Study compares 18F-based PSMA radiotracers to [68Ga]Ga-PSMA-11
“[18F]DCFPyL was assessed to be a suitable alternative to [68Ga]Ga-PSMA-11 in PCa diagnosis and staging due to its similar lesion uptake rate with no increase in benign uptakes," the authors wrote.
A recent meta-analysis comparing 18F-based prostate-specific membrane antigen (PSMA) radiotracers with [68Ga]Ga-PSMA-11 showed no significant differences in clinical impacts between [18F]DCFPyL and [68Ga]Ga-PSMA-11, but deemed [18F]DCFPyL as a suitable alternative for prostate cancer diagnosis and staging.1
![Included in the assessment were several 18F-based tracers, including [18F]PSMA-1007, [18F]DCFPyL, [18F]JK-PSMA-7, [18F]rhPSMA-7, and [18F]AlF-PSMA-11.](https://www.urologytimes.com/_next/image?url=https%3A%2F%2Fcdn.sanity.io%2Fimages%2F0vv8moc6%2Furologytimes%2F05175eccc72521b2df7a5a848d1602a44b55382e-640x640.webp%3Ffit%3Dcrop%26auto%3Dformat&w=1920&q=75 "Included in the assessment were several 18F-based tracers, including [18F]PSMA-1007, [18F]DCFPyL, [18F]JK-PSMA-7, [18F]rhPSMA-7, and [18F]AlF-PSMA-11.")
Included in the assessment were several 18F-based tracers, including [18F]PSMA-1007, [18F]DCFPyL, [18F]JK-PSMA-7, [18F]rhPSMA-7, and [18F]AlF-PSMA-11.
In total, the investigators assessed 24 studies conducted in the past 10 years via the MEDLINE, EMBASE, PubMed, and Web of Science databases. Included studies were those that directly compared 18F-based PSMA radiotracers and [68Ga]Ga-PSMA-11 in primary diagnosis and/or secondary staging of prostate cancer following biochemical recurrence. Specifically, the investigators assessed comparisons in normal organ standardized uptake value (SUV) or the lesion SUV or the detection rate.
The investigators found that overall, 18F-based PSMA radiotracers showed a higher SUVmax and a marginally higher detection rate compared with [68Ga]Ga-PSMA-11. However, the authors noted that “these differences were not significant and there is a paucity of high-quality head-to-head comparative data.”
Included in the assessment were several 18F-based tracers, including [18F]PSMA-1007, [18F]DCFPyL, [18F]JK-PSMA-7, [18F]rhPSMA-7, and [18F]AlF-PSMA-11. The 2 most commonly assessed tracers were [18F]DCFPyL and [18F]PSMA-1007, with [18F]DCFPyL demonstrating a similar lesion detection rate to [68Ga]Ga-PSMA-11 with no increase in false positive rates. A higher detection rate was seen with [18F]DCFPyL in comparison with [68Ga]Ga-PSMA-11, which may be due to the better image spatial resolution by 18F, the authors noted. [18F]DCFPyL also showed a similar biodistribution rate to [68Ga]Ga-PSMA-11.
They wrote, “Overall, there was not enough evidence in differentiating [18F]DCFPyL and [68Ga]Ga-PSMA-11 in their clinical impacts. The decision to use [18F]DCFPyL or [68Ga]Ga-PSMA-11 is largely based on infrastructure available at the individual health service.”
[18F]PSMA-1007, however, demonstrated a greater local lesion detection rate vs [68Ga]Ga-PSMA-11 due to its predominant hepatobiliary excretory route, according to the authors. Other advantages with [18F]PSMA-1007 included its accuracy in local lesion delineation. However, the local lesion detection rate was similar with [68Ga]Ga-PSMA-11 when patients were administered furosemide prior to the scan. Overall, [18F]PSMA-1007 was found to be less preferable due to its high benign bone uptakes.
Regarding new 18F-based PSMA tracers, all 3 assessed ([18F]JK-PSMA-7, [18F]rhPSMA-7, and [18F]AlF-PSMA-11) demonstrated marginally greater detection rates over [68Ga]Ga-PSMA-11. When diuretics were administered prior to the scan, [18F]-rhPSMA-7 demonstrated greater efficacy in detecting lesions adjacent to the bladder, suggesting that the tool may have lower urinary excretion compared with [68Ga]Ga-PSMA-11.
The investigators also compared production and cost among the radiotracers, with 1 study showing a cheaper production of [18F]PSMA-1007 compared with [68Ga]Ga-PSMA-11 when assessing the production process, maintenance, and waste disposal. The authors noted that production and transportation of 68Ga is more difficult due to the requirement of an on-site generator and its short half-life, respectively.
The authors concluded, “[18F]DCFPyL was assessed to be a suitable alternative to [68Ga]Ga-PSMA-11 in PCa diagnosis and staging due to its similar lesion uptake rate with no increase in benign uptakes. [18F]PSMA-1007 was assessed to be less preferrable to [68Ga]Ga-PSMA-11 due to its significant number of benign bone uptakes.”
References
1. Huang S, Ong S, McKenzie D, et al. Comparison of 18F-based PSMA radiotracers with [68Ga]Ga-PSMA-11 in PET/CT imaging of prostate cancer–a systematic review and meta-analysis. Nature. Published online and accessed November 28, 2023. doi:10.1038/s41391-023-00755-2
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