Utility of 18F-Fluciclovine PET/MRI for Staging Newly Diagnosed High-Risk Prostate Cancer and Evaluating Response to Initial Androgen Deprivation Therapy: A Prospective Single-Arm Pilot Study

ACR Appropriateness Criteria® Post-Treatment Follow-up of Prostate Cancer: 2022 Update

Prostate cancer has a wide spectrum ranging between low-grade localized disease and castrate-resistant metastatic disease. Although whole gland and systematic therapies result in cure in the majority of patients, recurrent and metastatic prostate cancer can still occur. Imaging approaches including anatomic, functional, and molecular modalities are continuously expanding. Currently, recurrent and metastatic prostate cancer is grouped in three major categories: 1) Clinical concern for residual or recurrent disease after radical prostatectomy, 2) Clinical concern for residual or recurrent disease after nonsurgical local and pelvic treatments, and 3) Metastatic prostate cancer treated by systemic therapy (androgen deprivation therapy, chemotherapy, immunotherapy). This document is a review of the current literature regarding imaging in these settings and the resulting recommendations for imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Designing Intelligent Nanomaterials to Achieve Highly Sensitive Diagnoses and Multimodality Therapy of Bladder Cancer

Bladder cancer (BC) is among the most common malignant tumors of the genitourinary system worldwide. In recent years, the rate of BC incidence has increased, and the recurrence rate is high, resulting in poor quality of life for patients. Therefore, how to develop an effective method to achieve synchronous precise diagnoses and BC therapies is a difficult problem to solve clinically. Previous reports usually focus on the role of nanomaterials as drug delivery carriers, while a summary of the functional design and application of nanomaterials is lacking. Summarizing the application of functional nanomaterials in high-sensitivity diagnosis and multimodality therapy of BC is urgently needed. This review summarizes the application of nanotechnology in BC diagnosis, including the application of nanotechnology in the sensoring of BC biomarkers and their role in monitoring BC. In addition, conventional and combination therapies strategy in potential BC therapy are analyzed. Moreover, different kinds of nanomaterials in BC multimodal therapy according to pathological features of BC are also outlined. The goal of this review is to present an overview of the application of nanomaterials in the theranostics of BC to provide guidance for the application of functional nanomaterials to precisely diagnose and treat BC.

Management Impact of Metachronous Oligometastatic Disease Identified on 18F-Fluciclovine (Axumin™) PET/CT in Biochemically Recurrent Prostate Cancer

PURPOSE

We assessed the incidence rate and management impact of oligometastatic disease detected on ¹⁸F-fluciclovine (Axumin™) PET/CT in men with first biochemical recurrence (BCR) of prostate cancer (PCA) after definitive primary therapy.

METHODS AND MATERIALS

We retrospectively reviewed our clinical database for men with PCA who underwent ¹⁸F-fluciclovine PET/CT for imaging evaluation of BCR with negative or equivocal findings on conventional imaging. We included patients with up to and including 5 metastases (oligometastases) regardless of imaging evidence for local recurrence in the treated prostate bed. We examined the association between mean serum prostate specific antigen (PSA) levels with the number of oligometastases (non-parametric ANOVA) and between patients with or without local recurrence (Student t-test). The management impact of oligometastatic disease was tabulated.

RESULTS

We identified 21 patients with oligometastases upon first BCR (PSA 0.2-56.8 ng/mL) out of 89 eligible patients. There was a significant difference (p = 0.04) in the mean PSA levels between patients with local recurrence (n = 12) and those without local recurrence (n = 9). In the subgroup of analysis of patients without local recurrence, there was no significant association between mean PSA level and number of oligometastases (p = 0.83). Distribution of oligometastases included 66.7% isolated nodal disease and 33.3% bone only. Twelve (57.1%) patients had change in management to include change in ADT, salvage therapy, or both. Treatment change was initiated in 62.5%, 28.6%, 66.7%, 100%, and 100% of patients with 1, 2, 3, 4, and 5 oligometastatic lesions, respectively.

CONCLUSION

The incidence rate of oligometastatic disease in men with first BCR of PCA undergoing ¹⁸F-fluciclovine PET/CT for imaging evaluation of BCR was 23.6% in our eligible patient population. There was no significant association between serum PSA level and the number of oligometastases. Treatment management was affected in 57.1% of patients with oligometastases.

