The clinical value of the hepatic venous pressure gradient in patients undergoing hepatic resection for hepatocellular carcinoma with or without liver cirrhosis.

The role of hepatic venous pressure gradient (HVPG) measurement in risk stratification before liver resection is an ongoing area of debate. This study examines the impact of preoperative HVPG levels on overall survival (OS)/time to recurrence (TTR) and postoperative complications after hepatic resection of hepatocellular carcinoma (HCC). Thirty-eight HCC patients undergoing HVPG measurement before liver resection at Cambridge University Hospitals NHS Foundation Trust between January 2014 and April 2022 were retrospectively analysed. Statistical analysis comprised univariable/multivariable Cox/logistic regression to identify risk factors of reduced OS/TTR or 90-day post-resection complications and Kaplan-Meier estimator, log-rank, chi-squared, Fisher's exact, and Mann-Whitney U test, or Student's t-test for survival/subgroup analysis. The median HPVG was 6 (range: 0-14) mmHg. The HVPG was an independent risk factor for poorer TTR in the overall cohort (cut-off: ≥7.5 mmHg (17.18/43.81 months; P = 0.009)). In the subgroup analysis of cirrhotic patients (N = 29 (76%)), HVPG was additionally an independent risk factor for lower OS (cut-off: ≥8.5 mmHg [44.39/76.84 months; P = 0.012]). The HVPG had no impact on OS/TTR in non-cirrhotic patients (N = 9 (24%)), nor was it associated with postoperative complications in any cohort. In conclusion, preoperative HVPG levels are useful predictors for TTR and OS in cirrhotic HCC patients undergoing hepatic resection.

Paris classification of colonic polyps using CT colonography: prospective cohort study of interobserver variation.

BACKGROUND: The Paris classification categorises colorectal polyp morphology. Interobserver agreement for Paris classification has been assessed at optical colonoscopy (OC) but not CT colonography (CTC). We aimed to determine the following: (1) interobserver agreement for the Paris classification using CTC between radiologists; (2) if radiologist experience influenced classification, gross polyp morphology, or polyp size; and (3) the extent to which radiologist classifications agreed with (a) colonoscopy and (b) a combined reference standard. METHODS: Following ethical approval for this non-randomised prospective cohort study, seven radiologists from three hospitals classified 52 colonic polyps using the Paris system. We calculated interobserver agreement using Fleiss kappa and mean pairwise agreement (MPA). Absolute agreement was calculated between radiologists; between CTC and OC; and between CTC and a combined reference standard using all available imaging, colonoscopic, and histopathological data. RESULTS: Overall interobserver agreement between the seven readers was fair (Fleiss kappa 0.33; 95% CI 0.30-0.37; MPA 49.7%). Readers with < 1500 CTC experience had higher interobserver agreement (0.42 (95% CI 0.35-0.48) vs. 0.33 (95% CI 0.25-0.42)) and MPA (69.2% vs 50.6%) than readers with ≥ 1500 experience. There was substantial overall agreement for flat vs protuberant polyps (0.62 (95% CI 0.56-0.68)) with a MPA of 87.9%. Agreement between CTC and OC classifications was only 44%, and CTC agreement with the combined reference standard was 56%. CONCLUSION: Radiologist agreement when using the Paris classification at CT colonography is low, and radiologist classification agrees poorly with colonoscopy. Using the full Paris classification in routine CTC reporting is of questionable value. CLINICAL RELEVANCE STATEMENT: Interobserver agreement for radiologists using the Paris classification to categorise colorectal polyp morphology is only fair; routine use of the full Paris classification at CT colonography is questionable. KEY POINTS: • Overall interobserver agreement for the Paris classification at CT colonography (CTC) was only fair, and lower than for colonoscopy. • Agreement was higher for radiologists with < 1500 CTC experience and for larger polyps. There was substantial agreement when classifying polyps as protuberant vs flat. • Agreement between CTC and colonoscopic polyp classification was low (44%).

Evaluation of simultaneous multi-slice acquisition with advanced processing for free-breathing diffusion-weighted imaging in patients with liver metastasis.

