1. Failure Patterns by PSMA PET for Recurrent Prostate Cancer after Prostatectomy and Salvage Radiation.
- Author
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Imber BS, O'Dwyer E, Lobaugh S, McBride SM, Hopkins M, Kollmeier M, Gorovets D, Brennan V, Pike LRG, Gewanter R, Mychalczak B, Zhang Z, Schöder H, and Zelefsky MJ
- Subjects
- Male, Humans, Gallium Isotopes, Prostate-Specific Antigen, Prospective Studies, Gallium Radioisotopes, Neoplasm Recurrence, Local surgery, Tomography, X-Ray Computed, Prostatectomy, Salvage Therapy methods, Positron-Emission Tomography, Positron Emission Tomography Computed Tomography methods, Prostatic Neoplasms diagnostic imaging, Prostatic Neoplasms radiotherapy, Prostatic Neoplasms surgery
- Abstract
Objective: To characterize patterns of failure using prostate-specific membrane antigen positron emission tomography (PSMA PET) after radical prostatectomy (RP) and salvage radiotherapy (SRT)., Methods: Patients with rising PSA post-RP+SRT underwent
68 Ga-HBED-iPSMA PET/CT on a single-arm, prospective imaging trial (NCT03204123). Scans were centrally reviewed with pattern-of-failure analysis by involved site. Positive scans were classified using 3 failure categories: pelvic nodal, extra-pelvic nodal or distant non-nodal. Associations with failure categories were analyzed using cumulative incidence and generalized logits regression., Results: We included 133 men who received SRT a median of 20 months post-RP; 56% received SRT to the prostatic fossa alone, while 44% received pelvic SRT. PSMA PET/CT was performed a median of 48 months post-SRT. Overall, 31% of PSMA PET/CT scans were negative, 2% equivocal and 67% had at least 1 positive site. Scan detection was significantly associated with PSA level prior to PSMA PET/CT. Analysis of 89 positive scans demonstrated pelvic nodal (53%) was the most common relapse and fossa relapse was low (9%). Overall, positive scans were pelvic (n = 35, 26%), extra-pelvic nodal (n = 26, 20%) or distant non-nodal failure (n = 28, 21%), and 70% of positive scans were oligorecurrent. We observed similar cumulative incidence for all failure categories and relatively few clinicodemographic associations. Men treated with pelvic SRT had reduced odds of pelvic failure versus exclusive fossa treatment., Conclusion: Pelvic, extra-pelvic nodal, and distant non-nodal failures occur with similar incidence post-SRT. Regional nodal relapse is relatively common, especially with fossa-only SRT. A high oligorecurrence rate suggests a potentially important role for PSMA-guided focal therapies., (Copyright © 2022. Published by Elsevier Inc.)- Published
- 2022
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