MRI-guided Biopsy Research Articles

Accuracy of Sampling PI-RADS 4–5 Index Lesions Alone by MRI-guided In-bore Biopsy in Biopsy–naive Patients Undergoing Radical Prostatectomy

BackgroundTargeting multiparametric magnetic resonance imaging (MP-MRI)-suspicious regions alone in biopsy-naive patients is not common practice, since it may miss clinically significant prostate cancer (PCa). ObjectiveTo investigate the accuracy of in-bore MRI-guided biopsy of Prostate Imaging Reporting and Data System (PI-RADS) 4 and 5 index lesions alone in biopsy-naive patients undergoing radical prostatectomy (RP). Design, setting, and participantsA total of 170 patients underwent MRI-guided in-bore biopsy for PI-RADS 4 and 5 index lesions alone between 2013 and 2018, of whom 136 patients were diagnosed with PCa. Fifty-two patients without prior biopsy who underwent RP were included in this study. MP-MRI findings, biopsy results, and whole-mount step-section specimen evaluation were retrospectively analyzed. Outcome measurements and statistical analysisContinuous variables were reported as mean (standard deviation) or median (range). Differences in parametric variables were calculated by Student t test. Results and limitationsOverall International Society of Urological Pathology grade group (GG) up- and downgrading rates were 23.0% and 7.6% per patient and 24.5% and 6.5% per focus, respectively. Ten of 12 biopsy-detected GG 1 foci were upgraded in the final pathology. In 30 patients, a total of 43 different tumor foci were identified outside the sampled index lesion. Average biopsied and nonbiopsied tumor volumes were found to be 2.02 and 0.45 cm³, respectively (p < 0.001). The index lesion was the largest focus of tumor in all patients’ final histopathological examination; upgrading was identified in only one nonbiopsied focus in a single patient. Limitations include retrospective design and nonstandard indications of in-bore MRI biopsy. ConclusionsIn-bore MRI-guided biopsy of PI-RADS 4–5 index lesions alone in biopsy-naive patients is a safe and accurate diagnostic modality allowing appropriate patient selection for individualized treatment. Patient summaryIn-bore magnetic resonance imaging–guided prostate biopsy of suspicious lesions alone allows accurate risk stratification of patients and reduces the detection of insignificant prostate cancer.

Serial Comparison of Cancer Detection Rate Between Transrectal Ultrasound Sonography Guided Biopsy and Magnetic Resonance Imaging for Repeat Biopsy by a Propensity Score Matching Cohort: A Single Center Experience

Purpose To compare biopsy performance of 2 approaches for multiparametric magnetic resonance imaging (MRI) guided biopsy and transrectal ultrasonography (TRUS)-guided biopsy with 2nd and 3rd repeat biopsy patients in prostate cancer detection. Materials and Methods This retrospective study reviewed 2,868 patients who was performed prostate biopsy between September 2013 to March 2017 at Samsung Medical Center, Seoul, Korea with TRUS-guided random biopsy and MRI fusion, MRI cognitive, and MRI-guided biopsy as 2nd and 3rd repeat biopsy and propensity matching was applied to reduce bias. Detection rate of each study was compared with 1:1 matching. Results Among 265 patients who performed TRUS 2nd biopsy, positivity rate for prostate cancer (PCa) was 18.49% (n=49/265) while 54.72% (n=145/265) for MRI-guided biopsy. In 3rd biopsy, positivity rate for PCa of TRUS biopsy was 17.74% (n=11/62) while 56.45% (n=35/62) for MRI guided biopsy. There was no significant difference in the detection rate for the patient with Gleason score 8 or more. Conclusions MRI-guided biopsy was associated with a higher detection rate of prostate cancer with especially in patients with prior negative biopsy. Key Words: Prostatic neoplasm; Repeat biopsy; Magnetic resonance imaging; Transrectal ultrasonography; Outcome.

Establishing MRI-guided prostate intervention at a UK Centre.

To describe our preliminary experience in establishing an MRI suite capable to deliver targeted prostate biopsy and cryoablation. This article includes a description of the necessary infrastructure alterations, scanning sequence suggestions, anaesthetic advice, and practical procedural considerations. We aim to examine the anticipated issues most UK centres would encounter and offer our experience in overcoming them. During this process we will also explore some of the technical aspects of MRI-guided prostate biopsy and cryoablation. The clinical indication, treatment rationale, intervention strategy, and initial clinical outcomes are described for our first series of patients. MRI-guided prostate intervention provides many theoretical advantages over traditional TRUS guidance. This article demonstrates some of the complexities encountered in establishing this technique in a UK centre, and the proposed solutions. This article gives an account of establishing the first MRI intervention suite in the UK. It demonstrates some of the logistical considerations, and offers the unit's early experience.

