbor SC. We examined the predictive values of MRI for RP pathology in each segment, and then conducted simulated analyses on MRI performance in combination with SBx with various numbers of cores. RESULTS: The number of segments with positive MRI findings in the ventral-base (VB)/dorsal-base (DB)/ventral-mid (VM)/dorsal-mid (DM)/ventral-apex (VA)/dorsal-apex (DA) were 59/53/149/138/121/107 (18/16/46/43/37/33%), respectively. In VB/DB/VM/DM/VA/DA of RP specimens, cancer was found in 70/59/228/199/180/192 segments (22/18/70/61/56/59%), respectively, and SC was found in 58/53/153/146/134/140 segments (18/16/47/45/41/43%), respectively. In both the ventral and dorsal sides, the basal thirds had less MRI positivity and less SC than the other thirds (p < 0.001 for both). The positive predictive value, NPV, sensitivity, and specificity of MRI for SC in VB/DB/VM/DM/VA/DA were 85/83/85/84/80/92%, 97/97/84/84/82/81%, 86/83/82/79/72/70%, and 97/97/86/88/87/95%, respectively. There was no difference in the NPV between ventral and dorsal sides in each third. The basal thirds had superior NPV (97/97% in VB/DB) compared to the other thirds (84/84/82/81% in VM/DM/VA/DA) (p < 0.001 in both the ventral and dorsal sides). In cases where no cancer was found in the mid-apical region of each prostatic quadrant through 2-, 3-, and 4-core sampling (subsets of 8-, 12-, and 14-core SBx, respectively), the NPV of MRI for SC in VM/DM/VA/DA increased to 89/87/90/85%, 90/94/90/90%, and 93/95/90/93% (MRI alone vs. MRI with the regional 4-core biopsy, p < 0.05 in VM/DM/DA, p = 0.08 in VA), respectively. CONCLUSIONS: The basal prostate with negative MRI findings could be assigned as untreated area with the NPV of 97% for SC, even in the absence of biopsy information. In contrast, the NPV in the mid and apical prostate remained at 81 to 84%, suggesting that SBx sampling for the pretreatment assessment of FT should be focused on the mid and apical prostate to reduce the risk of undertreatment in untreated areas.