The cornerstone of standard treatment for patients with primary bone metastatic prostate cancer (mPCa) is androgen deprivation therapy (ADT). Retrospective studies suggest a survival benefit for ...treatment of the primary prostatic tumour in mPCa, but to date, no randomised-controlled-trials (RCTs) have been published addressing this issue.
To determine whether overall survival is prolonged by adding local treatment of the primary prostatic tumour with external beam radiation therapy (EBRT) to ADT.
The HORRAD trial is a multicentre RCT recruiting 432 patients with prostate-specific antigen (PSA) >20ng/ml and primary bone mPCa on bone scan between 2004 and 2014.
Patients were randomised to either ADT with EBRT (radiotherapy group) or ADT alone (control group).
Primary endpoint was overall survival. Secondary endpoint was time to PSA progression. Crude and adjusted analyses were applied to evaluate treatment effect.
Median PSA level was 142ng/ml and 67% of patients had more than five osseous metastases. Median follow up was 47 mo. Median overall survival was 45 mo (95% confidence interval CI, 40.4–49.6) in the radiotherapy group and 43 mo (95% CI: 32.6–53.4) in the control group (p=0.4). No significant difference was found in overall survival (hazard ratio HR: 0.90; 95% CI: 0.70–1.14; p=0.4). Median time to PSA progression in the radiotherapy group was 15 mo (95% CI: 11.8–18.2), compared with 12 mo (95% CI: 10.6–13.4) in the control group. The crude HR (0.78; 95% CI: 0.63–0.97) was statistically significant (p=0.02).
The current RCT comparing ADT to ADT with EBRT to the prostate in patients with primary bone mPCa did not show a significant difference in overall survival, although the CI cannot exclude a substantial survival benefit. Further research is needed to confirm our findings.
This study investigated the effect of adding radiation therapy to the prostate to hormonal therapy in prostate cancer patients with metastasis to the bone at diagnosis. In our patient group, additional radiotherapy did not improve overall survival. Further research is needed to confirm our findings.
Adding radiotherapy to the prostate in patients with bone metastatic prostate cancer does not improve overall survival.
In the current randomised controlled trial, there is no improvement in overall survival when comparing androgen deprivation therapy alone to androgen deprivation therapy with concurrent radiotherapy to the prostate in patients with primary bone metastatic prostate cancer.
The efficacy of an immediate single chemotherapy instillation after transurethral resection of a bladder tumour (TURBT) in patients with non–muscle-invasive bladder cancer (NMIBC) remains a topic of ...debate. Evidence is even more scarce when an immediate instillation is followed by adjuvant instillations.
To compare the effect of a mitomycin C (MMC) instillation within 24h to an instillation 2 wk after TURBT in patients with NMIBC with or without adjuvant instillations.
Between 1998 and 2003, 2844 NMIBC patients were randomised for immediate versus delayed MMC instillation after TURBT. Patients were categorised in low-risk (LOR), intermediate-risk (IMR), and high-risk (HIR) groups. Total numbers of instillations in these groups were 1, 9, and 15, respectively.
Primary end point was 3-yr recurrence risk for the IMR and HIR groups and 5-yr risk for the LOR group. Secondary outcomes were time to recurrence and incidence of adverse events. Analyses were performed with the log-rank test, Cox-regression, and χ2 test in SPSS.
A total of 2243 patients were eligible on an intention-to-treat basis. Recurrence risks were 43% and 46% in the LOR group (5-yr follow-up, p=0.11), 20% and 32% in the IMR group (3-yr follow-up, p=0.037), and 28% and 35% in the HIR group (3-yr follow-up, p=0.007), for an immediate and a delayed instillation, respectively. For all patients, the recurrence risk was 27% (95% confidence interval CI, 24–30) in the immediate and 36% (95% CI, 33–39) in the delayed instillation group (p<0.001) with a 27% reduction in relative recurrence risk (hazard ratio: 0.73, 95% CI, 0.63–0.85, p<0.001). The incidence of adverse events did not differ significantly between treatment groups (immediate instillation 25%, delayed instillation 22%, p=0.08). The risk groups in our study differ slightly from the current guidelines, which is a limitation of our study.
An immediate, single instillation after TURBT reduces the recurrence risk in NMIBC patients, independent of the number of adjuvant installations.
