Performance of 4Kscore as a Reflex Test to Prostate-specific Antigen in the GÖTEBORG-2 Prostate Cancer Screening Trial.

BACKGROUND AND OBJECTIVE: We investigated whether adding 4Kscore as a reflex test to prostate-specific antigen (PSA) could improve the screening algorithm for prostate cancer (PC). METHODS: In the GÖTEBORG-2 PC screening trial, 38 000men (50-60 yr) were invited to PSA testing and, if elevated, followed by magnetic resonance imaging (MRI). For 571 men with PSA ≥3.0 ng/ml and evaluable outcomes, 4Kscore was calculated. The performance using a prespecified 4Kscore cutoff of 7.5% was evaluated. KEY FINDINGS AND LIMITATIONS: The area under the curve for 4Kscore to identify intermediate- and high-risk PC was 0.84 (95% confidence interval 0.79-0.89), and the positive predictive value, and negative predictive value were 15% (0.12-0.20) and 99% (97-100%), respectively. Of the 54 men diagnosed with intermediate- or high-grade PC, two had a 4Kscore cutoff below 7.5%, both with organ-confined intermediate-risk PC. Per 1000 men with elevated PSA, adding 4Kscore would have resulted in avoidance of MRI for 408 (41%) men, biopsies for 95 (28% reduction) men, and diagnosis of 23 low-grade cancers (23% reduction) while delaying the diagnosis of four men with intermediate-grade cancers (4%). CONCLUSIONS AND CLINICAL IMPLICATIONS: Including 4Kscore as a reflex test for men with elevated PSA reduces the need for MRI and biopsy markedly, and results in less overdiagnosis of low-grade PC at the cost of delaying the diagnosis of intermediate-grade PC in a few men. These results add further evidence for including new blood-based biomarkers in addition to PSA to improve the harm and benefit ratio of PC screening and reduce the need for resource-demanding MRI and biopsies. PATIENT SUMMARY: In this study, 4Kscore, a blood-based biomarker, as a reflex test for men with elevated prostate-specific antigen (PSA), reduces the need for magnetic resonance imaging and biopsy. These results support the inclusion of new blood-based biomarkers in addition to PSA.

Prostate Cancers in the Prostate-specific Antigen Interval of 1.8-3 ng/ml: Results from the Göteborg-2 Prostate Cancer Screening Trial.

BACKGROUND: Magnetic resonance imaging (MRI) and targeted biopsies reduce overdiagnosis of prostate cancer (PC). It is uncertain how this strategy performs for low prostate-specific antigen (PSA) levels. OBJECTIVE: To investigate the Prostate Imaging Reporting and Data System (PI-RADS) distribution, frequency, and characteristics of screen-detected PC with PSA of 1.8-<3 ng/ml and 3-<10 ng/ml. DESIGN, SETTING, AND PARTICIPANTS: In the population-based Göteborg-2 screening study, 17974 men choose to participate by having a PSA test (2015-2020). One-third of the participants (n = 6006) were randomized to arm 3, men with a PSA value of ≥1.8 ng/ml were recommended for MRI. Men with positive MRI (PI-RADS 3-5) had four targeted biopsies from each MRI-visible lesion. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Clinically significant PC was defined as Gleason score ≥3 + 4. RESULTS AND LIMITATIONS: A total of 6006 men were included. The median age was 55.9 yr (interquartile range [IQR] 52.6-59.6). Of them, 4929 (82%) had PSA of <1.8 ng/ml, 670 (11%) had PSA of 1.8-<3 ng/ml (low-PSA group, median PSA 2.1 ng/ml [IQR 1.9-2.5]), and 377 (6.3%) had PSA of 3-<10 ng/ml (high-PSA group, median PSA 3.9 ng/ml [IQR 3.3-5.0]). PI-RADS scores of 3, 4, and 5 were observed in 7.8%, 15%, and 1.0% of men in the low-PSA group, and in 6.9%, 17%, and 5.3% of men in the high-PSA group, respectively. PC was found in 64 men (41%, 95% confidence interval [CI] 0.33-0.49) with positive MRI findings in the low-PSA group, of whom 33 (21%) had Gleason 6 (insignificant PC) and 31 (20%) had Gleason ≥7 (significant PC). In the high-PSA group, PC was detected in 61 men (56%, 95% CI 0.46-0.66), of whom 26 (24%) had Gleason 6 (insignificant PC) and 35 (32%) had Gleason ≥7 (significant PC). Limitations include results from only a single screening round. CONCLUSIONS: A non-negligible number of men with PSA 1.8-3 ng/ml have clinically significant PC. Whether a delay in the diagnosis of these tumors until they reached PSA ≥3 ng/ml would impair their chance of cure remains to be evaluated. PATIENT SUMMARY: We studied screening using prostate-specific antigen (PSA) and magnetic resonance imaging in men with PSA 1.8-3 ng/ml. We found a non-negligible number of potentially harmful prostate cancers in these men.

Manual prostate MRI segmentation by readers with different experience: a study of the learning progress.

