Prospective comparison of simultaneous [68Ga]Ga-PSMA-11 PET/MR versus PET/CT in patients with biochemically recurrent prostate cancer

Abstract

Objectives PSMA-PET has become the PET technique of choice to localise the site of biochemically recurrent prostate cancer (PCa). With hybrid PET/MRI, the advantages of MRI are added to molecular characteristic of PET. The aim of this study was to investigate the incremental value of PET/MR versus PET/CT in patients with biochemically recurrent PCa by head-to-head comparison. Methods Thirty-four patients with biochemically recurrent PCa were prospectively included. They underwent [ 68 Ga]Ga-PSMA-11 PET/CT, followed by simultaneous PET/MR. All PET (PET CT , PET MR ), CT and MR images were evaluated for number of lesions and location. The number of lesions at specific sites was compared using Wilcoxon-sign-rank test. For PET, the maximum and mean standardised uptake values (SUVs) were calculated for each lesion compared using a two-sided paired t test.Results PET CT and PET MR scans were positive in 19 and 20 patients, detecting 73 and 79 lesions respectively. All lesions detected on PET CT were also detected on PET MR . CT and MRI only were positive in 14 and 17 patients, detecting 38 and 50 lesions, respectively, which was significantly lower than PET CT and PET MR respectively. Combined interpretation showed more lesions on PET/MR than on PET/CT (88 vs 81). No significant difference in detection of presence of local recurrence nor distant metastases was found. SUV mean and SUV max values were significantly higher on PET MR than on PET CT in local recurrence and lymph node metastases. Conclusions [ 68 Ga]Ga-PSMA-11 PET/MR was able to detect biochemically recurrent PCa at least as accurately as PET/CT for local recurrence, lymph node metastasis and distant metastasis. Key Points• PSMA PET/MRI detects the location of biochemical recurrence at least as accurately as PET/CT. • Substitution of PET/CT by PET/MRI adds sensitivity in PSMA lesion detection also in the setting of distant recurrence due to both the MR and TOF PET components.

Intra-individual qualitative and quantitative comparison of [68Ga]Ga-DOTATATE PET/CT and PET/MRI

“…The PET/MRI acquisition consisted of a TOF PET scan of 5 min per bed position (5–6 bed positions per patient) with simultaneous recordings of axial DW-MRI images, followed by T1- and T2-weighted imaging. Detailed acquisition parameters of the MRI sequences (DWI, T1 and T2) can be found in Supplemental Information (see also Jentjens et al 19 ).…”

Hybrid magnetic resonance and PET imaging for prostate cancer recurrence

“…Due to small numbers of patients, statistical power has been limited in these studies. In 34 patients, Jentjens et al [48 ▪▪ ] found that 68 Ga-PSMA-11 PET/MRI performed at least as well as PET/CT, and in this small study, although not statistically significant, PET/MRI found more patients with positive lesions and more lesions over all (88 versus 81), including lymph nodes (57 versus 51) and bone metastases (16 versus 15), than by PET/CT despite not including mpMRI sequences; further, PET/MRI was more sensitive for lymph node metastases than MRI or CT alone. In a study of 62 patients with recurrence and 150 lesions, 68 Ga-PSMA-11 PET/MR detected 11 lesions not seen by PET/CT, including five lymph nodes and six local recurrences, with the latter being statistically significant; further, interpreting PET/MR resulted in higher diagnostic confidence than PET/CT [49 ▪▪ ].…”

68Ga-PSMA-11 PET/CT versus 68Ga-PSMA-11 PET/MRI for the detection of biochemically recurrent prostate cancer: a systematic review and meta-analysis

“…There were still 55 studies for full-text screening, and another 18 were disqualified due to the following reasons: non-English studies (n = 3); cannot extract positivity rate data (n = 7); and different radiotracers (n = 8). 37 studies that satisfied the criteria for the meta-analysis were finally included, including 25 articles for 68 Ga-PSMA-11 PET/CT (14-38) and 13 articles for 68 Ga-PSMA-11 PET/MRI (4,26,(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49). One of the studies included not only 68 Ga-PSMA-11 PET/CT but also 68 Ga-PSMA-11 PET/MRI.…”