Impact of sodium 18F-fluoride PET/CT, 18F-fluorocholine PET/CT and whole-body diffusion-weighted MRI on the management of patients with prostate cancer suspicious for metastasis: a prospective multicentre study

ACR Appropriateness Criteria® Pretreatment Detection, Surveillance, and Staging of Prostate Cancer: 2022 Update

Prostate cancer is second leading cause of death from malignancy after lung cancer in American men. The primary goal during pretreatment evaluation of prostate cancer is disease detection, localization, establishing disease extent (both local and distant), and evaluating aggressiveness, which are the driving factors of patient outcomes such as recurrence and survival. Prostate cancer is typically diagnosed after the recognizing elevated serum prostate-specific antigen level or abnormal digital rectal examination. Tissue diagnosis is obtained by transrectal ultrasound-guided biopsy or MRI-targeted biopsy, commonly with multiparametric MRI without or with intravenous contrast, which has recently been established as standard of care for detecting, localizing, and assessing local extent of prostate cancer. Although bone scintigraphy and CT are still typically used to detect bone and nodal metastases in patients with intermediate- or high-risk prostate cancer, novel advanced imaging modalities including prostatespecific membrane antigen PET/CT and whole-body MRI are being more frequently utilized for this purpose with improved detection rates. The ACR 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.

Prospective study of Na[18F]F PET/CT for cancer staging in morbidly obese patients compared with [99mTc]Tc-MDP whole-body planar, SPECT and SPECT/CT

PURPOSE

This prospective study aims to assess the diagnostic test characteristics of Na[¹⁸F]F PET/CT for the skeletal staging of cancer in morbidly obese patients compared with ^99mTc-methylene diphosphonate (MDP), whole-body planar (WBS), SPECT, and SPECT/CT acquisitions.

MATERIAL AND METHODS

One hundred seventeen obese patients (BMI 46.5 ± 6.1 kg/m² and mean age, 59.0 years; range 32-89 years) with BMI > 40 kg/m² were prospectively enrolled and underwent [^99mTc]Tc-MDP WBS, SPECT, SPECT/CT, and Na[¹⁸F]F PET/CT within two weeks for the osseous staging of a malignancy. Images were assessed qualitatively using a 3-point scale. Patient and lesion-based diagnostic test characteristics were estimated using an optimistic and pessimistic dichotomization method.

RESULTS

Bone metastases were confirmed in 44 patients. Patient-based optimistic diagnostic test characteristics were (sensitivity, specificity, overall accuracy): Na[¹⁸F]F PET/CT (95.5%, 95.9%, 95.7%), [^99mTc]Tc-MDP WBS (52.3%, 71.2%, 64.1%), SPECT (61.4%, 80.8%, 73.5%) and SPECT/CT (65.9%, 91.8%, 82.1%). Lesion-based optimistic diagnostic test characteristics were: Na[¹⁸F]F PET/CT (97.7%, 97.9%, 97.7%), [^99mTc]Tc-MDP WBS (39%, 67%, 48.9%), SPECT (52.9%, 93.6%, 67.3%) and SPECT/CT (65.9%, 91.8%, 82.1%). There was no significant difference in the specificity of Na[¹⁸F]F and SPECT/CT. All other pairwise comparisons were significant (p<.001). ROC curve analysis showed a high overall accuracy of Na[¹⁸F]F with significantly higher AUCs for Na[¹⁸F]F PET/CT compared to [^99mTc]Tc-MDP WBS, SPECT, and SPECT/CT on both patient and lesion-based analysis (p<.001). Moreover, Na[¹⁸F]F PET/CT changed patient management in 38% of patients.

CONCLUSIONS

Na[¹⁸F]F PET/CT may be the preferred imaging modality for skeletal staging in morbidly obese patients. The technique provides excellent diagnostic test characteristics superior to [^99mTc]Tc-MDP bone scan (including SPECT/CT), impacts patient management, has an acceptable radiation exposure profile, and is well-tolerated. Further cost-effectiveness evaluations are warranted.

Use of 18F-NaF PET in the staging of skeletal metastases of newly diagnosed, high-risk prostate cancer patients: a nationwide cohort study

OBJECTIVE

To determine whether preoperative staging of high-risk prostate cancer with ¹⁸F-sodium-fluoride (¹⁸F-NaF) positron emission tomography (PET) reduces the risk of skeletal metastases.

DESIGN

Nationwide, population-based cohort study using real-world data.

