A Gradient Stiffness-Programmed Circuit Board by Spatially Controlled Phase-Transition of Supercooled Hydrogel for Stretchable Electronics Integration

Due to emerging demands in soft electronics, there is an increasing need for material architectures that support robust interfacing between soft substrates, stretchable electrical interconnects, and embedded rigid microelectronics chips. Though researchers have adopted rigid-island structures to solve the issue, this approach merely shifts stress concentrations from chip-conductor interfaces to rigid-island-soft region interfaces in the substrate. Here, a gradient stiffness-programmed circuit board (GS-PCB) that possesses high stretchability and stability with surface mounted chips is introduced. The board comprises a stiffness-programmed hydrogel substrate and a laser-patterned liquid metal conductor. The hydrogel simultaneously obtains a large stiffness disparity and robust interfaces between rigid-islands and soft regions. These seemingly contradictory conditions are accomplished by adopting a gradient stiffness structure at the interfaces, enabled by combining polymers with different interaction energies and a supercooled sodium acetate solution. By integrating the gel with laser-patterned liquid metal with exceptional properties, GS-PCB exhibits higher electromechanical stability than other rigid-island research. To highlight the practicality of this approach, a finger-sensor device that successfully distinguishes objects by direct physical contact is fabricated, demonstrating its stability under various mechanical disturbances.

Utility of Prostate Health Index Density for Biopsy Strategy in Biopsy-Naïve Patients With PI-RADS v2.1 Category 3 Lesions

BACKGROUND

Category 3 lesions in PI-RADSv2.1 pose diagnostic challenges, complicating biopsy decisions. Recent biomarkers like prostate health index (PHI) have shown higher specificity in detecting clinically significant prostate cancer (csPCa) than prostate-specific antigen (PSA). Yet their integration with MRI remains understudied.

PURPOSE

To evaluate the utility of PSA and PHI with its derivatives for detecting csPCa in biopsy-naïve patients with category 3 lesion on initial prostate MRI scan.

STUDY TYPE

Retrospective.

POPULATION

One hundred ninety-three biopsy-naïve patients who underwent MRI, PSA, and PHI testing, followed by both targeted and systematic biopsies.

FIELD STRENGTH/SEQUENCE

Turbo spin-echo T2-weighted imaging, diffusion-weighted single-shot echo-planar imaging, and dynamic contrast-enhanced T1-weighted fast field echo sequence imaging in 3 T.

ASSESSMENT

PHI density (PHID) and PSA density (PSAD) derived by dividing serum PHI and PSA with prostate volume (MRI based methodology suggested by PI-RADSv2.1). Risk-stratified models to evaluate the utility of markers in triaging patients for biopsy, including low-, intermediate-, and high-risk groups.

STATISTICAL TESTS

Independent t-test, Mann-Whitney U test, Mantel-Haenszel test, generalized estimating equation, and receiver operating characteristic (ROC) curve analysis were used. Statistical significance defined as P < 0.05.

RESULTS

CsPCa was found in 16.6% (32/193) of patients. PHID had the highest area under the ROC curve (AUROC) of 0.793, followed by PHI of 0.752, PSAD of 0.750, and PSA of 0.654. PHID with two cut-off points (0.88/mL and 1.82/mL) showed the highest potential biopsy avoidance of 47.7% (92/193) with 5% missing csPCa, and the lowest intermediate-risk group (borderline decision group) at 38.9% (75/193), compared to PSA and PHI.

DATA CONCLUSION

PHID demonstrated better potential in triaging patients with category 3 lesions, possibly aiding more selective and confident biopsy decisions for csPCa detection, than traditional markers.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 5.

[Transvaginal Ultrasound-Guided Biopsy]

Percutaneous ultrasound-guided biopsy is useful for the pathologic confirmation of variable body lesions to establish diagnostic and therapeutic approaches. However, deep pelvic lesions are a challenge for pathologic diagnoses because of the presence of the bowel, bladder, major vessels, and pelvic bones which make a percutaneous approach difficult and dangerous. In female, the vagina is elastic and near the pelvic internal organs. Therefore, transvaginal ultrasound may serve as an effective and safe guide for the pathologic diagnosis of pelvis lesions. This review aimed to introduce the indications for, and the method of transvaginal ultrasound-guided biopsy, and to describe the reported diagnostic accuracy and safety.

Laser-Based Selective Material Processing for Next-Generation Additive Manufacturing

The connection between laser-based material processing and additive manufacturing is quite deeply rooted. In fact, the spark that started the field of additive manufacturing is the idea that two intersecting laser beams can selectively solidify a vat of resin. Ever since, laser has been accompanying the field of additive manufacturing, with its repertoire expanded from processing only photopolymer resin to virtually any material, allowing liberating customizability. As a result, additive manufacturing is expected to take an even more prominent role in the global supply chain in years to come. Herein, an overview of laser-based selective material processing is presented from various aspects: the physics of laser-material interactions, the materials currently used in additive manufacturing processes, the system configurations that enable laser-based additive manufacturing, and various functional applications of next-generation additive manufacturing. Additionally, current challenges and prospects of laser-based additive manufacturing are discussed.

A phase I trial of LXS196, a protein kinase C (PKC) inhibitor, for metastatic uveal melanoma

BACKGROUND

Up to 50% of patients with uveal melanoma develop metastases (MUM) with a poor prognosis and median overall survival of approximately 1 year.

METHODS

This phase I study evaluated the safety, tolerability, pharmacokinetics, pharmacodynamics and efficacy of the oral protein kinase C inhibitor LXS196 in 68 patients with MUM (NCT02601378). Patients received LXS196 doses ranging from 100-1000 mg once daily (QD; n = 38) and 200-400 mg twice daily (BID; n = 30).

RESULTS

First cycle dose-limiting toxicities (DLTs) were observed in 7/38 (18.4%) QD and 2/17 (11.8%) BID patients. Hypotension was the most common DLT, occurring at doses ≥500 mg/day, and manageable with LXS196 interruption and dose reduction. Median duration of exposure to LXS196 was 3.71 months (range: 1.81-15.28) for QD and 4.6 months (range: 0.33-58.32) for BID dosing. Clinical activity was observed in 6/66 (9.1%) evaluable patients achieving response (CR/PR), with a median duration of response of 10.15 months (range: 2.99-41.95); 45/66 had stable disease (SD) per RECIST v1.1. At 300 mg BID, the recommended dose for expansion, 2/18 (11.1%) evaluable patients achieved PR and 12/18 (66.7%) had SD.

CONCLUSION

These results suggest manageable toxicity and encouraging clinical activity of single-agent LXS196 in patients with MUM.

Leveraging metabolic modeling to identify functional metabolic alterations associated with COVID-19 disease severity

OBJECTIVE

Since the COVID-19 pandemic began in early 2020, SARS-CoV2 has claimed more than six million lives world-wide, with over 510 million cases to date. To reduce healthcare burden, we must investigate how to prevent non-acute disease from progressing to severe infection requiring hospitalization.

METHODS

To achieve this goal, we investigated metabolic signatures of both non-acute (out-patient) and severe (requiring hospitalization) COVID-19 samples by profiling the associated plasma metabolomes of 84 COVID-19 positive University of Virginia hospital patients. We utilized supervised and unsupervised machine learning and metabolic modeling approaches to identify key metabolic drivers that are predictive of COVID-19 disease severity. Using metabolic pathway enrichment analysis, we explored potential metabolic mechanisms that link these markers to disease progression.

