TOPLINE:

A retrospective study found that preoperative imaging methods all had limited sensitivity for detecting lymph node invasion in patients with intermediate-risk prostate cancer. However, prostate-specific membrane antigen (PSMA)-PET had some prognostic value.

METHODOLOGY:

• Accurate lymph node staging affects prognosis and treatment selection for patients with intermediate‑risk prostate cancer. Guidelines conflict on the routine use of CT, MRI, and PSMA‑PET because of low event rates, variable sensitivity, and concerns about cost and radiation. Consequently, the optimal staging strategy remains uncertain, underscoring the need for comparative data on diagnostic accuracy and oncologic outcomes.
• To address this gap, researchers retrospectively analyzed 8043 patients (median age, 64 years) with intermediate-risk prostate cancer who underwent radical prostatectomy with extended pelvic lymph node dissection between 2015 and 2021. Overall, 36.7% had favorable and 63.3% had unfavorable intermediate-risk disease, based on National Comprehensive Cancer Network guidelines.
• Kaplan-Meier analyses were used to assess biochemical recurrence‑free and metastasis‑free survival after radical prostatectomy. Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively), and overall accuracy of all modalities were determined.
• Overall, 25.8% (n = 2079), 5.0% (n = 400), and 1.8% (n = 148) of patients had abdominal CT, PSMA-PET, and abdominal MRI for staging, respectively. In patients with unfavorable vs favorable disease, CT (29.1% vs 20.2%) and PSMA-PET (6.1% vs 3.0%) were more frequently performed.

TAKEAWAY:

• Lymph node invasion was confirmed on pathology in 624 of 8043 (7.8%) patients. The prevalence was 3.2% among those with favorable disease and 10.4% among those with unfavorable disease.
• All imaging modalities showed low sensitivity for lymph node invasion. The sensitivity of PSMA‑PET was 13%, (30.0% PPV and 89.5% NPV); the sensitivity of MRI was 8.3% (100% PPV and 92.5% NPV); and the sensitivity of CT was 0.9% (22.2% PPV and 89.0% NPV). The relatively better performance of PSMA-PET suggests it might identify a subset of patients with nodal disease not detected on conventional imaging, the authors noted.
• A higher International Society of Urological Pathology Grade Group, a higher clinical T stage, a higher preoperative level of PSA, older age at radical prostatectomy, and a higher number of positive biopsy cores independently predicted lymph node invasion.
• PSMA-PET appeared useful in the prediction of oncologic outcomes. At 60 months after surgery, PSMA‑PET-negative patients vs PSMA‑PET-positive patients had better outcomes, with a biochemical recurrence‑free survival of 75.1% vs 45.4%, and metastasis‑free survival of 95.5% vs 75.8%.

IN PRACTICE:

“The performance of commonly used imaging methods — CT, abdominal MRI, and even PSMA-PET — was suboptimal in this setting, with particularly low sensitivity across all modalities,” the authors wrote. While PSMA-PET “may be considered selectively,” they concluded, the findings suggest that distant staging can be skipped for most patients with intermediate-risk prostate cancer.

SOURCE:

The study, led by Christopher Kniep and Tobias Maurer, Martini-Klinik Prostate Cancer Center, University Hospital Hamburg Eppendorf, Hamburg, Germany, was published online in BJU International.

LIMITATIONS:

The retrospective nature of the study may have introduced selection bias. Imaging modality use was not standardized and likely varied by patient and physician preference. Additionally, PSMA‑PET was available for only a subset of patients, and specific tracer details were not available, which may have influenced detection rates.

DISCLOSURES:

The study received open access funding enabled and organized by Projekt DEAL. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.