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.

Inter-method agreement between wash-in and wash-out computed tomography for characterizing hyperattenuating adrenal lesions as adenomas or non-adenomas.

OBJECTIVES: To investigate inter-method agreement between wash-out and wash-in computed tomography (CT) to determine whether hyperattenuating adrenal lesions are characterized as adenomas or non-adenomas. METHODS: We evaluated 243 patients who underwent wash-out CT for a solid enhancing hyperattenuating (i.e., > 10 Hounsfield unit [HU]) adrenal mass of ≥ 1 to < 4 cm. Wash-out (absolute percentage wash-out [APW]; relative percentage wash-out [RPW]) and wash-in values (enhancement ratio [ER]; relative enhancement ratio [RER]) were analyzed by two independent readers. Diagnostic criteria of wash-out CT for adenoma were APW ≥ 60% or RPW ≥ 40% (conventional method). Three different criteria for wash-in CT were set: ER ≥ 3.0; RER ≥ 200%; and RER ≥ 210%. Concordance rate and inter-method agreement between wash-out and wash-in CT were investigated using Gwet's AC1. RESULTS: For all lesions, concordance rates between wash-out and wash-in CT were > 83%. AC1 between conventional method and ER ≥ 3.0 or between conventional method and RER ≥ 200% were identically 0.843 for reader 1 and 0.776 for reader 2. AC1 between conventional method and RER ≥ 210% were 0.780 for reader 1 and 0.737 for reader 2. For lesions of > 10 to ≤ 30 HU, concordance rates between wash-out and wash-in CT were > 89%. AC1 between conventional method and ER ≥ 3.0 or between conventional method and RER ≥ 200% were identically 0.914 for reader 1 and 0.866 for reader 2. AC1 between conventional method and RER ≥ 210% were 0.888 for reader 1 and 0.874 for reader 2. CONCLUSION: In approximately 90% of patients with a hyperattenuating adrenal lesion of ≥ 1 to < 4 cm and >10 to ≤ 30 HU, wash-out CT with 15-min contrast-enhanced images may be replaced by wash-in CT. KEY POINTS: • An enhancement ratio of ≥ 3.0 or a relative enhancement ratio of ≥ 200% appears to be appropriate as the threshold of wash-in computed tomography (CT) comprising unenhanced and 1-min contrast-enhanced CT. • Measurement of enhancement ratio or relative enhancement ratio was reproducible. • We found good agreement between wash-in and wash-out CT for determining whether hyperattenuating adrenal lesions of ≥ 1 to < 4 cm and >10 to ≤ 30 Hounsfield unit would be characterized as adenomas.

Biparametric Magnetic Resonance Imaging-Derived Nomogram to Detect Clinically Significant Prostate Cancer by Targeted Biopsy for Index Lesion.