RESULTS

Enriched metabolites associated with tryptophan in non-acute COVID-19 samples suggest mitigated innate immune system inflammatory response and immunopathology related lung damage prevention. Increased prevalence of histidine- and ketone-related metabolism in severe COVID-19 samples offers potential mechanistic insight to musculoskeletal degeneration-induced muscular weakness and host metabolism that has been hijacked by SARS-CoV2 infection to increase viral replication and invasion.

CONCLUSIONS

Our findings highlight the metabolic transition from an innate immune response coupled with inflammatory pathway inhibition in non-acute infection to rampant inflammation and associated metabolic systemic dysfunction in severe COVID-19.

Paradigm Shift in Prostate Cancer Diagnosis: Pre-Biopsy Prostate Magnetic Resonance Imaging and Targeted Biopsy

With regard to the indolent clinical characteristics of prostate cancer (PCa), the more selective detection of clinically significant PCa (CSC) has been emphasized in its diagnosis and management. Magnetic resonance imaging (MRI) has advanced technically, and recent international cooperation has provided a standardized imaging and reporting system for prostate MRI. Accordingly, prostate MRI has recently been investigated and utilized as a triage tool before biopsy to guide tissue sampling to increase the detection rate of CSC beyond the staging tool for patients in whom PCa was already confirmed on conventional systematic biopsy. Radiologists must understand the current paradigm shift for better PCa diagnosis and management. This article reviewed the recent literature, demonstrating the diagnostic value of pre-biopsy prostate MRI with targeted biopsy and discussed unsolved issues regarding the paradigm shift in the diagnosis of PCa.

Blood oxygenation level-dependent MRI at 3T for differentiating prostate cancer from benign tissue: a preliminary experience

OBJECTIVE

Blood oxygenation-level dependent (BOLD) MRI may identify or quantify the regional distribution of hypoxia within a tumor. We aimed to evaluate the feasibility of BOLD MRI at 3 T in differentiating prostate cancer from benign tissue.

METHODS

A total of 145 patients with biopsy-proven prostate cancer underwent BOLD MRI at 3 T. BOLD MRI was performed using a multiple fast field echo sequence to acquire 12 T₂*-weighted images. The R2* value (rate of relaxation, s^-1) was measured in the index tumor, and benign peripheral (PZ) and transition zone (TZ), and the results were compared. The variability of R2* measurements was evaluated.

RESULTS

Tumor R2* values (25.95 s^-1) were significantly different from the benign PZ (27.83 s^-1) and benign TZ (21.66 s^-1) (p < 0.001). For identifying the tumor, the area under the receiver operating characteristic of R2* was 0.606, with an optimal cut-off value of 22.8 s^-1 resulting in 73.8% sensitivity and 52% specificity. In the Bland-Altman test, the mean differences in R2* values were 8.5% for tumors, 13.3% for benign PZ, and 6.8% for benign TZ. No associations between tumor R2* value and Gleason score, age, prostate volume, prostate-specific antigen, or tumor size.

CONCLUSION

BOLD MRI at 3 T appears to be a feasible tool for differentiating between prostate cancer and benign tissue. However, further studies are required for a direct clinical application.

ADVANCES IN KNOWLEDGE

The R2* values are significantly different among prostate cancer, benign PZ, and benign TZ.

Transparent Soft Actuators/Sensors and Camouflage Skins for Imperceptible Soft Robotics

The advent of soft robotics has led to great advancements in robots, wearables, and even manufacturing processes by employing entirely soft-bodied systems that interact safely with any random surfaces while providing great mechanical compliance. Moreover, recent developments in soft robotics involve advances in transparent soft actuators and sensors that have made it possible to construct robots that can function in a visually and mechanically unobstructed manner, assisting the operations of robots and creating more applications in various fields. In this aspect, imperceptible soft robotics that mainly consist of optically transparent imperceptible hardware components is expected to constitute a new research focus in the forthcoming era of soft robotics. Here, the recent progress regarding extended imperceptible soft robotics is provided, including imperceptible transparent soft robotics (transparent soft actuators/sensors) and imperceptible nontransparent camouflage skins. Their principles, materials selections, and working mechanisms are discussed so that key challenges and perspectives in imperceptible soft robotic systems can be explored.

Circularity Index on Contrast-Enhanced Computed Tomography Helps Distinguish Fat-Poor Angiomyolipoma from Renal Cell Carcinoma: Retrospective Analyses of Histologically Proven 257 Small Renal Tumors Less Than 4 cm

OBJECTIVE

To evaluate circularity as a quantitative shape factor of small renal tumor on computed tomography (CT) in differentiating fat-poor angiomyolipoma (AML) from renal cell carcinoma (RCC).

MATERIALS AND METHODS

In 257 consecutive patients, 257 pathologically confirmed renal tumors (either AML or RCC less than 4 cm), which did not include visible fat on unenhanced CT, were retrospectively evaluated. A radiologist drew the tumor margin to measure the perimeter and area in all the contrast-enhanced axial CT images. In each image, a quantitative shape factor, circularity, was calculated using the following equation: 4 × π × (area ÷ perimeter²). The median circularity (circularity index) was adopted as a representative value in each tumor. The circularity index was compared between fat-poor AML and RCC, and the receiver operating characteristic (ROC) curve analysis was performed. Univariable and multivariable binary logistic regression analysis was performed to determine the independent predictor of fat-poor AML.

RESULTS

Of the 257 tumors, 26 were AMLs and 231 were RCCs (184 clear cell RCCs, 25 papillary RCCs, and 22 chromophobe RCCs). The mean circularity index of AML was significantly lower than that of RCC (0.86 ± 0.04 vs. 0.93 ± 0.02, p < 0.001). The mean circularity index was not different between the subtypes of RCCs (0.93 ± 0.02, 0.92 ± 0.02, and 0.92 ± 0.02 for clear cell, papillary, and chromophobe RCCs, respectively, p = 0.210). The area under the ROC curve of circularity index was 0.924 for differentiating fat-poor AML from RCC. The sensitivity and specificity were 88.5% and 90.9%, respectively (cut-off, 0.90). Lower circularity index (≤ 0.9) was an independent predictor (odds ratio, 41.0; p < 0.001) for predicting fat-poor AML on multivariable logistic regression analysis.

CONCLUSION

Circularity is a useful quantitative shape factor of small renal tumor for differentiating fat-poor AML from RCC.

Yield of concurrent systemic biopsy during MRI-targeted biopsy according to Prostate Imaging Reporting and Data System version 2 in patients with suspected prostate cancer

OBJECTIVES

To investigate the yield of concurrent systemic biopsy (SB) during MRI-targeted biopsy (MRTB) as Prostate Imaging Reporting and Data System (PI-RADS) version 2 (v2) interpretations in patients with suspected prostate cancer (PCa).

METHODS

A total of 285 patients with suspected PCa underwent prebiopsy 3-T MRI, followed by MRI-transrectal ultrasound fusion targeted biopsy and concurrent standard SB for lesions with PI-RADS v2 scores 3-5. Detection rates and positive core rates of PCa and clinically significant cancer (CSC) were evaluated.

RESULTS

In concurrent MRTB and SB, PCa and CSC detection rates were 18.9% and 9.4% for PI-RADS score 3, 45.9% and 32.4% for PI-RADS score 4, and 82.1% and 72.6% for PI-RADS score 5, respectively. Overall detection rate of CSCs (40.0%) for concurrent MRTB and SB was significantly higher than that of MRTB (34.4%, p = 0.004) or SB alone (27.7%, p < 0.001): an increase of 5.6% (16 patients) compared with MRTB alone. For patients with PI-RADS score 4 or 5, the CSC detection rate of concurrent MRTB and SB was 47.0%, an increase of 6.1% when compared with MRTB (40.9%) only (p < 0.001). Of the 110 patients with both MRTB- and SB-positive findings, 22 (20.0%) had the highest Gleason score in SB compared with that in MRTB. In 9.5% (27/285) patients including 12 patients with CSCs, only SB was positive, with negative MRTB.

