Pattern of Prostate Cancer Recurrence Assessed by 68Ga-PSMA-11 PET/CT in Men Treated with Primary Local Therapy

Abstract

Imaging plays a vital role in detecting the recurrence of prostate cancer (PCa) to guide the choice of salvage therapy. Gallium-68 prostate-specific membrane antigen positron-emission tomography/computed tomography (68Ga-PSMA-11 PET/CT) is useful for detecting PCa recurrence. We assessed the pattern of PCa recurrence stratified by serum prostate-specific antigen level and type of primary local treatment in men with biochemical recurrence (BCR) after primary local therapy with radical prostatectomy or external beam radiotherapy (EBRT) using 68Ga-PSMA-11 PET/CT. We reviewed patients imaged with 68Ga-PSMA-11 PET/CT for the localization of the site of PCa recurrence. We determined the site and number of lesions due to PCa recurrence at different PSA levels. A total of 247 men (mean age of 65.72 ± 7.51 years and median PSA of 2.70 ng/mL (IQR = 0.78–5.80)) were included. 68Ga-PSMA-11 PET/CT detected the site of recurrence in 81.4% of patients with a median number of lesions per patient of 1 (range = 1–5). 68Ga-PSMA-11 PET/CT positivity was 43.6%, 75.7%, 83.3%, 90.0%, and 95.8% at PSA levels of <0.5, 0.5–1.0., 1.1–2.0, 2.1–5.0, and 5.0–10.0, respectively. The most common site of recurrence was in the prostate gland/bed at all PSA levels. Pelvic, extra-pelvic, and combined pelvic and extra-pelvic sites of recurrence were seen in 118, 50, and 33 patients, respectively. The risk of extra-pelvic recurrence increases with rising PSA levels. 68Ga-PSMA-11 PET/CT has a high lesion detection rate for biochemical recurrence of PCa in patients previously treated with primary local therapy.

The SAFE Pilot Trial—SAlvage Focal Irreversible Electroporation—For Recurrent Localized Prostate Cancer: Rationale and Study Protocol

“…Hence, a significant proportion remains with a relevant window for a definitive cure ( 7 ). Similar figures are confirmed by recent PET-PSMA imaging studies, as more than half of recurrences are localized to the prostatic bed only ( 8 , 9 ).…”

PSMA PET-CT in the Diagnosis and Staging of Prostate Cancer

“…Lawal et al (2021) identified 247 patients with BCR post external beam radiotherapy (EBRT) or RP. When comparing EBRT and RP, the site of recurrence on PSMA PET-CT was 67.4% vs. 43.4% at the prostate bed, 17.4% vs. 16.5% at SV, 37.2% vs. 34.7% in pelvic nodes and 9.3% vs. 18.3% to bone, respectively, [ 117 ]. Similar results were demonstrated in a review by Armstrong et al (2020), which also found that patients who underwent RP had a lower local recurrence rate than those who had radiotherapy (21.3% vs. 63.3%) but shorter time from initial therapy to recurrence (27.7 months vs. 54.6 months).…”

Topography of Prostate Cancer Recurrence: A Single-centre Analysis of Salvage Radical Prostatectomy Specimens and Implications for Focal Salvage Treatments

“…At first glance, these figures do not seem justified considering that half of men with radioresistant PCa have not experienced metastases by 5 yr, which thus represents a significant window for cure. More recently, prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging studies revealed that more than half of recurrences are confined to the prostate [8] , [9] .…”