OBJECTIVE: To evaluate the learning progress of less experienced readers in prostate MRI segmentation. MATERIALS AND METHODS: One hundred bi-parametric prostate MRI scans were retrospectively selected from the Göteborg Prostate Cancer Screening 2 Trial (single center). Nine readers with varying degrees of segmentation experience were involved: one expert radiologist, two experienced radiology residents, two inexperienced radiology residents, and four novices. The task was to segment the whole prostate gland. The expert's segmentations were used as reference. For all other readers except three novices, the 100 MRI scans were divided into five rounds (cases 1-10, 11-25, 26-50, 51-76, 76-100). Three novices segmented only 50 cases (three rounds). After each round, a one-on-one feedback session between the expert and the reader was held, with feedback on systematic errors and potential improvements for the next round. Dice similarity coefficient (DSC) > 0.8 was considered accurate. RESULTS: Using DSC > 0.8 as the threshold, the novices had a total of 194 accurate segmentations out of 250 (77.6%). The residents had a total of 397/400 (99.2%) accurate segmentations. In round 1, the novices had 19/40 (47.5%) accurate segmentations, in round 2 41/60 (68.3%), and in round 3 84/100 (84.0%) indicating learning progress. CONCLUSIONS: Radiology residents, regardless of prior experience, showed high segmentation accuracy. Novices showed larger interindividual variation and lower segmentation accuracy than radiology residents. To prepare datasets for artificial intelligence (AI) development, employing radiology residents seems safe and provides a good balance between cost-effectiveness and segmentation accuracy. Employing novices should only be considered on an individual basis. CLINICAL RELEVANCE STATEMENT: Employing radiology residents for prostate MRI segmentation seems safe and can potentially reduce the workload of expert radiologists. Employing novices should only be considered on an individual basis. KEY POINTS: • Using less experienced readers for prostate MRI segmentation is cost-effective but may reduce quality. • Radiology residents provided high accuracy segmentations while novices showed large inter-reader variability. • To prepare datasets for AI development, employing radiology residents seems safe and might provide a good balance between cost-effectiveness and segmentation accuracy while novices should only be employed on an individual basis.

Men's Acceptance of Screening for Prostate Cancer with Prostate-specific Antigen, Magnetic Resonance Imaging, and Prostate Biopsy.

BACKGROUND: A prerequisite before introducing a screening program is that the screening examinations are acceptable to participants. OBJECTIVE: To evaluate the acceptance and bother of prostate cancer screening examinations. DESIGN, SETTING, AND PARTICIPANTS: The randomized population-based GÖTEBORG-2 prostate cancer screening trial invited >37 000 men for prostate-specific antigen (PSA) testing followed by magnetic resonance imaging (MRI) in case of elevated PSA and prostate biopsy (targeted and/or systematic) if indicated. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Participants were asked to fill out a questionnaire and rate the level of bother associated with each examination (PSA, MRI, and prostate biopsy) on a categorical scale ranging from 1 to 5 (1 = "not at all bothersome" and 5 = "very bothersome"), and to rate their willingness to repeat the examinations, by marking an X on a continuous scale ranging from 0 to 10 (0 = "yes, without any hesitation" and 10 = "no, absolutely not"). Wilcoxon signed rank test was used. RESULTS AND LIMITATIONS: Compliance with MRI was 96% (1790/1872), compliance with biopsy was 89% (810/907), and the response rate to the questionnaire was 75% (608/810). Men who underwent all examinations (n = 577) responded that biopsy was more bothersome than PSA test (p < 0.001) and MRI (p < 0.001). High levels of bother (≥4 out of 5) were reported by 2% (12/577) for PSA test, 8% (46/577) for MRI, and 43% (247/577) for biopsy. Men were more willing to repeat MRI than biopsy (p < 0.001), but the difference was small (median 0.2 [interquartile range 0.1-0.6] vs 0.5 [0.1-2.0]). CONCLUSIONS: Biopsies are more bothersome than MRI, but a large majority of men accept to repeat both examinations if necessary. Omitting biopsy for MRI-negative men and shifting to targeted biopsies only will reduce bother for men participating in prostate cancer screening. PATIENT SUMMARY: We asked men how bothersome they found the prostate-specific antigen (PSA) test, magnetic resonance imaging (MRI), and prostate biopsies. Biopsies were more bothersome than PSA and MRI, but most men were willing to repeat all procedures if necessary.

Revised Swedish guidelines on intravenous iodine contrast medium-induced acute kidney injury 2022: A summary.

The Swedish Society of Uroradiology has revised their computed tomography (CT) guidelines regarding iodine contrast media-induced acute kidney injury (CI-AKI). They are more cautious compared to the European Society of Urogenital Radiology and the American College of Radiology since the actual risk of CI-AKI remains uncertain in patients with moderate to severe kidney damage due to a lack of prospective controlled studies and mainly based on retrospective propensity score-matched studies with low-grade evidence. Another source of uncertainty is the imprecision of glomerular filtration rate (GFR) estimating equations. However, randomized hydration studies indictae an upper limit risk of CI-AKI of about 5% for outpatients with a GFR in the range of 30-44 or 45-59 mL/min/1.73m2 combined with multiple risk factors. Apart from GFR limits, the guideline also includes limits for systemic contrast medium exposure expressed in gram-iodine/GFR ratio.