CONCLUSION

Concurrent SB with MRTB based on PI-RADS v2 can yield a higher CSC detection rate compared with MRTB alone in patients with suspected PCa.

KEY POINTS

• Concurrent SB with MRTB yields an increase of 5.6% CSC detection compared with MRTB alone. • Of both MRTB- and SB-positive findings, 20.0% patients have upgraded Gleason score in SB. • In 18.4% patients, only SB was positive, with negative MRTB. Adding MRTB to SB is helpful for adequate risk stratification, reducing diagnostic uncertainty of PCa.

P785 Left ventricular geometry and myocardial contractility modulate impact of statins on prognosis in patients with acute heart failure

Funding Acknowledgements

N/A

Background/Introduction: The benefit of statins in patients with heart failure (HF) remains controversial and the mechanism of action is largely speculative. We investigated whether survival benefit with statins differs according to left ventricular (LV) geometry and myocardial contractility in acute HF patients.

Methods

We enrolled 1792 acute HF patients receiving statins and 2296 patients not receiving statins admitted from 2009 to 2016. The LV and right ventricular (RV) global longitudinal strain (GLS) was assessed as a measure of myocardial contractility. Patients were classified into 2 groups based on ischemic etiology of HF and further divided into 4 subgroups according to the median values of LV-GLS or RV-GLS. The primary outcome was 5-year all-cause mortality. The study protocol was approved by the ethics committee at each institute and complied with the Declaration of Helsinki. The need for written informed consent was waived.

Results

During the 5-year follow-up, 1740 (40.4%) patients died and they had more unfavorable baseline characteristics. Statin therapy was significantly associated with improved survival in overall patients and in both groups with and without ischemic etiology (all p &lt;0.001). Patients with concentric remodeling/hypertrophy and eccentric hypertrophy demonstrated survival benefit with statin therapy (P = 0.033, 0.004, and 0.008, respectively), while those with normal geometry did not (p = 0.123). In the non-ischemic HF group, survival benefit with statin therapy was confined to patients with low LV-GLS (p = 0.045) or those with low RV-GLS p = 0.003). On the contrary, in ischemic HF group, survival benefit with statin therapy was observed in all patients regardless of the values of LV-GLS or RV-GLS. Significant interactions were present between statin use and diabetes mellitus and IHD (p for interaction = 0.027 and 0.003, respectively) regarding mortality.

Conclusions

LV geometry and myocardial contractility may modulate the effects of statins in patients with acute HF. These echocardiographic measures can provide prognostic information to guide tailored statin treatment in this population. Our findings may also help to develop more well-designed prospective studies, in terms of a more homogenous study population, to confirm survival benefit with statin therapy.

Abstract P785 Figure. Multivariate Cox survival curves

Prognostic Significance for Long-Term Outcomes Following Radical Prostatectomy in Men with Prostate Cancer: Evaluation with Prostate Imaging Reporting and Data System Version 2

Objective

To retrospectively determine whether the use of the Prostate Imaging Reporting and Data System (PI-RADS) version 2 (v2) helps predict long-term outcomes for prostate cancer (PCa) patients following radical prostatectomy (RP).

Materials and Methods

A total of 166 patients with localized PCa evaluated with multiparametric magnetic resonance imaging (mpMRI) at 3T before RP were enrolled. Three groups were created based on PI-RADS v2 score used to predict clinical outcomes: group A, ≥ 3; group B, ≥ 4; group C, 5. We calculated biochemical recurrence-free survival (RFS) and progression-free survival (PFS). Cox proportion hazards models were used to identify variables predictive of biochemical recurrence and disease progression.

Results

During a median follow-up of 9.1 years, biochemical recurrence occurred in 67 patients (40.4%) and disease progression occurred in 55 patients (33.1%). In all groups, 10-year RFS and 10-year PFS were significantly lower for PI-RADS scores ≥ 3, ≥ 4 and 5 than for score < 3, < 4 and < 5 (p <0.05), respectively. In multivariate analysis, PI-RADS score ≥ 3 and score 5 were significant independent risk marker for biochemical recurrence (hazard ratio [HR] = 5.58, p = 0.018; HR = 1.75, p = 0.033) and disease progression (HR = 3.99, p = 0.047; HR = 2.31, p = 0.040). Moderate inter-observer agreement was seen for PI-RADS scoring.

Conclusion

PI-RADS v2 may be used to predict long-term outcomes following RP in PCa.

Stretchable and Transparent Kirigami Conductor of Nanowire Percolation Network for Electronic Skin Applications

Recent research progress of relieving discomfort between electronics and human body involves serpentine designs, ultrathin films, and extraordinary properties of nanomaterials. However, these strategies addressed thus far each face own limitation for achieving desired form of electronic-skin applications. Evenly matched mechanical properties anywhere on the body and imperceptibility of electronics are two essentially required characteristics for future electronic-skin (E-skin) devices. Yet accomplishing these two main properties simultaneously is still very challenging. Hence, we propose a novel fabrication method to introduce kirigami approach to pattern a highly conductive and transparent electrode into diverse shapes of stretchable electronics with multivariable configurability for E-skin applications. These kirigami engineered patterns impart tunable elasticity to the electrodes, which can be designed to intentionally limit strain or grant ultrastretchability depending on applications over the range of 0 to over 400% tensile strain with strain-invariant electrical property and show excellent strain reversibility even after 10 000 cycles stretching while exhibiting high optical transparency (>80%). The versatility of this work is demonstrated by ultrastretchable transparent kirigami heater for personal thermal management and conformal transparent kirigami electrophysiology sensor for continuous health monitoring of human body conditions. Finally, by integrating E-skin sensors with quadrotor drones, we have successfully demonstrated human-machine-interface using our stretchable transparent kirigami electrodes.

A Novel Collateral Imaging Method Derived from Time-Resolved Dynamic Contrast-Enhanced MR Angiography in Acute Ischemic Stroke: A Pilot Study

BACKGROUND AND PURPOSE

Assessment of the collateral status has been emphasized for appropriate treatment decisions in patients with acute ischemic stroke. The purpose of this study was to introduce a multiphase MRA collateral imaging method (collateral map) derived from time-resolved dynamic contrast-enhanced MRA and to verify the value of the multiphase MRA collateral map in acute ischemic stroke by comparing it with the multiphase collateral imaging method (MRP collateral map) derived from dynamic susceptibility contrast-enhanced MR perfusion.

MATERIALS AND METHODS

From a prospectively maintained registry of acute ischemic stroke, MR imaging data of patients with acute ischemic stroke caused by steno-occlusive lesions of the unilateral ICA and/or the M1 segment of the MCA were analyzed. We generated collateral maps using dynamic signals from dynamic contrast-enhanced MRA and DSC-MRP using a Matlab-based in-house program and graded the collateral scores of the multiphase MRA collateral map and the MRP collateral map independently. Interobserver reliabilities and intermethod agreement between both collateral maps for collateral grading were tested.

RESULTS

Seventy-one paired multiphase MRA and MRP collateral maps from 67 patients were analyzed. The interobserver reliabilities for collateral grading using multiphase MRA or MRP collateral maps were excellent (weighted κ = 0.964 and 0.956, respectively). The agreement between both collateral maps was also excellent (weighted κ = 0.884; 95% confidence interval, 0.819-0.949).

