RPS 2116 - Advances in imaging genitourinary cancer

Author Block: L. D'Erme¹, A. Candito², G. Avesani¹, S. Bottazzi¹, R. Emsley², D. Meo², J. Carmichael², N. Tunariu², D-M. Koh²; ¹Rome/IT, ²London/UK
Purpose: To investigate the relationship between total bone diffusion volume (tBDV) and global apparent diffusion coefficient (gADC) derived from whole-body diffusion-weighted MRI (WBDWI); as well as automatic bone scan index (aBSI) derived from bone scintigraphy with disease overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC).
Methods or Background: In this IRB approved study, we retrospectively reviewed 302 mCRPC patients (Jan 2015 - Dec 2023) who underwent baseline WBDWI before systemic anticancer treatment. Segmentation masks of bone disease on b900 WBDWI images were generated by an automated tool, and refined by a 3-year experienced oncological radiologist, to derive the tBDV and gADC values. The aBSI was derived in 265 patients with available baseline bone scintigraphy. Kaplan-Meier survival curves and log-rank tests for 5-years OS, including their hazard ratios (HR) and 95% confidence intervals (CI), were compared between the three groups, stratified by the median values of tBDV (89 mL), gADC (0.83), and aBSI (0.021). Significance was set at p < 0.05.
Results or Findings: Patients with tBDV < 89 mL demonstrated significantly longer OS compared to those with tBDV ≥ 89 mL (40.8 vs 23.7 months; p < 0.0001; HR 2.28, 95%CI 1.76–2.94). No significant survival difference was observed between the gADC groups (32.0 vs 27.2 months; p = 0.4293). OS was significantly longer in patients with aBSI < 0.021 than those with aBSI ≥ 0.021 (40.8 vs 24.4 months; p < 0.0001; HR 2.18, 95%CI 1.66–2.85).
Conclusion: WBDWI-derived tBDV is a strong independent prognostic marker for OS in mCRPC patients. The tBDV measurement is comparable if not superior to aBSI as a predictor of disease survival.
Limitations: Retrospective design and longitudinal imaging data were not considered.
Funding for this study: This study represents independent research funded by the National Institute for Health and Care Research (NIHR) Biomedical Research Centre at The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, London, and by the Royal Marsden Cancer Charity, and Cancer Research UK (CRUK) National Cancer Imaging Trials Accelerator (NCITA) and Prostate Cancer UK. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. This work uses data provided by patients and collected by the NHS as part of their care and support.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was approved by the Institutional Ethics Committee (no. 21/LO/0605).

Author Block: S. Bottazzi¹, L. Russo¹, G. Avesani¹, L. D'Erme¹, C. Messiou², D-M. Koh², E. Sala¹, N. Tunariu²; ¹Rome/IT, ²Sutton/UK
Purpose: To compare changes on computed tomography (CT) with the MET-RADS-P response assessment categories (RAC) of bone metastases in advanced prostate cancer patients (APCb) during treatment.
Methods or Background: 102 patients (median age 68years, range 51-83) with APCb who underwent both CT and whole-body magnetic resonance imaging (WBMRI) within 30 days at baseline and during treatment were included. Up to five focal lesions > 10 mm per patient were selected based on one or more of the following: [1] Sclerotic, lytic or mixed lesion on CT; [2] active bone marrow lesion on WBMRI [3] newly developed CT or MR lesion. Each lesion was assigned a CT pattern of change - based on changes in size and Hounsfield Unit (HU) – and a RAC according to METRADS-P criteria. The CT patterns were corroborated with the RAC, grouped as response (RAC1-2), stable (RAC3), and progression (RAC4-5).
Results or Findings: 358 lesions were identified. Of these, 70% (252/358) were sclerotic (SL), 6% (21/358) lytic (LL) and 4% (13/258) mixed lesions (ML). 20% (72/358) showing MR characteristics of active bone metastases were undetectable on CT. The most frequent CT patterns of change on treatment were: stable SL (no changes in density or size) in 35.8% (128/358), increasing in size SL (>5 mm) in 11.4% (41/358), new SL (appeared during treatment) in 10.6% (38/358). Stable SL corresponded to the RAC classifications as follows: 22.3% (29/128) stable treated disease, 25.8% (33/128) responding, 23.4% progressing (30/128) and 28.1% (36/128) stable active disease. New SLs corresponded to responding disease in 28.9% (11/38).
Conclusion: 20% of bone metastases are occult on CT. A stable SL on CT is a poor predictor of disease status. Hence, CT appears unreliable in the assessment of bone disease response inAPCb
Limitations: Na
Funding for this study: This study represents independent research funded by the National Institute for Health and Care Research (NIHR) Biomedical Research Centre at The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, London, and by the Royal Marsden Cancer Charity, and Cancer Research UK (CRUK) National Cancer Imaging Trials Accelerator (NCITA) and Prostate Cancer UK. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. This work uses data provided by patients and collected by the NHS as part of their care and support.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Reference no. 21/LO/0605