SETTING

The study used national health registries, including all sites in Denmark from 2011 to 2018.

PARTICIPANTS

Newly diagnosed high-risk prostate cancer patients who underwent radical prostatectomy from 2011 to 2018. Patients were stratified into two groups according to the preoperative imaging modality of either ¹⁸F-NaF PET or bone scintigraphy.

MAIN OUTCOME MEASURES

The risk of skeletal-related events (SREs) as a proxy for skeletal metastases following radical prostatectomy. The secondary endpoint was overall survival.

RESULTS

Between 1 January 2011 and 31 December 2018, 4183 high-risk patients underwent radical prostatectomy. Of these patients, 807 (19.3%) underwent ¹⁸F-NaF PET and 2161 (51.7%) underwent bone scintigraphy. The remaining 30% were examined by a different imaging method or did not undergo imaging. Using the inverse probability of treatment weighting to control potential confounding, the HR of experiencing an SRE for patients in the ¹⁸F-NaF PET group versus the bone scintigraphy group was 1.15 (95% CI 0.86 to 1.54). The 3-year survival rates were 97.4% (95% CI 96.1 to 98.7) and 97.1% (95% CI 96.4 to 97.9) for patients receiving ¹⁸F-NaF PET and bone scintigraphy, respectively.

CONCLUSION

Patients with high-risk prostate cancer undergoing preoperative staging with ¹⁸F-NaF PET did not display a lower risk of developing SREs after prostatectomy compared with patients undergoing bone scintigraphy. The survival rates were similar between the two groups.

Narrative review of PET/CT performances at biochemical recurrence in prostate cancer after radical prostatectomy and impact on patient disease management: Revue narrative à propos des performances de la TEP/TDM en cas de récidive biochimique après prostatectomie radicale dans le cancer de la prostate et impact sur la prise en charge des patients

Patients treated by radical prostatectomy (RP) for localized prostate cancer (PCa) may experience biochemical recurrence (BCR) in approximately 30% of cases. Recently, advances in imaging modalities and in particular Positron-Emission Tomography with computed tomography (PET/CT) imaging allow for better detection and characterization of lesions outside the prostatic bed at recurrence. Thus, treatment at BCR can be significantly improved by a tailored strategy based on new generation imaging. A more precise and accurate staging of the disease at recurrence paves the way to more appropriate treatment, potentially translating into better survival outcomes of these patients. This review therefore highlights the interest of PET/CT at the time of BCR, its superiority over standard imaging in terms of staging, and its impact on guiding the different therapeutic possibilities depending on the site, number, and volumes of recurrence. Indeed, we will discuss below about different strategies and their indications: salvage radiotherapy of the prostate bed, systemic therapies, stereotactic body radiotherapy and others therapeutical strategies. The various innovative approaches based on PET/CT implementation are partly underway within protocol trials to prove their benefits on clinically meaningful endpoints. © 2022 Elsevier Masson SAS. All rights reserved.

Whole-Body MRI vs. PET/CT for the Detection of Bone Metastases in Patients With Prostate Cancer: A Systematic Review and Meta-Analysis

Purpose: A recent meta-analysis in patients with non-small cell lung cancer showed no difference between whole-body magnetic resonance imaging (WBMRI) and positron emission tomography/computed tomography (PET/CT), but no such study is available for prostate cancer (PCa). This study aimed to compare WBMRI and PET/CT for bone metastasis detection in patients with PCa.

Materials and Methods: PubMed, Embase, and the Cochrane library were searched for papers published up to April 2020. The population was the patients with untreated prostate cancer diagnosed by WBMRI or PET/CT. The outcomes were the true positive and negative and false positive and negative rates for WBMRI and PET/CT. The summarized sensitivity, specificity, positive likelihood ratios (PLR), negative likelihood ratios (NLR), and diagnostic odds ratios (DOR) were calculated with their 95% confidence intervals (CIs).

Results: Four prospective and one retrospective study are included (657 patients). Significant differences are observed between WBMRI and PET/CT for sensitivity (WBMRI/PET/CT: 0.896; 95% CI: 0.813–0.987; P = 0.025) and NLR (WBMRI/PET/CT: 2.38; 95% CI: 1.13–5.01; P = 0.023), but not for specificity (WBMRI/PET/CT: 0.939; 95% CI: 0.855–1.031; P = 0.184) and PLR (WBMRI/PET/CT: 0.42; 95% CI: 0.08–2.22; P = 0.305). WBMRI has a similar a DOR compared with PET/CT (WBMRI/PET/CT: 0.13; 95% CI: 0.02–1.11; P = 0.062). The summary area under the receiver operating characteristic curves for WBMRI is 0.88 (standard error: 0.032) and 0.98 (standard error: 0.013) for PET/CT for diagnosing bone metastases in PCa.