Positive Effect of Parathyroidectomy Compared to Observation on BMD in a Randomized Controlled Trial of Mild Primary Hyperparathyroidism.

Mild or asymptomatic disease is now the dominating presentation of primary hyperparathyroidism (PHPT). However, bone involvement with decreased bone mineral density (BMD) and an increased risk of fractures has been demonstrated. Indications for parathyroidectomy (PTX) in mild PHPT have been debated for years. There is a need of long-term randomized studies comparing PTX with observation without intervention (OBS). Here, we present bone health data from the Scandinavian Investigation of Primary Hyperparathyroidism (SIPH), a randomized controlled trial, comparing PTX to OBS. This study included 191 patients (96 OBS/95 PTX), and 129 patients (64 OBS/65 PTX) were followed for 10 years to the end of study (EOS). BMD was measured with dual-energy X-ray absorptiometry (DXA), peripheral fractures were noted, and spine radiographs were obtained for vertebral fracture assessment. There was a significant treatment effect of PTX on BMD compared with OBS for all analyzed compartments, most explicit for the lumbar spine (LS) and femoral neck (FN) (p < 0.001). The mean changes in T-score from baseline to 10 years were from 0.41 for radius 33% (Rad33) to 0.58 for LS greater in the PTX group than in the OBS group. There was a significant decrease in BMD for all compartments in the OBS group, most pronounced for FN, Rad33, and ultradistal radius (UDR) (p < 0.001). Even though there was a significant treatment effect of PTX compared with OBS, there was only a significant increase in BMD over time for LS (p < 0.001). We found no difference between groups in fracture frequency in the 10-year cohort, neither with modified intention-to-treat (mITT) analysis nor per protocol analysis. Because BMD is only a surrogate endpoint of bone health and PTX did not reduce fracture risk, observation could be considered a safe option for many patients with mild PHPT regarding bone health in a 10-year perspective. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Predictive characteristics for disease recurrence and overall survival in non-metastatic clinical T1 renal cell carcinoma - results from the National Swedish Kidney Cancer Register.

OBJECTIVE: Patients with clinical T1 renal cell carcinoma (cT1RCC) have risks for recurrence and reduced overall survival despite being in the best prognostic group. This study aimed to evaluate the association of different treatments on disease recurrence and overall survival using clinical and pathological characteristics in a nation-wide cT1RCC cohort. MATERIALS AND METHODS: A total of 4,965 patients, registered in the National Swedish Kidney Cancer Register (NSKCR) between 2005 and 2014, with ≥ 5-years follow-up were identified: 3,040 males and 1,925 females, mean age 65 years. Times to recurrence and overall survival were analyzed with Kaplan-Meier curves, log-rank test, and Cox regression models. RESULTS: Age, TNM-stage, tumor size, RCC-type, and performed treatment were all associated with disease recurrence. Patients selected for ablative treatments had increased risk for recurrent disease: hazard ratio (HR) = 3.79 [95% confidence interval (CI) = 2.69-5.32]. In multivariate analyses, age, gender, tumor size, RCC-type, N-stage, recurrence and performed treatment were all independently associated with overall survival. Patients with chRCC had a 41% better overall survival (HR = 0.59, 95% CI = 0.44-0.78; p < 0.001) than ccRCC. Patients treated with partial nephrectomy (PN) had an 18% better overall survival (HR = 0.83, 95% CI = 0.71-0.95, p < 0.001) than patients treated with radical nephrectomy. CONCLUSIONS: Age, gender, T-stage, tumor size, RCC type and treatment modality are all associated with risk of recurrence. Furthermore, age, male gender, tumor size, N-stage and recurrence are associated with reduced overall survival. Patients with chRCC, compared with ccRCC and pRCC patients, and PN compared with RN treated patients, had an advantageous overall survival, indicating a possible survival advantage of nephron sparing treatment.

Prostate Cancer Screening with PSA and MRI Followed by Targeted Biopsy Only.

BACKGROUND: Screening for prostate cancer is burdened by a high rate of overdiagnosis. The most appropriate algorithm for population-based screening is unknown. METHODS: We invited 37,887 men who were 50 to 60 years of age to undergo regular prostate-specific antigen (PSA) screening. Participants with a PSA level of 3 ng per milliliter or higher underwent magnetic resonance imaging (MRI) of the prostate; one third of the participants were randomly assigned to a reference group that underwent systematic biopsy as well as targeted biopsy of suspicious lesions shown on MRI. The remaining participants were assigned to the experimental group and underwent MRI-targeted biopsy only. The primary outcome was clinically insignificant prostate cancer, defined as a Gleason score of 3+3. The secondary outcome was clinically significant prostate cancer, defined as a Gleason score of at least 3+4. Safety was also assessed. RESULTS: Of the men who were invited to undergo screening, 17,980 (47%) participated in the trial. A total of 66 of the 11,986 participants in the experimental group (0.6%) received a diagnosis of clinically insignificant prostate cancer, as compared with 72 of 5994 participants (1.2%) in the reference group, a difference of -0.7 percentage points (95% confidence interval [CI], -1.0 to -0.4; relative risk, 0.46; 95% CI, 0.33 to 0.64; P<0.001). The relative risk of clinically significant prostate cancer in the experimental group as compared with the reference group was 0.81 (95% CI, 0.60 to 1.1). Clinically significant cancer that was detected only by systematic biopsy was diagnosed in 10 participants in the reference group; all cases were of intermediate risk and involved mainly low-volume disease that was managed with active surveillance. Serious adverse events were rare (<0.1%) in the two groups. CONCLUSIONS: The avoidance of systematic biopsy in favor of MRI-directed targeted biopsy for screening and early detection in persons with elevated PSA levels reduced the risk of overdiagnosis by half at the cost of delaying detection of intermediate-risk tumors in a small proportion of patients. (Funded by Karin and Christer Johansson's Foundation and others; GÖTEBORG-2 ISRCTN Registry number, ISRCTN94604465.).