Author Block: G. Agrotis, E. H. P. Pooch, R. G. H. Beets-Tan, I. G. Schoots; Amsterdam/NL
Purpose: To assess and compare cancer detection rates (CDRs) of transition zone (TZ) lesions that were upgraded from PI-RADSv2.1 score 2 to 3("2+1") or from score 3 to 4("3+1") using diffusion-weighted imaging (DWI) and evaluate their clinical impact.
Methods or Background: A systematic literature search was conducted in Embase, Medline and Web of Science for studies evaluating TZ lesions with the use of DWI, with histology proven Grade Group≥2 cancer (GG≥2) as primary outcome. Pooled estimates for sensitivity, specificity, CDRs, and Odds Ratio (OR) were derived from extracted data at lesion level and quantitatively pooled using a bivariate binomial and random effects model.
Results or Findings: A total of 7 studies included 1,437 TZ lesions. GG≥2 CDRs for PI-RADSv2.1 scores of 1, 2, 2+1, 3, 3+1, 4, and 5 were respectively 2%[95% CI:0%-12%], 7%[4%-11%], 12%[6%-24%], 21%[18%-25%], 37%[23%-53%], 53%[33%-72%], and 86%[40%-98%].
GG≥2 CDRs of TZ scores '2+1' and '2' were statistically different, with OR 3.13[1.31-7.48],p=0.01, while '2+1' and '3' scores were not, with an OR of 0.76[0.42-1.33],p=0.34. GG≥2 CDRs of TZ score '3+1' and '3' were statistically different, with an OR of 2.3[1.07-4.95],p=0.03, while scores '3+1' and '4' were not with an OR of 0.63[0.28-1.38],p=0.25. Still, false positive rates were substantial in both subcategories ('2+1': 76%[73.8%-78.2%] and '3+1': 45%[42.4%-47.6%]).
Conclusion: The risk of having significant prostate cancer in ‘2+1’ and ‘3+1’ Transition Zone lesions, with an upgrading based on DWI images, is appropriately categorized within the PI-RADS v2.1 scoring system, as shown by this meta-analysis. Especially TZ lesions with score ‘3+1’ may impact individualized biopsy-decisions, as 2-in-5 harbor significant disease, similar to score ‘4’ lesions. Still, the high false positive rate in this sub-category emphasizes the need for strategies to minimize overdiagnosis.
Limitations: Data availability and population differences
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Not applicable

Author Block: X. Zhang¹, G. Zhang¹, H. Sun¹, Z. Jin¹, X. Lu², S-H. Yu¹, L. Xu³, J. Zhang¹, X. Bai¹; ¹Beijing/CN, ²Shenyang/CN, ³Hangzhou/CN
Purpose: To explore the value of arterial enhancement fraction (AEF) and extracellular volume fraction (ECV) obtained from dual-layer spectral CT in the typing and grading of renal cell carcinoma (RCC).
Methods or Background: In this retrospective study, patients with pathologically confirmed RCC who has undergone dual-layer spectral CT were included. RCC was classified into non-clear cell (non-ccRCC) and clear cell (ccRCC). The ccRCC cases were further categorized as high-grade or low-grade based on the WHO/ISUP grading system. AEF and ECV parameter maps were generated from both contrast-enhanced and iodine concentration (IC) images, producing quantitative parameters AEFHU, ECVHU, AEFIC, and ECVIC. Receiver operating characteristic curves were used to evaluate the ability of these parameters in RCC typing and grading.
Results or Findings: The study included 68 patients, comprising 13 with non-ccRCC and 55 with ccRCC. CcRCC showed higher values of AEFHU, ECVHU, AEFIC, and ECVIC compared with non-ccRCC. The multivariate model comprising AEFIC, and ECVIC demonstrated the highest diagnostic accuracy for ccRCC, with an area under curve (AUC) of 0.822, sensitivity of 83.6%, and specificity of 76.9%. Among the ccRCC cases, 34 were low-grade and 21 were high-grade. High-grade ccRCCs exhibited significantly higher ECVHU and ECVIC than low-grade tumors. The multivariate model with tumor diameter, and ECVIC achieved the highest diagnostic accuracy in identifying high-grade ccRCC, with an AUC of 0.909, sensitivity of 90.5%, and specificity of 76.5%.
Conclusion: AEF and ECV derived from dual-layer spectral CT can help distinguish ccRCC from non-ccRCC. Additionally, ECV can accurately identify high-grade ccRCC, offering valuable insights for RCC.
Limitations: Given the retrospective design and relatively small sample size of the present study, further studies should aim to include larger cohorts and consider prospective data collection to validate these findings.
Funding for this study: This study has received funding by the National High Level Hospital Clinical Research Funding [2022-PUMCH-A-033]; the Natural Science Foundation of Beijing Municipality [L232133]; the Chinese Academy of Medical Sciences Initiative for Innovative Medicine [2022-I2M-C&T-B-019]; National High Level Hospital Clinical Research Funding [2022-PUMCH-A-035]; National High Level Hospital Clinical Research Funding [2022-PUMCH-B-069].
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was conducted in accordance with the principles of the Declaration of Helsinki and approved by the institutional Research Ethics Committee

