Non-Invasive Tumor Grade Evaluation in Von Hippel-Lindau-Associated Clear Cell Renal Cell Carcinoma: A Magnetic Resonance Imaging-Based Study

BACKGROUND

Pathology grading is an essential step for the treatment and evaluation of the prognosis in patients with clear cell renal cell carcinoma (ccRCC).

PURPOSE

To investigate the utility of texture analysis in evaluating Fuhrman grades of renal tumors in patients with Von Hippel-Lindau (VHL)-associated ccRCC, aiming to improve non-invasive diagnosis and personalized treatment.

STUDY TYPE

Retrospective analysis of a prospectively maintained cohort.

POPULATION

One hundred and thirty-six patients, 84 (61%) males and 52 (39%) females with pathology-proven ccRCC with a mean age of 52.8 ± 12.7 from 2010 to 2023.

FIELD STRENGTH AND SEQUENCES

1.5 and 3 T MRIs. Segmentations were performed on the T1-weighted 3-minute delayed sequence and then registered on pre-contrast, T1-weighted arterial and venous sequences.

ASSESSMENT

A total of 404 lesions, 345 low-grade tumors, and 59 high-grade tumors were segmented using ITK-SNAP on a T1-weighted 3-minute delayed sequence of MRI. Radiomics features were extracted from pre-contrast, T1-weighted arterial, venous, and delayed post-contrast sequences. Preprocessing techniques were employed to address class imbalances. Features were then rescaled to normalize the numeric values. We developed a stacked model combining random forest and XGBoost to assess tumor grades using radiomics signatures.

STATISTICAL TESTS

The model's performance was evaluated using positive predictive value (PPV), sensitivity, F1 score, area under the curve of receiver operating characteristic curve, and Matthews correlation coefficient. Using Monte Carlo technique, the average performance of 100 benchmarks of 85% train and 15% test was reported.

RESULTS

The best model displayed an accuracy of 0.79. For low-grade tumor detection, a sensitivity of 0.79, a PPV of 0.95, and an F1 score of 0.86 were obtained. For high-grade tumor detection, a sensitivity of 0.78, PPV of 0.39, and F1 score of 0.52 were reported.

DATA CONCLUSION

Radiomics analysis shows promise in classifying pathology grades non-invasively for patients with VHL-associated ccRCC, potentially leading to better diagnosis and personalized treatment.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 2.

Is prostatic adenocarcinoma with cribriform architecture more difficult to detect on prostate MRI?

BACKGROUND

Cribriform (CBFM) pattern on prostate biopsy has been implicated as a predictor for high-risk features, potentially leading to adverse outcomes after definitive treatment. This study aims to investigate whether the CBFM pattern containing prostate cancers (PCa) were associated with false negative magnetic resonance imaging (MRI) and determine the association between MRI and histopathological disease burden.

METHODS

Patients who underwent multiparametric magnetic resonance imaging (mpMRI), combined 12-core transrectal ultrasound (TRUS) guided systematic (SB) and MRI/US fusion-guided biopsy were retrospectively queried for the presence of CBFM pattern at biopsy. Biopsy cores and lesions were categorized as follows: C0 = benign, C1 = PCa with no CBFM pattern, C2 = PCa with CBFM pattern. Correlation between cancer core length (CCL) and measured MRI lesion dimension were assessed using a modified Pearson correlation test for clustered data. Differences between the biopsy core groups were assessed with the Wilcoxon-signed rank test with clustering.

RESULTS

Between 2015 and 2022, a total of 131 consecutive patients with CBFM pattern on prostate biopsy and pre-biopsy mpMRI were included. Clinical feature analysis included 1572 systematic biopsy cores (1149 C0, 272 C1, 151 C2) and 736 MRI-targeted biopsy cores (253 C0, 272 C1, 211 C2). Of the 131 patients with confirmed CBFM pathology, targeted biopsy (TBx) alone identified CBFM in 76.3% (100/131) of patients and detected PCa in 97.7% (128/131) patients. SBx biopsy alone detected CBFM in 61.1% (80/131) of patients and PCa in 90.8% (119/131) patients. TBx and SBx had equivalent detection in patients with smaller prostates (p = 0.045). For both PCa lesion groups there was a positive and significant correlation between maximum MRI lesion dimension and CCL (C1 lesions: p < 0.01, C2 lesions: p < 0.001). There was a significant difference in CCL between C1 and C2 lesions for T2 scores of 3 and 5 (p ≤ 0.01, p ≤ 0.01, respectively) and PI-RADS 5 lesions (p ≤ 0.01), with C2 lesions having larger CCL, despite no significant difference in MRI lesion dimension.

