Toru Matsugasumi

Magnetic Resonance Imaging–Transectal Ultrasound Image-fusion Biopsies Accurately Characterize the Index Tumor: Correlation with Step-sectioned Radical Prostatectomy Specimens in 135 Patients

BACKGROUND Prostate biopsies targeted by elastic fusion of magnetic resonance (MR) and three-dimensional (3D) transrectal ultrasound (TRUS) images may allow accurate identification of the index tumor (IT), defined as the lesion with the highest Gleason score or the largest volume or extraprostatic extension. OBJECTIVE To determine the accuracy of MR-TRUS image-fusion biopsy in characterizing ITs, as confirmed by correlation with step-sectioned radical prostatectomy (RP) specimens. DESIGN, SETTING, AND PARTICIPANTS Retrospective analysis of 135 consecutive patients who sequentially underwent pre-biopsy MR, MR-TRUS image-fusion biopsy, and robotic RP at two centers between January 2010 and September 2013. INTERVENTION Image-guided biopsies of MR-suspected IT lesions were performed with tracking via real-time 3D TRUS. The largest geographically distinct cancer focus (IT lesion) was independently registered on step-sectioned RP specimens. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS A validated schema comprising 27 regions of interest was used to identify the IT center location on MR images and in RP specimens, as well as the location of the midpoint of the biopsy trajectory, and variables were correlated. RESULTS AND LIMITATIONS The concordance between IT location on biopsy and RP specimens was 95% (128/135). The coefficient for correlation between IT volume on MRI and histology was r=0.663 (p<0.001). The maximum cancer core length on biopsy was weakly correlated with RP tumor volume (r=0.466, p<0.001). The concordance of primary Gleason pattern between targeted biopsy and RP specimens was 90% (115/128; κ=0.76). The study limitations include retrospective evaluation of a selected patient population, which limits the generalizability of the results. CONCLUSION Use of MR-TRUS image fusion to guide prostate biopsies reliably identified the location and primary Gleason pattern of the IT lesion in >90% of patients, but showed limited ability to predict cancer volume, as confirmed by step-sectioned RP specimens. PATIENT SUMMARY Biopsies targeted using magnetic resonance images combined with real-time three-dimensional transrectal ultrasound allowed us to reliably identify the spatial location of the most important tumor in prostate cancer and characterize its aggressiveness.

Predictive Value of Magnetic Resonance Imaging Determined Tumor Contact Length for Extracapsular Extension of Prostate Cancer

PURPOSE Tumor contact length is defined as the amount of prostate cancer in contact with the prostatic capsule. We evaluated the ability of magnetic resonance imaging determined tumor contact length to predict microscopic extracapsular extension compared to existing predictors of extracapsular extension. MATERIALS AND METHODS We retrospectively analyzed the records of 111 consecutive patients with magnetic resonance imaging/ultrasound fusion targeted, biopsy proven prostate cancer who underwent radical prostatectomy from January 2010 to July 2013. Median patient age was 64 years and median prostate specific antigen was 8.9 ng/ml. Clinical stage was cT1 in 93 cases (84%) and cT2 in 18 (16%). Postoperative pathological analysis confirmed pT2 in 71 patients (64%) and pT3 in 40 (36%). We evaluated 1) in the radical prostatectomy specimen the correlation of microscopic extracapsular extension with pathological cancer volume, pathological tumor contact length and Gleason score, 2) the correlation between microscopic extracapsular extension and magnetic resonance imaging tumor contact length, and 3) the ability of preoperative variables to predict microscopic extracapsular extension. RESULTS Logistic regression analysis revealed that pathological tumor contact length correlated better with microscopic extracapsular extension than the predictive power of pathological cancer volume (0.821 vs 0.685). The Spearman correlation between pathological and magnetic resonance imaging tumor contact length was r = 0.839 (p <0.0001). ROC AUC analysis revealed that magnetic resonance imaging tumor contact length outperformed cancer core involvement on targeted biopsy and the Partin tables to predict microscopic extracapsular extension (0.88 vs 0.70 and 0.63, respectively). At a magnetic resonance imaging tumor contact length threshold of 20 mm the accuracy for diagnosing microscopic extracapsular extension was superior to that of conventional magnetic resonance imaging criteria (82% vs 67%, p = 0.015). We developed a predicted probability plot curve of extracapsular extension according to magnetic resonance imaging tumor contact length. CONCLUSIONS Magnetic resonance imaging determined tumor contact length could be a promising quantitative predictor of microscopic extracapsular extension.