The role of MRI in prostate cancer: current and future directions

There has been an increasing role of magnetic resonance imaging (MRI) in the management of prostate cancer. MRI already plays an essential role in the detection and staging, with the introduction of functional MRI sequences. Recent advancements in radiomics and artificial intelligence are being tested to potentially improve detection, assessment of aggressiveness, and provide usefulness as a prognostic marker. MRI can improve pretreatment risk stratification and therefore selection of and follow-up of patients for active surveillance. MRI can also assist in guiding targeted biopsy, treatment planning and follow-up after treatment to assess local recurrence. MRI has gained importance in the evaluation of metastatic disease with emerging technology including whole-body MRI and integrated positron emission tomography/MRI, allowing for not only better detection but also quantification. The main goal of this article is to review the most recent advances on MRI in prostate cancer and provide insights into its potential clinical roles from the radiologist's perspective. In each of the sections, specific roles of MRI tailored to each clinical setting are discussed along with its strengths and weakness including already established material related to MRI and the introduction of recent advancements on MRI.

Defining Oligometastatic Disease in the New Era of PSMA-PET Imaging for Primary Staging of Prostate Cancer

Oligometastatic prostate cancer has traditionally been defined in the literature as a limited number of metastatic lesions (either to soft tissue or bone), typically based on findings seen on CT, MRI, and skeletal scintigraphy. Although definitions have varied among research studies, many important clinical trials have documented effective treatments and prognostication in patients with oligometastatic prostate cancer. In current clinical practice, prostate-specific membrane antigen (PSMA)-PET/CT is increasingly utilized for the initial staging of high-risk patients and, in many cases, detecting metastases that would have otherwise been undetected with conventional staging imaging. Thus, patients with presumed localized and/or oligometastatic prostate cancer undergo stage migration based on more novel molecular imaging. As a result, it is challenging to apply the data from the era before widespread PET utilization to current clinical practice and to relate current trials using PSMA-PET/CT for disease detection to older studies using conventional staging imaging alone. This manuscript aims to review the definition of oligometastatic prostate cancer, summarize important studies utilizing both PSMA-PET/CT and conventional anatomic imaging, discuss the concept of stage migration, and discuss current problems and challenges with the current definition of oligometastatic disease.

Molecular Imaging Assessment of Androgen Deprivation Therapy in Prostate Cancer

Hormonal therapy has long been recognized as a mainstay treatment for prostate cancer. New generation imaging agents have provided unprecedented opportunities at all phases along the natural history of prostate cancer. We review the literature on the effect of androgens and androgen deprivation therapy on prostate tumor at its various biological phases using the new generation molecular imaging agents in conjunction with positron emission tomography.

18F-Fluciclovine versus PSMA PET Imaging in Primary Tumor Detection during Initial Staging of High-Risk Prostate Cancer: A Systematic Review and Meta-Analysis

Purpose Fluorine 18 (¹⁸F)-fluciclovine and prostate-specific membrane antigen (PSMA) tracers are commonly used for localizing biochemical recurrence of prostate cancer, but their accuracy in primary tumor detection in the initial staging of high-risk prostate cancer has not been established. Materials and Methods A systematic review was performed of the electronic databases for original studies published between 2012 and 2020. Included studies were those in which ¹⁸F-fluciclovine or PSMA PET was used for initial staging of patients with high-risk prostate cancer. The diagnostic performance data were collected for primary tumor with histopathologic results as reference standard. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used for quality appraisal. A random-effects model was used to summarize the effect sizes and to evaluate the difference between two groups. Results Overall, 28 studies met the eligibility criteria, and 17 were included in the meta-analysis (¹⁸F-fluciclovine = 4, PSMA = 13). Of these 17 studies, 12 (70%) were judged to have high risk of bias in one of the evaluated domains, and nine studies were deemed to have applicability concerns. The pooled sensitivity, specificity, and diagnostic odds ratio for ¹⁸F-fluciclovine versus PSMA were 85% (95% CI: 73%, 92%) versus 84% (95% CI: 77%, 89%) (P = .78), 77% (95% CI: 60%, 88%) versus 83% (95% CI: 76%, 89%) (P = .40), and 18.88 (95% CI: 5.01, 71.20) versus 29.37 (95% CI: 13.35, 64.60) (P = .57), respectively, with no significant difference in diagnostic test accuracy. Conclusion ¹⁸F-fluciclovine and PSMA PET demonstrated no statistically significant difference in diagnostic accuracy in primary tumor detection during initial staging of high-risk prostate cancer. Keywords: PET, Prostate, Molecular Imaging-Cancer, Staging Supplemental material is available for this article. © RSNA, 2022.