Surgical waiting times and all-cause mortality in patients with non-metastatic renal cell carcinoma.

OBJECTIVE: To examine the association between surgical waiting times (SWTs) and all-cause mortality (ACM) in non-metastatic patients with RCC, in relation to tumour stage. PATIENTS AND METHODS: This nation-wide population-based cohort study included 9,918 M0 RCC patients registered in the National Swedish Kidney Cancer Register, between 2009 and 2021, followed-up for ACM until 9 December 2021, and having measured SWTs. The associations between primarily SWTs from date of radiological diagnosis to date of surgery (WRS) and secondarily SWTs from date of radiological diagnosis to date of treatment decision (WRT) and date of treatment decision to date of surgery (WTS), in relation to ACM, were analysed using Cox regression analysis, adjusted for clinical and demographic characteristics, stratified and unstratified according to T-stage. RESULTS: During a mean follow-up time of 5 years (49,873 person-years), 23% (n = 2291) of the patients died. The adjusted hazard ratio (AHR) for WRS (months) for all patients was 1.03 (95% confidence interval [CI] = 1.02-1.04; p < 0.001). When subdividing WRS on T-stage, the AHRs were 1.03 (95% CI = 1.01-1.04; p < 0.001) and 1.05 (95% CI = 1.02-1.08; p = 0.003) for stages T1 and T3, respectively, while non-significant for T2 (p = 0.079) and T4 (p = 0.807). Similar results were obtained for WRT and WTS. CONCLUSIONS: Prolonged SWTs significantly increased the risk of early overall death among patients with RCC. The increased risk of early death from any cause show the importance of shortening SWTs in clinical work of patients with this malignant disease.

Clinical T1a Renal Cell Carcinoma, Not Always a Harmless Disease-A National Register Study.

Background: T1a renal cell carcinoma (RCC) is typically considered a curable disease, irrespective of the choice of local treatment modality. Objective: To identify factors associated with the risk of local and distant recurrence, and overall survival (OS) in patients with primary nonmetastatic clinical T1a RCC. Design setting and participants: A population-based nationwide register study of all 1935 patients with cT1a RCC, diagnosed during 2005-2012, identified through The National Swedish Kidney Cancer Register, was conducted. Outcome measurements and statistical analysis: Outcome variables were recurrence (local or distant) and OS. Possible explanatory variables included tumor size, RCC type, T stage, surgical technique, age, and gender. Associations with disease recurrence and OS were evaluated by multivariable regression and Cox multivariate analyses, respectively. Results and limitations: Among 1935 patients, 938 were treated with radical nephrectomy, 738 with partial nephrectomy, and 169 with ablative treatments, while 90 patients had no surgery. Seventy-eight (4%) patients were upstaged to pT3. Local or metastatic recurrences occurred in 145 (7.5%) patients, significantly more often after ablation (17.8%). The risk of recurrence was associated with tumor size, upstaging, and ablation. Larger tumor size, disease recurrence, and older age adversely affected OS, whereas partial nephrectomy and chromophobe RCC (chRCC) were associated with improved survival. Limitations include register design and a lack of comorbidity or performance status data. Conclusions: Upstaging and recurrence occurred, respectively, in 4.0% and 7.5% of patients with nonmetastatic RCCs ≤4 cm. Tumor size upstaging and ablation were associated with the risk for recurrence, while tumor size and recurrence were associated with decreased OS. Patients with chRCC and partial nephrectomy had prolonged OS in a real-world setting. Patient summary: We studied factors that may influence the risk of disease recurrence and overall survival, in a large nationwide patient cohort having nonmetastatic renal cell carcinoma ≤4 cm. Tumor size, tumor type, and treatment were associated with the risk of recurrence and overall death. Partial nephrectomy prolonged overall survival.

Mortality and Morbidity in Mild Primary Hyperparathyroidism: Results From a 10-Year Prospective Randomized Controlled Trial of Parathyroidectomy Versus Observation.