Effect of targeted biopsy guided by elastic image fusion of MRI with 3D-TRUS on diagnosis of anterior prostate cancer

PURPOSE To evaluate the effect of targeted biopsy (TB) with elastic fused magnetic resonance imaging (MRI) and 3-dimensional transrectal ultrasound (3D-TRUS) guidance in the diagnosis of anterior prostate cancer (APCa). MATERIAL AND METHOD A retrospective study was performed on patients who underwent TB with elastic fused MRI/3D-TRUS guidance using a 1.5-T MRI with T2- and diffusion-weighted images. APCa was defined as TB-proven cancer whose MR-imaged center was located anteriorly according to standardized MRI reporting schema. Prostate Imaging Reporting and Data System was used to quantify MRI suspicion. Maximum cancer core length (MCCL), cancer core involvement, primary Gleason grade pattern, and Gleason score (GS) on TB were assessed. A clinically significant cancer on TB was MCCL ≥ 5mm of GS 6 or any cancer with GS ≥ 7. Agreement between TB and radical prostatectomy step sections was assessed for all subjects when possible. RESULTS A total of 211 consecutive subjects were included. APCa was found in 81% (170/211). Median (range) of TB per patient, MCCL, and cancer core involvement were 2 (1-5), 10mm (4-23), and 57% (10%-100%), respectively. According to the level of MRI suspicion, positive rate for any cancer vs. clinically significant cancer was 96% (114/119) vs. 86% (102/119) for highly suspicious, 80% (46/57) vs. 68% (39/57) for likely, and 29% (10/35) vs. 20% (7/35) for equivocal, respectively (P = 0.016 and<0.001). Step-section analysis was possible for 70 patients. Concordance of primary Gleason grade pattern and GS between TB and radical prostatectomy was 90% (κ = 0.7) and 77% (κ = 0.64), respectively. CONCLUSION TB with elastic fused MRI/3D-TRUS guidance significantly enhanced accuracy in diagnosing clinically significant APCa.

Prostate Cancer Volume Estimation by Combining Magnetic Resonance Imaging and Targeted Biopsy Proven Cancer Core Length: Correlation with Cancer Volume

PURPOSE Multiparametric magnetic resonance imaging often underestimates or overestimates pathological cancer volume. We developed what is to our knowledge a novel method to estimate prostate cancer volume using magnetic resonance/ultrasound fusion, biopsy proven cancer core length. MATERIALS AND METHODS We retrospectively analyzed the records of 81 consecutive patients with magnetic resonance/ultrasound fusion, targeted biopsy proven, clinically localized prostate cancer who underwent subsequent radical prostatectomy. As 7 patients each had 2 visible lesions on magnetic resonance imaging, 88 lesions were analyzed. The dimensions and estimated volume of visible lesions were calculated using apparent diffusion coefficient maps. The modified formula to estimate cancer volume was defined as the formula of vertical stretching in the anteroposterior dimension of the magnetic resonance based 3-dimensional model, in which the imaging estimated lesion anteroposterior dimension was replaced by magnetic resonance/ultrasound targeted, biopsy proven cancer core length. Agreement of pathological cancer volume with magnetic resonance estimated volume or the novel modified volume was assessed using a Bland-Altman plot. RESULTS Magnetic resonance/ultrasound fusion, biopsy proven cancer core length was a stronger predictor of the actual pathological cancer anteroposterior dimension than magnetic resonance estimated lesion anteroposterior dimension (r = 0.824 vs 0.607, each p <0.001). Magnetic resonance/ultrasound targeted, biopsy proven cancer core length correlated with pathological cancer volume (r = 0.773, p <0.001). The modified formula to estimate cancer volume demonstrated a stronger correlation with pathological cancer volume than with magnetic resonance estimated volume (r = 0.824 vs 0.724, each p <0.001). Agreement of modified volume with pathological cancer volume was improved over that of magnetic resonance estimated volume on Bland-Altman plot analysis. Predictability was more enhanced in the subset of lesions with a volume of 2 ml or less (ie if spherical, the lesion was approximately 16 mm in diameter). CONCLUSIONS Combining magnetic resonance estimated cancer volume with magnetic resonance/ultrasound fusion, biopsy proven cancer core length improved cancer volume predictability.