CONCLUSIONS

The extent of disease for CBFM-containing tumors is difficult to capture on mpMRI. When comparing MRI lesions of similar dimensions and PIRADS scores, CBFM-containing tumors appear to have larger cancer yield on biopsy. Proper staging and planning of therapeutic interventions is reliant on accurate mpMRI estimation. Special considerations should be taken for patients with CBFM pattern on prostate biopsy.

Evaluating the performance of Generative Pre-trained Transformer-4 (GPT-4) in standardizing radiology reports

OBJECTIVE

Radiology reporting is an essential component of clinical diagnosis and decision-making. With the advent of advanced artificial intelligence (AI) models like GPT-4 (Generative Pre-trained Transformer 4), there is growing interest in evaluating their potential for optimizing or generating radiology reports. This study aimed to compare the quality and content of radiologist-generated and GPT-4 AI-generated radiology reports.

METHODS

A comparative study design was employed in the study, where a total of 100 anonymized radiology reports were randomly selected and analyzed. Each report was processed by GPT-4, resulting in the generation of a corresponding AI-generated report. Quantitative and qualitative analysis techniques were utilized to assess similarities and differences between the two sets of reports.

RESULTS

The AI-generated reports showed comparable quality to radiologist-generated reports in most categories. Significant differences were observed in clarity (p = 0.027), ease of understanding (p = 0.023), and structure (p = 0.050), favoring the AI-generated reports. AI-generated reports were more concise, with 34.53 fewer words and 174.22 fewer characters on average, but had greater variability in sentence length. Content similarity was high, with an average Cosine Similarity of 0.85, Sequence Matcher Similarity of 0.52, BLEU Score of 0.5008, and BERTScore F1 of 0.8775.

CONCLUSION

The results of this proof-of-concept study suggest that GPT-4 can be a reliable tool for generating standardized radiology reports, offering potential benefits such as improved efficiency, better communication, and simplified data extraction and analysis. However, limitations and ethical implications must be addressed to ensure the safe and effective implementation of this technology in clinical practice.

CLINICAL RELEVANCE STATEMENT

The findings of this study suggest that GPT-4 (Generative Pre-trained Transformer 4), an advanced AI model, has the potential to significantly contribute to the standardization and optimization of radiology reporting, offering improved efficiency and communication in clinical practice.

KEY POINTS

• Large language model-generated radiology reports exhibited high content similarity and moderate structural resemblance to radiologist-generated reports. • Performance metrics highlighted the strong matching of word selection and order, as well as high semantic similarity between AI and radiologist-generated reports. • Large language model demonstrated potential for generating standardized radiology reports, improving efficiency and communication in clinical settings.

Contemporary care patterns in the management of small renal masses

OBJECTIVES

Incidental small renal masses (SRMs) now account for the majority of new diagnoses of renal cancers. Although there are established management guidelines, referral and management patterns can vary. We aimed to explore identification, practice patterns, and management of identified SRMs in an integrated health system.

STUDY DESIGN

Retrospective analysis.

METHODS

We identified patients with a newly diagnosed SRM measuring 3 cm or less from January 1, 2013, to December 31, 2017, at Kaiser Permanente Southern California. These patients were flagged at the time of radiographic identification to ensure adequate notification of findings. Diagnostic modality, referral, and treatment patterns were analyzed.

RESULTS

Of 519 patients with SRMs, 65% were found on abdominal CT and 22% on renal/abdominal ultrasounds. Within 6 months, 70% of patients consulted with a urologist. Initial management patterns were as follows: active surveillance (60%), partial/radical nephrectomy (18%), and ablation (4%). Among 312 patients on surveillance, 14% eventually received treatment. The majority of patients (69.4%) did not receive guideline-recommended chest imaging for initial staging. Urologist visit within 6 months of SRM diagnosis was associated with increased adherence to staging (P = .003) and subsequent surveillance imaging (P < .001).

CONCLUSIONS

In this contemporary analysis of an integrated health system's experience, referral to a urologist was associated with guideline-concordant staging and surveillance imaging. Frequent utilization of active surveillance with a low rate of progression to active treatment was noted in both groups. These findings shed light on care patterns upstream of urologic evaluation and support the need for clinical pathways to be implemented at the time of radiologic diagnosis.

Perioperative Nephrectomy Outcomes for Patients with Liver Disease: Implications for Liver Transplant Candidates

OBJECTIVE

To improve the management of cirrhotic patients diagnosed with new renal masses, we used a nationally representative cohort to assess the perioperative outcomes of nephrectomy in the setting of liver disease. The incidences of liver disease and renal masses are both rising in the US. Delaying liver transplantation to address other health concerns may have life changing consequences in these patients, thus these results help to guide treatment decisions at this critical junction in care.