Author Block: C. Sattin¹, C. Pizzi¹, F. Arnone¹, P. Hoxha¹, D. Berloco¹, F. Zugni¹, P. Summers¹, A. R. R. Padhani², G. Petralia¹; ¹Milan/IT, ²Northwood/UK
Purpose: To investigate the potential of the response assessment category (RAC) from MET-RADS-P guidelines as prognostic biomarker in metastatic castrate resistant prostate cancer (mCRPC) patients.
Methods or Background: We enrolled mCRPC patients who underwent whole-body MRI at baseline and at each time point (every 12 weeks disease until progression) after systemic anti-cancer therapy (SACT). We correlated the maximum RAC at time point 1 (TP1) with overall survival (OS). Patients were divided in two groups: those with a maximum RAC 1-2 (highly likely or likely to be responding, respectively) and those with a maximum RAC 3-4-5 (stable disease, likely or highly likely to be progressing) at TP1. Survival curves were depicted in Kaplan-Meier plots and compared via a log-rank test and hazard ratio (HR) using Cox regression model, with point comparisons of three-year survival and median survival duration, using R.
Results or Findings: Out of 31 mCRPC patients enrolled, a higher OS was observed in patients with a maximum RAC 1-2 (N=11) than in those with a maximum RAC 3-4-5 (N=21) at TP1 (log-rank test p=0.005): median 34 months (lower bound 95%CI = 27 months) vs median 12 months (95%CI 11-28 months). The HR for the RAC 3-4-5 patients was 1.34 (95%CI 0.83 – 1.85, p= 0.009). Three-year OS was 30.3% for RAC1-2 vs 5.3% for RAC 3-4-5, for a difference of 25.0% (95%CI -11.1% - 61.2%, p=0.175).
Conclusion: Our observations support the potential of RAC after TP1 as a prognostic biomarker in mCRPC undergoing SACT.
Limitations: Retrospective and monocentric study.
Funding for this study: No fundings
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Not applicable

Author Block: N. Di Meo, C. Buizza, P. Rondi, A. Dalla Volta, A. Borghesi, M. Ravanelli, A. Berruti, D. Farina; Brescia, BS/IT
Purpose: To assess the prognostic significance of bone marrow adipose tissue (BMAT) in prostate cancer patients with hormone-sensitive bone metastases undergoing whole-body MRI (WB-MRI) and receiving enzalutamide treatment.
Methods or Background: Imaging was conducted on a 1.5T MRI scanner using a MET-RADS-P-compliant protocol. Manual single-slice segmentation of fat fraction (FF%) sequences was performed by one operator (R1) at the L3 vertebral level and across three contiguous slices at the femoral head. WB-MRI was performed at baseline and at 6 and 12 months following the initiation of therapy. Absolute BMAT values and temporal changes were recorded and correlated with survival outcomes.
Results or Findings: Of the 126 patients enrolled in this prospective phase 2 clinical trial, 100 were available for analysis. No correlation was found between BMAT measurements at the L3 vertebra and the femoral head, with the latter showing significantly higher values (90.7% vs. 63.9%, respectively). A significant positive correlation was identified between baseline L3 BMAT and both progression-free survival (PFS) and overall survival (OS), with hazard ratios (HR) of 0.37 and 0.33, respectively, after a median split. Additionally, early changes in L3 BMAT were inversely associated with PFS and OS, with HRs of 1.89 and 2.96, respectively. BMAT at the femoral head was not associated with survival outcomes.
Conclusion: L3 BMAT is a valuable prognostic and predictive biomarker that can be easily derived from WB-MRI. It may contribute to more personalized treatment strategies for patients with metastatic prostate cancer.
Limitations: No external validation.
Funding for this study: No Funding
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: No