Defining Diagnostic Criteria for Prostatic Ductal Adenocarcinoma at Multiparametric MRI

Background Prostatic ductal adenocarcinoma (DAC) is an aggressive histologic variant of prostate cancer that often warrants multimodal therapy and poses a significant diagnostic challenge clinically and at imaging. Purpose To develop multiparametric MRI criteria to define DAC and to assess their diagnostic performance in differentiating DAC from prostatic acinar adenocarcinoma (PAC). Materials and Methods Men with histologically proven DAC who had multiparametric MRI before radical prostatectomy were retrospectively identified from January 2011 through November 2018. MRI features were predefined using a subset of nine DACs and then compared for men with peripheral-zone DACs 1 cm or greater in size and men with matched biopsy-confirmed International Society of Urological Pathology grade group 4-5 PAC, by four independent radiologists blinded to the pathologic diagnosis. Diagnostic performance was determined by consensus read. Patient and tumor characteristics were compared by using the Fisher test, t-tests, and Mann-Whitney U test. Agreement (Cohen κ) and sensitivity analyses were also performed. Results There were 59 men with DAC (median age, 63 years [interquartile range, 56, 67 years]) and 59 men with PAC (median age, 64 years [interquartile range, 59, 69 years]). Predefined MRI features, including intermediate T2 signal, well-defined margin, lobulation, and hypointense rim, were detected in a higher proportion of DACs than PACs (76% [45 of 59] vs 5% [three of 59]; P < .001). On consensus reading, the presence of three or more features demonstrated 76% sensitivity, 94% specificity, 94% positive predictive value [PPV], and 80% negative predictive value [NPV] for all DACs and 100% sensitivity, 95% specificity, 81% PPV, and 100% NPV for pure DACs. The DACs and PACs showed no difference in contrast enhancement (100% vs 100%; P >.99, median T2 signal intensity (254 vs 230; P = .99), or apparent diffusion coefficient (median, 677 10^-6 mm²/sec vs 685 10^-6 mm²/sec; P = .73). Conclusion The presence of intermediate T2 signal, well-defined margin, lobulation, and/or hypointense rim, together with restricted diffusion and contrast enhancement at multiparametric MRI of the prostate, suggests prostatic ductal adenocarcinoma rather than prostatic acinar adenocarcinoma. © RSNA, 2022 Online supplemental material is available for this article.

Role of molecular imaging in the detection of localized prostate cancer

Molecular imaging of prostate cancer continues to grow, with recent inclusion of several positron emission tomography (PET) radiotracers into the recent National Comprehensive Cancer Network guidelines and the US Food and Drug Administration approval of prostate-specific membrane antigen (PSMA)-targeted radiotracers. While much of the work for many of these radiotracers is focused on systemic staging and restaging in both newly diagnosed high-risk prostate cancer and biochemically recurrent disease patients, the potential role of molecular imaging for the detection of localized prostate cancer has not yet been fully established. The primary aim of this article will be to present the potential role for molecular imaging in the detection of localized prostate cancer and discuss potential advantages and disadvantages to utilization of both PET/computed tomography (CT) and PET/magnetic resonance imaging (MRI) for this clinical indication of use.

Validating Modern NRG Oncology Pelvic Nodal and Groupe Francophone de Radiothérapie Urologique Prostate Bed Contouring Guidelines for Post-Prostatectomy Salvage Radiation: A Secondary Analysis of the LOCATE Trial

PURPOSE

We used the patterns of recurrence on ¹⁸F-fluciclovine positron emission tomography (PET)-computed tomography (CT) in patients enrolled in the LOCATE trial after prostatectomy to evaluate how well the most recent NRG Oncology and Groupe Francophone de Radiothérapie Urologique (GFRU) contouring recommendations encompassed all sites of recurrence in the prostate fossa and pelvic nodes in comparison to former Radiation Therapy Oncology Group (RTOG) recommendations.

