Accuracy of standard clinical 3T prostate MRI for pelvic lymph node staging: Comparison to 68Ga-PSMA PET-CT

Abstract

The aim was to assess the performance of prostate 3T MRI for pelvic lymph node (LN) staging in prostate cancer (PCa), in comparison to 68 Gallium-prostate specific membrane antigen PET-CT ( 68 Ga-PSMA PET-CT) as reference standard for LN detection. 130 patients with PCa underwent non-contrast-enhanced multiparametric prostate 3T MRI and 68 Ga-PSMA-PET-CT within 180 days at our institution. Overall, 187 LN metastases (n = 43 patients) detected by 68 Ga-PSMA-PET-CT were characterized by calculating maximum standardized uptake value (SUVmax), area, diameter and anatomical location including iliac, obturator, presacral and inguinal region. MRI achieved an overall sensitivity, specificity, positive and negative predictive value of 81.6% (CI 71.1–88.9%), 98.6% (CI 97.6–99.2%), 73.5% (CI 52.1–87.6%) and 99.5% (CI 98.8–99.8%), respectively. On a region-based analysis, detection rates differed non-significantly (ps > 0.12) in the anatomical regions. On a size-dependent analysis, detection of LN > 10 mm did not differ significantly (ps > 0.09) from LN ≤ 10 mm. In comparison to single T1 sequence evaluation, additional use of the T2 weighted sequences did not improve the overall performance significantly (p > 0.05). 3T prostate MRI represented an accurate tool for the detection of LN compared to 68 Ga-PSMA-PET-CT. Especially for LN metastases smaller than 10 mm, MRI was less accurate compared to 68 Ga-PSMA-PET-CT.

Intraindividual comparison between 68Ga-PSMA-PET/CT and mpMRI for intraprostatic tumor delineation in patients with primary prostate cancer: a retrospective analysis in 101 patients

“…Hence, merely in patients with large tumor volumes in mpMRI, 68 Ga-PSMA-PET/CT might give little complimentary information. However, these patients bear a high risk for lymph node or distant metastases [32], and 68 Ga-PSMA-PET shows high sensitivities and specificities for lymph node detection, especially in metastases smaller than 10 mm and thus is beneficial for lymph node staging [33,34]. Consequently, our data encourage the usage of 68 Ga-PSMA-PET and mpMRI for biopsy guidance and planning of focal therapies and show that 68 Ga-PSMA-PET should at least be performed in patients with intermediate and high-risk PCa since it gives highly complementary information.…”

Development and validation of novel nomogram to identify the candidates for extended pelvic lymph node dissection for prostate cancer patients in the robotic era

“…As for imaging modalities, 68 Ga-PSMA-PET for identification of LNI was reported to be more sensitive than 3T-MRI. 21 Furthermore, combination of 68 Ga-PSMA-PET, ISUP biopsy Grade and PI-RADS score by mpMRI was reported to be useful for prediction of LNI. 22 A recent study showed that integration of SUV max by PSMA-PET, the neutrophillymphocyte and platelet-lymphocyte ratios, initial PSA, and clinical T stage served as predictors for LNI diagnosis.…”

“…As for imaging modalities, 68 Ga‐PSMA‐PET for identification of LNI was reported to be more sensitive than 3T‐MRI 21 . Furthermore, combination of 68 Ga‐PSMA‐PET, ISUP biopsy Grade and PI‐RADS score by mpMRI was reported to be useful for prediction of LNI 22 .…”

Whole-body magnetic resonance imaging: technique, guidelines and key applications

“…MRI and CT, dependent on morphological assessment of nodal disease, have similar but unfortunately limited levels of performance in detection of metastatic nodal detection [61]. Several PET tracers, including 2-deoxy-2-( 18 F)fluoro-D-glucose, sodium ( 18 F)fluoride, ( 11 C)choline and ( 18 F)choline have been found to perform comparably or worse than MRI and CT for nodal disease, but recent preliminary reports suggest that PET/CT with some (PSMA)-based tracers may permit greater sensitivity without sacrificing specificity [62,63]. Nonetheless in light of the above-mentioned performance for bone metastases, WB-MRI remains attractive alone or in combination with PSMA PET as the clinical significance of the sub-centimetre nodes that are poorly seen with WB-MRI remains to be established.…”