A novel technique using three-dimensionally documented biopsy mapping allows precise re-visiting of prostate cancer foci with serial surveillance of cell cycle progression gene panel

Conventional systematic biopsy has the shortcoming of sampling error and reveals “no evidence of cancer” with a rate of >50% on active surveillance (AS). The objective of this study is to report our initial experience of applying a 3D‐documented biopsy‐mapping technology to precisely re‐visit geographically documented low‐risk prostate cancer and to perform serial analysis of cell‐cycle‐progression (CCP) gene‐panel.

Three-dimensional navigation system integrating position-tracking technology with a movable tablet display for percutaneous targeting

To assess the feasibility of a novel percutaneous navigation system (Translucent Medical, Inc., Santa Cruz, CA, USA) that integrates position‐tracking technology with a movable tablet display.

Real‐time transrectal ultrasonography‐guided hands‐free technique for focal cryoablation of the prostate

To describe, step‐by‐step, our hands‐free technique for focal cryoablation of prostate cancer.

Localized chromophobe carcinomas treated by nephron-sparing surgery have excellent oncologic outcomes

OBJECTIVE To evaluate the oncologic outcomes of nephron-sparing surgery (NSS) for localized chromophobe renal cell carcinoma (cRCC). MATERIAL AND METHODS We performed a multicenter international study involving the French Network for Research on Kidney Cancer (UroCCR) and 5 international teams. Data from 808 patients treated with NSS between 2004 and 2014 for non-clear cell RCCs were analyzed. RESULTS We included 234 patients with cRCC. There were 123 (52.6%) females. Median age was 61 (23-88) years. Median tumor size was 3 (1-11)cm. A positive surgical margin was identified in 14 specimens (6%). Pathologic stages were T1, T2, and T3a in 202 (86.3%), 9 (3.8%), and 23 (9.8%) cases, respectively. After a mean follow-up of 46.6 ± 36 months, 2 (0.8%) patients experienced a local recurrence. No patient had metastatic progression, and no patient died from cancer. Three-years estimated cancer-free survival and cancer-specific survival were 99.1% and 100%, respectively. CONCLUSION Oncological results of NSS for localized cRCC are excellent. In this series, only 2 patients had a local recurrence, and no patient had metastatic progression or died from cancer.

Does Computed Tomography Still Have Limitations to Distinguish Benign from Malignant Renal Tumors for Radiologists

Objectives: To evaluate the current accuracy of CT for diagnosing benign renal tumors. Materials and Methods: We retrospectively reviewed 905 patients who underwent preoperative CT followed by surgical resection. The final pathology was benign in 156 patients (17%). After exclusions, 140 patients with 163 benign tumors were included and 3 sets of the CT interpretations by radiologists with varying levels of experience were analyzed. Results: The histological breakdown was as follows: oncocytomas (54.6%), angiomyolipomas (AMLs; 30.7%), renal cysts (8.0%), other miscellaneous benign tumors (6.7%). The sensitivities of diagnosing oncocytomas were 3.4, 9.0, and 13.5% in primary radiological reports, second blinded reviews, and third non-blinded reviews, respectively (p = 0.055). The sensitivities of diagnosing AMLs were 46.0, 58.0, and 62.0% in the 3-sets of CT interpretations, respectively (p = 0.246). As for renal cysts, the sensitivities were 69.2, 92.3, and 100% in the 3-sets of CT interpretations, respectively (p = 0.051). In primary reports, the positive predictive values were 95.8% in lipid poor (lp)-AMLs, 60.0% in oncocytomas, 69.2% in renal cysts, respectively (p < 0.05). Conclusions: Current conventional CT imaging still has limitations in differentiating oncocytomas and lp-AMLs from renal cell carcinomas, even when images were re-examined by experienced radiologists.

Robotic transmural ablation of bladder tumors using high-intensity focused ultrasound: Experimental study.

To evaluate the feasibility of robot‐assisted laparoscopic high‐intensity focused ultrasound for targeted, extravesical, transmural, full‐thickness ablation of intact bladder wall and tumor.