METHODS AND MATERIALS

Patients with biochemically recurrent prostate cancer after radical prostatectomy with a positive finding within the prostate fossa or pelvic nodes on ¹⁸F-fluciclovine PET/CTs were identified from the LOCATE patient population. Areas of gross disease were delineated. Prostate fossa contours were delineated using both the 2010 RTOG consensus guidelines and the recently published 2020 GFRU consensus guidelines. Pelvic nodes were contoured with both the 2009 RTOG consensus guidelines and the 2020 NRG consensus guidelines. The performance of the contouring guidelines was assessed by determining what proportion of gross recurrent lesions were encompassed completely or marginally.

RESULTS

Of the 213 patients within the LOCATE trial, 45 patients were eligible for analysis with positive ¹⁸F-fluciclovine PET findings. Of the 30 total prostate fossa recurrences, the 2010 RTOG contour covered 20 (67%) and missed or marginally covered 10 (33%). The 2020 GFRU contour covered 27 recurrences (90%), and missed or marginally covered 3 (10%). Of the 43 total nodal recurrences, the 2009 RTOG pelvic nodal contour covered 29 nodes (67%), and missed or marginally covered 14 (32%). The 2020 NRG pelvic nodal contour covered 43 nodes (100%), with no misses or marginal coverage.

CONCLUSIONS

This secondary analysis of the LOCATE trial exemplifies the improved coverage of the latest prostate fossa contouring recommendations from the GFRU. Similarly, it also validates the updated 2020 NRG pelvic nodal contouring guidelines by demonstrating improved coverage of recurrent disease in this patient population.

[18F]-Fluciclovine PET/CT for preoperative nodal staging in high-risk primary prostate cancer: final results of a prospective trial

PURPOSE

The conventional imaging flowchart for prostate cancer (PCa) staging may fail in correctly detecting lymph node metastases (LNM). Pelvic lymph node dissection (PLND) represents the only reliable method, although invasive. A new amino acid PET compound, [18F]-fluciclovine, was recently authorized in suspected PCa recurrence but not yet included in the standard staging work-up of primary PCa. A prospective monocentric study was designed to evaluate [18F]-fluciclovine PET/CT diagnostic performance for preoperative LN staging in primary high-risk PCa.

METHODS

Consecutive patients (pts) with biopsy-proven PCa, standard staging (including [11C]choline PET/CT), eligible for PLND, were enrolled to undergo an investigational [18F]-fluciclovine PET/CT. Nodal uptake higher than surrounding background was reported by at least two readers (blinded to [11C]choline) using a visual 5-point scale (1-2 probably negative; 4-5 probably positive; 3 equivocal); SUVmax, target-to-background (aorta-A; bone marrow-BM) ratios (TBRs), were also calculated. PET results were validated with PLND. [18F]-fluciclovine PET/CT performance using visual score and semi-quantitative indexes was analyzed both per patient and per LN anatomical region, compared to conventional [11C]choline and clinical predictive factors (to note that diagnostic performance of [18F]-fluciclovine was explored for LNM but not examined for intrapelvic or extrapelvic M1 lesions).

RESULTS

Overall, 94 pts underwent [18F]-fluciclovine PET/CT; 72/94 (77%) high-risk pts were included in the final analyses (22 pts excluded: 8 limited PLND; 3 intermediate-risk; 2 treated with radiotherapy; 4 found to be M1; 5 neoadjuvant hormonal therapy). Median LNM risk by Briganti nomogram was 19%. LNM confirmed on histology was 25% (18/72 pts). Overall, 1671 LN were retrieved; 45/1671 (3%) LNM detected. Per pt, median no. of removed LN was 22 (mean 23 ± 10; range 8-51), of LNM was 2 (mean 3 ± 2; range 1-10). Median LNM size was 5 mm (mean 5 ± 2.5; range 2-10). On patient-based analyses (n = 72), diagnostic performance for LNM resulted significant with [18F]-fluciclovine (AUC 0.66, p 0.04; 50% sensitivity, 81% specificity, 47% PPV, 83% NPV, 74% accuracy), but not with [11C]choline (AUC 0.60, p 0.2; 50%, 70%, 36%, 81%, and 65% respectively). Briganti nomogram (OR = 1.03, p = 0.04) and [18F]-fluciclovine visual score (≥ 4) (OR = 4.27, p = 0.02) resulted independent predictors of LNM at multivariable analyses. On region-based semi-quantitative analyses (n = 576), PET/CT performed better using TBR parameters (TBR-A similar to TBR-BM; TBR-A fluciclovine AUC 0.61, p 0.35, vs choline AUC 0.57 p 0.54; TBR-BM fluciclovine AUC 0.61, p 0.36, vs choline AUC 0.58, p 0.52) rather than using absolute LN SUVmax (fluciclovine AUC 0.51, p 0.91, vs choline AUC 0.51, p 0.94). However, in all cases, diagnostic performance was not statistically significant for LNM detection, although slightly in favor of the experimental tracer [18F]-fluciclovine for each parameter. On the contrary, visual interpretation significantly outperformed PET semi-quantitative parameters (choline and fluciclovine: AUC 0.65 and 0.64 respectively; p 0.03) and represents an independent predictive factor of LNM with both tracers, in particular [18F]-fluciclovine (OR = 8.70, p 0.002, vs OR = 3.98, p = 0.03).