BACKGROUND: Currently, it is necessary to investigate how to combine biparametric magnetic resonance imaging (bpMRI) with various clinical parameters for the detection of clinically significant prostate cancer (csPCa). PURPOSE: To develop a multivariate prebiopsy nomogram using clinical and bpMRI parameters for estimating the probability of csPCa. STUDY TYPE: Retrospective, single-center study. SUBJECTS: Two hundred and twenty-six patients who underwent targeted biopsy (TBx) for the MRI-suspected index lesion because of clinical suspicions of PCa. FIELD STRENGTH/SEQUENCE: A 3 T MRI including turbo spin-echo T2 -weighted and diffusion-weighted single-shot echo-planar imaging sequences. ASSESSMENT: Prebiopsy clinical and bpMRI parameters were patient age, biopsy history (biopsy-naïve or repeated biopsy status), prostate-specific antigen density (PSAD), Prostate Imaging-Reporting and Data System version 2.1 (PI-RADSv2.1), and apparent diffusion coefficient ratio (ADCR). ADCR was defined as mean ADC of the index lesion divided by mean ADC of the contralateral prostatic region. A multivariate prebiopsy nomogram for csPCa (i.e. Gleason sum ≥7) was developed. Area under the curve (AUC) of each parameter and prebiopsy nomogram was assessed. Five-fold cross-validation was performed for robust estimation of performance of the prebiopsy nomogram. STATISTICAL TESTS: Logistic regression, receiver-operating curve, and 5-fold cross-validation. P-value < 0.05 was considered statistically significant. RESULTS: Proportion of csPCa was 31.9% (72/226). The AUCs of age, biopsy-naïve status, PSAD, PI-RADSv2.1, ADCR, and prebiopsy nomogram were 0.657 (95% confidence interval [CI], 0.580-0.733), 0.593 (95% CI, 0.525-0.660), 0.762 (95% CI, 0.697-0.826), 0.824 (95% CI, 0.770-0.878), 0.829 (95% CI, 0.769-0.888), and 0.906 (95% CI, 0.863-0.948), respectively: AUC of nomogram was significantly different than that of individual parameter. In the 5-fold cross-validation, the mean AUC of the prebiopsy nomogram for csPCa was 0.888 (95% CI, 0.786-0.983). DATA CONCLUSIONS: This multivariate prebiopsy nomogram using clinical and bpMRI parameters may help estimate the probability of csPCa in patients undergoing TBx. ADCR seems to enhance the role of bpMRI in detecting csPCa. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Impact of no residual disease on postoperative computed tomography on survival in patients with optimally debulked advanced high-grade serous ovarian cancer during upfront surgery.

OBJECTIVE: We sought to investigate the impact of size of residual tumors as determined by postoperative computed tomography (CT) on survival of patients with advanced, high-grade serous ovarian carcinoma (HGSC) who achieved residual disease less than 1 cm after primary debulking surgery (PDS). METHODS: We collected data of patients with stage III HGSC who had residual tumor less than 1 cm after PDS between 2013 and 2018. Surgeon-assessed residual disease during surgery was defined as sR0 (no gross residual) or sR1 (gross residual <1 cm), and radiologist-assessed residual disease on postoperative CT was defined as rR0 (no evidence of disease) or rRany (existing residual disease). All patients were classified into the following groups: sR0/rR0, sR1/rR0, sR0/rRany, and sR1/rRany. RESULTS: A total of 436 patients was placed into the sR0/rR0 (n = 187, 42.9%), sR1/rR0 (n = 59, 13.5%), sR0/rRany (n = 79, 18.1%), or sR1/rRany group (n = 111, 25.5%). Discrepancies between surgical and radiological assessments were recorded for 176 patients (40.4%) including 38 cases of sR1/rRany group with discordant residual tumor location indicated between two methods. During multivariate analysis, patients with ascites on preoperative CT, sR0/rRany group inclusion, and sR1/rRany group inclusion showed unfavorable progression-free and overall survival. CONCLUSIONS: The incorporation of surgical and radiological evaluations for determining the size of residual tumors was more accurate than surgical evaluation only for predicting survival among patients with advanced ovarian cancer who underwent PDS to residual disease less than 1 cm.

Ovarian Masses in Patients With Breast Cancer.

PURPOSE: The aim of the study was to investigate the characteristic findings of computed tomography (CT) or magnetic resonance imaging (MRI) to discriminate metastasis from primary ovarian tumors in patients with a history of breast cancer. METHODS: This retrospective study enrolled consecutive 72 patients with a history of breast cancer who underwent surgical confirmation of an ovarian mass detected on CT or MRI (primary ovarian tumors, n = 66; metastases, n = 6). Two independent readers analyzed the grade of solid portions of the ovarian mass using a 5-point scale on CT or MRI. A predominantly cystic mass was defined as a solid grade of 1 to 2. Cancer antigen 125 (CA 125) and the initial stage of breast cancer were also investigated. RESULTS: The proportions of predominantly cystic masses were significantly different between metastases (0% for both readers) and primary ovarian tumors (59% for reader 1 and 53% for reader 2, P < 0.05). For masses of solid portion grades 3 to 5, CA 125 was significantly higher for malignant epithelial tumors than for the other tumors ( P < 0.001), and the initial stage of breast cancer was significantly higher for metastases than for the other tumors ( P < 0.001), respectively. CONCLUSIONS: In patients with a history of breast cancer, predominantly cystic masses detected on CT or MRI seem to be primary ovarian tumors. For the other masses, knowledge of CA 125 and initial breast cancer stage may help in the differential diagnosis.

