Should PSMA PET/CT Supplant MRI For Staging of Patients with High-Risk PCa?

Pointing out variability challenges with prostate MRI interpretation and enhanced detection of metastasis with PSMA PET/CT, researchers offered a literature review at the recent RSNA conference that explored the possibility of standalone use of PSMA PET/CT for staging higher-risk prostate cancer (PCa).

Here are seven key takeaways from the literature review.

1. For lymph node metastasis detection, PSMA PET/CT offers nearly 35 percent higher sensitivity (73.7 percent sensitivity vs. 38.9 percent) and 14.9 percent higher specificity (97.5 percent vs. 82.6 percent) than prostate MRI.
2. Staging with PSMA PET/CT has revealed lymph node metastases in approximately one-third of patients with high-risk PCa, according to the review authors.
3. In a 2024 study comparing PSMA PET/CT and multiparametric MRI (mpMRI) for locoregional PCa staging, researchers found an approximately 26 percent lower rate of under-staging with PSMA PET/CT (40 percent vs. 66 percent).
4. In addition to PSMA PET/CT providing an imaging alternative for patients who cannot undergo a MRI scan due to claustrophobia or implants, the review authors maintained that PSMA PET/CT enables one-visit local, nodal and distant staging.

(Editor’s note: For additional coverage of the RSNA conference, click here.)

5. The review authors noted that mpMRI offers a 91 percent negative predictive value for ISUP grade > 2 PCa and enables more than a quarter of men to avoid unnecessary biopsies. However, the researchers also pointed out significant variability with mpMRI’s positive predictive value (PPV), scan quality for diffusion-weighted imaging (DWI) sequences and inter-reader agreement for radiologists with less experience.

6. Citing superior spatial resolution and the presence of PSMA-positive cells prior to bone remodeling, the researchers noted that PSMA PET/CT offers 25 percent higher sensitivity for detecting bone metastasis in comparison to bone scintigraphy. The use of PSMA PET/CT for primary staging detected bone metastases in approximately one sixth of patients with high-risk pCa, according to a 2021 study.

7. While acknowledging that PSMA PET/CT is unreliable for detecting lymph node metastases < 5 mm and offers negligible value for staging of PSMA-negative PCa, the review authors maintained that PSMA PET/CT provides potential standalone staging utility in older patients, those with elevated PSA levels and patients with suspected extraprostatic extension on a digital rectal examination.

(Editor’s note: For related content, see “Study: PSMA PET/CT Changed Treatment Plans for Over a Third of Men with Prostate Cancer,” “Nine Takeaways from New Review of PSMA PET/CT and Whole-Body MRI for Advanced Prostate Cancer” and “Meta-Analysis Shows Benefits of PSMA PET in Detecting Recurrence and Metastasis with PCa.”)

Reference

1. Teigen J, Martin-Macintosh E. Is prostate MRI always necessary?: Exploring PSMA PET/CT as a standalone modality in prostate cancer imaging. Presented at the Radiological Society of North America (RSNA) annual meeting, November 30-December 4, 2025, Chicago. Available at: https://rsna.apprisor.org/epsWelcome.cfm?CFID=6979231&CFTOKEN=67f30e315dfda998-2D3A0C35-975D-DAB7-38CA2B3D9E6E6FEF .