A single instillation of chemotherapy after the resection of non–muscle-invasive bladder cancer reduces the recurrence risk, even if patients are treated with an adjuvant schedule of instillations.
An intravesical instillation with mitomycin C within 24h after transurethral resection of a bladder tumour reduces the risk of recurrence in non–muscle-invasive bladder cancer patients, independent of the number of adjuvant installations.
The DROP-IN gamma probe facilitates minimally invasive, robot-assisted prostate-specific membrane antigen–targeted radioguided surgery in patients with recurrent prostate cancer. This procedure holds ...promise for improving the intraoperative identification and removal of prostate cancer lesions.
It has been proven that intraoperative prostate-specific membrane antigen (PSMA)-targeted radioguidance is valuable for the detection of prostate cancer (PCa) lesions during open surgery. Rapid extension of robot-assisted, minimally invasive surgery has increased the need to make PSMA-radioguided surgery (RGS) robot-compliant.
To evaluate whether the miniaturized DROP-IN gamma probe facilitates translation of PSMA-RGS to robotic surgery in men with recurrent PCa.
This prospective feasibility study included 20 patients with up to three pelvic PCa recurrences (nodal or local) on staging PSMA positron emission tomography (PET) after previous curative-intent therapy.
Robot-assisted PSMA-RGS using the DROP-IN gamma probe was carried out 19–23 h after intravenous injection of 99mtechnetium PSMA-Investigation & Surgery (99mTc-PSMA-I&S).
The primary endpoint was the feasibility of robot-assisted PSMA-RGS. Secondary endpoints were a comparison of the radioactive status (positive or negative) of resected specimens and final histopathology results, prostate-specific antigen (PSA) response following PSMA-RGS, and complications according to the Clavien-Dindo classification.
Using the DROP-IN probe, 19/21 (90%) PSMA-avid lesions could be resected robotically. On a per-lesion basis, the sensitivity and specificity of robot-assisted PSMA-RGS was 86% and 100%, respectively. A prostate-specific antigen (PSA) reduction of >50% and a complete biochemical response (PSA <0.2 ng/ml) were seen in 12/18 (67%) and 4/18 (22%) patients, respectively. During follow-up of up to 15 mo, 4/18 patients (22%) remained free of biochemical recurrence (PSA ≤0.2 ng/ml). One patient suffered from a Clavien-Dindo grade >III complication.
The DROP-IN probe helps in realizing robot-assisted PSMA-RGS. The procedure is technically feasible for intraoperative detection of nodal or local PSMA-avid PCa recurrences.
A device called the DROP-IN probe facilitates minimally invasive, robot-assisted surgery guided by radioactive tracers in patients with recurrent prostate cancer. This procedure holds promise for improving the intraoperative identification and removal of prostate cancer lesions.
Purpose
Quantitative prostate-specific membrane antigen (PSMA) PET analysis may provide for non-invasive and objective risk stratification of primary prostate cancer (PCa) patients. We determined the ...ability of machine learning-based analysis of quantitative
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FDCFPyL PET metrics to predict metastatic disease or high-risk pathological tumor features.
Methods
In a prospective cohort study, 76 patients with intermediate- to high-risk PCa scheduled for robot-assisted radical prostatectomy with extended pelvic lymph node dissection underwent pre-operative
18
FDCFPyL PET-CT. Primary tumors were delineated using 50–70% peak isocontour thresholds on images with and without partial-volume correction (PVC). Four hundred and eighty standardized radiomic features were extracted per tumor. Random forest models were trained to predict lymph node involvement (LNI), presence of any metastasis, Gleason score ≥ 8, and presence of extracapsular extension (ECE). For comparison, models were also trained using standard PET features (SUVs, volume, total PSMA uptake). Model performance was validated using 50 times repeated 5-fold cross-validation yielding the mean receiver-operator characteristic curve AUC.
Results
The radiomics-based machine learning models predicted LNI (AUC 0.86 ± 0.15,
p
< 0.01), nodal or distant metastasis (AUC 0.86 ± 0.14,
p
< 0.01), Gleason score (0.81 ± 0.16,
p
< 0.01), and ECE (0.76 ± 0.12,
p
< 0.01). The highest AUCs reached using standard PET metrics were lower than those of radiomics-based models. For LNI and metastasis prediction, PVC and a higher delineation threshold improved model stability. Machine learning pre-processing methods had a minor impact on model performance.