METHODS

A retrospective study of the 2016-2019 Nationwide Readmissions Database was performed in adults undergoing nephrectomy for non-emergent indications. Outcomes were compared between 3 cohorts: no chronic liver disease (no CLD), chronic liver disease (CLD), and decompensated cirrhosis (DC). Mixed regression models were used to evaluate the association between CLD and DC with outcomes of interest including morbidity, mortality, readmission rates, non-home discharges, length of stay, and costs.

RESULTS

A total of 183,362 patients were evaluated. The mortality rate in the DC cohort (7%) was higher than with CLD (0.4%) and no CLD (0.3%), (P <.001). DC was associated with higher mortality (OR 8.29, 95% CI 4.07 - 16.88), postoperative bleeding requiring transfusion (OR 5.55, 95% CI 3.72 - 8.26), non-home discharge (OR 5.12, 95% CI 3.16 - 8.30) and readmission (OR 1.79, 95% CI 1.09 - 2.94) compared to no CLD. The DC cohort had the greatest length of stay and costs.

CONCLUSION

Patients undergoing nephrectomy with DC have increased morbidity, mortality, readmission rates, non-home discharges, LOS and costs. Alternative management strategies may be considered in these patients.

Scrotal fibrous hamartoma of infancy: A case report and literature review of a rare tumor of the genitourinary tract

Fibrous hamartoma of infancy (FHI) is a rare, benign soft tissue lesion observed in infants characterized histologically by triphasic appearance of bland fibroblastic fascicles, mature adipose tissue, and nodules of primitive myxoid mesenchyme. Preoperative and intraoperative recognition of FHI presents a significant diagnostic challenge due to nonspecific imaging findings and its histologic similarities to alternate benign and malignant entities. Management requires complete local excision and clinical follow-up to monitor for recurrence. Here, we present the diagnosis, management, and two-year follow-up of a 13-month-old boy with a scrotal FHI in addition to a comprehensive literature review of this entity.

Decisional Regret and Financial Toxicity among Patients with Benign Renal Masses

INTRODUCTION

Treatment of benign renal masses may often be unnecessary and can lead to significant morbidity, mortality, and health care costs. However, individual burdens such as decisional regret and financial costs associated with treatment are not well understood.

METHODS

Members of a support group who have been diagnosed with benign renal tumors were surveyed to evaluate demographic and clinical characteristics as well as decisional regret, using the modified Decision Regret Scale (DRS), and financial toxicity, using the Comprehensive Score for Financial Toxicity (COST). Predictors of decisional regret (DRS score >25) and financial toxicity were explored using logistic and linear regression analyses, respectively.

RESULTS

Of 70 respondents with complete data, 49 (70%) received definitive treatment while 21 (30%) elected surveillance. Decisional regret was expressed by 34/70 (49%) of patients and was associated with increasing age, smaller tumor size, and use of surveillance vs active treatment in univariable analysis. Patients reported significant financial toxicity from the diagnosis of a benign renal mass with a median COST score of 24, similar to a historical cohort of patients with stage IV solid organ cancers undergoing chemotherapy. Qualitative analysis of patient responses identified a lack of discussion by the provider of the likelihood of benign disease, postoperative complications, and financial burden as common themes in their experiences.

CONCLUSIONS

High levels of decisional regret and financial toxicity were found among individuals with benign renal lesions regardless of treatment approach. Improved counseling and diagnostic tools may limit the psychological and financial burdens from these benign entities.

Genetic risk assessment for hereditary renal cell carcinoma: Clinical consensus statement

BACKGROUND

Although renal cell carcinoma (RCC) is believed to have a strong hereditary component, there is a paucity of published guidelines for genetic risk assessment. A panel of experts was convened to gauge current opinions.

METHODS

A North American multidisciplinary panel with expertise in hereditary RCC, including urologists, medical oncologists, clinical geneticists, genetic counselors, and patient advocates, was convened. Before the summit, a modified Delphi methodology was used to generate, review, and curate a set of consensus questions regarding RCC genetic risk assessment. Uniform consensus was defined as ≥85% agreement on particular questions.

RESULTS

Thirty-three panelists, including urologists (n = 13), medical oncologists (n = 12), genetic counselors and clinical geneticists (n = 6), and patient advocates (n = 2), reviewed 53 curated consensus questions. Uniform consensus was achieved on 30 statements in specific areas that addressed for whom, what, when, and how genetic testing should be performed. Topics of consensus included the family history criteria, which should trigger further assessment, the need for risk assessment in those with bilateral or multifocal disease and/or specific histology, the utility of multigene panel testing, and acceptance of clinician-based counseling and testing by those who have experience with hereditary RCC.

CONCLUSIONS

In the first ever consensus panel on RCC genetic risk assessment, 30 consensus statements were reached. Areas that require further research and discussion were also identified, with a second future meeting planned. This consensus statement may provide further guidance for clinicians when considering RCC genetic risk assessment.