Hyperattenuating adrenal lesions in lung cancer: biphasic CT with unenhanced and 1-min enhanced images reliably predicts benign lesions.

OBJECTIVES: To investigate usefulness of biphasic computed tomography (CT) in characterizing hyperattenuating adrenal lesions in lung cancer. METHODS: This retrospective study included 239 patients with lung cancer who underwent adrenal CT for hyperattenuating (> 10 Hounsfield unit) adrenal lesions. Adrenal CT comprised unenhanced and 1-min and 15-min enhanced images. We dichotomized adrenal lesions depending on benign or metastatic lesions. Reference standard for benignity was histologic confirmation or ≥ 6-month stability on follow-up CT. Two independent readers analyzed absolute (APW) or relative percentage wash-out (RPW) using triphasic CT, and enhancement ratio (ER) or percentage wash-in (PWI) using biphasic CT (i.e., unenhanced and 1-min enhanced CT). Criteria for benignity were as follows: criteria 1, (a) APW ≥ 60% or (b) RPW ≥ 40%, and criteria 2, (a) ER > 3 and (b) PWI > 200%. We analyzed area under the curve (AUC) and accuracy for benignity, and inter-reader agreement. RESULTS: Proportion of benign adrenal lesion was 71.1% (170/239). For criteria 1 and 2, AUCs were 0.872 (95% confidence interval [CI], 0.822-0.911) and 0.886 (95% CI, 0.838-0.923), respectively, for reader 1 (p = 0.566) and 0.816 (95% CI, 0.761-0.863) and 0.814 (95% CI, 0.759-0.862), respectively, for reader 2 (p = 0.955), and accuracies were 87.9% (210/239) and 86.2% (206/239), respectively, for reader 1 (p = 0.479) and 81.2% (194/239) and 80.3% (192/239), respectively, for reader 2 (p = 0.763). Weighted kappa was 0.725 (95% CI, 0.634-0.816) for criteria 1 and 0.736 (95% CI, 0.649-0.824) for criteria 2. CONCLUSION: Biphasic CT can reliably characterize hyperattenuating adrenal lesions in patients with lung cancer. KEY POINTS: • Criteria from biphasic computed tomography (CT) for diagnosing benign adrenal lesions were enhancement ratio of > 3 and percentage wash-in of > 200%. • In the analysis by two independent readers, area under the curve between criteria 1 and 2 was not significantly different (0.872 and 0.886 for reader 1; 0.816 and 0.814, for reader 2; p > 0.05 for each comparison). • Wash-in characteristics from biphasic CT are helpful to predict benign adrenal lesions in lung cancer.

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.

Necessity of differentiating small (< 10 mm) and large (≥ 10 mm) PI-RADS 4.

PURPOSE: Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) provides reasonable performance in detecting significant cancers. Still, it is unclear about whether all PI-RADS 4 lesions show the same cancer detection rate (CDR) regardless of tumor size. The aim was to compare the CDRs of small (< 10 mm) and large (≥ 10 mm) PI-RADS 4. METHODS: After magnetic resonance imaging (MRI) was performed in 684 men, a radiologist interpreted the MR images and detected 281 index lesions categorized as PI-RADS 4 in 281 men. PI-RADS 4 lesions were divided into small and large groups on size of 10 mm. Overall and significant CDRs were compared between the groups. A significant cancer was defined as one with Gleason score (GS) ≥ 7 or tumor volume ≥ 0.5 ml. Tumor volumes were roughly calculated as πr34/3 (π = 3.14 and r = a half of tumor size) and were compared between the groups. Standard reference was a biopsy examination. Fisher's exact and Mann-Whitney tests were used for statistical analysis. RESULTS: The overall CDRs of small and large groups were 39.0% (53/136) and 59.3% (86/145), respectively, (p = 0.0008). The median tumor volumes of cancer-proven small and large groups were 0.18 ml (0.01-0.38 ml) and 0.70 ml (0.52-1.44 ml), respectively (p < 0.0001). Using GS or tumor volume, the significant CDRs of these groups were 26.5% (36/136) and 59.3% (86/145), respectively (p < 0.0001), and using GS alone, 26.5% (36/136) and 39.3% (57/145), respectively (p = 0.0232). CONCLUSIONS: PI-RADS 4 lesions should be sub-divided on size of 10 mm because of different significant CDRs.

