Imaging techniques are utilized to classify and grade prostate cancer that is clinically relevant. For a study, researchers examined the accuracy of locoregional staging and intraprostatic tumor detection using 68Ga-PSMA PET/CT (PSMA) and multiparametric prostate MRI (mp-MRI).

Forty-nine patients with prostate cancer who had mp-MRI and PSMA prior to radical prostatectomy were included after the ethics committee gave its clearance. The extraprostatic extension (EPE), seminal vesicle invasion (SVI), lymph node invasion (LNI), and bladder neck invasion (BNI) were retrospectively assessed, as well as preoperative and postoperative PSA, transrectal ultrasound-guided prostate biopsy (TRUS-Bx) ISUP grade, radical prostatectomy ISUP grade, body mass index (BMI), TRUS prostate volume, and mp-MRI tumor mapping, PSMAtumor mapping, and pathologic tumor mapping. On a 12-sector prostate pathology map, the index tumor was detected by a uroradiologist, a nuclear medicine expert, and a uropathologist. Their accuracy and locoregional clinical staging were compared with one another.

The mean preoperative PSA readings were 21.11± 32.56 ng/ml, and the patients’ average age was 66.18± 6.67 years. It was revealed that the pathology in nearly half (44.9%) of the patients was ISUP grade 4 and 5%, and 18.4% of the patients had surgical margin positivity. The pathological results showed that 362 out of 588 sectors, 174 out of 362 sectors in the mp-MRI, and 175 out of 362 sectors in the PSMA were tumor-positive. Both PSMA and mp-MRI were equivalent (P=0.823) and reliable in identifying the intraprostatic index tumor’s site (AUC=0.66 vs. 0.69, P=0.82). For localizing intraprostatic index tumors, the PSMA and mp-MRI had sensitivity and specificity ratios of 42.5% vs. 49.5% and 90.7% vs. 88.6%, respectively. Both approaches were equivalent in terms of SVI (AUC=0.75 vs. AUC=0.75, P=0.886) and BNI (AUC=0.51 vs. AUC=0.59, P=0.597), with mp-MRI being more accurate than PSMA in terms of EPE (AUC=0.8 vs. AUC=0.57 respectively, P=0.027). In terms of LNI, PSMA and mp-MRI were equivalent (AUC=0.76 vs. AUC=0.64, P=0.39).

Particularly before deciding whether to do nerve-sparing surgery on high-risk patients, mp-MRI should be taken into consideration due to its high accuracy in the identification of EPE. The intraprostatic index tumor could be localized with accuracy using both imaging modalities. PSMA is effective at identifying LNI.

Reference: onlinelibrary.wiley.com/doi/10.1002/pros.24420