Author Block: L. Chen, Y. Yang, F. Yao; Wenzhou/CN
Purpose: This study aimed to investigate the value of periprostatic fat area and 18F-PSMA-1007 uptake in predicting high ISUP grade and postoperative PSA persistence in prostate cancer patients using 18F-PSMA-1007 PET/CT.
Methods or Background: A retrospective analysis was conducted on clinical data and 18F-PSMA-1007 PET/CT data of 350 prostate cancer patients. 3D-Slicer and Lifex software were utilized for delineating the region of interest for periprostatic fat and measuring periprostatic fat area and 18F-PSMA-1007 uptake. The primary outcome of this study was the ISUP grade greater than 3 based on surgical pathological results of radical prostatectomy. The secondary outcome was postoperative PSA persistence, defined as routine follow-up tPSA > 0.1 ng/ml. Logistic regression analyses were performed to assess the association between characteristics and outcomes and construct predictive models. Receiver operating characteristic curves were utilized to determine optimal cutoff values and evaluate model performance.
Results or Findings: Larger periprostatic fat area emerged as an independent risk factor for higher ISUP grade (p < 0.001) and postoperative PSA persistence (p = 0.009) in prostate cancer patients. Higher 18F-PSMA-1007 uptake was also closely associated with higher ISUP grade (p < 0.001) and postoperative PSA persistence (p < 0.001). Models respectively established to predict higher ISUP grade and postoperative PSA persistence showed good predictive performance, with AUC values of 0.736 and 0.745.
Conclusion: Larger periprostatic fat area and higher 18F-PSMA-1007 uptake are independent risk factors for high ISUP grade and postoperative PSA persistence, which can be used to predict high ISUP grade and the persistence of PSA.
Limitations: This is a small sample study. The generalizability of the results requires further consideration.
Funding for this study: This study was supported by the Wenzhou Major Program of Science and Technology Innovation (Grant No. ZY2020012).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This retrospective study has been reviewed and approved by the the first affiliated hospital of Wenzhou Medical University ethics committee.

Author Block: F. Jungmann, L. Steinhelfer, M. R. Makowski, M. Eiber, R. Braren; Munich/DE
Purpose: Lutetium-177 (177Lu) prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) is a novel treatment option for metastatic, castration-resistant prostate cancer (mCRPC). Evidence is increasing that nephrotoxicity is a delayed side effect in a considerable fraction of patients. The purpose of this study was to identify prognostic markers for clinically significant deterioration of kidney function in patients undergoing 177Lu-PSMA RLT.
Methods or Background: Total kidney volume (TKV) at 3 and 6 months following 177Lu-PSMA RLT was extracted from routine clinical CT scans using deep learning. A cut-off at ≥30% eGFR decline was defined as clinically significant deterioration of kidney function, given its indication as a substantial risk of end-stage renal disease. Differences between patients developing an eGFR decline of ≥30% after 12 months and those who did not considering baseline renal parameters, their relative changes (∆%), nephrotoxic risk factors, and the number of 177Lu-PSMA cycles were analyzed. Furthermore, distinct threshold values of significant features to differentiate between the two patient groups were identified based on ROC analysis using the Youden-Index.
Results or Findings: A ≥10% decrease in TKV at six months predicted a severe eGFR decline of ≥30% at 12 months with high diagnostic accuracy (ROC-AUC of 0.90), surpassing all other parameters. Baseline risk factors, the number of prior treatment regimens and 177Lu-PSMA cycles did not correlate with a higher eGFR decrease at 12 months.
Conclusion: Our retrospective analysis demonstrates the feasibility of fully automated kidney volume assessment from routine clinical imaging data to predicting significant deterioration of kidney function at 12-month after 177Lu-PSMA RLT in mCRPC. It is more accurate than early relative eGFR change and might contribute as a non-invasive biomarker when treatment decisions are pending including determining whether to continue/discontinue or adapt 177LuPSMA treatment.
Limitations: Retrospective, single-center
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethical approval for this retrospective, HIPAA-compliant analysis was obtained from the local institutional review boards. The requirement for informed consent was waived because of its retrospective design.