Low-dose CT angiography using ASiR-V for potential living renal donors: a prospective analysis of image quality and diagnostic accuracy.

PURPOSE: To assess image quality and diagnostic accuracy of low-dose computed tomography (CT) angiography using adaptive statistical iterative reconstruction V (ASiR-V) for evaluating the anatomy of renal vasculature in potential living renal donors. MATERIALS AND METHODS: Eighty of 100 potential living renal donors were prospectively enrolled and underwent multiphase CT angiography (e.g., unenhanced, arterial, and venous phases) to evaluate the kidney for donation. Either low-dose using ASiR-V or standard protocol was randomly applied. Image quality was analyzed qualitatively and quantitatively with contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). Renal artery and vein number, early branching vessel from renal arteries, and drainage of left-sided ascending lumbar vein to left renal vein were assessed. Reference standard for renal vasculature was surgical confirmation. RESULTS: Size-specific dose estimate of low-dose CT angiography (9.5 ± 0.8 mGy) was significantly lower than standard CT angiography (22.7 ± 4.1 mGy) (p < 0.001). Thus, radiation dose was reduced by 58.2% with low-dose CT. Both CNR and SNR of low-dose CT were significantly higher than those of standard CT (p < 0.001). Between the two CT methods, image quality was similar qualitatively (p > 0.05). Of 80 participants, 44 (55.0%) underwent nephrectomy. Both CT methods accurately predicted the anatomy of renal vasculature (standard CT, 100% for all variables; low-dose CT, 96.6% for renal vessel number or early branching vessel and 85.7% for drainage of left-sided ascending lumbar vein to left renal vein; p > 0.05 for all comparisons). CONCLUSION: Low-dose CT angiography using ASiR-V is useful to evaluate renal vasculature for potential living renal donors. KEY POINTS: • In this prospective study, adaptive statistical iterative reconstruction V (ASiR-V) allowed 58.2% dose reduction while maintaining diagnostic image quality for renal vessels. • As compared with the standard protocol, the dose with ASiR-V was significantly lower (9.5 ± 0.8 mGy) than with standard computed tomography (CT) angiography (22.7 ± 4.1 mGy). • Low-dose CT using ASiR-V is useful for living donor evaluation before nephrectomy.

Postoperative Biochemical Failure in Patients With PI-RADS Category 4 or 5 Prostate Cancers: Risk Stratification According to Zonal Location of an Index Lesion.