CONCLUSIONS

We demonstrated that the dynamic signals of dynamic contrast-enhanced MRA could be used to generate multiphase collateral images and showed the possibility of the multiphase MRA collateral map as a useful collateral imaging method in acute ischemic stroke.

Association of clinicopathological features of melanoma with total naevus count and a history of dysplastic naevi: a cross-sectional retrospective study within an academic centre

BACKGROUND

High naevus count (HNC) (≥ 50 naevi) and presence of dysplastic naevi (DN) are risk factors for malignant melanoma (MM); however, MMs also occur in patients with low naevus count (LNC) (< 50 naevi) and in patients without DN. Little is known about differences between MMs in these groups.

AIM

To characterize the clinicopathological differences between MMs in patients with HNC and those in patients with LNC, with or without biopsy-proven DN.

METHODS

This was a cross-sectional retrospective chart review of 281 patients with MM seen between April 2013 and March 2014 at an academic pigmented lesion clinic (Boston, MA, USA).

RESULTS

Patients with LNC MMs were diagnosed at an older age (51 vs. 41 years, P < 0.001, OR = 0.95, 95% CI 0.93-0.97), with more aggressive MM features, including greater Breslow thickness (1.1 vs. 0.8 mm, P = 0.01), more mitoses (2 vs. 1 mitoses/mm² , P < 0.001), lower rate of superficial spreading subtype (58 vs. 78%, P < 0.01, OR = 2.57, 95% CI 1.31-5.03) and higher MM stage (P < 0.001), compared to patients with HNC. Patients with DN had similar trends as those in patients with HNC described above, and in addition, were more likely to have a truncal MM (55 vs. 39%, P < 0.01, OR = 1.97, 95% CI 1.22-3.18) with less ulceration (13 vs. 29%, P < 0.01, OR = 0.36, 95% CI 0.19-0.71). Patients without DN were more likely to have a history of a non-MM skin cancer (32 vs. 19%, P = 0.01, OR = 0.49, 95% CI 0.28-0.85) and an amelanotic MM (33 vs 21%, P = 0.03, OR = 0.55, 95% CI 0.31-0.96).

CONCLUSIONS

Patients with LNC may develop MMs with more aggressive features at an older age than patients with HNC. A history of biopsy-proven DN reveals distinct MM differences compared to patients without DN.

Anti-PD-1 therapy in patients with advanced melanoma and preexisting autoimmune disorders or major toxicity with ipilimumab

Background

Anti-PD-1 antibodies (anti-PD-1) have clinical activity in a number of malignancies. All clinical trials have excluded patients with significant preexisting autoimmune disorders (ADs) and only one has included patients with immune-related adverse events (irAEs) with ipilimumab. We sought to explore the safety and efficacy of anti-PD-1 in such patients.

Patients and methods

Patients with advanced melanoma and preexisting ADs and/or major immune-related adverse events (irAEs) with ipilimumab (requiring systemic immunosuppression) that were treated with anti-PD-1 between 1 July 2012 and 30 September 2015 were retrospectively identified.

Results

One hundred and nineteen patients from 13 academic tertiary referral centers were treated with anti-PD-1. In patients with preexisting AD (N = 52), the response rate was 33%. 20 (38%) patients had a flare of AD requiring immunosuppression, including 7/13 with rheumatoid arthritis, 3/3 with polymyalgia rheumatica, 2/2 with Sjogren's syndrome, 2/2 with immune thrombocytopaenic purpura and 3/8 with psoriasis. No patients with gastrointestinal (N = 6) or neurological disorders (N = 5) flared. Only 2 (4%) patients discontinued treatment due to flare, but 15 (29%) developed other irAEs and 4 (8%) discontinued treatment. In patients with prior ipilimumab irAEs requiring immunosuppression (N = 67) the response rate was 40%. Two (3%) patients had a recurrence of the same ipilimumab irAEs, but 23 (34%) developed new irAEs (14, 21% grade 3-4) and 8 (12%) discontinued treatment. There were no treatment-related deaths.

Conclusions

In melanoma patients with preexisting ADs or major irAEs with ipilimumab, anti-PD-1 induced relatively frequent immune toxicities, but these were often mild, easily managed and did not necessitate discontinuation of therapy, and a significant proportion of patients achieved clinical responses. The results support that anti-PD-1 can be administered safely and can achieve clinical benefit in patients with preexisting ADs or prior major irAEs with ipilimumab.

Non-invasive evaluation of stable renal allograft function using point shear-wave elastography

OBJECTIVE

To investigate the feasibility of point shear-wave elastography (SWE) in evaluating patients with stable renal allograft function who underwent protocol biopsies.

METHODS

95 patients with stable renal allograft function that underwent ultrasound-guided biopsies at predefined time points (10 days or 1 year after transplantation) were enrolled. Ultrasound and point SWE examinations were performed immediately before protocol biopsies. Patients were categorized into two groups: subclinical rejection (SCR) and non-SCR. Tissue elasticity (kPa) on SWE was measured in the cortex of all renal allografts.

RESULTS

SCR was pathologically confirmed in 34 patients. Tissue elasticity of the SCR group (31.0 kPa) was significantly greater than that of the non-SCR group (24.5 kPa) (=0.016), while resistive index value did not show a significant difference between the two groups (p = 0.112). Tissue elasticity in renal allografts demonstrated significantly moderate negative correlation with estimated glomerular filtration rate (correlation coefficient = -0.604, p < 0.001). Tissue elasticity was not independent factor for SCR prediction on multivariate analysis.

CONCLUSION

As a non-invasive tool, point SWE appears feasible in distinguishing between patients with SCR and without SCR in stable functioning renal allografts. Moreover, it may demonstrate the functional state of renal allografts. Advances in knowledge: On point SWE, SCR has greater tissue elasticity than non-SCR.

The utility of CT and MRI in detecting male urethral recurrence after radical cystectomy

PURPOSE

To evaluate the utility of computed tomography (CT) and magnetic resonance imaging (MRI) in detecting male urethral recurrence (UR).

MATERIALS AND METHODS

Between December 2008 and March 2016, 12 men (age range 61-85 years; median, 74 years) with urethral bloody discharge or pain were histologically confirmed as UR after radical cystectomy due to urothelial carcinoma. Of these patients, eight underwent both CT and MRI. The remaining four patients underwent CT only. CT and MRI were compared regarding UR detection rate. CT and MRI were also evaluated to determine which modality was more accurate for depicting UR. UR detection rate of each MRI sequence were recorded. Standard reference was biopsy or urethrectomy in 11 patients and size change in one patient after treatment.

RESULTS

UR detection rate with CT was 41.7% (5/12), while that with MRI was 100% (8/8) (p = 0.0147). Of the eight patients who were diagnosed UR with MRI, six were detected with MRI alone and two with both MRI and CT (p = 0.0313). UR detection rates of T2-weighted, T1-weighted, diffusion-weighted, and contrast-enhanced MRI were 87.5% (7/8), 62.5% (5/8), 100% (5/5), and 87.5% (7/8), respectively.

CONCLUSION

MRI is superior to CT in detecting male URs in symptomatic patients after radical cystectomy. T2-weighted, diffusion-weighted, and contrast-enhanced MRI sequences are useful for detecting male UR.

Sacral nerve stimulation can be an effective treatment for low anterior resection syndrome

AIM

Sacral nerve stimulation has become a preferred method for the treatment of faecal incontinence in patients who fail conservative (non-operative) therapy. In previous small studies, sacral nerve stimulation has demonstrated improvement of faecal incontinence and quality of life in a majority of patients with low anterior resection syndrome. We evaluated the efficacy of sacral nerve stimulation in the treatment of low anterior resection syndrome using a recently developed and validated low anterior resection syndrome instrument to quantify symptoms.