OBJECTIVES: Diffusion-weighted imaging (DWI) with simultaneous multi-slice (SMS) acquisition and advanced processing can accelerate acquisition time and improve MR image quality. This study evaluated the image quality and apparent diffusion coefficient (ADC) measurements of free-breathing DWI acquired from patients with liver metastases using a prototype SMS-DWI acquisition (with/without an advanced processing option) and conventional DWI. METHODS: Four DWI schemes were compared in a pilot 5-patient cohort; three DWI schemes were further assessed in a 24-patient cohort. Two readers scored image quality of all b-value images and ADC maps across the three methods. ADC measurements were performed, for all three methods, in left and right liver parenchyma, spleen, and liver metastases. The Friedman non-parametric test (post-hoc Wilcoxon test with Bonferroni correction) was used to compare image quality scoring; t-test was used for ADC comparisons. RESULTS: SMS-DWI was faster (by 24%) than conventional DWI. Both readers scored the SMS-DWI with advanced processing as having the best image quality for highest b-value images (b750) and ADC maps; Cohen's kappa inter-reader agreement was 0.6 for b750 image and 0.56 for ADC maps. The prototype SMS-DWI sequence with advanced processing allowed a better visualization of the left lobe of the liver. ADC measured in liver parenchyma, spleen, and liver metastases using the SMS-DWI with advanced processing option showed lower values than those derived from the SMS-DWI method alone (t-test, p < 0.0001; p < 0.0001; p = 0.002). CONCLUSIONS: Free-breathing SMS-DWI with advanced processing was faster and demonstrated better image quality versus a conventional DWI protocol in liver patients. CLINICAL RELEVANCE STATEMENT: Free-breathing simultaneous multi-slice- diffusion-weighted imaging (DWI) with advanced processing was faster and demonstrated better image quality versus a conventional DWI protocol in liver patients. KEY POINTS: • Diffusion-weighted imaging (DWI) with simultaneous multi-slice (SMS) can accelerate acquisition time and improve image quality. • Apparent diffusion coefficients (ADC) measured in liver parenchyma, spleen, and liver metastases using the simultaneous multi-slice DWI with advanced processing were significantly lower than those derived from the simultaneous multi-slice DWI method alone. • Simultaneous multi-slice DWI sequence with inline advanced processing was faster and demonstrated better image quality in liver patients.

Development and Evaluation of Machine Learning in Whole-Body Magnetic Resonance Imaging for Detecting Metastases in Patients With Lung or Colon Cancer: A Diagnostic Test Accuracy Study.

OBJECTIVES: Whole-body magnetic resonance imaging (WB-MRI) has been demonstrated to be efficient and cost-effective for cancer staging. The study aim was to develop a machine learning (ML) algorithm to improve radiologists' sensitivity and specificity for metastasis detection and reduce reading times. MATERIALS AND METHODS: A retrospective analysis of 438 prospectively collected WB-MRI scans from multicenter Streamline studies (February 2013-September 2016) was undertaken. Disease sites were manually labeled using Streamline reference standard. Whole-body MRI scans were randomly allocated to training and testing sets. A model for malignant lesion detection was developed based on convolutional neural networks and a 2-stage training strategy. The final algorithm generated lesion probability heat maps. Using a concurrent reader paradigm, 25 radiologists (18 experienced, 7 inexperienced in WB-/MRI) were randomly allocated WB-MRI scans with or without ML support to detect malignant lesions over 2 or 3 reading rounds. Reads were undertaken in the setting of a diagnostic radiology reading room between November 2019 and March 2020. Reading times were recorded by a scribe. Prespecified analysis included sensitivity, specificity, interobserver agreement, and reading time of radiology readers to detect metastases with or without ML support. Reader performance for detection of the primary tumor was also evaluated. RESULTS: Four hundred thirty-three evaluable WB-MRI scans were allocated to algorithm training (245) or radiology testing (50 patients with metastases, from primary 117 colon [n = 117] or lung [n = 71] cancer). Among a total 562 reads by experienced radiologists over 2 reading rounds, per-patient specificity was 86.2% (ML) and 87.7% (non-ML) (-1.5% difference; 95% confidence interval [CI], -6.4%, 3.5%; P = 0.39). Sensitivity was 66.0% (ML) and 70.0% (non-ML) (-4.0% difference; 95% CI, -13.5%, 5.5%; P = 0.344). Among 161 reads by inexperienced readers, per-patient specificity in both groups was 76.3% (0% difference; 95% CI, -15.0%, 15.0%; P = 0.613), with sensitivity of 73.3% (ML) and 60.0% (non-ML) (13.3% difference; 95% CI, -7.9%, 34.5%; P = 0.313). Per-site specificity was high (>90%) for all metastatic sites and experience levels. There was high sensitivity for the detection of primary tumors (lung cancer detection rate of 98.6% with and without ML [0.0% difference; 95% CI, -2.0%, 2.0%; P = 1.00], colon cancer detection rate of 89.0% with and 90.6% without ML [-1.7% difference; 95% CI, -5.6%, 2.2%; P = 0.65]). When combining all reads from rounds 1 and 2, reading times fell by 6.2% (95% CI, -22.8%, 10.0%) when using ML. Round 2 read-times fell by 32% (95% CI, 20.8%, 42.8%) compared with round 1. Within round 2, there was a significant decrease in read-time when using ML support, estimated as 286 seconds (or 11%) quicker ( P = 0.0281), using regression analysis to account for reader experience, read round, and tumor type. Interobserver variance suggests moderate agreement, Cohen κ = 0.64; 95% CI, 0.47, 0.81 (with ML), and Cohen κ = 0.66; 95% CI, 0.47, 0.81 (without ML). CONCLUSIONS: There was no evidence of a significant difference in per-patient sensitivity and specificity for detecting metastases or the primary tumor using concurrent ML compared with standard WB-MRI. Radiology read-times with or without ML support fell for round 2 reads compared with round 1, suggesting that readers familiarized themselves with the study reading method. During the second reading round, there was a significant reduction in reading time when using ML support.