LAY SUMMARY

The contribution of germline genetics to the development of renal cell carcinoma (RCC) has long been recognized. However, there is a paucity of guidelines to define how and when genetic risk assessment should be performed for patients with known or suspected hereditary RCC. Without guidelines, clinicians struggle to define who requires further evaluation, when risk assessment or testing should be done, which genes should be considered, and how counseling and/or testing should be performed. To this end, a multidisciplinary panel of national experts was convened to gauge current opinion on genetic risk assessment in RCC and to enumerate a set of recommendations to guide clinicians when evaluating individuals with suspected hereditary kidney cancer.

Genetic risk assessment for hereditary RCC: Report from the consensus panel meeting

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Background: While many genes are now known to be associated with hereditary kidney cancer syndromes, there is a paucity of guidelines or uniform consensus on genetic testing for these patients. An expert panel was organized to assess who, what, when and how patients should be evaluated and what testing should be initiated. Methods: A national, multidisciplinary, panel of experts in urology, medical oncology, clinical geneticists, genetic counselors and patient advocates with background and knowledge in hereditary syndromic kidney cancer convened in person in September 2019. A renal cell carcinoma (RCC) genetic risk assessment questionnaire consisting of 52 questions was compiled prior to the meeting using modified Delphi methodology. The questions were then discussed and reviewed with uniform consensus defined as a minimum of 85% agreement in accordance with the National Comprehensive Cancer Network criteria. Results: The panel consisted of twenty-six attendees represented by urologists (43%), medical oncologist (23%), genetic counselors (13%), clinical geneticists (7%), and patient advocates (3%). The questionnaire consisted of fifty-five statements focusing on who, what, when and how genetic testing should be performed in a patient suspected of hereditary RCC syndrome. A >85% agreement was reached on 30/52 statements with 18/25 (72%) achieving consensus addressing “who”, 2/6 (33%) achieving consensus in “what’ category, 2/7 (29%) in ‘when’ and 4/6 (67%) on how. The questions with least consensus were found in the “what/when?” category with only 4/13 questions with minimum 85% agreement. Specific areas of debate included an age cutoff for prompting a genetic risk assessment as well as need for familial testing in patients with variants of unknown significance. Conclusions: Despite experience of the panel in management of hereditary RCC, the consensus was reached only on 66% of genetic testing. While many issues will need to be discussed further, those statements with consensus may be used to guide physicians and patients on who, what, when and how genetic RCC risk assessment should be performed.

PI-RADS Version 2 Category on 3 Tesla Multiparametric Prostate Magnetic Resonance Imaging Predicts Oncologic Outcomes in Gleason 3 + 4 Prostate Cancer on Biopsy

PURPOSE

Three Tesla multiparametric magnetic resonance imaging with PI-RADS™ (Prostate Imaging Reporting and Data System) version 2 scoring is a common tool in prostate cancer diagnosis which informs the likelihood of a cancerous lesion. We investigated whether PI-RADS version 2 also predicts adverse pathology features mainly in patients with biopsy Gleason score 3 + 4 disease.

MATERIALS AND METHODS

We reviewed the records of 326 consecutive men with a preoperative template and/or magnetic resonance imaging-ultrasound fusion biopsy Gleason score of 6-7 from a prospectively maintained database of men who underwent robotic radical prostatectomy. The primary analysis was done in patients with biopsy Gleason score 3 + 4 to assess the primary outcome of adverse pathology features on univariate and multivariate logistic regression. The secondary outcome was biochemical recurrence-free survival using the Kaplan-Meier method. Similar analysis was done in patients with a biopsy Gleason score of 6-7.

RESULTS

Of men with Gleason score 3 + 4 findings 27%, 15%, 36% and 23% showed a PI-RADS version 2 score of 0-2, 3, 4 and 5, respectively. On univariate analysis PI-RADS version 2 category 5 predicted adverse pathology features vs categories 0-2 (OR 10.7, 95% CI 3.7-31, p ≤0.001). On multivariate analysis the PI-RADS version 2 category 5 was associated with adverse pathology when adjusting for preoperative magnetic resonance imaging targeted biopsy (OR 11.4, 95% CI 3.7-35, p ≤0.0001). In men with a targeted biopsy Gleason score of 3 + 4 prostate cancer PI-RADS version 2 category 5 was associated with adverse pathology (OR 14.7, 95% CI 1.5-146.9, p = 0.02). Of men with biopsy Gleason score 3 + 4 disease 92% and 58% with a PI-RADS version 2 score of 4 and 5, respectively, had 2-year biochemical recurrence-free survival.