METHOD

A retrospective review of consecutive patients undergoing sacral nerve stimulation for the treatment of low anterior resection syndrome was performed. Procedures took place in the Division of Colon and Rectal Surgery at two academic tertiary medical centres. Pre- and post-treatment Cleveland Clinic Incontinence Scores and Low Anterior Resection Syndrome scores were assessed.

RESULTS

Twelve patients (50% men) suffering from low anterior resection syndrome with a mean age of 67.8 (±10.8) years underwent sacral nerve test stimulation. Ten patients (83%) proceeded to permanent implantation. Median time from anterior resection to stimulator implant was 16 (range 5-108) months. At a median follow-up of 19.5 (range 4-42) months, there were significant improvements in Cleveland Clinic Incontinence Scores and Low Anterior Resection Syndrome scores (P < 0.001).

CONCLUSION

Sacral nerve stimulation improved symptoms in patients suffering from low anterior resection syndrome and may therefore be a viable treatment option.

Prospective analysis of the sealing ability of the ENSEAL® G2 Articulating Tissue Sealer and transector on human mesenteric vessels in colorectal surgery

BACKGROUND

The sealing and transection of mesenteric vessels is a crucial step in minimally invasive colorectal surgery. We examined the sealing quality of the ENSEAL^® G2 Articulating Tissue Sealer in three different articulations in mesenteric vessels.

METHODS

This was a prospective experimental study within a tertiary healthcare center, and 30 patients were recruited. Burst pressures for each specimen were measured as the primary outcome. Ten specimens at each of the three articulations were also histologically assessed for the quality of seal.

RESULTS

We evaluated 54 sets of specimens from 30 patients for bursting pressure, all of which were harvested and sealed in the operating room. No statistical difference was seen in burst pressures from seals recorded at no angulation, half-maximal angulation, or maximal angulation (1604, 1507, 1478 mmHg; p = 0.07). Histological analysis showed no statistical differences in the average vessel diameter (p = 0.57), lateral extent of thermal injury (p = 0.48), degree of vascular sclerosis, or the integrity of seal at the three articulations. No cases of intraoperative or postoperative bleeding were observed in any of the patients. Five (16.7%) of the ENSEAL^® devices developed breaks in the black, heat-shrink, polyethylene covering as a result of repeated articulation and disarticulation. Electrical arcing did not appear to have occurred as a result of the break, although this was not formally examined.

CONCLUSIONS

The maximum sustainable pressure in mesenteric vessels sealed with a bipolar electrothermal device is supraphysiological, and consequently, the device can be safely used at various articulations to seal vessels during colorectal surgery.

Role of PI-RADSv2 with multiparametric MRI in determining who needs active surveillance or definitive treatment according to PRIAS

PURPOSE

To evaluate the role of Prostate Imaging Reporting and Data System v. 2 (PI-RADSv2) in triaging patients with prostate cancer according to Prostate Cancer Research International: Active Surveillance (PRIAS).

MATERIALS AND METHODS

Between January 2012 and December 2014, 456 patients with biopsy-proven cancer underwent multiparametric 3T magnetic resonance imaging (MRI) using T₂ -weighted, diffusion-weighted, and dynamic contrast-enhanced MRI sequences, and then radical prostatectomy. Two radiologists independently reviewed MR images using PI-RADSv2. For AS, PRIAS required clinical stage <T3, prostate-specific antigen (PSA) ≤10 ng/mL, PSA density <0.2 ng/mL² , Gleason score (GS) ≤6, and the number of positive cores ≤2. For AS, PI-RADSv2 required an index lesion scored <4. Standard reference was prostatectomy, in which insignificant cancer was defined as a small (<0.5 cm³ ) organ-confined lesion with GS ≤6. Sensitivity and specificity for insignificant cancer were obtained with PRIAS, PI-RADSv2, and both.

RESULTS

The sensitivity and specificity with PRIAS were 82.9% (68/82) and 70.9% (265/374), respectively. PI-RADSv2 decreased the sensitivity to 61% (50/82) to 80.5% (66/82), but increased the specificity to 77.8% (291/374) to 90.8% (340/374). The combination of PRIAS and PI-RDASv2 increased significantly the specificity to 89.6% (335/374) to 92.8% (347/374) (P < 0.001).

CONCLUSION

PRIAS using multiparametric MRI can identify a greater number of insignificant cancers than PI-RADSv2. However, PI-RADSv2 helps detect many significant cancers that are misdiagnosed as insignificant cancer with PRIAS.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1753-1759.

Evaluation of extracapsular extension in prostate cancer using qualitative and quantitative multiparametric MRI

PURPOSE

To investigate the value of multiparametric magnetic resonance imaging (mpMRI) for extracapsular extension (ECE) in prostate cancer (PCa).

MATERIALS AND METHODS

In all, 292 patients who received radical prostatectomy and underwent preoperative mpMRI at 3T were enrolled retrospectively. For determining the associations with ECE, the likelihood of ECE was assessed qualitatively on T₂ -weighted imaging (T₂ WI) and combined T₂ WI and diffusion-weighted imaging (DWI) or dynamic contrast-enhanced imaging (DCEI). Quantitative MRI parameters were measured in PCa based on histopathological findings. Two models for detecting ECE including imaging and clinical parameters were developed using multivariate analysis: Model 1 excluding combined T₂ WI and DWI and DCEI and Model 2 excluding combined T₂ WI and DWI, and combined T₂ WI and DCEI. Diagnostic performance of imaging parameters and models was evaluated using the area under the receiver operating characteristics curve (Az).

RESULTS

For detecting ECE, the specificity, accuracy, and Az of combined T₂ WI and DWI or DCEI were statistically better than those of T₂ WI (P < 0.05), and all quantitative MRI parameters showed a statistical difference between the patients with and without ECE (P < 0.05). On multivariate analysis, significant independent markers in Model 1 were combined T₂ WI and DWI, combined T₂ WI and DCEI, and K^trans (P < 0.05). In Model 2, significant markers were combined T₂ WI and DWI and DCEI, K^trans , K_ep , and Ve (P < 0.05). The Az values of models 1 and 2 were 0.944 and 0.957, respectively.

CONCLUSION

mpMRI may be useful to improve diagnostic accuracy of the models for determining the associations with ECE in PCa.

LEVEL OF EVIDENCE

4 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1760-1770.

Postoperative Outcome of Cystic Renal Cell Carcinoma Defined on Preoperative Imaging: A Retrospective Study

PURPOSE

We evaluated the postoperative outcome of cystic renal cell carcinoma defined on preoperative computerized tomography. We also sought to find the optimal cutoff of the cystic proportion in association with patient prognosis.

MATERIAL AND METHODS

In this institutional review board approved study with waiver of informed consent, 1,315 patients were enrolled who underwent surgery for a single renal cell carcinoma with preoperative computerized tomography. The cystic proportion of renal cell carcinoma was determined on computerized tomography. The optimal cutoff of the cystic proportion was explored regarding cancer specific survival. Renal cell carcinomas were categorized as cystic or noncystic renal cell carcinoma according to a conventional cutoff (ie cystic proportion 75% or greater) and an optimal cutoff. Postoperative outcomes were then compared between the 2 groups. Multivariate Cox regression analysis was performed to determine the independent predictor of cancer specific survival.