MRI-guided frame-based stereotactic brainstem biopsy procedure: A single-center experience.

This study aims at presenting our experience of the MRI-guided frame-based stereotactic brainstem biopsy method, and evaluating the outcomes of the procedure. The current study involved 18 cases that underwent MRI-guided frame-based stereotactic biopsy for brainstem lesions between 2011 and 2018 in our clinic. The relevant data regarding the technique of the biopsy procedure, morbidity, histopathological diagnosis it yields and diagnostic accuracy was retrospectively analyzed. Stereotactic biopsy procedure was performed on 18 patients, including 16 adults and two children. MRI was used as guidance for the biopsy procedure in all patients. The adult patients had the biopsy under local anesthesia; as for the pediatric patients local anesthesia plus sedation was used. All patients received diagnosis based on the histopathological examination of their biopsy samples. No equivocal or negative results, and no major morbidity or mortality was seen in the patients after the procedure. MRI-guided frame-based stereotactic biopsy can be considered as a safe and efficient diagnostic method for brainstem lesions when its diagnostic yield and its morbidity and/or mortality rates are evaluated. Choosing the best trajectory for each lesion, using MRI as guidance for targeting, taking a limited number of biopsy samples are valuable criteria for the decreased morbidity rates in stereotactic brainstem biopsy procedures.

Papillary and sclerosing lesions of the breast detected and biopsied by MRI: Clinical management, upgrade rate, and association with apocrine metaplasia.

Benign papillary and sclerosing lesions of the breast (intraductal papillomas, complex sclerosing lesions, radial scars) are considered high-risk lesions due to the potential for upgrade to carcinoma on subsequent surgical excision. Optimal clinical management of such lesions remains unclear due to variable reported upgrade rates. Apocrine metaplasia is a common finding in breast tissue and its role in MRI enhancing lesions is increasingly being recognized. The purpose of this study was to investigate the MRI features of papillary and sclerosing lesions of the breast, evaluate the clinical management and upgrade rate of such lesions, and examine the contribution of apocrine metaplasia tothe imaging findings. A 13-year retrospective review of MRI-guided biopsies identified 70 MRI-detected and -biopsied papillary and sclerosing lesions. Sixteen lesions without atypia underwent surgical excision; only one case (6%) was upgraded to pleomorphic lobular carcinoma in situ. The majority (64%) of biopsies contained apocrine metaplasia either within or adjacent to the targeted lesion. We found that half of MRI-detected lesions had T2 hyperintense foci (2-5mm) or masses (>5mm) adjacent to the lesion. Histologic correlation showed apocrine cysts were likely responsible for this imaging finding in 56% of these cases.

Impact of Direct MRI-Guided Biopsy of the Prostate on Clinical Management.

OBJECTIVE. The purpose of this study is to investigate the impact of direct MRI-guided biopsy of the prostate on clinical management in practice. MATERIALS AND METHODS. We retrospectively identified 127 patients with unknown (n = 98) or untreated prostate cancer with a Gleason score of 6 (n = 29) who underwent direct MRI-guided biopsy of the prostate at our institution between August 2013 and January 2018, after initial multiparametric endorectal MRI examination revealed one or more Prostate Imaging Reporting and Data System (PI-RADS or PI-RADSv2) category 4 or 5 target lesion. All available medical and imaging records were reviewed to determine pertinent clinical details, biopsy findings, and postbiopsy management. RESULTS. The mean patient age was 68 years (interquartile range, 63-73 years). Findings from MRI-guided biopsy were positive for 93 of 127 patients (73%), with prostate cancer of Gleason score of 7 or higher diagnosed in 84 of these 93 patients (90%). When stratified by clinical scenario, the rate of positive biopsy findings was 66% (57/86) for patients who had negative findings from one or more prior transrectal ultrasound-guided biopsies, 83% (10/12) for biopsy-naive patients, and 90% (26/29) for patients undergoing active surveillance. Overall, 90 of 127 patients (71%) received a new (n = 67) or upgraded (n = 23) diagnosis of prostate cancer, and 57 of these 90 patients (63%) proceeded to receive treatment with prostatectomy, radiation, or androgen deprivation therapy. CONCLUSION. The results of this study suggest that direct MRI-guided biopsy is associated with high rates of significant prostate cancer detection and subsequent definitive treatment across common clinical scenarios and should be considered an important supplementary diagnostic tool in the appropriate setting.

