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Updated: Jun 4, 2025

A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound
Published on: March 21, 2025
Is there a comparable Mp-MRI for incidental prostate uptake on 18 F-FDG PET/CT?
Merve Şam Özdemir1, Nurullah Kaya2, Metin Savun3
1Department of Radiology, Başaksehir Çam and Sakura City Hospital, Istanbul, Turkey. mervesam@msn.com.
Purpose:
Although 18 F-FDG-PET/CT is helpful in defining many types of cancer, localized prostate cancer should not be treated with this technique. This study describes the use of multi-parametric MRI (mpMRI) to characterize incidental 18 F-FDG uptake in the prostate.
Methods And Materials:
While 18 F-FDG-PET/CT is useful for characterizing a variety of cancers, it is not advised for prostate cancer that is localized. This work investigates the use of mpMRI to describe incidental 18 F-FDG uptake in the prostate.mpMRI included T2-weighted (T2W), dynamic contrast enhancement (DCE), and apparent diffusion coefficient (ADC) sequences. Patients were classified according to PI-RADS (Prostate Imaging Reporting and Data System) version 2.1 by an experienced uroradiologist, and 18 F-FDG-PET was evaluated to determine whether the area of involvement on CT had a counterpart in mpMRI. A biopsy was performed on 30 of the 92 patients. These patients' maximum standardized uptake values (SUVmax) 6 < and ≥ 6, PS(PSA) density 0.15 < and ≥ 0.15, PSA level, uptake pattern (focal involvement/diffuse involvement), and PI-RADS scores were compared. P < .05 was considered statistically significant. Logistic regression was used to analyze PI-RADS score groups age, PSA, PSA density and SUVmax.
Results:
In the study, 92 patients with incidental 18 F-FDG-PET/CT prostate uptake were examined. Median age was 66, PSA median was 3.6 ng/ml (range: 0-3198 ng/ml). Notably, in 70.6% of cases, PET/CT uptake didn't correlate with mp-MRI findings. Among PI-RADS 3-4-5 patients (29.3%), there was a correlation. Biopsies in 30 patients revealed 43.3% benign, 56.7% malignant. Significant differences between benign and malignant cases were observed in PSA density, PI-RADS scores, and PSA levels (p < .05), while SUVmax and uptake pattern were not significant. In multivariate logistic regression analysis, PI-RADS score groups were found to be independent risk factors for predicting malignancy.
Conclusions:
Our study showed that incidental 18 F-FDG-PET/CT prostate uptake was detected and that high PSA density values, PI-RADS scores, and PSA values, such as in routine patients, and not PET-CT findings such as SUVmax and uptake pattern, were more predictive of malignancy.
Insights
Incidental prostate 18F-FDG-PET/CT uptake is not always indicative of cancer. Multi-parametric MRI (mpMRI) and Prostate Imaging Reporting and Data System (PI-RADS) scores are more reliable predictors of malignancy than PET/CT findings alone.
Area of Science:
- Radiology
- Oncology
- Medical Imaging
Background:
- 18F-FDG-PET/CT is valuable for many cancers but not recommended for localized prostate cancer.
- Incidental findings of 18F-FDG uptake in the prostate require further characterization.
- Multi-parametric MRI (mpMRI) offers detailed prostate imaging.
Purpose of the Study:
- To investigate the utility of mpMRI in characterizing incidental 18F-FDG uptake in the prostate.
- To compare the predictive value of mpMRI findings versus 18F-FDG-PET/CT metrics for prostate cancer malignancy.
Main Methods:
- Evaluated 92 patients with incidental 18F-FDG-PET/CT prostate uptake.
- Utilized mpMRI sequences (T2W, DCE, ADC) and PI-RADS v2.1 scoring.
- Correlated PET/CT findings (SUVmax, uptake pattern) with mpMRI and biopsy results in 30 patients.
Main Results:
- 70.6% of incidental 18F-FDG uptake did not correlate with mpMRI findings.
- Correlation was observed in PI-RADS 3-5 lesions (29.3%).
- Biopsies showed 56.7% malignancy; PSA density, PSA levels, and PI-RADS scores were significant predictors, unlike SUVmax or uptake pattern.
Conclusions:
- Incidental 18F-FDG-PET/CT prostate uptake requires careful interpretation.
- High PSA density, PSA levels, and PI-RADS scores are more predictive of malignancy than PET/CT findings.
- mpMRI plays a crucial role in evaluating incidental prostate 18F-FDG uptake.
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