RESULTS

Of the 1,315 lesions 107 (8.1%) were identified as cystic renal cell carcinoma according to a conventional cutoff. The postoperative outcome of cystic renal cell carcinoma was significantly better than that of noncystic renal cell carcinoma (p <0.001). Neither metastasis nor recurrence developed after surgery in patients with cystic renal cell carcinoma. In association with the cancer specific survival rate, the optimal cutoff of the cystic proportion was 45% and 197 cases (15.0%) were accordingly defined as cystic renal cell carcinoma. On Cox regression analysis, a cystic proportion of 45% or greater of the renal cell carcinoma was an independent predictor of a favorable outcome regarding cancer specific survival (HR 0.34, p = 0.03).

CONCLUSIONS

Cystic renal cell carcinoma defined on preoperative computerized tomography is associated with low metastatic potential and favorable outcomes after surgery. Particularly, a cystic proportion of 45% or greater is an independent prognostic factor for favorable survival.

CT-Guided Radiofrequency Ablation of T1a Renal Cell Carcinoma in Korea: Mid-Term Outcomes

Objective

To evaluate the mid-term outcomes of percutaneous radiofrequency ablation (RFA) treatment in patients with small (< 4 cm) renal cell carcinoma (RCC) in Korea.

Materials and Methods

Between 2010 and 2015, 51 patients (40 men and 11 women; median age, 57 years) with biopsyproven 51 RCC were treated using CT-guided RFA. All patients were clinically staged T1aN0M0 prior to RFA. The median tumor size and follow-up period were 2.1 cm (range, 1.0–3.9 cm) and 26 months (4–60 months), respectively. Local tumor progression, distant metastasis, primary and secondary effectiveness rates, and major complication rates were recorded. Estimated glomerular filtration rates (GFRs) between pre-RFA and last follow-up were compared using paired t tests. The 2-year recurrence-free survival rate was calculated using Kaplan-Meier survival analysis.

Results

Of the 51 patients, 2 (3.9%) experienced local tumor progression, and 1 (2.0%) had lymph node metastasis after the first RFA session. Primary and secondary effectiveness rates were 96.1% (49/51) and 100% (1/1), respectively. Only 1 patient experienced a major complication (uretero-pelvic stricture) after the second RFA session for treating a local tumor progression, and the major complication rate was 1.9% (1/52). The median pre-RFA and last follow-up GFRs were 87.1 mL/ min/1.73 m² (14.2–142.7 mL/min/1.73 m²) and 72.0 mL/min/1.73 m² (7.2–112.6 mL/min/1.73 m²), respectively (p < 0.0001). The 2-year recurrence-free survival rate was 96.0%.

Conclusion

CT-guided RFA is a safe and effective treatment in Korean patients with T1a RCC because of excellent mid-term outcomes.

Can diffusion-weighted magnetic resonance imaging predict tumor recurrence of uterine cervical cancer after concurrent chemoradiotherapy?

PURPOSE

To retrospectively investigate the utility of diffusion-weighted imaging (DWI) for predicting clinical outcome after concurrent chemoradiotherapy (CCRT) in uterine cervical cancer.

MATERIALS AND METHODS

Seventy-four consecutive patients with biopsy-proven cervical cancer who received CCRT underwent DWI at 3T. All patients had MR examinations before therapy (preTx) and at 4 weeks of initiating therapy (midTx). At each point, ADC (apparent diffusion coefficient) was measured in the tumors and ADC change between preTx and midTx were also calculated. For predicting tumor recurrence, MR variables and clinical variables were evaluated and the results were compared.

RESULTS

During a mean follow-up of 32.1 months, tumor recurrence developed in 15 (20%) patients: local recurrence (n = 7), distant metastasis (n = 5), and both (n = 3). MidTx tumor ADCs and tumor ADC changes between preTx and midTx were significantly different between the recurrence and non-recurrence groups (P < 0.05), while preTx tumor ADCs were not significantly different between the groups (P = 0.892). Univariate analysis revealed that histologic type, stage, preTx tumor size and volume, and tumor ADC change were significantly related to tumor recurrence (all P < 0.05). However, on multivariate analysis, tumor ADC changes [hazard ratio (HR) 0.886; 95% confidence interval (CI) 0.836-0.940; P = 0.001] and histological type (HR 6.063; 95% CI 1.404-26.187; P = 0.016) were the significant independent predictors of tumor recurrence.

CONCLUSION

Tumor ADC changes between preTx and midTx might be a useful biomarker for the prediction of cervical cancer recurrence after CCRT.

Long-term outcomes of magnetic resonance imaging-invisible endometrial cancer

OBJECTIVE

Magnetic resonance imaging (MRI) is useful for staging endometrial cancer. The treatment and prognosis of MRI-invisible endometrial cancer remain unclear. The purpose of this study was to retrospectively evaluate the long-term outcomes of patients with MRI-invisible endometrial cancer.

METHODS

Between February 1995 and December 2011, we reviewed the medical records of 433 patients with endometrial cancer, which was staged IA on MRI. Of these patients, 89 had MRI-invisible cancer and 344 had MRI-visible cancer. Both cancers were treated with simple hysterectomy with or without lymph node dissection according to the surgeon's decision. Both cancers were compared regarding pathologic findings, recurrence rates, and survival rates.

RESULTS

The median sizes of MRI-invisible and MRI-visible cancers were 4 mm (0 to 40 mm) and 20 mm (0 to 89 mm), respectively (p<0.001). Myometrial invasion of these groups were detected in 20.2% (18/89) and 56.7% (195/344), respectively (p<0.001). Lymphadenectomy and follow-up imaging revealed no lymph node metastasis in patients with MRI-invisible cancers, while those revealed in 4.7% (16/344) of patients with MRI-visible cancers (p=0.052). The recurrence rates of MRI-invisible and MRI-visible cancers were 1.1% (1/89) and 7.8% (27/344), respectively (p=0.026). The recurrence-free survival rates of these groups were 98.9% (88/89) and 91.6% (315/344), respectively (p=0.022).

CONCLUSION

MRI-invisible endometrial cancer can be treated with less invasive surgery because of its lower tumor burden and better prognosis. This cancer may not require lymphadenectomy because of no metastasis or recurrence in lymph nodes.

Evaluation of hyperdense renal lesions incidentally detected on single-phase post-contrast CT using dual-energy CT

OBJECTIVE

To investigate the utility of dual-energy CT (DECT) for differentiating between solid and benign cystic lesions presenting as hyperdense renal lesions incidentally detected on single-phase post-contrast CT.

METHODS

90 hyperdense renal lesions incidentally detected on single-phase post-contrast CT were evaluated with follow-up DECT. DECT protocols included true non-contrast (TNC), DE corticomedullary and DE late nephrographic phase imaging. The CT numbers of hyperdense renal lesions were calculated on linearly blended and iodine overlay (IO) images, and the results were compared.

RESULTS

In total, 47 benign cystic and 43 solid renal lesions were analyzed. For differentiating between solid and benign cystic lesions on the two phases, the specificity and accuracy of all lesions and lesions <1.5 cm were statistically lower in IO images than in linearly blended images (p < 0.05), while those for lesions ≥1.5 cm were not statistically different between them (p > 0.05). For all types of lesions ≥1.5 cm, the CT numbers between linearly blended and IO images and between TNC and virtual non-contrast images were not statistically different (p > 0.05).

CONCLUSION

DECT may be useful for differentiating between solid and benign cystic lesions presenting as hyperdense renal lesions incidentally detected on single-phase post-contrast CT, particularly with the size ≥1.5 cm.

ADVANCES IN KNOWLEDGE

DECT may be used to characterize hyperdense renal lesions ≥1.5 cm incidentally detected on single-phase post-contrast CT, without the use of TNC images.