MP18-19 A RANDOMIZED CONTROLLED TRIAL TO INVESTIGATE THE INFECTIOUS OUTCOMES OF INTRARECTAL POVIDONE-IODINE CLEANSING PLUS FORMALIN DISINFECTION OF NEEDLE TIP DURING TRANSRECTAL ULTRASOUND GUIDED PROSTATE BIOPSY

INTRODUCTION AND OBJECTIVES:The ultrasound or MRI-guided prostate biopsy is mostly performed through the transrectal route worldwide; and infectious complications are a growing concern, once the ra...

Calming Alternatives Learned During MRI-Guided Breast Biopsy

Calming Alternatives Learned During MRI-Guided Breast Biopsy

PAX7 target gene repression is a superior FSHD biomarker than DUX4 target gene activation, associating with pathological severity and identifying FSHD at the single-cell level.

Facioscapulohumeral muscular dystrophy (FSHD) is a prevalent, incurable skeletal myopathy. The condition is linked to hypomethylation of the D4Z4 macrosatellite repeat at chromosome 4q35, leading to epigenetic derepression of the transcription factor DUX4; coupled with a permissive 4qA haplotype supplying a poly(A) signal. DUX4 may drive FSHD pathology via both induction of target genes and inhibition of the function of the myogenic master regulator PAX7. Biomarkers for FSHD have focused on DUX4 target gene expression. We have, however, reported that PAX7 target gene repression is a hallmark of FSHD skeletal muscle. Here we demonstrate that PAX7 target gene repression is an equivalent biomarker to DUX4 target gene expression when considering RNA-Sequencing data from magnetic resonance imaging-guided muscle biopsies. Moreover, PAX7 target gene repression correlates with active disease, independent to DUX4 target gene expression. PAX7 target genes are also repressed in RNA-Sequencing data from single cells, representing a significantly better biomarker of FSHD cells than DUX4 target gene expression. Importantly, PAX7 target gene repression is a significant biomarker in the majority of FSHD cells that are DUX4 target gene negative, and on which the DUX4 biomarker is indiscriminate. To facilitate the evaluation of validated biomarkers we provide a simple tool that outputs biomarker values from a normalized expression data matrix. In summary, PAX7 target gene repression in FSHD correlates with disease severity, independently of DUX4 target gene expression. At the single-cell level, PAX7 target gene repression can efficiently discriminate FSHD cells, even when no DUX4 target genes are detectable.

Magnetic Resonance Imaging-guided Stereotactic Biopsy: A Review of 83 Cases with Outcomes.

Background:The purpose of this study was to determine the relationship between the radiological and histopathological distribution of the cerebral lesions diagnosed with stereotactic biopsy (STB) procedure and its outcomes.Materials and Methods:In the current study, a retrospective analysis of 83 patients that underwent the STB in our clinic from January 2011 to December 2015 was made. T1-weighted contrast-enhanced cranial magnetic resonance imaging examinations were performed on patients on whom Leksell stereotactic frame system was installed. The histopathological and the radiological data derived from the STB procedure were classified.Results:In terms of localization, glial tumor (56.6%) was the most common lesion in all regions, except for the multifocal lesions. Contrary to the common knowledge, lymphoma (14.4%) was found to be the most common lesion among multifocal lesions. The success of obtaining positive STB samples in the current series was 95.2% and the complication rate was 3.6%.Conclusion:Had a routine computed tomography scan been performed on each patient in this series, the number of clinically insignificant small intracerebral hematomas would have probably been higher. Nevertheless, the rate of the STB sampling accuracy and the complication rate were similar to those reported in the relevant literature.

T2 Mapping in Prostate Cancer.