CONCLUSION

In high-risk primary PCa, [18F]-fluciclovine demonstrates some advantages compared with [11C]choline but sensitivity for metastatic LN detection is still inadequate compared to PLND. Visual (combined morphological and functional), compared to semi-quantitative assessment, is promising but relies mainly on readers' experience rather than on unquestionable LN avidity.

TRIAL REGISTRATION

EudraCT number: 2014-003,165-15.

MRI/PET Imaging in elevated PSA and localized prostate cancer: a narrative review

Objective

To review the recent milestones in MRI and PET based imaging and evaluate their evolving role in the setting of elevated PSA as well as localized prostate cancer.

Background

The importance of multiparametric MRI (mpMRI) and PET based imaging for the diagnosis and staging of prostate cancer cannot be understated. Accurate staging has become another significant milestone with the use of PET scans, particularly with prostate specific radiotracers like 68-Gallium Prostate Specific Membrane Antigen (68Ga-PSMA). Integrated PET/MRI systems are commercially available and can be modulated to evaluate the unique needs of localized as well as recurrent prostate cancer.

Methods

A literature search was performed using PubMed and Google Scholar using the MeSH compliant and other keywords that included prostate cancer, PSA, mpMRI, PET CT, PET/MRI.

Conclusions

mpMRI has now established itself as the gold-standard of local prostate imaging and has been incorporated into international guidelines as part of the diagnostic work-up of prostate cancer. PSMA PET/CT has shown superiority over conventional imaging even in staging of localized prostate cancer based on recent randomized control data. Imaging parameters from PET/MRI have been shown to be associated with malignancy, Gleason score and tumour volume. As mpMRI and PSMA PET/CT become more ubiquitous and established; we can anticipate more high-quality data, cost optimization and increasing availability of PET/MRI to be ready for primetime in localized prostate cancer.

Nanotechnology in Bladder Cancer: Diagnosis and Treatment

Bladder cancer (BC) is the second most common cancer of the urinary tract in men and the fourth most common cancer in women, and its incidence rises with age. There are many conventional methods for diagnosis and treatment of BC. There are some current biomarkers and clinical tests for the diagnosis and treatment of BC. For example, radiotherapy combined with chemotherapy and surgical, but residual tumor cells mostly cause tumor recurrence. In addition, chemotherapy after transurethral resection causes high side effects, and lack of selectivity, and low sensitivity in sensing. Therefore, it is essential to improve new procedures for the diagnosis and treatment of BC. Nanotechnology has recently sparked an interest in a variety of areas, including medicine, chemistry, physics, and biology. Nanoparticles (NP) have been used in tumor therapies as appropriate tools for enhancing drug delivery efficacy and enabling therapeutic performance. It is noteworthy, nanomaterial could be reduced the limitation of conventional cancer diagnosis and treatments. Since, the major disadvantages of therapeutic drugs are their insolubility in an aqueous solvent, for instance, paclitaxel (PTX) is one of the important therapeutic agents utilized to treating BC, due to its ability to prevent cancer cell growth. However, its major problem is the poor solubility, which has confirmed to be a challenge when improving stable formulations for BC treatment. In order to reduce this challenge, anti-cancer drugs can be loaded into NPs that can improve water solubility. In our review, we state several nanosystem, which can effective and useful for the diagnosis, treatment of BC. We investigate the function of metal NPs, polymeric NPs, liposomes, and exosomes accompanied therapeutic agents for BC Therapy, and then focused on the potential of nanotechnology to improve conventional approaches in sensing.