CONCLUSIONS

A PI-RADS version 2 category 5 lesion in patients with a biopsy Gleason score 3 + 4 lesion predicted adverse pathology features and biochemical recurrence-free survival. These findings suggest that preoperative 3 Tesla multiparametric magnetic resonance imaging may serve as a prognostic marker of treatment outcomes independently of biopsy Gleason score or biopsy type.

Beyond transrectal ultrasound-guided prostate biopsies: available techniques and approaches

OBJECTIVES

Recent advances have led to the use of magnetic resonance imaging (MRI) alone or with fusion to transrectal ultrasound (TRUS) images for guiding biopsy of the prostate. Our group sought to develop consensus recommendations regarding MRI-guided prostate biopsy based on currently available literature and expert opinion.

METHODS

The published literature on the subject of MRI-guided prostate biopsy was reviewed using standard search terms and synthesized and analyzed by four different subgroups from among the authors. The literature was grouped into four categories-MRI-guided biopsy platforms, robotic MRI-TRUS fusion biopsy, template mapping biopsy and transrectal MRI-TRUS fusion biopsy. Consensus recommendations were developed using the Oxford Center for Evidence Based Medicine criteria.

RESULTS

There is limited high level evidence available on the subject of MRI-guided prostate biopsy. MRI guidance with or without TRUS fusion can lead to fewer unnecessary biopsies, help identify high-risk (Gleason ≥ 3 + 4) cancers that might have been missed on standard TRUS biopsy and identify cancers in the anterior prostate. There is no apparent significant difference between MRI biopsy platforms. Template mapping biopsy is perhaps the most accurate method of assessing volume and grade of tumor but is accompanied by higher incidence of side effects compared to TRUS biopsy.

CONCLUSIONS

Magnetic resonance imaging-guided biopsies are feasible and better than traditional ultrasound-guided biopsies for detecting high-risk prostate cancer and anterior lesions. Judicious use of MRI-guided biopsy could enhance diagnosis of clinically significant prostate cancer while limiting diagnosis of insignificant cancer.

Overall survival in patients with residual disease after radical cystectomy and neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy (NAC) has been shown to improve survival in patients with urothelial carcinoma (UC). However, there are a subset of patients who do not respond or progress despite systemic treatment.

METHODS

Data from the National Cancer Database on patients who underwent a radical cystectomy (RC) with or without NAC from 2006 to 2013 were abstracted. Covariates were balanced using inverse probability weighting methods. The primary outcome of overall survival in patients with residual disease by stage was evaluated using 90-day conditional landmark analysis and Cox proportional hazards modeling. Secondary outcome of predictors of residual disease was evaluated using multivariable logistic regression analysis.

RESULTS

A total of 20,128 patients met our inclusion criteria; 16,058 patients underwent RC only (80%) and 4070 underwent RC with NAC (20%). Patients who received NAC were younger and healthier, treated at an academic center, and presented with higher stage. NAC was associated with improved overall survival amongst patients with cT3-4aN0 (HR 0.84 95% CI 0.73-0.97; p = 0.02) and cN+ (HR 0.70, 95% CI 0.58-0.86; p = 0.001). Predictors of no residual disease were NAC (OR 0.17, 95% CI 0.14-0.21; p < 0.001) and treatment at an academic facility (OR 0.47, 95% CI 0.37-0.60; p < 0.001). Patients with cT3-4a or cN+ had increased odds of having residual UC (OR 2.01, 95% CI 1.53-2.64; p < 0.001, and OR 2.14, 95% CI 1.43-3.21; p < 0.001, respectively) compared with cT2.

CONCLUSION

In patients with residual UC, NAC is associated with a significant survival benefit in higher stage disease only. Furthermore, those treated with NAC or at an academic center were less likely to have residual disease. Given the toxicity of NAC, more prudent patient selection for NAC is warranted and requires further study.

The role of MRI in prostate cancer diagnosis and management

Multiparametric MRI of the prostate demonstrates strong potential to address many limitations of traditional prostate cancer diagnosis and management strategies. Recent evidence supports roles for prostate MRI in prebiopsy risk stratification, guidance of targeted biopsy and preoperative disease staging. Prostate MRI may also assist the planning and follow-up of investigational partial gland ablative therapies. This article reviews the impact of prostate MRI on such diagnostic and therapeutic paradigms in contemporary prostate cancer management.

Risk Stratification by Urinary Prostate Cancer Gene 3 Testing Before Magnetic Resonance Imaging-Ultrasound Fusion-targeted Prostate Biopsy Among Men With No History of Biopsy

OBJECTIVE

To determine whether a combination of prostate cancer gene 3 (PCA3) and magnetic resonance imaging (MRI) suspicion score (mSS) could further optimize detection of prostate cancer on MRI fusion-targeted biopsy (MRF-TB) among men with no history of biopsy.