The Role of Preoperative Imaging in the Detection of Lateral Lymph Node Metastases in Rectal Cancer: A Systematic Review and Diagnostic Test Meta-analysis.

BACKGROUND: Different techniques exist for the imaging of lateral lymph nodes in rectal cancer. OBJECTIVE: This study aimed to compare the diagnostic accuracy of pelvic MRI, 18 F-FDG-PET/CT, and 18 F-FDG-PET/MRI for the identification of lateral lymph node metastases in rectal cancer. DATA SOURCES: Data sources include PubMed, Embase, Cochrane Library, and Google Scholar. STUDY SELECTION: All studies evaluating the diagnostic accuracy of pelvic MRI, 18 F-FDG-PET/CT, and 18 F-FDG-PET/MRI for the preoperative detection of lateral lymph node metastasis in patients with rectal cancer were selected. INTERVENTIONS: The interventions were pelvic MRI, 18 F-FDG-PET/CT, and/or 18 F-FDG-PET/MRI. MAIN OUTCOME MEASURES: Definitive histopathology was used as a criterion standard. RESULTS: A total of 20 studies (1,827 patients) were included out of an initial search yielding 7,360 studies. The pooled sensitivity of pelvic MRI was 0.88 (95% CI, 0.85-0.91), of 18 F-FDG-PET/CT was 0.83 (95% CI, 0.80-0.86), and of 18 F-FDG-PET/MRI was 0.72 (95% CI, 0.51-0.87) for the detection of lateral lymph node metastasis. The pooled specificity of pelvic MRI was 0.85 (95% CI, 0.78-0.90), of 18 F-FDG-PET/CT was 0.95 (95% CI, 0.86-0.98), and of 18 F-FDG-PET/MRI was 0.90 (95% CI, 0.78-0.96). The area under the curve was 0.88 (95% CI, 0.85-0.91) for pelvic MRI and was 0.83 (95% CI, 0.80-0.86) for 18 F-FDG-PET/CT. LIMITATIONS: Heterogeneity in terms of patients' populations, definitions of suspect lateral lymph nodes, and administration of neoadjuvant treatment. CONCLUSIONS: For the preoperative identification of lateral lymph node metastasis in rectal cancer, this review found compelling evidence that pelvic MRI should constitute the imaging modality of choice. In contrast, to confirm the presence of lateral lymph node metastasis, 18 F-FDG-PET/MRI modalities allow discarding false positive cases because of increased specificity. PROSPERO REGISTRATION NUMBER: CRD42020200319.

Diagnostic Accuracy of FEC-PET/CT, FDG-PET/CT, and Diffusion-Weighted MRI in Detection of Nodal Metastases in Surgically Treated Endometrial and Cervical Carcinoma.