BACKGROUND: Primary hyperparathyroidism (PHPT) is a common endocrine disorder associated with increased risk for fractures, cardiovascular disease, kidney disease, and cancer and increased mortality. In mild PHPT with modest hypercalcemia and without known morbidities, parathyroidectomy (PTX) is debated because no long-term randomized trials have been performed. OBJECTIVE: To examine the effect of PTX on mild PHPT with regard to mortality (primary end point) and key morbidities (secondary end point). DESIGN: Prospective randomized controlled trial. (ClinicalTrials.gov: NCT00522028). SETTING: Eight Scandinavian referral centers. PATIENTS: From 1998 to 2005, 191 patients with mild PHPT were included. INTERVENTION: Ninety-five patients were randomly assigned to PTX, and 96 were assigned to observation without intervention (OBS). MEASUREMENTS: Date and causes of death were obtained from the Swedish and Norwegian Cause of Death Registries 10 years after randomization and after an extended observation period lasting until 2018. Morbidity events were prospectively registered annually. RESULTS: After 10 years, 15 patients had died (8 in the PTX group and 7 in the OBS group). Within the extended observation period, 44 deaths occurred, which were evenly distributed between groups (24 in the PTX group and 20 in the OBS group). A total of 101 morbidity events (cardiovascular events, cerebrovascular events, cancer, peripheral fractures, and renal stones) were also similarly distributed between groups (52 in the PTX group and 49 in the OBS group). During the study, a total of 16 vertebral fractures occurred in 14 patients (7 in each group). LIMITATION: During the study period, 23 patients in the PTX group and 27 in the OBS group withdrew. CONCLUSION: Parathyroidectomy does not appear to reduce morbidity or mortality in mild PHPT. Thus, no evidence of adverse effects of observation was seen for at least a decade with respect to mortality, fractures, cancer, cardiovascular and cerebrovascular events, or renal morbidities. PRIMARY FUNDING SOURCE: Swedish government, Norwegian Research Council, and South-Eastern Norway Regional Health Authority.

Once-only colonoscopy or two rounds of faecal immunochemical testing 2 years apart for colorectal cancer screening (SCREESCO): preliminary report of a randomised controlled trial.

BACKGROUND: Screening for colorectal cancer is done with lower gastrointestinal endoscopy or stool-based tests. There is little evidence from randomised trials to show primary colonoscopy reduces mortality in colorectal cancer. We aimed to investigate the effect of screening with once-only colonoscopy or two rounds of faecal immunochemical test screening on colorectal cancer mortality and incidence. METHODS: We did a randomised controlled trial in Sweden (SCREESCO). Residents in 18 of 21 regions who were age 60 years in the year of randomisation were identified from a population register maintained by the Swedish Tax Agency. A statistician with no further involvement in the trial used a randomised block method to assign individuals to once-only colonoscopy, two rounds of faecal immunochemical testing (OC-Sensor; 2 years apart), or a control group (no intervention; standard diagnostic pathways), in a ratio of 1:6 for colonoscopy versus control and 1:2 for faecal immunochemical testing versus control. Masking was not possible due to the nature of the trial. The primary endpoints of the trial are colorectal cancer mortality and colorectal cancer incidence. Here, we report preliminary participation rates, baseline findings, and adverse events from March, 2014, to December, 2020, in the two intervention groups after completion of recruitment and screening, up to the completion of the second faecal immunochemical testing round. Analyses were done in the intention-to-screen population, defined as all individuals who were randomly assigned to the respective study group. This study is registered with ClinicalTrials.gov, NCT02078804. FINDINGS: Between March 1, 2014, and Dec 31, 2020, 278 280 people were included in the study; 31 140 were assigned to the colonoscopy group, 60 300 to the faecal immunochemical test group, and 186 840 to the control group. 10 679 (35·1%) of 30 400 people who received an invitation for colonoscopy participated. 33 383 (55·5%) of 60 137 people who received a postal faecal immunochemical test participated. In the intention-to-screen analysis, colorectal cancer was detected in 49 (0·16%) of 31 140 people in the colonoscopy group versus 121 (0·20%) of 60 300 in the faecal immunochemical test group (relative risk [RR] 0·78, 95% CI 0·56-1·09). Advanced adenomas were detected in 637 (2·05%) people in the colonoscopy group and 968 (1·61%) in the faecal immunochemical test group (RR 1·27, 95% CI 1·15-1·41). Colonoscopy detected more right-sided advanced adenomas than faecal immunochemical testing. There were two perforations and 15 major bleeds in 16 555 colonoscopies. No intervention-related deaths occurred. INTERPRETATION: The diagnostic yield and the low number of adverse events indicate that the design from this trial, both for once-only colonoscopy and faecal immunochemical test screening, could be transferred to a population-based screening service if a benefit in disease-specific mortality is subsequently shown. FUNDING: Swedish regions, County Council, Regional Cancer Center Mellansverige, Swedish Cancer Society, Aleris Research and Development Fund, Eiken Chemical.

The Influence of DXA Hardware, Software, Reference Population and Software Analysis Settings on the Bone Mineral Density and T-Score Relationship.