MATERIALS AND METHODS

We included in this study 187 men presenting to our institution between June 2012 and August 2014 who underwent multiparametric MRI (mpMRI) and PCA3 before MRF-TB. Biopsy results, stratified by biopsy indication and PCA3 score, were recorded. Receiver operating characteristics curves and multivariable logistic regressions were used to model the association of PCA3 and mSS with cancer detection on MRF-TB.

RESULTS

PCA3 is associated with cancer detection on MRF-TB for men with no prior biopsies (area under the curve: 0.67, 95% confidence interval: 0.59-0.76). Using a cutoff of ≥35, PCA3 was associated with cancer risk among men with mSS 2-3 (P = .004), but not among those with mSS 4-5 (P = .340). The interaction of PCA3 and mSS demonstrated significantly higher discrimination for cancer than mSS alone (area under the curve: 0.83 vs 0.79, P = .0434).

CONCLUSION

Urinary PCA3 is associated with mSS and the detection of cancer on MRF-TB for men with no prior biopsies. PCA3 notably demonstrates a high negative predictive value among mSS 2-3. However, in the case of high-suspicion mpMRI, PCA3 is not associated with cancer detection on MRF-TB, adding little to cancer diagnosis. Further studies are needed to evaluate the utility of PCA3 in predicting cancer among men with normal mpMRI.

Multiparametric MRI and targeted prostate biopsy: Improvements in cancer detection, localization, and risk assessment

Introduction

Multiparametric-MRI (mp-MRI) is an evolving noninvasive imaging modality that increases the accurate localization of prostate cancer at the time of MRI targeted biopsy, thereby enhancing clinical risk assessment, and improving the ability to appropriately counsel patients regarding therapy.

Material and methods

We used MEDLINE/PubMed to conduct a comprehensive search of the English medical literature. Articles were reviewed, data was extracted, analyzed, and summarized. In this review, we discuss the mp-MRI prostate exam, its role in targeted prostate biopsy, along with clinical applications and outcomes of MRI targeted biopsies.

Results

Mp-MRI, consisting of T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced imaging, and possibly MR spectroscopy, has demonstrated improved specificity in prostate cancer detection as compared to conventional T2-weighted images alone. An MRI suspicion score has been developed and is depicted using an institutional Likert or, more recently, a standardized reporting scale (PI-RADS). Techniques of MRI-targeted biopsy include in-gantry MRI guided biopsy, TRUS-guided visual estimation biopsy, and software co-registered MRI-US guided biopsy (MRI-US fusion). Among men with no previous biopsy, MRI-US fusion biopsy demonstrates up to a 20% increase in detection of clinically significant cancers compared to systematic biopsy while avoiding a significant portion of low risk disease. These data suggest a potential role in reducing over-detection and, ultimately, over-treatment. Among men with previous negative biopsy, 72–87% of cancers detected by MRI targeted biopsy are clinically significant. Among men with known low risk cancer, repeat biopsy by MR-targeting improves risk stratification in selecting men appropriate for active surveillance secondarily reducing the need for repetitive biopsy during surveillance.

Conclusions

Use of mp-MRI for targeting prostate biopsies has the potential to reduce the sampling error associated with conventional biopsy by providing better disease localization and sampling. MRI-ultrasound fusion-targeted prostate biopsy may improve the identification of clinically significant prostate cancer while limiting detection of indolent disease, ultimately facilitating more accurate risk stratification. Literature supports the clinical applications of MRI-targeted biopsy in men who have never been biopsied before, those with a prior negative biopsy, and those with low risk disease considering active surveillance.

Prebiopsy MRI and MRI-ultrasound Fusion-targeted Prostate Biopsy in Men With Previous Negative Biopsies: Impact on Repeat Biopsy Strategies

OBJECTIVE

To report outcomes of magnetic resonance imaging (MRI)-ultrasound fusion-targeted biopsy (MRF-TB) and 12-core systematic biopsy (SB) over a 26-month period in men with prior negative prostate biopsy.

MATERIALS AND METHODS

Between June 2012 and August 2014, 210 men presenting to our institution for prostate biopsy with ≥1 prior negative biopsy underwent multiparametric MRI followed by MRF-TB and SB and were entered into a prospective database. Clinical characteristics, maximum mpMRI suspicion scores (mSS), and biopsy results were queried from the database, and the detection rates of Gleason ≥7 prostate cancer (PCa) and overall PCa were compared between biopsy techniques using McNemar's test.

RESULTS

Forty seven (29%) of 161 men meeting inclusion criteria (mean age, 65 ± 8 years; mean prostate-specific antigen, 8.9 ± 8.9) were found to have PCa. MRF-TB and SB had overall cancer detection rates (CDRs) of 21.7% and 18.6% (P = .36), respectively, and CDR for Gleason score (GS) ≥7 disease of 14.9% and 9.3% (P = .02), respectively. Of 26 men with GS ≥7 disease, MRF-TB detected 24 (92.3%) whereas SB detected 15 (57.7%; P < .01). Using UCSF-CAPRA criteria, only 1 man was restratified from low risk to higher risk based on SB results compared to MRF-TB alone. Among men with mSS <4, 72% of detected cancers were low risk by UCSF-CAPRA criteria.