OBJECTIVE. The objective of our study was to assess postoperative biochemical failure in patients with prostate cancer according to zonal location of an index lesion classified as Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) category 4 or 5. MATERIALS AND METHODS. Consecutive patients (n = 232) with prostate cancer who had PI-RADSv2 category 4 or 5 lesions on MRI and who underwent radical prostatectomy were retrospectively evaluated. We investigated clinical (prostate-specific antigen density), MRI (PI-RADSv2 category of index lesion and zonal location, assessed as peripheral zone [PZ] or transition zone [TZ], of index lesion), and pathologic (tumor volume, tumor grade, and presence of extraprostatic extension) parameters. We analyzed Kaplan-Meier survival curves and the Cox proportional hazards model to assess 2-year biochemical failure-free survival and identify significant parameters associated with postoperative biochemical failure RESULTS. Biochemical failure occurred in 14.2% of patients (33/232). Two-year biochemical failure-free survival of patients with a PI-RADSv2 category 4 or 5 index lesion was 81.3%. For all patients, 2-year biochemical failure-free survival was different according to PI-RADSv2 category (category 4, 86.4%; category 5, 74.5%; p = 0.021) or zonal location (PZ, 75.3%; TZ, 96.8%; p = 0.003). Two-year biochemical failure-free survival in patients with category 4 lesions was similar in patients with PZ lesions (83.1%) and those with TZ lesions (100.0%) (p = 0.072), whereas it was different in patients with category 5 lesions (PZ, 62.0%; TZ, 95.0%; p = 0.002). In multivariate analysis, only zonal location of an index lesion on MRI was associated with biochemical failure (hazard ratio = 0.155; p = 0.012). CONCLUSION. Zonal location of an index lesion on MRI may be a useful imaging bio-marker to predict postoperative biochemical failure.

Diagnostic Performance of Mass Enhancement on Dynamic Contrast-Enhanced MRI for Predicting Clinically Significant Peripheral Zone Prostate Cancer.

OBJECTIVE. Current criteria for positive findings on dynamic contrast-enhanced MRI (DCE-MRI) are unclear. We compared the diagnostic performance of mass enhancement on DCE-MRI versus conventional DCE-MRI criteria for identifying clinically significant prostate cancer (csPCa) in the peripheral zone (PZ). MATERIALS AND METHODS. A total of 173 consecutive patients with MRI- and surgically proven prostate cancer (PCa) were evaluated. Two readers independently interpreted DCE-MRI examinations of the PZ. Criteria denoting a positive DCE-MRI examination included conventional criteria from the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) and mass enhancement. The diagnostic performance of and interreader agreement for the two types of enhancement criteria in identifying csPCa in the PZ that met Epstein criteria were investigated. RESULTS. The proportion of csPCa in the PZ was 69.3% (120/173). For both readers, the specificity and positive predictive value of mass enhancement were increased compared with conventional enhancement criteria (specificity, 75.5% vs 5.7% [for reader 1] and 84.9% vs 30.2% [for reader 2], respectively; positive predictive value, 87.1% vs 70.6% [for reader 1] and 91.5% vs 75.3% [for reader 2], respectively). The AUC value of mass enhancement was higher than that of conventional criteria (for reader 1, 0.744 [95% CI, 0.672-0.807] vs 0.528 [95% CI, 0.451-0.605] [p < 0.001], respectively; for reader 2, 0.783 [95% CI, 0.714-0.842] vs 0.602 [95% CI, 0.497-0.700] [p < 0.001], respectively). The weighted kappa value for agreement between the two readers was 0.206 for conventional criteria and 0.613 for mass enhancement. CONCLUSION. PZ lesions with mass enhancement on DCE-MRI are more likely to be csPCa. This enhancement pattern may need to be considered as one of the criteria in PI-RADS.

Histogram analysis of apparent diffusion coefficients for predicting pelvic lymph node metastasis in patients with uterine cervical cancer.

OBJECTIVE: To investigate the value of apparent diffusion coefficient (ADC) histogram analysis in predicting pelvic lymph node (LN) metastasis in patients with cervical cancer undergoing surgery. MATERIALS AND METHODS: A total of 162 cervical cancer patients who underwent radical abdominal hysterectomy with pelvic LN dissection performed with pelvic 3 T-MRI including diffusion-weighted imaging were enrolled in this study. The ADC histogram variables (minimum, mean, median, 97.5th percentile [ADC97.5], and maximum) of the tumors were developed using in-house software. For predicting pelvic LN metastasis, clinical and imaging variables were evaluated using logistic regression and receiver-operating characteristic (ROC) analyses. RESULTS: Pelvic LN metastasis was identified histopathologically in 50 patients (30.9%). In patients with LN metastasis, all ADC histogram variables were significantly different from those without LN metastasis (all p < 0.01). Univariate analysis demonstrated that long- and short-axis diameter of LN, MRI T-stage, squamous cell carcinoma antigen, tumor size, and the ADC97.5 were significantly associated with pelvic LN metastasis (all p < 0.05). However, multivariate analysis demonstrated that the ADC97.5 was the only independent predictor of pelvic LN metastasis (odds ratio, 0.996; p = 0.001). The area under the ROC curve of ADC97.5 was 0.782, which was the greatest among all variables. Interobserver agreement of all ADC histogram variables was fair to good. DISCUSSION: The ADC97.5 from histogram analysis may be a useful marker for the prediction of pelvic LN metastasis in patients with cervical cancer.