The aim of the study was to determine the quantitative T2 values in prostate tissue and evaluate them for detection and grading of prostate cancer. After approval from the local ethics committee, morphological T2-weighted (T2w) images, apparent diffusion coefficient (ADC) maps from diffusion-weighted images, quantitative T2 maps, and calculated T2w images from 75 men (median age, 66.3 years; median PSA, 8.2 ng/mL) were acquired at 3 T magnetic resonance imaging (MRI). Data were retrospectively evaluated for their distinction between prostate pathologies.Eight hundred fifty-seven areas of normal gland (n = 378), prostate cancer (54x Gleason score 6, 98x Gleason score 7, 25x Gleason score 8), benign prostatic hyperplasia (BPH) nodes (n = 150), prostatitis (n = 119), and precancerous lesions (n = 33) were determined on calculated and morphological T2w images. Histological criterion standards were whole gland sections (16 patients), MRI-guided in-bore biopsies (32 patients), MRI/transrectal ultrasound-fusion biopsies (15 patients), and systematic 12-core transrectal ultrasound-guided biopsies (12 patients). Significance was assumed to be P < 0.05. The quantitative T2 values vary significantly between prostate cancer and normal gland tissue (area under the curve [AUC], 0.871), cancer and BPH nodes (AUC = 0.827), and Gleason score 6 and 7 or higher (AUC, 0.742). The quantitative T2 values decrease with increasing Gleason scores and correlate significantly with the ADC values (r = 0.806).The detection accuracy of prostate cancer on calculated (AUC = 0.682) and morphological T2w images (AUC = 0.658) is not significantly different. Quantitative T2 values seem to be suitable for distinguishing between prostate cancer and normal gland tissue or BPH nodes. Similar to the ADC values, they offer an indication of the aggressiveness of the prostate cancer.

Abstract No. 513 Magnetic resonance imaging–guided renal biopsy: tertiary cancer center experience

To investigate the technical success and outcome of magnetic resonance imaging (MRI)-guided renal biopsies using a closed-bore, high magnetic- field (1.5-T) MRI unit. We retrospectively reviewed all percutaneous MRI-guided renal biopsies performed at our institution over the last 4 years (May 2013-July 2017). For each patient, we recorded: demographics, tumor characteristics, MRI sequence, biopsy technique, complications (immediate or delayed), pathological outcome and reviewed follow up imaging. A total of 43 biopsies for 43 lesions (20 right kidney and 23 left kidney) were performed in 42 patients (22 Male and 20 females, average of 62 years old). Of the 43 biopsies, 13 biopsies were associated with renal cryoablation in the same setting. The average tumor size was 3 cm (range1-14 cm). All the lesions were solid except 3 lesions with cystic components. A fat saturation steady state free precession sequence was most commonly used for guidance during the biopsy procedures (62%). All biopsies were performed using coaxial technique with a 16F guide needle, 18 gauge side cutting core, and 22 gauge chiba for fine-needle aspiration (FNA). Samples were obtained using both FNA and cores in 20 biopsies (46.5%), cores only in 22 (51%) lesions and FNA only in one (2.5%) lesion. Samples were diagnostic in 41/43 (95.5%) lesions. Thirty three lesions (77%) were renal cell carcinoma. A single patient had perinephric hematoma managed conservatively. None of the patients developed major complications. The average follow up with imaging was 2.27 years (0.04-5.03 years) and none of the patients developed tumor seeding. Magnetic resonance imaging–guided biopsy in a closed-bore, high-field-strength magnet is a safe and effective technique for sampling of renal lesions with favorable diagnostic yield and low complication rate.

Abstract No. 547 Frozen section analysis of MRI-guided transrectal prostate biopsy specimens: is it accurate?

The standard for prostate biopsy consists of a non-targeted 12-50 core retrieval using transrectal, ultrasound techniques or template transperineal techniques performed in the operating room. With 3 Tesla multiparametric MRI now providing sensitive and specific findings for focal prostate cancers, we are targeting focal biopsies in the MRI suite. This reduces the invasiveness and damage caused by yearly indiscriminate biopsies. However, since we target prostate lesions, it is very important that we obtain a “quick stain” analysis of the tissue while the patient is still in the MRI scanner. This is standard image-guided biopsy workflow in radiology. We are simply applying it to a new organ. The purpose is to insure that frozen section biopsies of the prostate are accurate as compared to the final histopathologic diagnosis. Thirty nine consecutive prostate biopsy patients had in-bore MRI-guided, transrectal biopsy. We transport two 18g core specimens in saline and two other specimens in formalin to the surgical pathology department (the patient remains in MRI with the transrectal probe in place). Frozen section analysis of the two saline specimens gave a preliminary diagnosis. We compared the frozen section analysis with final histopathology to determine true negative and positive rate and accuracy of frozen section analysis of core prostate biopsy specimens. Of the 39 biopsy procedures, 21 patients had true positive results and 15 had true negative results by frozen section analysis. No false positives occurred and 3 false negatives resulted when the final histopathology detected small foci of atypia or low risk prostate cancer. The sensitivity, specificity, positive predictive value, and negative predictive values were 87.5%, 100%, 100%, and 83.3%, respectively. The preliminary diagnosis from frozen section analysis of targeted transrectal prostate core biopsy specimens is highly accurate when malignancy is present. False negative results occur in less than 20% of cases when traces of malignancy are discovered at final histopathology.Tabled 1Frozen versus Final Histopathology of Prostate BiopsiesFinalFrozenPositiveNegativePositive210Negative315 Open table in a new tab