Self-expandable metal stents for malignant esophageal obstruction: a comparative study between extrinsic and intrinsic compression

Self-expandable metal stents (SEMSs) are effective for malignant esophageal obstruction, but usefulness of SEMSs in extrinsic lesions is yet to be elucidated. This study is aimed at evaluating the clinical usefulness of SEMSs in the extrinsic compression compared with intrinsic. A retrospective review was conducted for 105 patients (intrinsic, 85; extrinsic, 20) with malignant esophageal obstruction who underwent endoscopic SEMSs placement. Technical and clinical success rates were evaluated and clinical outcomes were compared between extrinsic and intrinsic group. Extrinsic group was mostly pulmonary origin. Overall technical and clinical success rate was 100% and 91%, respectively, without immediate complications. Extrinsic and intrinsic group did not differ significantly in clinical success rate. The median stent patency time was 131.3 ± 85.8 days in intrinsic group while that of extrinsic was 54.6 ± 45.1 due to shorter survival after stent insertion. The 4-, 8-, and 12-week patency rates were 90.5%, 78.8%, and 64.9% respectively in intrinsic group, while stents of extrinsic group remained patent until death. Uncovered, fully covered, and double-layered stent were used evenly and the types did not influence patency in both groups. In conclusion, esophageal SEMSs can safely and effectively be used for malignant extrinsic compression as well as intrinsic.

Adrenal imaging for adenoma characterization: imaging features, diagnostic accuracies and differential diagnoses

Adrenocortical adenoma is the most common adrenal tumour. This lesion is frequently encountered on cross-sectional imaging that has been performed for unrelated reasons. Adrenal adenoma manifests various imaging features on CT, MRI and positron emission tomography/CT. The learning objectives of this review are to describe the imaging findings of adrenocortical adenoma, to compare the sensitivities of different imaging modalities for adenoma characterization and to introduce differential diagnoses.

Induction of proinflammatory cytokine production in intervertebral disc cells by macrophage-like THP-1 cells requires mitogen-activated protein kinase activity

OBJECT

To determine the role played by mitogen-activated protein kinase (MAPK) signaling in the interactions between macrophages and intervertebral disc (IVD) cells, it was hypothesized that MAPK inhibition would modulate the production of the proinflammatory cytokines associated with inflammatory reaction in IVD cells.

METHODS

Human annulus fibrosus (AF) and nucleus pulposus (NP) cells were cocultured with phorbol myristate acetate-stimulated macrophage-like THP-1 cells, with and without SB202190 (a p38-α and -β inhibitor), SP600125 (a c-Jun N-terminal kinase [JNK] inhibitor), and PD98059 (an extracellular signal-regulated kinase [ERK] 1/2 inhibitor). The cytokines in conditioned media from cocultured and macrophage-exposed (nemotic) cells were assayed using enzyme-linked immunosorbent assays (ELISAs).

RESULTS

Interleukin (IL)-6 and IL-8 were secreted in greater quantities by the cocultured cells compared with naive IVD cells and macrophages (MΦ) cultured alone. The tumor necrosis factor (TNF)- α and IL-6 levels produced by the NP cells cocultured with MΦs (NP-MΦ) were significantly lower than those produced by AF cells cocultured with MΦs (AF-MΦ). SB202190 dose-dependently suppressed IL-6 secretion by AF-MΦ and NP-MΦ cocultures, and 10 μM SB202190 significantly decreased IL-6 and IL-8 production in nemotic AF and NP pellets. SP600125 at 10 μM significantly suppressed the production of TNF α IL-6. and IL-8 in AF-MΦ and NP-MΦ cocultures and significantly suppressed IL-1β production in the NP-MΦ coculture. Administration of 10 μM PD98059 significantly decreased IL-6 levels in the AF-MΦ coculture, and decreased the levels of TNF α and IL-8 in both the AF-MΦ and NP-MΦ cocultures.

CONCLUSIONS

The present study shows that inhibitors of p38 MAPK effectively controlled IL-6 production during inflammatory reactions and that JNK and ERK1/2 inhibitors successfully suppressed the production of major proinflammatory cytokines during interactions between macrophages and IVD cells. Therefore, selective blockade of these signals may serve as a therapeutic approach to symptomatic IVD degeneration.

Salvage computed tomography-guided transhepatic radiofrequency ablation for unresected aldosteronoma of adrenohepatic fusion after adrenalectomy

Adrenalectomy is a treatment of choice for functioning adrenocortical adenoma. We experienced a case of unresected aldosteronoma after right adrenalectomy. Computed tomography-guided transhepatic radiofrequency ablation was carried out to treat the unresected functioning adenoma. The purpose of our case report was to show the clinical findings, computed tomography imaging features and computed tomography-guided transhepatic ablation techniques for adrenocortical adenoma arising from adrenohepatic fusion.

Prostate diffusion-weighted imaging at 3T: effect of intravenous gadobutrol administration

OBJECTIVE

To investigate whether gadolinium-based contrast agent (GBCA) administration significantly affects diffusion-weighted imaging (DWI) at 3 T in the evaluation of prostate cancer and benign tissue.

METHOD

Thirty-four consecutive patients with surgically proven prostate cancer underwent preoperative DWI at 3 T before and after GBCA administration. Exponential apparent diffusion coefficient (EADC) and ADC maps were developed from DWI data. The ADC and EADC values pre- and post-contrast were measured in the cancer and benign tissue, respectively. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were evaluated on pre- and post-contrast DWI.

RESULTS

The ADC and EADC values of the cancer and benign transition zone were not significantly different between pre- and post-contrast, respectively (P > 0.05), while those in the benign peripheral zone were significantly different (P = 0.030 and 0.037, respectively). In all tissues, the SNRs and CNRs of the DWI, ADC map and EADC map were not significantly different between pre- and post-contrast (P > 0.05). Between pre- and post-contrast, ADC and EADC values showed excellent agreement (intraclass correlation coefficient ≥ 0.894) and variability of ≤3.2 %.

CONCLUSION

Prostate 3 T-DWI after GBCA administration may be used without a significant difference in SNR or CNR, with minimal variability of the cancer ADC and EADC values.

KEY POINTS

• ADCs and EADCs have excellent agreement before and after gadobutrol administration. • SNRs of prostate DWI are similar before and after gadobutrol administration. • CNRs of cancers are similar between pre- and post-contrast DWI.

Should anastomotic assessment with flexible sigmoidoscopy be routine following laparoscopic restorative left colorectal resection?

AIM

The aim of the study was to evaluate the value of routine intra-operative flexible sigmoidoscopy (IOFS) for left-sided anastomotic integrity and to determine the safest step after a positive leak test.

METHOD

All consecutive patients undergoing left-sided colorectal resections for benign and malignant disease between August 2005 and April 2011 were included. Data regarding procedure, type of anastomosis and outcomes of IOFS were collected. A positive intra-operative leak test resulted in redoing the anastomosis and repeating the leak test.

RESULTS

A total of 415 consecutive patients underwent hand-assisted laparoscopic colorectal resection with a colorectal/ileoanal anastomosis. All patients underwent IOFS. Seventeen patients had abnormality on IOFS. Fifteen patients had a positive air leak test. One patient had anastomotic bleeding. There was one stapler misfiring. Fourteen anastomoses were redone without diversion. One patient required diversion to protect the ileoanal anastomosis and another had already been diverted. Minor bleeding from the staple line in one patient resolved without intervention; however, he had a postoperative anastomotic leak needing surgical intervention. None of the patients who had a takedown and refashioning of the anastomosis following a positive leak on IOFS had postoperative anastomotic leakage or bleeding. Our overall anastomotic leak rate was 2.1%.

CONCLUSIONS

Intra-operative flexible sigmoidoscopy for restorative colorectal resection is safe and reliable and should be performed routinely to assess anastomotic integrity and bleeding. Refashioning the anastomosis after formal takedown would obviate the risk of leakage and is our recommended method of managing intra-operative leaks.