Diagnostic efficacy and safety of ultrasound-guided kidney transplant biopsy using cortex-only view: a retrospective single-center study.

PURPOSE: Cortical biopsy is the cornerstone to reveal a cause of unexplained dysfunction of the kidney transplant. Nevertheless, only a few studies have reported the biopsy technique with its performance. We described a novel technique of ultrasound (US)-guided kidney transplant biopsy using cortex-only view and analyzed its diagnostic efficacy and safety. MATERIALS AND METHODS: Between January 2014 and December 2016, a consecutive series of 188 patients who underwent US-guided kidney transplant biopsy using cortex-only view by an experienced radiologist were evaluated (mean age, 46.1 ± 12.5 years; range, 21-79 years). Biopsy time, biopsy distance, biopsy core number, and glomerular number per patient were recorded. Successful biopsy (e.g., adequate, 10 or more glomeruli; marginal, 7-9 glomeruli) and complication rates were investigated, using Banff criteria and Clavien-Dindo classification, respectively. RESULTS: Mean biopsy time, distance, and core number were 20.6 ± 6.7 min (range, 10-44 min), 3.2 ± 0.7 cm (range, 2.1-5.4 cm), and 1.9 ± 0.3 (range, 1.0-3.0), respectively. Mean glomerular number per patient was 20.4 ± 10.0 (range, 0-54). Adequate and marginal biopsy rates were 87.2% (164/188) and 95.2% (179/188), respectively. There was no major complication requiring treatment (no patient with Clavien-Dindo grade 2 or greater complication), while there were self-limiting minor complications in 5 patients (overall complication rate, 2.7%). CONCLUSION: US-guided biopsy using cortex-only view is feasible and safe in sampling cortical tissues of kidney transplant. KEY POINTS: • Ultrasound (US)-guided kidney transplant biopsy using cortex-only view is feasible and safe. • Adequate and marginal biopsy rates were 87.2% and 95.2%, respectively. • No major complication requiring treatment occurred after biopsy.

Correction to: Diagnostic efficacy and safety of ultrasound-guided kidney transplant biopsy using cortex-only view: a retrospective single-center study.

The original version of this article, published on 17 December 2018, unfortunately contained a mistake. The following correction has therefore been made in the original: The name of Jaeseung Shin was presented incorrectly. The corrected author list is given above.

Is Chest Computed Tomography Always Necessary Following Nephrectomy for Renal Cell Carcinoma? A Pilot Study in Single Tertiary Institution.