PURPOSE: Preoperative nodal staging is important for planning treatment in cervical cancer and endometrial cancer, but remains challenging. We compare nodal staging accuracy of 18F-ethyl-choline-(FEC)-PET/CT, 18F-fluoro-deoxy-glucose-(FDG)-PET/CT, and diffusion-weighted-MRI (DW-MRI) with conventional morphologic MRI. EXPERIMENTAL DESIGN: A prospective, multicenter observational study of diagnostic accuracy for nodal metastases was undertaken in 5 gyne-oncology centers. FEC-PET/CT, FDG-PET/CT, and DW-MRI were compared with nodal size and morphology on MRI. Reference standard was strictly correlated nodal histology. Eligibility included operable cervical cancer stage ≥ 1B1 or endometrial cancer (grade 3 any stage with myometrial invasion or grade 1-2 stage ≥ II). RESULTS: Among 162 consenting participants, 136 underwent study DW-MRI and FDG-PET/CT and 60 underwent FEC-PET/CT. In 118 patients, 267 nodal regions were strictly correlated at histology (nodal positivity rate, 25%). Sensitivity per patient (n = 118) for nodal size, morphology, DW-MRI, FDG- and FEC-PET/CT was 40%*, 53%, 53%, 63%*, and 67% for all cases (*, P = 0.016); 10%, 10%, 20%, 30%, and 25% in cervical cancer (n = 40); 65%, 75%, 70%, 80% and 88% in endometrial cancer (n = 78). FDG-PET/CT outperformed nodal size (P = 0.006) and size ratio (P = 0.04) for per-region sensitivity. False positive rates were all <10%. CONCLUSIONS: All imaging techniques had low sensitivity for detection of nodal metastases and cannot replace surgical nodal staging. The performance of FEC-PET/CT was not statistically different from other techniques that are more widely available. FDG-PET/CT had higher sensitivity than size in detecting nodal metastases. False positive rates were low across all methods. The low false positive rate demonstrated by FDG-PET/CT may be helpful in arbitration of challenging surgical planning decisions.

Whole-body diffusion-weighted MRI in lymphoma-comparison of global apparent diffusion coefficient histogram parameters for differentiation of diseased nodes of lymphoma patients from normal lymph nodes of healthy individuals.

BACKGROUND: Morphologic features yield low diagnostic accuracy to distinguish between diseased and normal lymph nodes. The purpose of this study was to compare diseased lymphomatous and normal lymph nodes using global apparent diffusion coefficient (gADC) histogram parameters derived from whole-body diffusion-weighted MRI (WB-DWI). METHODS: 1.5 Tesla WB-DWI of 23 lymphoma patients and 20 healthy volunteers performed between 09/2010 and 07/2015 were retrospectively reviewed. All diseased nodal groups in the lymphoma cohort and all nodes visible on b900 images in healthy volunteers were segmented from neck to groin to generate a total diffusion volume (tDV). A connected component-labelling algorithm separated spatially distinct nodes. Mean, median, skewness, kurtosis, minimum, maximum, interquartile range (IQR), standard deviation (SD), 10th and 90th centile of the gADC distribution were derived from the tDV of each patient/volunteer and from spatially distinct nodes. gADC and regional nodal ADC parameters were compared between malignant and normal nodes using t-tests and ROC curve analyses. A P value ≤0.05 was deemed statistically significant. RESULTS: Mean, median, IQR, 10th and 90th centiles of gADC and regional nodal ADC values were significantly lower in diseased compared with normal lymph nodes. Skewness, kurtosis and tDV were significantly higher in lymphoma. The SD, min and max gADC showed no significant difference between the two groups (P>0.128). The diagnostic accuracies of gADC parameters by AUC from highest to lowest were: 10th centile, mean, median, 90th centile, skewness, kurtosis and IQR. A 10th centile gADC threshold of 0.68×10-3 mm2/s identified diseased lymphomatous nodes with 91% sensitivity and 95% specificity. CONCLUSIONS: WB-DWI derived gADC histogram parameters can distinguish between malignant lymph nodes of lymphoma patients and normal lymph nodes of healthy individuals.

Quantitative Whole-Body Diffusion-weighted MRI after One Treatment Cycle for Aggressive Non-Hodgkin Lymphoma Is an Independent Prognostic Factor of Outcome.