Evaluation of suspected soft tissue lesion in the prostate bed after radical prostatectomy using 3T multiparametric magnetic resonance imaging

PURPOSE

To investigate the usefulness of multiparametric MR imaging (mp-MRI) at 3T for evaluating suspected soft tissue lesion in the prostate bed after radical prostatectomy (RP).

MATERIALS AND METHODS

Forty-three patients with biochemical recurrence (BCR) who received RP underwent mp-MRI at 3T with a phased-array coil, including T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCE-MRI) and were enrolled in this study. All patients with BCR had a suspected soft tissue lesion in the prostate bed, followed by transrectal ultrasound-guided biopsy. As a control group, 14 consecutive patients without BCR who received RP were also enrolled. Two experienced radiologists independently analyzed four different imaging datasets.

RESULTS

For predicting local recurrence, the specificity, accuracy and area under the curve for both readers were significantly greater on all combined imaging datasets than on T2WI alone (P<0.05). The sensitivity of all combined imaging datasets in both readers was not statistically different with T2WI alone (P>0.05), except for combined T2WI and DWI. Inter-reader agreements for the four different imaging datasets were moderate.

CONCLUSION

DCE-MRI or DWI in combination with T2WI at 3T with a phased-array coil appears to be more useful than T2WI alone in evaluating suspected soft tissue lesion of the prostate bed after RP.

Percutaneous radiofrequency ablation of sporadic Bosniak III or IV lesions: treatment techniques and short-term outcomes

PURPOSE

To evaluate retrospectively the techniques and outcomes of percutaneous radiofrequency (RF) ablation for treatment of Bosniak III or IV lesions.

MATERIALS AND METHODS

Between August 2006 and August 2013, 30 patients (25 men and 5 women; mean age, 57 y; range, 22-77 y) with 35 nonhereditary Bosniak III (n = 15) or IV (n = 20) lesions underwent computed tomography-guided RF ablation. The mean size of the lesions was 2.8 cm ± 0.9 (range, 1.1-4.3 cm). The mean follow-up period was 24 months ± 16 (range, 6-70 mo). Duration of ablation, number of sessions and electrode repositions, primary and secondary effectiveness rates, major complication rate, reduction rate of lesion size, estimated glomerular filtration rate (GFR), and local tumor progression were recorded. Wilcoxon signed rank test was used for statistical analysis.

RESULTS

Mean duration of ablation was 18 minutes ± 14 (range, 2-65 min), and median number of sessions was one. Median number of electrode repositions was 1.0 ± 1.6 (range, 0-6). Primary and secondary effectiveness rates were 97.1% (34 of 35) and 100% (1 of 1), respectively. Mean reduction rate of lesion size was significantly greater from before RF ablation to 1 month after RF ablation (7.1 mm/mo ± 4.5) compared with from 1 month after RF ablation to the last month of follow-up (0.2 mm/mo ± 0.2; P < .0001). Mean GFR after RF ablation (65.4 mL/min/1.73 m(2) ± 26.1) was minimally reduced but significantly different from mean GFR before RF ablation (76.0 mL/min/1.73 m(2) ± 28.4; P < .0001). Major complications occurred in 2 of 35 RF ablation sessions for a rate of 5.7%, resulting from pneumothorax. Of 30 patients, 29 (96.7%) did not have local tumor progression or metastasis for 2 years.

CONCLUSIONS

Percutaneous RF ablation is technically feasible and yields excellent short-term outcomes in treating sporadic Bosniak III or IV lesions.

Parametrial invasion in cervical cancer: fused T2-weighted imaging and high-b-value diffusion-weighted imaging with background body signal suppression at 3 T

PURPOSE

To retrospectively investigate the value of fused T2-weighted and high-b-value diffusion-weighted imaging with background body signal suppression (DWIBS) at 3 T to evaluate parametrial invasion in cervical cancer.

MATERIALS AND METHODS

In this institutional review board-approved study, 152 consecutive patients with biopsy-proven cervical cancer who underwent radical hysterectomies also underwent pretreatment magnetic resonance imaging (T2-weighted imaging and DWIBS) at 3 T. Two radiologists independently evaluated the presence of parametrial invasion at T2-weighted imaging, fused T2-weighted imaging and high-b-value DWIBS (ie, fused T2-weighted DWIBS), and combined T2-weighted imaging and fused T2-weighted DWIBS, and the results were compared with histopathologic findings.

RESULTS

Parametrial invasion was identified by pathologic analysis in 37 of 152 patients (24.3%). For association with parametrial invasion, the specificity and accuracy of fused T2-weighted DWIBS (97.4% and 90.1%, respectively, for reader 1; 95.7% and 89.5%, respectively, for reader 2) and combined T2-weighted imaging and fused T2-weighted DWIBS (99.1% and 93.4%, respectively, for reader 1; 96.5% and 92.8%, respectively, for reader 2) were significantly better than those of T2-weighted imaging alone (88.7% and 85.5%, respectively, for reader 1; 85.2% and 83.6%, respectively, for reader 2) (all P < .05). The respective sensitivity of T2-weighted imaging, fused T2-weighted DWIBS, and combined T2-weighted imaging and fused T2-weighted DWIBS was 75.7%, 67.6%, and 75.7% for reader 1 and 78.4%, 70.3%, and 81.1% for reader 2, and did not show significant differences (P value, ≤.375 to >.999). The respective area under the curve for association with parametrial invasion of T2-weighted imaging, fused T2-weighted DWIBS, and combined T2-weighted imaging and fused T2-weighted DWIBS was 0.912, 0.951, and 0.976 for reader 1 and 0.890, 0.932, and 0.968 for reader 2 (P < .05). Interreader agreements were excellent (κ = 0.89, 0.9, and 0.86 for T2-weighted imaging, fused T2-weighted DWIBS, and combined T2-weighted imaging and fused T2-weighted DWIBS, respectively).

CONCLUSION

Fusion of high-b-value DWIBS with T2-weighted imaging can improve the diagnostic performance in association with parametrial invasion in cervical cancer compared with T2-weighted imaging alone.

Comparison of RECIST 1.0 and RECIST 1.1 on computed tomography in patients with metastatic colorectal cancer

OBJECTIVE

We conducted this study to compare tumor measurement by computed tomography (CT) and tumor response assessment between Response Evaluation Criteria In Solid Tumors (RECIST) 1.0 and RECIST 1.1 in patients with metastatic colorectal cancer (CRC).

METHODS

We reviewed the medical records of patients with metastatic CRC who received first-line chemotherapy between January 2004 and December 2012 and compared CT tumor measurement using two RECIST versions.

RESULTS

A total of 58 patients who had target lesions according to RECIST 1.0 were included in the study. The number of target lesions recorded by RECIST 1.1 was significantly lower than that by RECIST 1.0, with a decrease experienced in 48 patients (82.7%). Six patients had no target lesions because of the new criteria of RECIST 1.1 for lymph node size. Out of 95 lymph nodes from 58 patients, only 40% were defined as target lesions according to RECIST 1.1. The overall response rate of first-line chemotherapy according to RECIST 1.0 and 1.1 was 41.5 and 40.4%, respectively. The best tumor responses showed almost perfect agreement between RECIST 1.1 and RECIST 1.0 (ĸ = 0.913). Three patients showed disagreement of the best responses between the two RECIST versions.

CONCLUSION

RECIST 1.1 showed a highly concordant response assessment with RECIST 1.0 in metastatic CRC and its clinical impact on therapeutic decisions was minimal.