PURPOSE: We evaluated patterns of thoracic recurrence from renal cell carcinoma (RCC) following nephrectomy as a pilot study. METHODS: Data of consecutive 39 patients who had recurrent RCC in the abdomen or thorax following curative nephrectomy were evaluated. Recurrence sites were analyzed with abdomen and chest computed tomography (CT), or positron emission tomography/CT. All patients had no metastasis before initial nephrectomy. Recurrence was classified into 3 types according to the site of initially detected recurrence: (a) abdomen-only type, (b) abdomen and thorax type, and (c) thorax-only type. Vertebral level of recurrence site in the thorax-only level was investigated. University of California Los Angeles-Integrated Staging System was utilized for risk stratification (eg, low, intermediate, and high-risk). RESULTS: Rate of intermediate or high risk was 89.7% (37/39). Rate of thoracic recurrence, regardless of concurrent abdominal recurrence, was 71.8% (28/39). Rate of thorax-only type was 53.8% (21/39). In thorax-only type, median vertebral level of recurrence site was T10 (range, T3-T12), and no patient with low risk had metastasis above the T10 level alone. In intermediate or high risk, 89.2% (33/37) had at least a recurrent lesion at the level of T7 or lower. CONCLUSIONS: In low-risk patients, upper thoracic recurrence alone may be very rare after curative surgery. In majority of intermediate- or high-risk patients, initial recurrence may occur in the abdomen or lower thorax, which indicates abdomen CT covering T7 level may be an effective tool for postoperative follow-up in RCC.

Percutaneous cryoablation for renal cell carcinoma using ultrasound-guided targeting and computed tomography-guided ice-ball monitoring: radiation dose and short-term outcomes.

BACKGROUND: Usefulness of ultrasound (US)-guided mass targeting and computed tomography (CT)-guided ice-ball monitoring in percutaneous cryoablation (PCA) for renal cell carcinoma (RCC) is still uncertain. PURPOSE: To assess radiation dose and short-term outcomes of PCA for RCC using US-guided targeting and CT-guided ice-ball monitoring. MATERIAL AND METHODS: Thirty-nine consecutive patients who underwent PCA for biopsy-proven RCC were included. Mass targeting was performed with US and ice-ball was monitored with CT guidance. Effective radiation dose of CT during PCA was recorded. Follow-up was conducted with contrast-enhanced CT or magnetic resonance imaging (MRI) (mean follow-up time = 10.1 ± 7.0 months). Local tumor progression was defined by the presence of focal enhancing areas at the ablation zone (CT, ≥ 20 HU; MRI, presence of focal enhancement on subtraction contrast-enhanced image). Technical success, major complication rate (e.g. Clavien-Dindo classification ≥ 3), and one-year local tumor progression-free survival (PFS) rate were analyzed. RESULTS: Mean effective radiation dose in association with PCA was 12.1 ± 4.5 mSv (range = 7.0-25.2 mSv). Technical success was achieved in 100%. Local tumor progression occurred in a single patient (2.6%, 1/39), and one-year local tumor PFS rate was 95.7%. No major complication was found. CONCLUSION: PCA using US-guided targeting and CT-guided ice-ball monitoring may allow acceptable local tumor control for RCC, as a radiation-reducing strategy.

Combined Analysis of Biparametric MRI and Prostate-Specific Antigen Density: Role in the Prebiopsy Diagnosis of Gleason Score 7 or Greater Prostate Cancer.

OBJECTIVE: The objective of our study was to investigate the diagnostic performance of prebiopsy biparametric MRI (bpMRI) and prostate-specific antigen density (PSAD) for Gleason score (GS) 7 or greater prostate cancer (PCa). MATERIALS AND METHODS: Sixty-eight consecutive patients who underwent prebiopsy bpMRI and biopsy were included. Pathologic results of systemic and targeted biopsies were the reference standard. Qualitative analyses comprised Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) and modified PI-RADSv2 (mPI-RADSv2). Quantitative analyses comprised mean apparent diffusion coefficient (ADC) of tumor, 10th percentile ADC of tumor, mean ADC ratio (ADCR) between benign tissues and PCa, and 10th percentile ADCR between benign tissues and PCa. The AUCs of the following combined models for GS 7 or greater PCa were investigated: model 1, PSAD and PI-RADSv2; model 2, PSAD and mPI-RADSv2; model 3, PSAD and mean ADC; model 4, PSAD and 10th percentile ADC; model 5, PSAD and mean ADCR; and model 6, PSAD and 10th percentile ADCR. RESULTS: The rate of GS 7 or greater PCa was 45.6% (31/68). AUCs of bpMRI parameters were 0.816 for PI-RADSv2, 0.838 for mPI-RADSv2, 0.820 for mean ADC, 0.823 for 10th percentile ADC, 0.780 for mean ADCR, and 0.763 for 10th percentile ADCR (p > 0.05 in all comparisons), whereas AUCs of prostate-specific antigen (PSA)-based parameters were 0.650 for PSA and 0.745 for PSAD (PSA vs PSAD, p = 0.017). AUCs of the combined models from 1 to 6 were 0.860, 0.880, 0.837, 0.844, 0.811, and 0.806, respectively, for biopsy GS 7 or greater PCa (p > 0.05 in all comparisons). CONCLUSION: Combined analysis of prebiopsy bpMRI and PSAD is useful for identifying GS 7 or greater PCa.