Purpose: To evaluate the prognostic utility of apparent diffusion coefficient (ADC) changes at whole-body diffusion-weighted (WB-DW) MRI after one treatment cycle for aggressive non-Hodgkin lymphoma (NHL) compared with response assessment at interim and end-of-treatment fluorine 18 (18F) fluorodeoxyglucose (FDG) PET/CT. Materials and Methods: This was a secondary analysis of a prospective study (ClinicalTrials.gov identifier: NCT01231269) in which participants with aggressive NHL were recruited between March 2011 and April 2015 and underwent WB-DW MRI before and after one cycle of immunochemotherapy. Volunteers were recruited for test-retest WB-DW MRI (ClinicalTrials.gov identifier: NCT01231282) to assess ADC measurement repeatability. Response assessment was based on ADC change after one treatment cycle at WB-DW MRI and Deauville criteria at 18F-FDG PET/CT. To evaluate prognostic factors of disease-free survival (DFS), Kaplan-Meier survival analysis and univariable and multivariable Cox regression were performed; intraclass correlation coefficient (ICC) and mean difference with limits of agreement were calculated to determine inter- and intraobserver repeatability of ADC measurements. Results: Forty-five patients (mean age, 58 years ± 17 [standard deviation]; 31 men) and nine volunteers (mean age, 22 years ± 3; seven men) were enrolled. Median DFS was 48 months (range, 2-48 months). Outcome prediction accuracy was 86.7% (39 of 45), 71.4% (30 of 42), and 73.8% (31 of 42) for WB-DW MRI and interim and end-of-treatment 18F-FDG PET/CT, respectively. WB-DW MRI (hazard ratio [HR], 17.8; P < .001) and interim (HR, 5; P = .008) and end-of-treatment (HR, 4.3; P = .017) 18F-FDG PET/CT were prognostic of DFS. After multivariable analysis, WB-DW MRI remained an independent predictor of outcome (HR, 26.8; P = .002). Intra- and interobserver agreement for ADC measurements were excellent (ICC = 0.85-0.99). Conclusion: Quantitative WB-DW MRI after only one cycle of immunochemotherapy predicts DFS in aggressive NHL and is noninferior to routinely performed interim and end-of-treatment 18F-FDG PET/CT.Keywords: MR-Diffusion Weighted Imaging, Lymphoma, Oncology, Tumor Response, Whole-Body ImagingSupplemental material is available for this article.© RSNA, 2021.

Phase I clinical trial repurposing all-trans retinoic acid as a stromal targeting agent for pancreatic cancer.

Pre-clinical models have shown that targeting pancreatic stellate cells with all-trans-retinoic-acid (ATRA) reprograms pancreatic stroma to suppress pancreatic ductal adenocarcinoma (PDAC) growth. Here, in a phase Ib, dose escalation and expansion, trial for patients with advanced, unresectable PDAC (n = 27), ATRA is re-purposed as a stromal-targeting agent in combination with gemcitabine-nab-paclitaxel chemotherapy using a two-step adaptive continual re-assessment method trial design. The maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D, primary outcome) is the FDA/EMEA approved dose of gemcitabine-nab-paclitaxel along-with ATRA (45 mg/m2 orally, days 1-15/cycle). Dose limiting toxicity (DLT) is grade 4 thrombocytopenia (n = 2). Secondary outcomes show no detriment to ATRA pharmacokinetics.. Median overall survival for RP2D treated evaluable population, is 11.7 months (95%CI 8.6-15.7 m, n = 15, locally advanced (2) and metastatic (13)). Exploratory pharmacodynamics studies including changes in diffusion-weighted (DW)-MRI measured apparent diffusion coefficient after one cycle, and, modulation of cycle-specific serum pentraxin 3 levels over various cycles indicate stromal modulation. Baseline stromal-specific retinoid transport protein (FABP5, CRABP2) expression may be predicitve of response. Re-purposing ATRA as a stromal-targeting agent with gemcitabine-nab-paclitaxel is safe and tolerable. This combination will be evaluated in a phase II randomized controlled trial for locally advanced PDAC. Clinical trial numbers: EudraCT: 2015-002662-23; NCT03307148. Trial acronym: STARPAC.

Comparison of a coaxial versus non-coaxial liver biopsy technique in an oncological setting: diagnostic yield, complications and seeding risk.

