Sheliyan Raveenthiran1, John Yaxley2,3,4, Troy Gianduzzo5, Boon Kua3, Louise McEwan6, David Wong6, Gail Tsang7, James MacKean7. 1. Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia. sheliyan99@hotmail.com. 2. Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia. 3. Wesley Urology Clinic, Brisbane, QLD, Australia. 4. Department of Medicine, University of Queensland, Brisbane, QLD, Australia. 5. Brisbane Prostate Clinic, Brisbane, QLD, Australia. 6. Wesley Medical Imaging, Brisbane, QLD, Australia. 7. Genesis Cancer Care, Brisbane, QLD, Australia.
Abstract
BACKGROUND: 68Ga-PET/CT PSMA scan is being increasingly used for the staging of biochemically recurrent disease. Early identification of recurrent disease after radiotherapy is important in considering suitability for early salvage therapy to improve prognosis. The aim is to identify patterns of suspected prostate cancer recurrence in relation to post-radiotherapy PSA levels, especially below the accepted Phoenix definition of PSA failure (PSA nadir + 2). METHODS: This was a retrospective single tertiary institution cohort study of consecutive men between July 2014 and June 2018 who received a 68Ga-PSMA PET/CT for elevated PSA levels following radiotherapy as primary treatment of prostate cancer. The primary outcome measure was to determine the relationship between pre-scan PSA and the probability of identifying PSMA-avid disease suggestive of recurrent prostate cancer. RESULTS: Two hundred and seventy-six patients met criteria for inclusion. The median PSA was 3.60 ng/mL. The overall detection rate for suspected recurrent prostate cancer was 86.3%. Local recurrence was the most common site, occurring in 56.9% (157/276) of men, with isolated local recurrence in 32.6% (90/276). A total of 75.3% (55/73) of men below Phoenix criteria had scans suggestive of recurrent disease, with 52.1% of men having salvageable disease. The regions surrounding the iliac arteries were the most common areas of nodal metastatic disease, with 55.6% of recurrence occurring in the iliac regions. CONCLUSIONS: 68Ga-PSMA PET/CT frequently identifies suspected recurrent disease prior to the accepted Phoenix definition of PSA nadir +2. Prospective outcome studies are required to determine if early identification of local recurrence improves outcomes by increasing the use of salvage local treatments and whether earlier identification of metastatic disease may improve outcomes with prompt initiation of multimodality therapies.
BACKGROUND: 68Ga-PET/CT PSMA scan is being increasingly used for the staging of biochemically recurrent disease. Early identification of recurrent disease after radiotherapy is important in considering suitability for early salvage therapy to improve prognosis. The aim is to identify patterns of suspected prostate cancer recurrence in relation to post-radiotherapy PSA levels, especially below the accepted Phoenix definition of PSA failure (PSA nadir + 2). METHODS: This was a retrospective single tertiary institution cohort study of consecutive men between July 2014 and June 2018 who received a 68Ga-PSMA PET/CT for elevated PSA levels following radiotherapy as primary treatment of prostate cancer. The primary outcome measure was to determine the relationship between pre-scan PSA and the probability of identifying PSMA-avid disease suggestive of recurrent prostate cancer. RESULTS: Two hundred and seventy-six patients met criteria for inclusion. The median PSA was 3.60 ng/mL. The overall detection rate for suspected recurrent prostate cancer was 86.3%. Local recurrence was the most common site, occurring in 56.9% (157/276) of men, with isolated local recurrence in 32.6% (90/276). A total of 75.3% (55/73) of men below Phoenix criteria had scans suggestive of recurrent disease, with 52.1% of men having salvageable disease. The regions surrounding the iliac arteries were the most common areas of nodal metastatic disease, with 55.6% of recurrence occurring in the iliac regions. CONCLUSIONS: 68Ga-PSMA PET/CT frequently identifies suspected recurrent disease prior to the accepted Phoenix definition of PSA nadir +2. Prospective outcome studies are required to determine if early identification of local recurrence improves outcomes by increasing the use of salvage local treatments and whether earlier identification of metastatic disease may improve outcomes with prompt initiation of multimodality therapies.
Authors: Kilian E Salerno; Baris Turkbey; Liza Lindenberg; Esther Mena; Erica E Schott; Alexandra K Brennan; Soumyajit Roy; Uma Shankavaram; Krishnan Patel; Theresa Cooley-Zgela; Yolanda McKinney; Bradford J Wood; Peter A Pinto; Peter Choyke; Deborah E Citrin Journal: Brachytherapy Date: 2022-05-04 Impact factor: 2.441