Solid Small Renal Mass Without Gross Fat: CT Criteria for Achieving Excellent Positive Predictive Value for Renal Cell Carcinoma.

OBJECTIVE: The purpose of this study was to evaluate CT criteria for achieving high positive predictive value (PPV) for renal cell carcinoma (RCC) in patients with solid small renal masses (SRMs) less than 4 cm without macroscopic fat. MATERIALS AND METHODS: One hundred fifty consecutive patients with a solid SRM without macroscopic fat (mean size ± SD, 2.5 ± 0.8 cm) who underwent CT including unenhanced, corticomedullary (CMP), and nephrographic phases (NP) were evaluated. Pathologically proven solid SRMs without macroscopic fat were classified into RCC (n = 131) and not RCC (n = 19). A "persistent low" sign was defined as a focal area or areas of low attenuation seen at the same location within the lesion on both CMP and NP imaging. Calcification, shape, and lesion attenuation on unenhanced CT were analyzed by two independent readers. RESULTS: PPV of CT criteria (calcification [criterion 1] or spherical shape, lower or equal attenuation, and persistent low sign [criterion 2]) for RCC was 98.3% (58/59) for reader 1 and 100% (53/53) for reader 2. Weighted kappa of interreader agreement was 1.000 for calcification, 0.966 of lower or equal attenuation, 0.834 for spherical shape, 0.823 for persistent low sign, and 0.829 for CT criteria. CONCLUSION: Interpretation of CT allowed reproducible and excellent PPV for RCC. Current CT criteria may effectively shorten the management process for solid SRMs without macroscopic fat by reducing unnecessary biopsy for a substantial number of RCCs showing typical CT findings.

Diffusion-weighted imaging predicts upgrading of Gleason score in biopsy-proven low grade prostate cancers.

OBJECTIVE: To analyse whether diffusion-weighted imaging (DWI) predicts Gleason score (GS) upgrading in biopsy-proven low grade prostate cancer (PCa). PATIENTS AND METHODS: A total of 132 patients who had biopsy-proven low grade (GS < 7) PCa, 3T DWI results, and surgical confirmation were retrospectively included in the study. Clinical variables (prostate-specific antigen, greatest percentage of cancer in a biopsy core and percentage of positive cores) and DWI variables (minimum apparent diffusion coefficient [ADCmin ] and mean ADC [ADCmean ]) were evaluated. ADCmin was measured, by two independent, blinded readers, using a region of interest (ROI) of 5-10 mm2 at the area of lowest ADC value within a cancer, while ADCmean was measured using an ROI covering more than half of a cancer. Logistic regression and receiver-operating characteristic curve analyses were performed. RESULTS: The rate of GS upgrading was 46.1% (61/132). In both univariate and multivariate analyses, ADCmin and ADCmean were persistently significant for predicting GS upgrading (P < 0.05), whereas clinical variables were not (P > 0.05). In both readers' results, the area under the curve (AUC) of ADCmin was significantly greater than that of ADCmean (reader 1: AUC 0.760 vs 0.711; P < 0.001; reader 2: AUC 0.752 vs 0.714; P = 0.003). CONCLUSION: Our results showed that DWI may predict GS upgrading of biopsy-proven low grade PCa. The variable ADCmin in PCa may perform better than ADCmean .