Different dual-energy x-ray absorptiometry (DXA) hardware can affect bone mineral density (BMD) measurements and different reference populations can affect t-scores. Long-term analyses describing differences in the relationship between BMD and t-scores are lacking. BMD-values were plotted against t-scores for 241 Lunar DXA scans on females obtained over 18 years from several centers in Sweden and Norway. The result of the plot was compared to hardware/software versions, reference populations and different software analysis settings (Basic vs Enhanced analysis for total body and Single Photon Absorptiometry (SPA) vs Lunar calibration for forearm). For the forearm compartments, we found different BMD-t-score relationships depending on the use of SPA or Lunar calibration (p<0.001). With Lunar calibration, BMD-values were 24% higher, but there was no effect on t-scores. Total body measurements with iDXA scanners and Enhanced analysis for Prodigy scanners (software version 14.10) resulted in a different BMD-t-score relationship compared to the other hardware/software versions (p<0.001), with the largest discrepancy for lower BMD-values. Switching from Basic to Enhanced analysis generally decreased BMD-values and often changed t-scores (both increased and decreased). For the femoral neck, there were two different BMD-t-score relationships caused by different reference populations (p<0.001). In contrast to total body, the difference for femoral neck was more pronounced for higher values, with little impact in the clinical decision-making area. Hardware, software, reference populations and software analysis settings can affect the BMD-t-score relationship, but do so differently for different compartments. The BMD-t-score-plot is a simple and effective tool to discover systematic differences. Longitudinal analyses of DXA scans should be performed based on raw data analyzed in "one run" with the same software version and settings, in order to avoid systematic differences.

Prostate Cancer Diffusion-Weighted Magnetic Resonance Imaging: Does the Choice of Diffusion-Weighting Level Matter?

BACKGROUND: Diffusion-weighted magnetic resonance imaging plays an important role in multiparametric assessment of prostate lesions. The derived apparent diffusion coefficient (ADC) could be a useful quantitative biomarker for malignant growth, but lacks acceptance because of low reproducibility. PURPOSE: To investigate the impact of the choice of diffusion-weighting levels (b-values) on contrast-to-noise ratio and quantitative measures in prostate diffusion-weighted MRI. STUDY TYPE: Retrospective and simulation based on published data. SUBJECTS: Patient cohort (21 men with Prostate Imaging-Reporting and Data System (PI-RADS) version 2 score ≥3) from a single-center study. FIELD STRENGTH/SEQUENCE: 3 T/diffusion-weighted imaging with single-shot echo-planar imaging. ASSESSMENT: Both clinical data and simulations based on previously acquired data were used to quantify the influence of b-value choice in normal peripheral zone (PZ) and PZ tumor lesions. For clinical data, ADC was determined for different combinations of b-values. Contrast-to-noise ratio and quantitative diffusion measures were simulated for a wide range of b-values. STATISTICAL TESTS: Tissue ADC and the lesion-to-normal tissue ADC ratios of different b-value combinations were compared with paired two-tailed Student's t-tests. A P-value <0.05 was considered statistically significant. RESULTS: Findings about b-value dependence derived from clinical data and from simulations agreed with each other. Provided measurement was limited to two b-values, simulation-derived optimal b-value choices coincided with PI-RADSv2 recommendations. For two-point measurements, ADC decreased by 15% when the maximum b-value increased from 1000 to 1500 seconds/mm2 , but corresponding lesion-to-normal tissue ADC ratio showed no significant change (P = 0.86 for acquired data). Simulations with three or more measurement points produced ADCs that declined by only 8% over this range of maximum b-value. Corresponding ADC ratios declined between 2.6% (three points) and 3.8% (21 points). Simulations also revealed an ADC reduction of about 19% with the shorter echo and diffusion time evaluated. DATA CONCLUSION: The comprehensive assessment of b-value dependence permits better formulation of protocol and analysis recommendations for obtaining reproducible results in prostate cancer diffusion-weighted MRI. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 2.

Prostate Cancer Screening with Magnetic Resonance Imaging: Results from the Second Round of the Göteborg Prostate Cancer Screening 2 Trial.

BACKGROUND: The Göteborg 2 prostate cancer (PC) screening (G2) trial evaluates screening with prostate-specific antigen (PSA) followed by magnetic resonance imaging (MRI) in case of elevated PSA levels. OBJECTIVE: To assess the safety of using a 2-yr interval in men who were previously screened positive with PSA but had negative MRI or positive MRI with a negative biopsy. DESIGN, SETTING, AND PARTICIPANTS: A total of 61 201 men aged 50-60 yr were randomized and 38 366 were invited for screening (years 2015-2020). Men with positive MRI (Prostate Imaging Reporting and Data System [PI-RADS] score ≥3) were scheduled for targeted biopsies. Men with negative MRI or negative biopsies were reinvited after 2 yr. Round 1 and 2 MRI scans (PI-RADS ≥3) of men not diagnosed with PC in round 1 were re-read and classified according to Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) by two radiologists. Interval PCs (detected outside the program before invitation to round 2) were identified by linking to the Regional PC Registry. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Tabulation of overall detection of PC was done. RESULTS AND LIMITATIONS: Between October 2017 and June 2020, 474 men with round 1 elevated PSA and MRI underwent a second screening. Of those, 19% had nonelevated PSA in round 2 and were not examined further. Of the remaining 376 men, 89% had negative MRI. Targeted biopsies yielded 14 PCs: nine grade group (GG) 1 and five GG 2-3. In men with PI-RADS ≥3 and PC diagnosed in round 2, only two (GG 1) progressed according to the PRECISE criteria and the remainder were stable. Ten interval PCs were diagnosed: seven GG 1, one GG 2, and two GG 5. The two GG 5 PCs were PI-RADS 4 and 5 with negative round 1 biopsy. CONCLUSIONS: A 2-yr interval seems to be safe in men with negative MRI, while men with PI-RADS 4 and 5 lesions with negative biopsies should have a closer follow-up. PATIENT SUMMARY: In prostate cancer screening, a 2-yr follow-up seems to be safe if magnetic resonance imaging did not show highly suspicious findings.