Conclusion
Machine learning-based analysis of quantitative
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FDCFPyL PET metrics can predict LNI and high-risk pathological tumor features in primary PCa patients. These findings indicate that PSMA expression detected on PET is related to both primary tumor histopathology and metastatic tendency. Multicenter external validation is needed to determine the benefits of using radiomics versus standard PET metrics in clinical practice.
Introduction
Radiomics extracted from prostate-specific membrane antigen (PSMA)-PET modeled with machine learning (ML) may be used for prediction of disease risk. However, validation of previously ...proposed approaches is lacking. We aimed to optimize and validate ML models based on
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F-DCFPyL-PET radiomics for the prediction of lymph-node involvement (LNI), extracapsular extension (ECE), and postoperative Gleason score (GS) in primary prostate cancer (PCa) patients.
Methods
Patients with intermediate- to high-risk PCa who underwent
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F-DCFPyL-PET/CT before radical prostatectomy with pelvic lymph-node dissection were evaluated. The training dataset included 72 patients, the internal validation dataset 24 patients, and the external validation dataset 27 patients. PSMA-avid intra-prostatic lesions were delineated semi-automatically on PET and 480 radiomics features were extracted. Conventional PET-metrics were derived for comparative analysis. Segmentation, preprocessing, and ML methods were optimized in repeated 5-fold cross-validation (CV) on the training dataset. The trained models were tested on the combined validation dataset. Combat harmonization was applied to external radiomics data. Model performance was assessed using the receiver-operating-characteristics curve (AUC).
Results
The CV-AUCs in the training dataset were 0.88, 0.79 and 0.84 for LNI, ECE, and GS, respectively. In the combined validation dataset, the ML models could significantly predict GS with an AUC of 0.78 (
p
<0.05). However, validation AUCs for LNI and ECE prediction were not significant (0.57 and 0.63, respectively). Conventional PET metrics-based models had comparable AUCs for LNI (0.59,
p
>0.05) and ECE (0.66,
p
>0.05), but a lower AUC for GS (0.73,
p
<0.05). In general, Combat harmonization improved external validation AUCs (-0.03 to +0.18).
Conclusion
In internal and external validation,
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F-DCFPyL-PET radiomics-based ML models predicted high postoperative GS but not LNI or ECE in intermediate- to high-risk PCa. Therefore, the clinical benefit seems to be limited. These results underline the need for external and/or multicenter validation of PET radiomics-based ML model analyses to assess their generalizability.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objectives
To review the literature to determine the sensitivity and specificity of gallium‐68 prostate‐specific membrane antigen (68Ga‐PSMA) positron‐emission tomography (PET) for detecting pelvic ...lymph node metastases in patients with primary prostate cancer (PCa), and the positive predictive value in patients with biochemical recurrence (BCR) after initial curative treatment, and, in addition, to determine the detection rate and management impact of 68Ga‐PSMA PET in patients with BCR after radical prostatectomy (RP).
Materials and Methods
We performed a comprehensive literature search. Search terms used in MEDLINE, EMBASE and Science Direct were ‘(PSMA, 68Ga‐PSMA, 68Gallium‐PSMA, Ga‐68‐PSMA or prostate‐specific membrane antigen)’ and ‘(histology, lymph node, staging, sensitivity, specificity, positive predictive value, recurrence, recurrent or detection)’. Relevant s were reviewed and full‐text articles obtained where possible. References to and from obtained articles were searched to identify further relevant articles.
Results
Nine retrospective and two prospective studies described the sensitivity and specificity of 68Ga‐PSMA PET for detecting pelvic lymph node metastases before initial treatment, which ranged from 33.3% to 100% and 80% to 100%, respectively. In eight retrospective studies, the positive predictive value of 68Ga‐PSMA PET in patients with BCR before salvage lymph node dissection ranged from 70% to 100%. The detection rate of 68Ga‐PSMA PET in patients with BCR after RP in the PSA subgroups <0.2 ng/mL, 0.2–0.49 ng/mL and 0.5 to <1.0 ng/mL ranged from 11.3% to 50.0%, 20.0% to 72.7% and 25.0% to 87.5%, respectively.
