Reflective Summary: Advancements in Prostate Cancer Imaging with 18F-Flotufolastat PET/CT
In a recent in-depth interview, Dr. Phillip H. Kuo, MD, PhD, FACR, from City of Hope National Medical Center, shared insights into the promising reproducibility of 18F-flotufolastat PET/CT imaging—a technology that is rapidly reshaping the diagnostic landscape in prostate cancer. Dr. Kuo, who led the pivotal study, detailed how the tracer, known commercially as Posluma, has demonstrated impressive interreader and intrareader agreement rates, which were crucial for its FDA approval.
High Reproducibility in Initial Staging
Dr. Kuo emphasized that the study, derived from two phase 3 multicenter trials—LIGHTHOUSE and SPOTLIGHT—focused on both newly diagnosed patients and those with biochemical recurrence. In the initial staging group, where patients had not yet undergone treatment, the consistency among three experienced nuclear radiologists was striking. The interreader agreement was consistently at or above 95%, while intrareader reliability exceeded 86%. This level of reproducibility reinforces the tracer’s reliability in identifying prostate cancer and establishes a robust standard for clinical interpretation.
Challenges in Recurrent Disease
The interview also shed light on the nuances encountered in patients with recurrent prostate cancer. In this group, particularly within the prostate or prostate bed region, the interreader agreement dropped noticeably—to between 59% and 84%. Dr. Kuo explained that this variability likely stems from the inherent challenges of reading images in areas altered by prior treatment, where urinary activity and post-treatment changes can obscure results. His comments underscored the need for heightened vigilance and refined interpretative strategies in recurrent cases.
Diagnostic Advantages and Future Perspectives
One notable aspect of 18F-flotufolastat discussed by Dr. Kuo is its slower renal excretion. This characteristic offers a potential advantage by reducing interference from urinary activity, thereby enhancing the detection of lesions near urinary structures such as the ureters and bladder. Such an advantage is critical when trying to identify small, yet clinically significant, metastatic sites. Dr. Kuo highlighted that this feature not only supports current diagnostic protocols but may also pave the way for future comparative studies—specifically, head-to-head evaluations with other F18-labeled PSMA agents like Pylarify.
Clinical Impact and Ongoing Research
Reflecting on the broader implications of his findings, Dr. Kuo noted that the high reproducibility observed in the study is a strong testament to the clinical utility of 18F-flotufolastat. He advised that while the high agreement rates in newly diagnosed patients offer clear benefits, the lower rates in the prostate/prostate bed area for recurrent cases remind clinicians to approach these images with extra caution. Continued research, he said, will be essential not only to refine image interpretation protocols but also to explore the therapeutic potential of radiohybrid agents—a concept that could eventually allow for combined diagnostic and treatment strategies.
Final Thoughts
In summarizing his insights, Dr. Kuo painted an optimistic picture of the future of prostate cancer imaging. The study’s outcomes not only validate the diagnostic accuracy of 18F-flotufolastat PET/CT scans but also highlight the ongoing evolution of nuclear medicine. As clinicians and researchers build on these findings, the promise of more precise imaging—and ultimately, better patient outcomes—appears increasingly within reach.
This reflective report captures the essence of Dr. Kuo’s interview and underscores the dynamic progress in the field of prostate cancer diagnostics. The advancements discussed today signal a significant leap forward, offering both reassurance and new challenges as the medical community continues to refine its approach to imaging and treatment.
Reference
1. Kuo PH, Esposito G, Ulaner GA, et al. Interreader and intrareader reproducibility of 18F-Flotufolastat image interpretation in patients with newly diagnosed or recurrent prostate cancer: Data from two phase 3 prospective multicenter studies. J Nucl Med. 2024;65(8):1239-1243. doi:10.2967/jnumed.123.267306