How to cite: Flavell, Robert “Incorporating New PET Imaging and Theranostic Approaches into Prostate Cancer Practice | Interesting Cases ” June 1, 2018. Accessed [date today]. https://dev.grandroundsinurology.com/incorporating-new-pet-imaging-and-theranostic-approaches-into-prostate-cancer-practice-interesting-cases/
Incorporating New PET Imaging and Theranostic Approaches into Prostate Cancer Practice | Interesting Cases – Summary:
In part two of this two-part series, an oncologist, urologist, and nuclear medicine physician review four distinct prostate cancer cases, sharing their thoughts and recommendations with regard to the use of recently developed imaging agents and therapies, including PSMA-based agents, fluciclovine, and 223Ra. Cases include patients at several stages, such as initial diagnosis, biochemical recurrence, and castrate-resistant prostate cancer.
Robert R. Flavell, MD, offers an introductory overview of theranostics and advances in nuclear imaging and therapies, especially prostate-specific membrane antigen (PSMA) agents. Subsequently, he leads a panel with Susan F. Slovin, MD, PhD, E. David Crawford, MD, and Phillip J. Koo, MD in reviewing four distinct prostate cancer cases, sharing their thoughts and recommendations with regard to use of recently developed imaging agents and therapies.
This panel discussion is part two of a two-part series. Part one is: “Incorporating New PET Imaging and Theranostic Approaches into Prostate Cancer Practice.”
The Role of Imaging During the Course of Prostate Cancer Progression
At this time, rapidly advancing positron-emission tomography (PET) imaging and theranostic approaches are changing the way physicians treat patients.
As an illustration of the role imaging plays in managing prostate cancer, Dr. Flavell presents a simplified timeline of the typical interventions physicians perform during the course of disease, describing imaging performed at the time of initial diagnosis, biochemical recurrence, and progression to castration-resistant prostate cancer (CRPC).
Next Generation Nuclear Imaging and Therapy Approaches
While a multitude of new nuclear medicine and positron-emission tomography (PET) imaging agents have emerged in recent years, Dr. Flavell focuses this discussion on PSMA agents and fluciclovine.
Currently, there are many diagnostic PSMA agents, notably gallium-68 and 18F-PSMA-1007. However, all PSMA agents are still investigational. PSMA often expresses in areas that are not prostate cancer, such as neovasculature in benign and malignant tumor subtypes. Also, PSMA sometimes expresses in normal variants, like cervical and stellate ganglion. Therefore, if physicians see PSMA uptake in solitary bone lesions or unexpected locations, they should beware of false positives or consider other tumors.
Although PSMA is arguably the most sensitive imaging option available for detecting metastatic disease in newly-diagnosed intermediate to high-risk prostate cancer, it still misses a significant portion of micrometastatic disease. It is unclear what role PSMA has in changing management, but it looks promising for guiding radiation planning and identifying distant metastatic disease.
Fluciclovine is a non-naturally occurring amino acid PET radiotracer, recently FDA-approved for detection of suspected recurrent prostate cancer. It is also highly sensitive for prostate cancer recurrence. Unlike many other radiopharmaceuticals, this agent is rapidly exported from cells, so imaging must occur very shortly after injection.
During the second half of this presentation, Dr. Flavell leads Dr. Slovin, a medical oncologist, Dr. Crawford, a urologist, and Dr. Koo, a nuclear medicine physician, in examining the efficacy of new PET imaging approaches through a case-based format. With this intention, the panelists review four cases, including a patient initially diagnosed with high-risk prostate cancer, two patients with biochemical recurrence post-radical prostatectomy and salvage radiotherapy, and a patient with CRPC.