Conclusion
The review results showed that 68Ga‐PSMA PET had a high specificity for the detection of pelvic lymph node metastases in primary PCa. Furthermore, 68Ga‐PSMA PET had a very high positive predictive value in detecting lymph node metastases in patients with BCR. By contrast, sensitivity was only moderate; therefore, based on the currently available literature, 68Ga‐PSMA PET cannot yet replace pelvic lymph node dissection to exclude lymph node metastases. In the salvage phase, 68Ga‐PSMA PET had both a high detection rate and impact on radiotherapy planning in early BCR after RP.
Quantitative evaluation of radiolabeled prostate-specific membrane antigen (PSMA) PET scans may be used to monitor treatment response in patients with prostate cancer (PCa). To interpret longitudinal ...differences in PSMA uptake, the intrinsic variability of tracer uptake in PCa lesions needs to be defined. The aim of this study was to investigate the repeatability of quantitative PET/CT measurements using 18F-DCFPyL (2-(3-(1-carboxy-5-(6-18F-fluoro-pyridine-3-carbonyl)-amino-pentyl)-ureido)-pentanedioic acid, a second-generation 18F-PSMA-ligand) in patients with PCa. Methods: Twelve patients with metastatic PCa were prospectively included, of whom 2 were excluded from final analyses. Patients received 2 whole-body 18F-DCFPyL PET/CT scans (median dose, 317 MBq; uptake time, 120 min) within a median of 4 d (range, 1–11 d). After semiautomatic (isocontour-based) tumor delineation, the following lesion-based metrics were derived: mean, peak, and maximum tumor-to-blood ratio; SUVmean, SUVpeak, and SUVmax normalized to body weight; tumor volume; and total lesion uptake (TLU). Additionally, patient-based total tumor volume (TTV) (sum of PSMA-positive tumor volumes) and total tumor burden (TTB) (sum of all lesion TLUs) were derived. Repeatability was analyzed using repeatability coefficients (RC) and intraclass correlation coefficients. Additionally, the effect of point-spread function (PSF) image reconstruction on the repeatability of uptake metrics was evaluated. Results: In total, 36 18F-DCFPyL PET–positive lesions were analyzed (≤5 lesions per patient). The RCs for mean, peak, and maximum tumor-to-blood ratio were 31.8%, 31.7%, and 37.3%, respectively. For SUVmean, SUVpeak, and SUVmax, the RCs were 24.4%, 25.3%, and 31.0%, respectively. All intraclass correlation coefficients were at least 0.97. Tumor volume delineations were quite repeatable, with an RC of 28.1% for individual lesion volumes and 17.0% for TTV. TTB had an RC of 23.2% and 33.4% when based on SUVmean and mean tumor-to-blood ratio, respectively. Small lesions (<4.2 cm3) had worse repeatability for volume measurements. The repeatability of SUVpeak, TLU, and all patient-level metrics was not affected by PSF reconstruction. Conclusion: 18F-DCFPyL uptake measurements are quite repeatable and can be used for clinical validation in future treatment response assessment studies. Patient-based TTV may be preferred for multicenter studies because its repeatability was both high and robust to different image reconstructions.
Targeting the prostate-specific membrane antigen (PSMA) protein has become of great clinical value in prostate cancer (PCa) care. PSMA positron emission tomography/computed tomography (PET/CT) is ...increasingly used in initial staging and restaging at biochemical recurrence in patients with PCa, where it has shown superior detection rates compared to previous imaging modalities. Apart from targeting PSMA for diagnostic purposes, there is a growing interest in developing ligands to target the PSMA-protein for radioligand therapy (RLT). PSMA-based RLT is a novel treatment that couples a PSMA-antibody to (alpha or beta-emitting) radionuclide, such as Lutetium-177 (
Lu), to deliver high radiation doses to tumor cells locally. Treatment with
Lu-PSMA RLT has demonstrated a superior overall survival rate within randomized clinical trials as compared to routine clinical care in patients with metastatic castration-resistant prostate cancer (mCRPC). The current review provides an overview of the literature regarding recent developments in nuclear medicine related to PSMA-targeted PET imaging and Theranostics.
Different nomograms exist for the preoperative prediction of pelvic lymph-node metastatic disease in individual patients with prostate cancer (PCa). These nomograms do not incorporate modern imaging ...techniques such as prostate-specific membrane antigen (PSMA) positron emission tomography (PET).