OBJECTIVES: Percutaneous liver biopsy (PLB) poses specific challenges in oncological patients such as bleeding and tumour seeding. This study's aim was to compare a coaxial (C-PLB) and non-coaxial (NC-PLB) biopsy technique in terms of diagnostic yield, safety and seeding risk of image-guided PLB techniques in an oncological setting. METHODS: Local research committee approval was obtained for this single-site retrospective study. Patients who underwent a PLB between November 2011 and December 2017 were consecutively included. Medical records were reviewed to determine diagnostic yield and complications. Follow-up imaging was re-reviewed for seeding, defined as visible tumour deposits along the PLB track. Mann-Whitney U and chi-squared tests were performed to investigate differences between biopsy techniques in sample number, complications and seeding rate. RESULTS: In total, 741 patients (62 ± 13 years, 378 women) underwent 932 PLB (C-PLB 72.9% (679/932); NC-PLB 27.1% (253/932)). More tissue cores (p < 0.001) were obtained with C-PLB (median 4 cores; range 1-12) compared with NC-PLB (2 cores; range 1-4) and diagnostic yield was similar for both techniques (C-PLB 92.6% (629/679); NC-PLB 92.5% (234/253); p = 0.940). Complication rate (9.3%; 87/932) using C-PLB (8.2% (56/679)) was lower compared with NC-PLB (12.3% (31/253); p = 0.024). Major complications were uncommon (C-PLB 2.7% (18/679); NC-PLB 2.8% (7/253)); bleeding developed in 1.2% (11/932; C-PLB 1.2% (8/679); NC-PLB 1.2% (3/253)). Seeding was a rare event, occurring significantly less in C-PLB cases (C-PLB 1.3% (7/544); NC-PLB 3.1% (6/197); p = 0.021). CONCLUSIONS: C-PLB allows for high diagnostic tissue yield with a lower complication and seeding rate than a NC-PLB and should be the preferred method in an oncological setting. KEY POINTS: • A coaxial percutaneous liver biopsy achieves a significant higher number of cores and fewer complications than a non-coaxial biopsy technique. • The risk of tumour seeding is very low and is significantly lower using the coaxial biopsy technique. • In this study, a larger number of cores (median = 4) could be safely acquired using the coaxial technique, providing sufficient material for advanced molecular analysis.

Visualizing the autonomic and somatic innervation of the female pelvis with 3D MR neurography: a feasibility study.

BACKGROUND: Treatment of female pelvic malignancies often causes pelvic nerve damage. Magnetic resonance (MR) neurography mapping the female pelvic innervation could aid in treatment planning. PURPOSE: To depict female autonomic and somatic pelvic innervation using a modified 3D NerveVIEW sequence. MATERIAL AND METHODS: Prospective study in 20 female volunteers (n = 6 normal, n = 14 cervical pathology) who underwent a modified 3D short TI inversion recovery (STIR) turbo spin-echo (TSE) scan with a motion-sensitive driven equilibrium (MSDE) preparation radiofrequency pulse and flow compensation. Modifications included offset independent trapezoid (OIT) pulses for inversion and MSDE refocusing. Maximum intensity projections (MIP) were evaluated by two observers (Observer 1, Observer 2); image quality was scored as 2 = high, 1 = medium, or 0 = low with the sciatic nerve serving as a reference. Conspicuity of autonomic superior (SHP) and bilateral inferior hypogastric plexuses (IHP), hypogastric nerves, and somatic pelvic nerves (sciatic, pudendal) was scored as 2 = well-defined, 1 = poorly defined, or 0 = not seen, and inter-observer agreement was determined. RESULTS: Images were of medium to high quality according to both observers agreeing in 15/20 (75%) of individuals. SHP and bilateral hypogastric nerves were seen in 30/60 (50%) of cases by both observers. Bilateral IHP was seen in 85% (34/40) by Observer 1 and in 75% (30/40) by Observer 2. Sciatic nerves were well identified in all cases, while pudendal nerves were seen bilaterally by Observer 1 in 65% (26/40) and by Observer 2 in 72.5% (29/40). Agreement between observers for scoring nerve conspicuity was in the range of 60%-100%. CONCLUSION: Modified 3D NerveVIEW renders high-quality images of the female autonomic and pudendal nerves.