Validation of vessel size imaging (VSI) in high-grade human gliomas using magnetic resonance imaging, image-guided biopsies, and quantitative immunohistochemistry

To evaluate the association between a vessel size index (VSIMRI) derived from dynamic susceptibility contrast (DSC) perfusion imaging using a custom spin-and-gradient echo echoplanar imaging (SAGE-EPI) sequence and quantitative estimates of vessel morphometry based on immunohistochemistry from image-guided biopsy samples. The current study evaluated both relative cerebral blood volume (rCBV) and VSIMRI in eleven patients with high-grade glioma (7 WHO grade III and 4 WHO grade IV). Following 26 MRI-guided glioma biopsies in these 11 patients, we evaluated tissue morphometry, including vessel density and average radius, using an automated procedure based on the endothelial cell marker CD31 to highlight tumor vasculature. Measures of rCBV and VSIMRI were then compared to histological measures. We demonstrate good agreement between VSI measured by MRI and histology; VSIMRI = 13.67 μm and VSIHistology = 12.60 μm, with slight overestimation of VSIMRI in grade III patients compared to histology. rCBV showed a moderate but significant correlation with vessel density (r = 0.42, p = 0.03), and a correlation was also observed between VSIMRI and VSIHistology (r = 0.49, p = 0.01). The current study supports the hypothesis that vessel size measures using MRI accurately reflect vessel caliber within high-grade gliomas, while traditional measures of rCBV are correlated with vessel density and not vessel caliber.

Difference in MRI-guided biopsy cancer detection rates between individual clinicians

ObjectiveA number of studies have described the overall institutional learning curve for magnetic resonance imaging-guided biopsy but none have evaluated differences and interactions between clinicians. Therefore, we aim to measure and compare the cancer detection rates between individual radiologists and urologists at a single academic institution. MethodsA consecutive sample of patients undergoing magnetic resonance imaging-guided biopsy at a single institution were included for analysis. The detection of any and clinically significant (Gleason score ≥3+4) prostate cancer was compared between radiologists and urologists after adjusting for relevant demographic and clinical characteristics. Analysis was conducted on a perlesion basis and only the results of the targeted cores were considered in the primary analysis. ResultsTwo hundred eighty-one patients with 418 lesions were included in the study. Prostate cancer of any grade was detected in 43.7% (183/418) of targeted lesions. There was no difference in the distribution of Prostate Imaging Reporting and Data System (PIRADS) scores attributed by each radiologist (p = 0.43). The individual radiologist cancer detection rate for both overall and clinically significant cancer was similar across each PIRADS score except for the detection of any cancer in PIRADS 3 lesions (p = 0.03). There was no difference in the detection rates of any grade or clinically significant cancer between urologists. ConclusionThis single institutional analysis found that the performance of radiologists and urologists was largely comparable. Theonly variation observed was among radiologists for PIRADS 3 lesions.

Abstract P5-02-06: High-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy: Imaging characteristics, outcome of surgical excision or imaging follow-up