To determine the predictive performance of the Briganti 2017, Memorial Sloan Kettering Cancer Center (MSKCC), and Briganti 2019 nomograms with the addition of PSMA-PET in an international, multicenter, present-day cohort of patients undergoing robot-assisted radical prostatectomy (RARP) and extended pelvic lymph-node dissection (ePLND) for localized PCa.
All 757 eligible patients who underwent a PSMA-PET prior to RARP and ePLND in three reference centers for PCa surgery between January 2016 and November 2020 were included.
Performance of the three nomograms was assessed using the receiver operating characteristic curve–derived area under the curve (AUC), calibration plots, and decision curve analyses. Subsequently, recalibration and addition of PSMA-PET to the nomograms were performed.
Overall, 186/757 patients (25%) had pelvic lymph-node metastatic (pN1) disease on histopathological examination. AUCs of the Briganti 2017, MSKCC, and Briganti 2019 nomograms were 0.70 (95% confidence interval 95% CI: 0.64–0.77), 0.71 (95% CI: 0.65–0.77), and 0.76 (95% CI: 0.71–0.82), respectively. PSMA-PET findings showed a significant association with pN1 disease when added to the nomograms (p < 0.001). Addition of PSMA-PET substantially improved the discriminative ability of the models yielding cross-validated AUCs of 0.76 (95% CI: 0.70–0.82), 0.77 (95% CI: 0.72–0.83), and 0.82 (95% CI: 0.76–0.87), respectively. In decision curve analyses, the addition of PSMA-PET to the three nomograms resulted in increased net benefits.
The addition of PSMA-PET to the previously developed nomograms showed substantially improved predictive performance, which suggests that PSMA-PET is a likely future candidate for a modern predictive nomogram.
Different tools have been developed to individualize the prediction of prostate cancer spread to lymph nodes before surgery. We found that the inclusion of modern imaging (prostate-specific membrane antigen positron emission tomography) improved substantially the overall performance of these prediction tools.
The addition of prostate-specific membrane antigen positron emission tomography (PSMA-PET) to the previously developed nomograms for the prediction of pelvic lymph-node metastases showed substantially improved predictive performance, which suggests that PSMA-PET is a likely future candidate for a modern predictive nomogram.
In contemporary oncologic diagnostics, molecular imaging modalities are pivotal for precise local and metastatic staging. Recent studies identified fibroblast activation protein as a promising target ...for molecular imaging across various malignancies. Therefore, we aimed to systematically evaluate the current literature on the utility of fibroblast activation protein inhibitor (FAPI) PET/CT for staging patients with genitourinary malignancies.
A systematic Embase and Medline search was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) process, on August 1, 2023. Relevant publications reporting on the diagnostic value of FAPI PET/CT in genitourinary malignancies were identified and included. Studies were critically reviewed using a modified version of a tool for quality appraisal of case reports. Study results were summarized using a narrative approach.
We included 22 retrospective studies with a cumulative total of 69 patients, focusing on prostate cancer, urothelial carcinoma of the bladder and of the upper urinary tract, renal cell carcinoma, and testicular cancer. FAPI PET/CT was able to visualize both local and metastatic disease, including challenging cases such as prostate-specific membrane antigen (PSMA)-negative prostate cancer. Compared with radiolabeled
F-FDG and PSMA PET/CT, FAPI PET/CT showed heterogeneous performance. In selected cases, FAPI PET/CT demonstrated superior tumor visualization (i.e., better tumor-to-background ratios and visualization of small tumors or metastatic deposits visible in no other way) over
F-FDG PET/CT in detecting local or metastatic disease, whereas comparisons with PSMA PET/CT showed both superior and inferior performances. Challenges in FAPI PET/CT arise from physiologic urinary excretion of most FAPI radiotracers, hindering primary-lesion visualization in the bladder and upper urinary tract, despite generally providing high tumor-to-background ratios.
The current findings suggest that FAPI PET/CT may hold promise as a future tool to aid clinicians in detecting genitourinary malignancies. Given the substantial heterogeneity among the included studies and the limited number of patients, caution in interpreting these findings is warranted. Subsequent prospective and comparative investigations are anticipated to delve more deeply into this innovative imaging modality and elucidate its role in clinical practice.
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