UK guidelines on 18F-fluciclovine PET/CT in prostate cancer imaging

Translation of PET radiotracers for cancer imaging: recommendations from the National Cancer Imaging Translational Accelerator (NCITA) consensus meeting

BACKGROUND

The clinical translation of positron emission tomography (PET) radiotracers for cancer management presents complex challenges. We have developed consensus-based recommendations for preclinical and clinical assessment of novel and established radiotracers, applied to image different cancer types, to improve the standardisation of translational methodologies and accelerate clinical implementation.

METHODS

A consensus process was developed using the RAND/UCLA Appropriateness Method (RAM) to gather insights from a multidisciplinary panel of 38 key stakeholders on the appropriateness of preclinical and clinical methodologies and stakeholder engagement for PET radiotracer translation. Panellists independently completed a consensus survey of 57 questions, rating each on a 9-point Likert scale. Subsequently, panellists attended a consensus meeting to discuss survey outcomes and readjust scores independently if desired. Survey items with median scores ≥ 7 were considered 'required/appropriate', ≤ 3 'not required/inappropriate', and 4-6 indicated 'uncertainty remained'. Consensus was determined as ~ 70% participant agreement on whether the item was 'required/appropriate' or 'not required/not appropriate'.

RESULTS

Consensus was achieved for 38 of 57 (67%) survey questions related to preclinical and clinical methodologies, and stakeholder engagement. For evaluating established radiotracers in new cancer types, in vitro and preclinical studies were considered unnecessary, clinical pharmacokinetic studies were considered appropriate, and clinical dosimetry and biodistribution studies were considered unnecessary, if sufficient previous data existed. There was 'agreement without consensus' that clinical repeatability and reproducibility studies are required while 'uncertainty remained' regarding the need for comparison studies. For novel radiotracers, in vitro and preclinical studies, such as dosimetry and/or biodistribution studies and tumour histological assessment were considered appropriate, as well as comprehensive clinical validation. Conversely, preclinical reproducibility studies were considered unnecessary and 'uncertainties remained' regarding preclinical pharmacokinetic and repeatability evaluation. Other consensus areas included standardisation of clinical study protocols, streamlined regulatory frameworks and patient and public involvement. While a centralised UK clinical imaging research infrastructure and open access federated data repository were considered necessary, there was 'agreement without consensus' regarding the requirement for a centralised UK preclinical imaging infrastructure.

CONCLUSIONS

We provide consensus-based recommendations, emphasising streamlined methodologies and regulatory frameworks, together with active stakeholder engagement, for improving PET radiotracer standardisation, reproducibility and clinical implementation in oncology.

Characterising 18F-fluciclovine uptake in breast cancer through the use of dynamic PET/CT imaging

BACKGROUND

18F-fluciclovine is a synthetic amino acid positron emission tomography (PET) radiotracer that is approved for use in prostate cancer. In this clinical study, we characterised the kinetic model best describing the uptake of 18F-fluciclovine in breast cancer and assessed differences in tracer kinetics and static parameters for different breast cancer receptor subtypes and tumour grades.

METHODS

Thirty-nine patients with pathologically proven breast cancer underwent 20-min dynamic PET/computed tomography imaging following the administration of 18F-fluciclovine. Uptake into primary breast tumours was evaluated using one- and two-tissue reversible compartmental kinetic models and static parameters.

RESULTS

A reversible one-tissue compartment model was shown to best describe tracer uptake in breast cancer. No significant differences were seen in kinetic or static parameters for different tumour receptor subtypes or grades. Kinetic and static parameters showed a good correlation.

CONCLUSIONS

18F-fluciclovine has potential in the imaging of primary breast cancer, but kinetic analysis may not have additional value over static measures of tracer uptake.

CLINICAL TRIAL REGISTRATION

NCT03036943.

Evaluation of the reporting quality of clinical practice guidelines on prostate cancer using the RIGHT checklist

Background

The International Reporting Items for Practice Guidelines in Healthcare (RIGHT) statement is a set of recommendations for reporting in clinical practice guidelines (CPGs). We aimed to use RIGHT to evaluate the reporting quality of CPGs on prostate cancer.

Methods

We systematically searched literature databases and websites from January 1, 2018 to December 1, 2020 to identify CPGs on prostate cancer. Two investigators reviewed the identified articles and assessed the reporting quality independently by using the RIGHT checklist. We reported the proportions of guidelines that complied with each of the 35 RIGHT checklist item and the mean reporting compliance percentages for each of the seven domains of RIGHT.

Results

A total of 38 CPGs were included. The mean overall reporting rate over the included CPGs was 51.6%. Eighteen items were reported by more than half of the guidelines four items (1a 3, 7a and 13a) were reported by all guidelines. Items 7b (10.5%), 13b (10.5%), 14c (13.2%), and 18b (7.9%) had the lowest reporting proportions. The mean reporting rates in each RIGHT domain were 74.6% for “Basic Information”, 26.3% for “Review and quality assurance”, 59.9% for “Background”, 43.7% for “Evidence”, 43.2% for “Recommendations”, 43.4% for “Funding and declaration and management of interests”, and 43.0% for “Other information”.