CONCLUSION

In men with previous negative biopsies and persistent suspicion of PCa, SB contributes little to the detection of GS ≥7 disease by MRF-TB, and avoidance of SB bears consideration. Based on the low likelihood of detecting GS ≥7 cancer and overall low-risk features of PCa in men with mSS <4, limiting biopsy to men with mSS ≥4 warrants further investigation.

Relationship Between Prebiopsy Multiparametric Magnetic Resonance Imaging (MRI), Biopsy Indication, and MRI-ultrasound Fusion-targeted Prostate Biopsy Outcomes

BACKGROUND

Increasing evidence supports the use of magnetic resonance imaging (MRI)-ultrasound fusion-targeted prostate biopsy (MRF-TB) to improve the detection of clinically significant prostate cancer (PCa) while limiting detection of indolent disease compared to systematic 12-core biopsy (SB).

OBJECTIVE

To compare MRF-TB and SB results and investigate the relationship between biopsy outcomes and prebiopsy MRI.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective analysis of a prospectively acquired cohort of men presenting for prostate biopsy over a 26-mo period. A total of 601 of 803 consecutively eligible men were included.

INTERVENTIONS

All men were offered prebiopsy MRI and assigned a maximum MRI suspicion score (mSS). Men with an MRI abnormality underwent combined MRF-TB and SB.

OUTCOMES

Detection rates for all PCa and high-grade PCa (Gleason score [GS] ≥7) were compared using the McNemar test.

RESULTS AND LIMITATIONS

MRF-TB detected fewer GS 6 PCas (75 vs 121; p<0.001) and more GS ≥7 PCas (158 vs 117; p<0.001) than SB. Higher mSS was associated with higher detection of GS ≥7 PCa (p<0.001) but was not correlated with detection of GS 6 PCa. Prediction of GS ≥7 disease by mSS varied according to biopsy history. Compared to SB, MRF-TB identified more GS ≥7 PCas in men with no prior biopsy (88 vs 72; p=0.012), in men with a prior negative biopsy (28 vs 16; p=0.010), and in men with a prior cancer diagnosis (42 vs 29; p=0.043). MRF-TB detected fewer GS 6 PCas in men with no prior biopsy (32 vs 60; p<0.001) and men with prior cancer (30 vs 46; p=0.034). Limitations include the retrospective design and the potential for selection bias given a referral population.

CONCLUSIONS

MRF-TB detects more high-grade PCas than SB while limiting detection of GS 6 PCa in men presenting for prostate biopsy. These findings suggest that prebiopsy multiparametric MRI and MRF-TB should be considered for all men undergoing prostate biopsy. In addition, mSS in conjunction with biopsy indications may ultimately help in identifying men at low risk of high-grade cancer for whom prostate biopsy may not be warranted.

PATIENT SUMMARY

We examined how magnetic resonance imaging (MRI)-targeted prostate biopsy compares to traditional systematic biopsy in detecting prostate cancer among men with suspicion of prostate cancer. We found that MRI-targeted biopsy detected more high-grade cancers than systematic biopsy, and that MRI performed before biopsy can predict the risk of high-grade cancer.

Detection of third and sixth cranial nerve palsies with a novel method for eye tracking while watching a short film clip

OBJECT

Automated eye movement tracking may provide clues to nervous system function at many levels. Spatial calibration of the eye tracking device requires the subject to have relatively intact ocular motility that implies function of cranial nerves (CNs) III (oculomotor), IV (trochlear), and VI (abducent) and their associated nuclei, along with the multiple regions of the brain imparting cognition and volition. The authors have developed a technique for eye tracking that uses temporal rather than spatial calibration, enabling detection of impaired ability to move the pupil relative to normal (neurologically healthy) control volunteers. This work was performed to demonstrate that this technique may detect CN palsies related to brain compression and to provide insight into how the technique may be of value for evaluating neuropathological conditions associated with CN palsy, such as hydrocephalus or acute mass effect.

METHODS

The authors recorded subjects' eye movements by using an Eyelink 1000 eye tracker sampling at 500 Hz over 200 seconds while the subject viewed a music video playing inside an aperture on a computer monitor. The aperture moved in a rectangular pattern over a fixed time period. This technique was used to assess ocular motility in 157 neurologically healthy control subjects and 12 patients with either clinical CN III or VI palsy confirmed by neuro-ophthalmological examination, or surgically treatable pathological conditions potentially impacting these nerves. The authors compared the ratio of vertical to horizontal eye movement (height/width defined as aspect ratio) in normal and test subjects.