Abstract PURPOSE To evaluate imaging characteristics, outcome of surgical excision or imaging follow-up on high-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy (MRI-VAB). MATERIALS AND METHODS We retrospectively reviewed 581 lesions, to include benign, high-risk and malignant lesions, undergoing 9-gauge MRI-VAB from January 2015 to April 2018. We collected patient demographics, risk factors and indications, breast MRI BI-RADS descriptors, histopathological diagnosis at MRI-VAB and surgical excision, frequency of upgrade to malignancy and imaging follow-up of high-risk lesions found in this period. RESULTS 101 patients with 107/581 (18.4% of all lesions) had high risk lesions at MRI-VAB, including atypical ductal hyperplasia (ADH)(n=19/107, 17.8%), lobular neoplasia (n=35/107, 32.7) including atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS), ALH plus LCIS, papillary lesions (n=44/107, 41.1%), radial scar/complex sclerosing lesion (RS/CSL)(n=8/107, 7.5%) and flat epithelial atypia (FEA)(n=1/107, 1%). 71/107 (66.4%) high risk lesions were excised. 16/71 (22.5%) were upgraded to malignancy (4 invasive cancer, 12 DCIS). The upgrade rate for ADH and lobular neoplasia was 5 /16 (31.3%) and 8/26 (30.8%) respectively. The upgrade rate for RS/CSL was 1/6 (16.7%). Of the 22 papillary lesions excised, 2 (9.1%) demonstrated pathologic atypia and were upgraded to DCIS. The other 20 papillary lesions had no upgrade or atypia. Excised high risk lesions showing upgrade varied from 0.4 to 6 cm in length (average 2.1 cm). Increasing size correlated with tendency towards increased upgrade to malignancy, but there were no other specific imaging features to predict malignancy upgrade. CONCLUSION There were no specific MRI imaging characteristics of high-risk lesions to predict malignancy upgrade. Therefore, surgical excision is recommended for high risk lesions especially ADH or lobular neoplasia. Additionally, non-atypical papillomas did not demonstrate malignancy upgrade in our small study. And further larger studies may demonstrate that these lesions may not need to be surgically excised. Citation Format: Okamoto S, Covelli JD, DeMartini WB, Daniel BL, Ikeda DM. High-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy: Imaging characteristics, outcome of surgical excision or imaging follow-up [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-02-06.

Evaluation of intraoperative MRI-assisted stereotactic brain tissue biopsy: a single-center experience in China

BackgroundThis study aimed to investigate the value of high field-strength intraoperative magnetic resonance imaging (iMRI)-guided stereotactic biopsy in the surgery of intracranial space-occupying lesions.MethodsA total of 87 patients who underwent stereotactic biopsy of intracranial lesions in the Peking University International Hospital from March 2016 to August 2018 were retrospectively surveyed; among these, 50 patients underwent MRI-guided stereotactic biopsy using the Leksell frame (iMRI group) and 37 cases received traditional stereotactic biopsy using the Leksell frame (control group). The accuracy rates and complications of the two groups were compared.ResultsA 100% positive diagnosis was observed in all cases (n = 50) in the iMRI group. In 4 cases, the biopsy site was clearly found to have deviated from the target point, and the biopsy was performed again. The control group had 33 cases (86.5%) with positive diagnosis. No severe complications like neural functional deficit were observed in the iMRI group, while two patients developed bleeding at the puncture site (1 case receiving surgery to remove the hematoma) in the control group. There were no deaths in either group.ConclusioniMRI-assisted stereotactic biopsy can confirm the target position and adjust the puncture path in real time. Compared to the traditional stereotactic biopsy technique, the iMRI method has a higher positive diagnostic rate, though surgical trauma and complications have no significant difference.

The Influence of Background Signal Intensity Changes on Cancer Detection in Prostate MRI.

The objective of this study was to develop a scoring system for background signal intensity changes or prostate homogeneity on prostate MRI and to assess these changes' influence on cancer detection. This institutional review board-approved, HIPAA-compliant, retrospective study included 418 prostate MRI examinations in 385 men who subsequently underwent MRI-guided biopsy. The Likert score for suspicion of cancer assigned by the primary radiologist was extracted from the original report, and histopathologic work-up of the biopsy cores served as the reference standard. Two readers assessed the amount of changes on T2-weighted sequences and assigned a predefined prostate signal-intensity homogeneity score of 1-5 (1 = poor, extensive changes; 5 = excellent, no changes). The sensitivity and specificity of Likert scores for detection of prostate cancer and clinically significant cancer (Gleason score ≥ 3+4) were estimated in and compared between subgroups of patients with different signal-intensity homogeneity scores (≤ 2, 3, and ≥ 4). Interreader agreement on signal-intensity homogeneity scores was substantial (κ = 0.783). Sensitivity for prostate cancer detection increased when scores were better (i.e., higher) (reader 1, from 0.41 to 0.71; reader 2, from 0.53 to 0.73; p ≤ 0.007, both readers). In the detection of significant cancer (Gleason score ≥ 3+4), sensitivity also increased with higher signal-intensity scores (reader 1, from 0.50 to 0.82; reader 2, from 0.63 to 0.86; p ≤ 0.028), though specificity decreased significantly for one reader (from 0.67 to 0.38; p = 0.009). Background signal-intensity changes on T2-weighted images significantly limit prostate cancer detection. The proposed scoring system could improve the standardization of prostate MRI reporting and provide guidance for applying prostate MRI results appropriately in clinical decision-making.