Conclusion: PET/CT presents a higher sensitivity and NLR for the bone metastasis detection from PCa, whereas no differences are found for specificity and PLR, compared with WBMRI.

Comparison of 18F-sodium fluoride PET/CT, 18F-fluorocholine PET/CT and diffusion-weighted MRI for the detection of bone metastases in recurrent prostate cancer: a cost-effectiveness analysis in France

Background

The diagnostic performance of ¹⁸F-sodium fluoride positron emission tomography/computed tomography (PET/CT) (NaF), ¹⁸F-fluorocholine PET/CT (FCH) and diffusion-weighted whole-body magnetic resonance imaging (DW-MRI) in detecting bone metastases in prostate cancer (PCa) patients with first biochemical recurrence (BCR) has already been published, but their cost-effectiveness in this indication have never been compared.

Methods

We performed trial-based and model-based economic evaluations. In the trial, PCa patients with first BCR after previous definitive treatment were prospectively included. Imaging readings were performed both on-site by local specialists and centrally by experts. The economic evaluation extrapolated the diagnostic performances of the imaging techniques using a combination of a decision tree and Markov model based on the natural history of PCa. The health states were non-metastatic and metastatic BCR, non-metastatic and metastatic castration-resistant prostate cancer and death. The state-transition probabilities and utilities associated with each health state were derived from the literature. Real costs were extracted from the National Cost Study of hospital costs and the social health insurance cost schedule.

Results

There was no significant difference in diagnostic performance among the 3 imaging modalities in detecting bone metastases. FCH was the most cost-effective imaging modality above a threshold incremental cost-effectiveness ratio of 3000€/QALY when imaging was interpreted by local specialists and 9000€/QALY when imaging was interpreted by experts.

Conclusions

FCH had a better incremental effect on QALY, independent of imaging reading and should be preferred for detecting bone metastases in patients with biochemical recurrence of prostate cancer.

Trial registration

NCT01501630. Registered 29 December 2011.

Observer Agreement and Accuracy of 18F-Sodium Fluoride PET/CT in the Diagnosis of Bone Metastases in Prostate Cancer

Our aim was to evaluate the interobserver agreement in ¹⁸F-sodium fluoride (NaF) PET/CT for the detection of bone metastases in patients with prostate cancer (PCa). Methods: ¹⁸F-NaF PET/CT scans were retrieved from all patients who participated in 4 recent prospective trials. Two experienced observers independently evaluated the ¹⁸F-NaF PET/CT scans on a patient level using a 3-category scale (no bone metastases [M0], equivocal for bone metastases, and bone metastases present [M1]) and on a dichotomous scale (M0/M1). In patients with no more than 10 lesions, the location and number of lesions were recorded. On a patient level, the diagnostic performance was calculated using a sensitivity analysis, in which equivocal lesions were handled as M0 as well as M1. Results: ¹⁸F-NaF PET/CT scans from 219 patients with PCa were included, of whom 129 patients were scanned for primary staging, 67 for biochemical recurrence, and 23 for metastatic castration-resistant PCa. Agreement between the observers was almost perfect on a patient level (3-category unweighted κ = 0.83 ± 0.05, linear weighted κ = 0.90 ± 0.06, and dichotomous κ = 0.91 ± 0.07). On a lesion level (dichotomous scale), the observers agreed on the number and location of bone metastases in 205 (93.6%) patients. In the remaining 14 patients, the readers disagreed on the number of lesions in 13 patients and the location of bone metastases in 1 patient. A final diagnosis of bone metastases was made for 211 of 219 patients. The sensitivity ranged from 0.86 to 0.92, specificity from 0.83 to 0.97, positive predictive value from 0.70 to 0.93, and negative predictive value from 0.94 to 0.96. Conclusion: The interobserver agreement on ¹⁸F-NaF PET/CT for the detection of bone metastases in patients with PCa was very high among trained observers, both on a patient level and on a lesion level. Moreover, the diagnostic performance of ¹⁸F-NaF PET/CT was satisfactory, rendering ¹⁸F-NaF PET/CT a robust tool in the diagnostic armamentarium.