EXTRACOLONIC FINDINGS-IDENTIFICATION AT LOW-DOSE CTC.

In contrast to optical colonoscopy, computed tomography colonography (CTC) has the ability to reveal pathology outside of the colon. While identification of colorectal lesions at CTC requires only limited radiation dose, the detection of abnormalities in extracolonic soft tissue requires more radiation. The purpose of this study was to investigate the influence of ultra-low-dose (ULD) CTC on the detection and characterisation of extracolonic findings. In a prospective study 49 patients with colorectal symptoms were examined with CTC adding a ULD series (mean effective dose 0.9 ± 0.4 mSv) to the normal unenhanced standard dose (SD) series (mean effective dose 3.6 ± 1.2 mSv). Five radiologists individually and blindly evaluated the ULD, followed by evaluation of the SD after ≥9 weeks (median 35 weeks). A ViewDEX-based examination protocol was used, including a confidence scale and a graded assessment of need for follow-up according to the CTC Reporting and Data System (C-RADS E0-E4). The reference findings comprised the combined information from CTC (ULD, SD and contrast-enhanced CTC series) and a 4-year radiological and clinical follow-up. For the overall detection of reference findings (E2-E4) we found a statistically significant difference in favour of SD. This, however, was not the case when looking at classification of possibly important/important reference findings (E3-E4). Our results suggest that CTC with ULD (0.9 mSv) is comparable to SD (3.6 mSv) for identification of clinically relevant extracolonic pathology, but there is a large inter-observer variability.

Bi- or multiparametric MRI in a sequential screening program for prostate cancer with PSA followed by MRI? Results from the Göteborg prostate cancer screening 2 trial.

OBJECTIVES: The PIRADS Steering Committee has called for "higher quality data before making evidence-based recommendations on MRI without contrast enhancement as an initial diagnostic work up," however, recognizing biparametric (bp) MRI as a reasonable option in a low-risk setting such as screening. With bpMRI, more men can undergo MRI at a lower cost and they can be spared the invasiveness of intravenous access. The aim of this study was to assess cancer detection in bpMRI vs mpMRI in sequential screening for prostate cancer (PCa). METHODS: Within the ongoing Göteborg PCa screening 2 trial, we assessed cancer detection in 551 consecutive participants undergoing prostate MRI. In the same session, readers first assessed bpMRI and then mpMRI. Four targeted biopsies were performed for lesions scored PIRADS 3-5 with bpMRI and/or mpMRI. RESULTS: Cancer was detected in 84/551 cases (15.2%; 95% CI: 12.4-18.4) with mpMRI and in 83/551 cases (15.1%; 95% CI: 12.3-18.2%) with bpMRI. The relative risk (RR) for cancer detection with bpMRI compared to mpMRI was 0.99 (95% one-sided CI: > 94.8); bpMRI was non-inferior to mpMRI (10% non-inferiority margin). bpMRI resulted in fewer false positives, 45/128 (35.2%), compared to mpMRI, 52/136 (38.2%), RR = 0.92; 95% CI: 0.84-0.98. Of 8 lesions scored positive only with mpMRI, 7 were false positives. The PPV for MRI and targeted biopsy was 83/128 (64.8%) for bpMRI and 84/136 (61.8%) for mpMRI, RR = 1.05, 95% CI: 1.01-1.10. CONCLUSIONS: In a PSA-screened population, bpMRI was non-inferior to mpMRI for cancer detection and resulted in fewer false positives. KEY POINTS: • In screening for prostate cancer with PSA followed by MRI, biparametric MRI allows radiologists to detect an almost similar number of prostate cancers and score fewer false positive lesions compared to multiparametric MRI. • In a screening program, high sensitivity should be weighed against cost and risks for healthy men; a large number of men can be saved the exposure of gadolinium contrast medium by adopting biparametric MRI and at the same time allowing for a higher turnover in the MRI room.

The GÖTEBORG prostate cancer screening 2 trial: a prospective, randomised, population-based prostate cancer screening trial with prostate-specific antigen testing followed by magnetic resonance imaging of the prostate.