Conclusions

The overall adherence of CPGs on prostate cancer to RIGHT checklist is poor. Following the RIGHT checklist during the development of the guideline could improve the quality of reporting in the future.

Prostate Cancer Liver Metastases Presenting as Relatively Photopenic Lesions on 18F-Fluciclovine PET/CT

ABSTRACT

A 66-year-old man with prostate adenocarcinoma status post radical retropubic prostatectomy and bilateral pelvic lymph node dissection, followed by salvage external beam radiation therapy to the prostate bed 1 year after surgery. Over the course of 17 years, the patient underwent multiple lines of systemic treatment for recurrent disease. He was referred for restaging 18F-fluciclovine PET/CT due to rising serum prostate-specific antigen levels. Contrast-enhanced 18F-fluciclovine PET/CT images demonstrated multiple new liver metastases, which were relatively photopenic in comparison with the physiologic radiotracer activity in the surrounding normal liver parenchyma.

The use of systematic review evidence to support the development of guidelines for positron emission tomography: a cross-sectional survey

OBJECTIVES

To examine to what degree guidelines for PET and PET/CT used systematic review evidence.

METHODS

The latest version of guidelines for PET, PET/CT or PET/MRI published in English in PubMed until December 2019 was analysed in two categories: (1) for indications, if mainly discussing the appropriate use of PET in diverse conditions; (2) for procedures, if providing step-by-step instructions for imaging. We surveyed the general characteristics and the use of systematic review evidence for developing recommendations across all guidelines, and surveyed the citation of evidence for five recommendation topics in guidelines for procedures.

RESULTS

Forty-seven guidelines, published between 2004 and 2020, were included. Guidelines for indications were developed mainly on systematic reviews (13 of 19, 68.4%). Among those, 12 (63.2%) reported the level of evidence, 4 (21.1%) reported the strength of recommendations, 3 (15.8%) described external review and 7 (36.8%) involved methodologists. Guidelines for procedures were seldom developed on systematic reviews (1 of 27, 3.7%). Among those, 1 (3.7%) reported the level of evidence, 1 (3.7%) reported the strength of recommendations, 3 (11.1%) described external review and 1 (3.7%) involved methodologists. Systematic review evidence was cited by 2 (7.4%) procedure guidelines per recommendation topic in median.

CONCLUSION

The use of systematic review evidence for developing recommendations among PET or PET/CT guidelines was suboptimal. While our survey is an icebreaking attempt to explore a key element (i.e. use of systematic review evidence) for developing nuclear medicine guidelines, assessments of other domains of guideline quality may help capture the entire picture.

KEY POINTS

• The use of systematic review evidence for developing recommendations among guidelines for PET or PET/CT was suboptimal. • Only 13 (68.4%) guidelines for indications and 1 (3.7%) guideline for procedures systematically reviewed the literature during guideline development. • For each recommendation topic we examined, only a median of 2 (7.4%) procedure guidelines cited systematic review evidence.

Diagnostic performance of F-18 fluciclovine PET/CT in post-radical prostatectomy prostate cancer patients with rising prostate-specific antigen level ≤0.5 ng/mL

PURPOSE

The aim of the study was to assess the diagnostic performance of fluciclovine positron emission tomography (PET)/computerized tomography (CT) in post-radical prostatectomy prostate cancer patients with rising prostate-specific antigen (PSA) ≤0.5 ng/mL, and identify the associated predictive factors of positive studies.

PATIENTS AND METHODS

From 30 June 2017 to 9 August 2019, patients with post-radical prostatectomy prostate cancer who underwent F-18 fluciclovine PET/CT and had PSA level within 2-week interval (PSAPET) ≤0.5 ng/mL were enrolled into this single-institution retrospective study. Data on tumor characteristics, including Gleason scores, extra-prostatic extension, seminal vesicle invasion, surgical margin and nodal metastasis, PSA after radical prostatectomy, previous hormonal therapy, PSA doubling time (PSADT), scanner type, PSAPET and site of recurrence were collected. Comparison of these factors between groups of positive and negative fluciclovine PET/CT was done by using Mann-Whitney U-test and Fisher's exact test.

RESULTS

Of 94 eligible patients with post-radical prostatectomy prostate cancer, 10 patients had positive studies (10.6%). Detection rate at PSAPET 0.1, 0.2, 0.3, 0.4 and 0.5 ng/mL were 0% (0/11), 0% (0/15), 20% (6/30), 4% (1/25) and 23.1% (3/13), respectively. Upon multivariate analysis of clinical factors, only a PSADT <3 months (P = 0.023) was shown to have a statistically significant correlation with a positive study.

CONCLUSION

In post-radical prostatectomy prostate cancer patients with rising PSA 0.1-0.5 ng/mL, the sensitivity of F-18 fluciclovine PET/CT for identifying tumor recurrence/metastases is poor with an overall detection rate of 10.6%. Larger prospective studies are required to validate these findings.