Author Block: V. Koch, T. Vogl, R. Strecker, C. Booz, S. Mahmoudi, L. D. Grünewald; Frankfurt/DE
Purpose: The purpose of this study was to investigate the impact of deep learning-accelerated T2-weighted MRI imaging of prostate cancer and benign prostatic hyperplasia (BPH).
Methods or Background: In this prospective study, adults who underwent 3-Tesla MRI of the prostate due to suspicion of prostate cancer or benign prostatic hyperplasia were included. Standard sequences were acquired according to a dedicated protocol compromising T1-, T2-, and diffusion-weighted imaging sequences. Additionally, T2-weighted imaging sequences using the deep learning algorithm (T2DL) were acquired in axial, coronal, and sagittal planes. Quantitative analysis encompassed time efficiency and objective imaging parameters, including signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Qualitative evaluation was independently performed by three blinded radiologists to assess diagnostic confidence, image quality, and lesion sharpness subjectively. Interreader agreement was calculated using Fleiss κ.
Results or Findings: A total of 46 male patients (mean age, 70 ± 9 years) were included. The study cohort encompassed 22 patients (48%) with prostatic cancer and 24 patients (52%) with BPH. Subjective evaluation of T2DL-sequences among all three readers revealed slightly superior diagnostic confidence, image quality, and lesion sharpness when compared to standard T2w sequences. Especially regarding focal lesions, T2DL-sequences allowed for significantly sharper demarcation with higher diagnostic confidence in cancer diagnosis. Objective image analysis of T2DL revealed significantly higher SNR and CNR values when compared to conventional T2w-sequences. Acquisition times of T2w-sequences (axial, coronal, and sagittal plane) could be reduced by an average of 50 % using T2DL-sequences.
Conclusion: Our findings suggest that deep learning-accelerated T2w-sequences in MRI imaging of the prostate allow a relevant reduction in acquisition time while maintaining both subjective and objective image quality.
Limitations: Single-center study.
Funding for this study: No funding.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Approval obtained.

Author Block: C. Meinzer¹, K. Zhang¹, R. Gnirs¹, O. Zivanovic¹, H-U. Kauczor¹, H-P. Schlemmer¹, F. Kurz², T. Mokry¹; ¹Heidelberg/DE, ²Geneva/CH
Purpose: To evaluate feasibility of arterial spin labeling (ASL) as a non-contrast MRI technique for assessing solid tissue of adnexal lesions and to compare its performance with dynamic contrast enhanced (DCE) MRI.
Methods or Background: We prospectively included 11 adnexal lesions with solid tissue in nine females. Regions of interest (ROIs) were annotated on DCE images, and then transferred anatomically to corresponding sites on ASL images. From these ROIs, we extracted semi-quantitative DCE parameters: area under the curve (AUC), relative area under the curve (relAUC), peak enhancement, time to peak, mean residence time, area under the first moment curve, and wash-in-rate (WiR). From ASL perfusion maps, we obtained mean adnexal blood flow (ABF). Correlation between ABF and DCE parameters was assessed using Pearson’s correlation coefficient. For those parameters showing significant correlation, Bland-Altman plots were generated to evaluate agreement.
Results or Findings: Pearson's correlation revealed significant correlations between ABF and two DCE parameters: relAUC (r=-0.75, p=0.008), WiR (r=0.65, p=0.031). Other analysed DCE parameters showed no statistically significant correlations with ABF (p>0.05).
Bland-Altman analysis was performed for the significantly correlating parameters. For relAUC, mean difference was 135.85 (SD=18.04). No data points fell outside the limits of agreement, indicating good agreement between ASL and DCE. Similarly, WiR showed a mean difference of -17.02 (SD=11.24), and no points outside the limits of agreement.
Conclusion: ABF demonstrated significant correlations with relAUC and WiR, indicating that ASL can provide comparable perfusion information to DCE for these metrics. The Bland-Altman analysis further suggests reasonable agreement between ASL-derived perfusion and DCE parameters for relAUC and WiR.
Limitations: The small sample size limits the generalisability of the findings. ASL MRI is susceptible to lower signal-to-noise ratios and variability in perfusion measurements, which can impact accuracy and reproducibility.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study received institutional review board approval and written informed consent was obtained from all participants (S-337/2016).