68Ga-PSMA PET/CT compared with MRI/CT and diffusion-weighted MRI for primary lymph node staging prior to definitive radiotherapy in prostate cancer: a prospective diagnostic test accuracy study.

BACKGROUND: The aim was to compare the diagnostic accuracy of 68Ga-PSMA PET/CT with conventional cross-sectional imaging and diffusion-weighted MRI (DW-MRI) for detecting lymph node metastasis (LNM) to stage prostate cancer patients. Twenty consecutive, newly- diagnosed prostate cancer patients were prospectively enrolled and underwent 68Ga-PSMA-11 PET/CT, anatomical MRI or contrast-enhanced CT, and DW-MRI prior to laparoscopic, template-based, extended lymph node dissection. Histopathological findings served as the reference test. RESULTS: Histopathology showed LNM in 13 of 20 patients (19 high-risk, 1 intermediate risk). Five patients had metastasis-suspected lymph nodes on 68Ga-PSMA PET/CT. Patient-based analysis showed that the sensitivity and specificity for detecting LNM were 39% and 100% with 68Ga-PSMA PET/CT, 8% and 100% with MRI/CT, and 36% and 83% with DW-MRI, respectively. The positive and negative predictive values were 100% and 49% with 68Ga-PSMA PET/C, 100% and 37% with MRI/CT, and 80% and 42% with DW-MRI. Of 573 dissected lymph nodes, 33 were LNM from 26 regions. True-positive LNM on 68Ga-PSMA PET/CT was 9-11 mm in diameter, whereas false-negative LNM had a median diameter of 4 mm, with only 3 of 30 lymph nodes being larger than 10 mm. LNM were positive for PSMA by immunostaining. CONCLUSIONS: The sensitivity of 68Ga-PSMA PET/CT was notably better than that of MRI/CT and comparable to that of DW-MRI. Some false positive findings with DW-MRI reduced its specificity and positive predictive value compared with those of 68Ga-PSMA PET/CT and MRI/CT.

Prospective comparison of 68Ga-PSMA PET/CT, 18F-sodium fluoride PET/CT and diffusion weighted-MRI at for the detection of bone metastases in biochemically recurrent prostate cancer.

PURPOSE: To prospectively compare diagnostic accuracies for detection of bone metastases by 68Ga-PSMA PET/CT, 18F-NaF PET/CT and diffusion-weighted MRI (DW600-MRI) in prostate cancer (PCa) patients with biochemical recurrence (BCR). METHODS: Sixty-eight PCa patients with BCR participated in this prospective study. The patients underwent 68Ga-PSMA PET/CT, a 18F-NaF PET/CT and a DW600-MRI (performed in accordance with European Society of Urogenital Radiology guidelines, with b values of 0 and 600 s/mm2). Bone lesions were categorized using a three-point scale (benign, malignant or equivocal for metastases) and a dichotomous scale (benign or metastatic) for each imaging modality by at least two experienced observers. A best valuable comparator was defined for each patient based on study-specific imaging, at least 12 months of clinical follow-up and any imaging prior to the study and during follow-up. Diagnostic performance was assessed using a sensitivity analysis where equivocal lesions were handled as non-metastatic and then as metastatic. RESULTS: Ten of the 68 patients were diagnosed with bone metastases. On a patient level, sensitivity, specificity and the area under the curve (AUC) by receiver operating characteristic analysis were, respectively, 0.80, 0.98-1.00 and 0.89-0.90 for 68Ga-PSMA PET/CT (n = 68 patients); 0.90, 0.90-0.98 and 0.90-0.94 for 18NaF PET/CT (n = 67 patients); and 0.25-0.38, 0.87-0.92 and 0.59-0.62 for DW600-MRI (n = 60 patients). The diagnostic performance of DW600-MRI was significantly lower than that of 68Ga-PSMA PET/CT and 18NaF PET/CT for diagnosing bone metastases (p < 0.01), and no significant difference in the AUC was seen between 68Ga-PSMA PET/CT and 18NaF PET/CT (p = 0.65). CONCLUSION: 68Ga-PSMA PET/CT and 18F-NaF PET/CT showed comparable and high diagnostic accuracies for detecting bone metastases in PCa patients with BCR. Both methods performed significantly better than DW600-MRI, which was inadequate for diagnosing bone metastases when conducted in accordance with European Society of Urogenital Radiology guidelines.

