18F-choline PET/MRI in suspected recurrence of prostate carcinoma

Comparison of MRI, PET, and 18F-choline PET/MRI in patients with oligometastatic recurrent prostate cancer

Objectives

The aims of the study were (i) to examine the PCa detection rate of 18F-choline (FCH) PET/MRI and (ii) to assess the impact of PET/MRI findings in patients with PCa who develop OMD using PSA response as a biomarker.

Methods

We retrospectively analyzed a cohort of 103 patients undergoing FCH PET/MRI for biochemical recurrence of PCa. The inclusion criteria were (1) previous radical prostatectomy (RP) with or without adjuvant radiotherapy (RT); (2) PSA levels available at the time of PET; (3) OMD, defined as a maximum of 5 lesions on PET/MRI; and (4) follow-up data available for at least 6 months after PET. All images were reviewed by two nuclear medicine physicians and interpreted with the support of two radiologists.

Results

Seventy patients were eligible for the study: 52 patients had a positive FCH PET/MRI and 18 had a negative scan. The overall PCa detection rates for MRI, PET, and PET/MRI were 65.7%, 37.1%, and 74.3%, respectively. Thirty-five patients were treated with radiotherapy (RT), 16 received hormonal therapy (HT), 3 had a combined therapy (RT + HT), and 16 (23%) underwent PSA surveillance. At follow-up, PSA levels decreased in 51 patients (73%), most of whom had been treated with RT or RT + HT. Therapeutic management was guided by PET/MRI in 74% of patients, which performed better than MRI alone (68% of patients).

Conclusion

FCH PET/MRI has a higher detection rate than MRI or PET alone for PCa patients with OMD and PSA levels > 0.5 ng/mL, prompting a better choice of treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00261-021-03131-7.

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.

Diagnostic value of retrospectively fused 64CuCl2 PET/MRI in biochemical relapse of prostate cancer: comparison with fused 18F-Choline PET/MRI, 64CuCl2 PET/CT, 18F-Choline PET/CT, and mpMRI

PURPOSE

To assess the diagnostic value of retrospectively fused PET/MRI by comparing the detection rates (DRs) of fused ⁶⁴CuCl₂ PET/MRI vs. fused ¹⁸F-Choline PET/MRI in patients with suspected prostatic cancer (PCa) recurrence. The secondary objective was to compare the DRs of fused PET/MRI vs. those of the separate imaging modalities.

METHODS

We retrospectively evaluated 50 PCa patients with biochemical relapse after radical prostatectomy (RP) or radiotherapy (RT). All patients underwent ⁶⁴CuCl₂ PET/CT, ¹⁸F-Choline PET/CT, and multiparametric magnetic resonance imaging (mpMRI) within 15 days. Fused ⁶⁴CuCl₂-PET/MRI and fused ¹⁸F-Choline PET/MRI images were obtained by retrospective co-registration of MRI and PET images. Experienced readers interpreted the images, and the DRs of each imaging modality were assessed.

RESULTS

In the patient-based analysis, overall DRs of fused ⁶⁴CuCl₂ PET/MRI, fused ¹⁸F-Choline PET/MRI, ⁶⁴CuCl₂ PET/CT, ¹⁸F-Choline PET/CT, and mpMRI were 88%, 68%, 82%, 56%, and 74%, respectively. In the lesion-based analysis, overall DRs of fused ⁶⁴CuCl₂ PET/MRI, fused ¹⁸F-Choline PET/MRI, ⁶⁴CuCl₂ PET/CT, ¹⁸ F-Choline PET/CT, and mpMRI were 95%, 66%, 87%, 58%, and 71%, respectively.

CONCLUSIONS

Retrospectively fused PET/MRI is able to overcome the limitations of the separate interpretation of the individual imaging modalities. Fused ⁶⁴CuCl₂ PET/MRI provided the highest diagnostic performance in the detection of PCa local relapse.

PET/MRI in prostate cancer: a systematic review and meta-analysis

Aim

In recent years, the clinical availability of scanners for integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) has enabled the practical potential of multimodal, combined metabolic-receptor, anatomical, and functional imaging to be explored. The present systematic review and meta-analysis summarize the diagnostic information provided by PET/MRI in patients with prostate cancer (PCa).

Materials and methods

A literature search was conducted in three different databases. The terms used were “choline” or “prostate-specific membrane antigen - PSMA” AND “prostate cancer” or “prostate” AND “PET/MRI” or “PET MRI” or “PET-MRI” or “positron emission tomography/magnetic resonance imaging.” All relevant records identified were combined, and the full texts were retrieved. Reports were excluded if (1) they did not consider hybrid PET/MRI; or (2) the sample size was < 10 patients; or (3) the raw data were not enough to enable the completion of a 2 × 2 contingency table.

Results

Fifty articles were eligible for systematic review, and 23 for meta-analysis. The pooled data concerned 2104 patients. Initial disease staging was the main indication for PET/MRI in 24 studies. Radiolabeled PSMA was the tracer most frequently used. In primary tumors, the pooled sensitivity for the patient-based analysis was 94.9%. At restaging, the pooled detection rate was 80.9% and was higher for radiolabeled PSMA than for choline (81.8% and 77.3%, respectively).

Conclusions

PET/MRI proved highly sensitive in detecting primary PCa, with a high detection rate for recurrent disease, particularly when radiolabeled PSMA was used.

Electronic supplementary material

The online version of this article (10.1007/s00259-020-05025-0) contains supplementary material, which is available to authorized users.