Use of MRI-Guided Biopsy for Selection and Follow-up of Men Undergoing Hemi-gland Cryoablation of Prostate Cancer

To investigate safety, efficacy, and quality of life impact of hemi-gland cryotherapy for clinically-significant prostate cancer (CaP), when patient selection and follow-up includes MRI-guided biopsy. Twenty-nine men with unilateral CaP (all clinically significant with prostate volume <60 cc) were enrolled in a prospective observational trial of hemi-gland cryotherapy. Mean patient age was 68.7 years. Median prostate-specific antigen (PSA) was 6.6 ng/mL. MRI-guided biopsy (3T-MRI, Artemis US fusion) was used for diagnosis and repeated at 6-month follow-up in all men. Treatment was under general anesthesia using the BTG/Galil system. Validated questionnaires were used to determine effects of treatment on urinary and sexual function and quality of life. Cryotherapy was completed satisfactorily in all 29 cases in <60 minutes with no intraoperative complications. Significant decreases in PSA (median decrease 5.6 ng/mL) and PSA density (median decrease 0.14 ng/mL/cc) were observed (P < .01). At 6 months, 23 patients (79%) demonstrated no residual cancer on follow-up MRI-guided biopsy of the treated side. Three patients (10%) revealed micro-residual disease. Three patients (10%) had residual cancer and underwent further treatment. Ipsilateral MRI lesions were present before treatment in 26 patients and after treatment in only 2, reflecting the gross ablative effect; however, MRI showed disappearance of lesions in 4 patients with residual tumor on biopsy. The single complication was 1 case of transient urinary retention; 85% of men who were sexually active continued without change after treatment. Voiding function was unchanged. Hemi-gland cryoablation for clinically-significant CaP is well-tolerated, and when patients are selected and followed by MRI/US fusion biopsy, cancer control appears promising at 6 months.

Addition of magnetic resonance imaging to real time trans-rectal ultrasound-based treatment planning for prostate implants.

PurposeThe greater soft tissue contrast of magnetic resonance imaging (MRI) allows improved accuracy in prostate contouring compared to transrectal ultrasound (TRUS) and helps in identifying specific regions within the prostate. This study attempts to evaluate the potential benefit of MRI-TRUS fusion in treatment planning for more accurate prostate contouring and tumor dose escalation.Material and methods14 patients with previous MRI-guided prostate biopsy and an low-dose-rate (LDR) permanent prostate seed implant have been selected. The prostate and tumor (5 patients) were contoured on the MRI images by a radiologist. The prostate was also contoured on TRUS images during LDR procedure together by a urologist and radiation oncologist. MRI and TRUS images were rigidly fused to compare prostate contours in MRI and TRUS. Prostate was then re-contoured by the radiation oncologist using this fusion. Moreover, V100, V150, and D90 differences were evaluated for localized tumor compared to prostate with negative values indicating cold tumor regions. These cases were re-planned to simulate dose escalation.ResultsThe prostate volume was contoured 8 ±10% smaller in TRUS images, compared to MRI images. The mean percent difference in tumor (compared to prostate) V100 was 0.3 ±–0.4%, V150 was –0.7 ±–24.8%, and D90 was 0.2 ±–12.1%. For the posteriorly located tumors (2 cases), V100 was 0.0 ±–0.3%, D90 was 9.5 ±–3.0%, and V150 was 26.1 ±–5.4%. For anteriorly located tumors (3 cases), V100 was 0.4 ±–0.4%, D90 was –6.0 ±–11.9%, and V150 was –18.5 ±–14.4% (became 15.6 ±14.6% after re-plan).ConclusionsThe MRI-TRUS image fusion is a feasible tool for the visualization of the prostate gland, particularly at the apex and base of the gland. Tumor identification presents the potential for dose escalation using fusion, especially for anteriorly located tumors.