RESULTS

In 157 normal controls, the aspect ratio (height/width) for the left eye had a mean value ± SD of 1.0117 ± 0.0706. For the right eye, the aspect ratio had a mean of 1.0077 ± 0.0679 in these 157 subjects. There was no difference between sexes or ages. A patient with known CN VI palsy had a significantly increased aspect ratio (1.39), whereas 2 patients with known CN III palsy had significantly decreased ratios of 0.19 and 0.06, respectively. Three patients with surgically treatable pathological conditions impacting CN VI, such as infratentorial mass effect or hydrocephalus, had significantly increased ratios (1.84, 1.44, and 1.34, respectively) relative to normal controls, and 6 patients with supratentorial mass effect had significantly decreased ratios (0.27, 0.53, 0.62, 0.45, 0.49, and 0.41, respectively). These alterations in eye tracking all reverted to normal ranges after surgical treatment of underlying pathological conditions in these 9 neurosurgical cases.

CONCLUSIONS

This proof of concept series of cases suggests that the use of eye tracking to detect CN palsy while the patient watches television or its equivalent represents a new capacity for this technology. It may provide a new tool for the assessment of multiple CNS functions that can potentially be useful in the assessment of awake patients with elevated intracranial pressure from hydrocephalus or trauma.

Patterns of repeat prostate biopsy in contemporary clinical practice

PURPOSE

The objectives of this study were to 1) describe the patterns of repeat prostate biopsy in men with a previous negative biopsy and 2) identify predictors of prostate cancer diagnosis on repeat biopsy in these men.

MATERIALS AND METHODS

From a university faculty group practice we identified 1,837 men who underwent prostate biopsy between January 1, 1995 and January 1, 2010. Characteristics of repeat biopsy were examined, including the indication for biopsy, the number of repeat biopsies performed, the number of cores obtained and total prostate specific antigen before biopsy. Features of prostate cancer diagnosed on repeat biopsy were examined, including Gleason score, number of positive cores, percent of tumor and treatment choice. Multivariable logistic regression was done to identify prostate cancer predictors.

RESULTS

Initial biopsy was negative in 1,213 men. In 255 men a total of 798 repeat biopsies were performed. Of the 63 men diagnosed with prostate cancer Gleason score was 6 or less in 33 (52%), 7 in 22 (35%) and 8-9 in 8 (13%). When categorized by Epstein criteria, the rate of clinically insignificant cancer diagnosis decreased substantially by the third and fourth repeat biopsies. Repeat biopsy in men older than 70 years, biopsies including more than 20 cores and the fourth repeat biopsy were associated with an increased likelihood of prostate cancer diagnosis.

CONCLUSIONS

In men selected for multiple repeat biopsies clinically significant cancer is found at each sampling round. Given the continued likelihood of cancer detection even by the fifth biopsy, early consideration of saturation or image guided biopsy may be warranted in the repeat biopsy population.

Focal laser ablation for localized prostate cancer: principles, clinical trials, and our initial experience

Focal therapy of prostate cancer is an evolving treatment strategy that destroys a predefined region of the prostate gland that harbors clinically significant disease. Although long-term oncologic control has yet to be demonstrated, focal therapy is associated with a marked decrease in treatment-related morbidity. Focal laser ablation is an emerging modality that has several advantages, most notably real-time magnetic resonance imaging (MRI) compatibility. This review presents the principles of laser ablation, the role of multiparametric MRI for delineating the site of significant prostate cancer, a summary of published clinical studies, and our initial experience with 23 patients, criteria for selecting candidates for focal prostate ablation, and speculation regarding future directions.

Joint segmentation of anatomical and functional images: applications in quantification of lesions from PET, PET-CT, MRI-PET, and MRI-PET-CT images

We present a novel method for the joint segmentation of anatomical and functional images. Our proposed methodology unifies the domains of anatomical and functional images, represents them in a product lattice, and performs simultaneous delineation of regions based on random walk image segmentation. Furthermore, we also propose a simple yet effective object/background seed localization method to make the proposed segmentation process fully automatic. Our study uses PET, PET-CT, MRI-PET, and fused MRI-PET-CT scans (77 studies in all) from 56 patients who had various lesions in different body regions. We validated the effectiveness of the proposed method on different PET phantoms as well as on clinical images with respect to the ground truth segmentation provided by clinicians. Experimental results indicate that the presented method is superior to threshold and Bayesian methods commonly used in PET image segmentation, is more accurate and robust compared to the other PET-CT segmentation methods recently published in the literature, and also it is general in the sense of simultaneously segmenting multiple scans in real-time with high accuracy needed in routine clinical use.