Prostate-specific membrane antigen (PSMA)-guided radical prostatectomy (RP) can remove positive lymph nodes missed during extended pelvic lymph node dissection (ePLND) in patients with locally advanced prostate cancer, investigators suggest.
In a retrospective study of 35 patients undergoing open RP with ePLND for primary treatment, preoperative PSMA positron emission tomography (PSMA-PET) detected 78 locoregional lymph node metastases. In 14 patients, 20 lymph node metastases (26%) were located outside the ePLND template field. In 7 patients, lymph node metastases were exclusively outside the standard ePLND field.
PSMA-PET radio-guided surgery resulted in resection of PSMA-positive lymph node metastases in 33 of the 35 patients (94%), Matthias M. Heck, MD, of Technical University of Munich in Germany, and colleagues reported in European Urology Oncology. Postoperative follow-up indicated false-positive PSMA PET results for 5 of the 78 lymph nodes (6%). Histopathology showed that 22 patients harbored lymph node metastases within the ePLND field that were not seen on PSMA PET, “underlining the necessity of performing ePLND,” the investigators pointed out.
In a small case series, PSMA-PET resulted in resection of lymph node metastases in 94% of patients with locally advanced prostate cancer. Source: Getty Images
Patients with 1-2 PSMA-positive lymph node metastases had better postoperative outcomes than those with a higher number of positive lymph nodes. Detection of more than 2 positive lymph nodes on PSMA-PET was significantly associated with a 2.6-fold higher risk of both biochemical recurrence and further treatment and a 3.1-fold higher risk of distant metastases.
This was a small case series, so large-scale prospective data are still needed to assess the clinical utility of PSMA-PET in this setting.
Reference
Lunger L, Steinhelfer L, Korn P, et al. Prostate-specific membrane antigen-radioguided surgery facilitates pelvic lymph node dissection during radical prostatectomy for the treatment of locally advanced prostate cancer with regional lymph node metastases. Eur Urol Oncol. 6(1):95-98. doi:10.1016/j.euo.2022.12.001
Summary:
A study has found that prostate-specific membrane antigen (PSMA)-guided radical prostatectomy (RP) can detect positive lymph nodes missed during extended pelvic lymph node dissection (ePLND) in patients with locally advanced prostate cancer. PSMA positron emission tomography (PSMA-PET) was used to detect 78 locoregional lymph node metastases in 35 patients undergoing open RP with ePLND for primary treatment. PSMA-PET radio-guided surgery resulted in the removal of 94% of PSMA-positive lymph node metastases in 33 of the 35 patients. However, histopathology showed that 22 patients had lymph node metastases within the ePLND field that were not seen on PSMA PET, which highlights the necessity of performing ePLND. Patients with 1-2 PSMA-positive lymph node metastases had better postoperative outcomes than those with a higher number of positive lymph nodes. Detection of more than 2 positive lymph nodes on PSMA-PET was significantly associated with a higher risk of both biochemical recurrence and further treatment and a higher risk of distant metastases. While this study shows promise for using PSMA-PET in detecting positive lymph nodes in locally advanced prostate cancer patients, large-scale prospective data are still needed to fully assess its clinical utility in this setting.