OBJECTIVE: To describe the study design of the GÖTEBORG prostate cancer screening (PC) 2 (Göteborg-2), a prospective, randomised, population-based trial of PC screening. This trial evaluates whether prostate-specific antigen (PSA) testing followed by 3 Tesla prostate magnetic resonance imaging (MRI) and targeted biopsy can reduce overdiagnosis, while maintaining the detection of clinically significant cancer, compared to PSA-screening and systematic biopsy. MATERIALS AND METHODS: A random sample of men 50-60 years in the Göteborg area, Sweden, identified from the Total Population Register, were randomised to either a screening or control group (CG). Participants in the screening group (SG) were further randomised into one of three arms: (1) PSA-test; if PSA ≥ 3 ng/mL, then MRI and systematic biopsy, plus targeted biopsy to suspicious lesions as per Prostate Imaging - Reporting and Data System, version 2 (PI-RADSv2) 3-5; (2) PSA-test; if PSA ≥ 3 ng/mL, then MRI, and targeted biopsy only if PI-RADSv2 3-5; (3) identical to Arm 2, except lower PSA-cut-off ≥1.8 ng/mL. The primary outcome is the detection rate of clinically insignificant PC (defined as Gleason Score 3 + 3 [Grade Group 1]) comparing all men with PSA ≥ 3 ng/mL in Arm 1 vs. Arm 2 + 3. RESULTS: Randomisation and enrolment started in September 2015. Accrual has hitherto resulted in 38,770 men randomised to the SG. The participation rate is 50%. Invitation to the first screening round was completed in June 2020. CONCLUSIONS: The Göteborg-2 trial will provide new knowledge about the performance of prostate MRI in a screening setting.

Computed tomography contrast enhancement pattern of the uterus in premenopausal women in relation to menstrual cycle and hormonal contraception.

BACKGROUND: There are different types of computed tomography (CT) contrast enhancement patterns of the uterus. It is not known whether these are hormonally dependent. PURPOSE: To assess the relationship between these patterns and the menstrual cycle in non-users of hormonal contraception, and the possible impact of hormonal contraception. MATERIAL AND METHODS: Prospective observational study of abdominal CT scans of 53 premenopausal women of whom 28 were non-users and 25 users of hormonal contraception. The non-users were divided according to menstrual cycle phase: follicular (n = 12); ovulatory (n = 1); and luteal (n = 12). The pattern and intensity of contrast enhancement of the uterine myometrium were assessed. RESULTS: The dominant pattern of contrast enhancement of the myometrium was the diffuse homogeneous type in both non-users and users. The intensity of the enhancement measured in Hounsfield units (HU) was higher in the follicular phase (median 102, range 73-130) compared to the luteal phase in non-users (median 92, range 57-130); however this was not statistically significant (P = 0.2). The HU values observed in users (median 95, range 45-160) were at the same levels compared to those of the luteal phase in non-users. CONCLUSION: The dominant pattern of contrast enhancement in the portal venous phase of the myometrium in fertile ages is the diffuse homogeneous type and is independent of menstrual cycle phase or the use of hormonal contraception. However, these factors seem to play a role in the intensity of contrast enhancement, with a tendency of higher HU values in the follicular phase of non-users.

Minimal risk of contrast-induced kidney injury in a randomly selected cohort with mildly reduced GFR.

OBJECTIVES: Previous large studies of contrast-induced or post-contrast acute kidney injury (CI-AKI/PC-AKI) have been observational, and mostly retrospective, often with patients undergoing non-enhanced CT as controls. This carries risk of inclusion bias that makes the true incidence of PC-AKI hard to interpret. Our aim was to determine the incidence of PC-AKI in a large, randomly selected cohort, comparing the serum creatinine (Scr) changes after contrast medium exposure with the normal intraindividual fluctuation in Scr. METHODS: In this prospective study of 1009 participants (age 50-65 years, 48% females) in the Swedish CArdioPulmonary bioImage Study (SCAPIS), with estimated glomerular filtration rate (eGFR) ≥ 50 mL/min, all received standard dose intravenous iohexol at coronary CT angiography (CCTA). Two separate pre-CCTA Scr samples and a follow-up sample 2-4 days post-CCTA were obtained. Change in Scr was statistically analyzed and stratification was used in the search of possible risk factors. RESULTS: Median increase of Scr post-CCTA was 0-2 µmol/L. PC-AKI was observed in 12/1009 individuals (1.2%) according to the old ESUR criteria (> 25% or > 44 µmol/L Scr increase) and 2 individuals (0.2%) when using the updated ESUR criteria (≥ 50% or ≥ 27 µmol/L Scr increase). Possible risk factors (e.g., diabetes, age, eGFR, NSAID use) did not show increased risk of developing PC-AKI. The mean effect of contrast media on Scr did not exceed the intraindividual Scr fluctuation. CONCLUSIONS: Iohexol administration to a randomly selected cohort with mildly reduced eGFR is safe, and PC-AKI is very rare, occurring in only 0.2% when applying the updated ESUR criteria. KEY POINTS: • Iohexol administration to a randomly selected cohort, 50-65 years old with mildly reduced eGFR, is safe and PC-AKI is very rare. • Applying the updated ESUR PC-AKI criteria resulted in fewer cases, 0.2% compared to 1.2% using the old ESUR criteria in this cohort with predominantly mild reduction of renal function. • The mean effect of CM on Scr did not exceed the intraindividual background fluctuation of Scr, regardless of potential risk factors, such as diabetes or NSAID use in our cohort of 1009 individuals.