Improving lymph node characterization in staging malignant lymphoma using first-order ADC texture analysis from whole-body diffusion-weighted MRI.

BACKGROUND: Correct staging and treatment initiation in malignant lymphoma depends on accurate lymph node characterization. However, nodal assessment based on conventional and diffusion-weighted (DWI) MRI remains challenging, particularly in smaller nodes. PURPOSE: To evaluate first-order apparent diffusion coefficient (ADC) texture parameters compared to mean ADC for lymph node characterization in non-Hodgkin lymphoma (NHL) using whole-body DWI (WB-DWI). STUDY TYPE: Retrospective. POPULATION: Twenty-eight patients with NHL. FIELD STRENGTH/SEQUENCE: 3T whole-body DWI using two b-values (0-1000 s/mm2 ). ASSESSMENT: Regions of interest were drawn on the three most hyperintense lymph nodes on b1000-images, irrespective of size, in all nodal body regions. Diagnostic performance of mean ADC (ADCmean ) was compared with first-order ADC texture parameters: standard deviation (ADCstdev ), kurtosis (ADCkurt ), and skewness (ADCskew ). Additional subanalyses focused on the accuracy of ADCmean and ADC texture parameters in different lymph node volumes and nodal regions. STATISTICAL TESTS: Benign and malignant nodes were compared using Mann-Whitney U-tests with 18-Fluoro-deoxyglucose positron emission tomography computed tomography and bone marrow biopsy as reference standard. Receiver operating characteristic analyses were performed to determine cutoff values and calculate sensitivity, specificity, accuracy, and positive and negative predictive value (PPV, NPV). RESULTS: ADCmean (P = 0.008), ADCskew and ADCkurt differed significantly between benign and malignant nodes (P < 0.001), while ADCstdev didn't (P = 0.21). ADCskew was the best discriminating parameter, with 79% sensitivity, 86% specificity, 83% accuracy, 85% PPV, and 81% NPV. In every volume category, ADCskew yielded the highest accuracy (88% in 0-25th percentile volume, 75% in 25th -75th percentile, 93% in 75-100th percentile). On a per-region basis, ADCskew accuracy varied 13.6% between nodal regions, while ADCmean , ADCkurt , and ADCstdev showed interregional variation of 17.4%, 20.3%, and 14.9%, respectively. DATA CONCLUSION: First-order ADC texture analysis with WB-DWI improved lymph node characterization compared to ADCmean . ADCskew was the most accurate and robust discriminatory parameter over all lymph node volumes and nodal body regions. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:897-906.

Whole-body diffusion-weighted magnetic resonance imaging at 3 Tesla for early assessment of treatment response in non-Hodgkin lymphoma: a pilot study.

OBJECTIVE: To evaluate 3 Tesla (T) whole-body diffusion-weighted magnetic resonance imaging (WB DWI) for early treatment assessment in aggressive non-Hodgkin lymphoma (NHL). METHODS: Fourteen patients with NHL treated with standard chemotherapy underwent 3-T WB DWI before and 2 and 4 weeks during treatment, using b-values of 0-1000 s/mm(2) from which the apparent diffusion coefficient (ADC) was calculated. Patient follow-up (average 20.3 months, range 15-23 months) was the reference standard. Volume and ADC changes between baseline and 2 weeks (Vratio2w, ADCratio2w) and 4 weeks (Vratio4w, ADCratio4w) of responding and non-responding lesions (lymph node and organ lesions) were compared using Mann-Whitney U tests. The per patient values of VratioN and ADCratioN to predict progression-free survival were determined with a log-rank test. RESULTS: Eight patients showed complete remission and 6 showed tumour progression. The ADCratio2w and ADCratio4w differed significantly in lesions showing tumour progression versus complete remission (ADCratio2w = 4 ± 21% versus 119 ± 68%; ADCratio4w = 18 ± 61% versus 155 ± 78%; both P < 0.0001); the Vratio2w and Vratio4w did not (P > 0.05). Per body region, the ADCratio2w showed a negative predictive value of 100% and positive predictive value of 86%. Per patient, the ADCratio2w and ADCratio4w correlated significantly with progression-free survival (P < 0.05). CONCLUSION: 3-T WB DWI with ADC quantification may enable early treatment assessment of aggressive NHL.