PET-CT Imaging for Prostate Cancer

Overseen By Jeffrey Wong, MD

Age: 18+

Sex: Male

Trial Phase: Academic

Sponsor: City of Hope Medical Center

Disqualifiers: Psychiatric disorder, Substance abuse, Weight, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

20 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new method to improve imaging for prostate cancer using a special PET-CT scan. It employs a tracer called 18F-rhPSMA to highlight cancer cells in the body. The researchers aim to determine if the RefleXion Medical Radiotherapy System, a type of radiotherapy device, can enhance these images, potentially improving future radiation treatments. This study suits individuals with prostate cancer who have already undergone a PET-CT scan showing cancerous activity and can attend a same-day imaging session. As an unphased trial, it offers a unique opportunity to contribute to innovative imaging techniques that could enhance future cancer treatments.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that this PET-CT imaging technique is safe for prostate cancer patients?

Research has shown that the imaging agent used in this trial, Posluma (18F-rhPSMA), is already approved for prostate cancer imaging, confirming its safety in humans. Studies have found the RefleXion Medical Radiotherapy System (RMRS) to be a promising tool for imaging and guiding cancer treatment. An initial study with humans successfully used it with a similar imaging agent.

Although detailed safety information for using RMRS with 18F-rhPSMA is limited, these technologies for imaging and treatment have not raised major safety concerns. The imaging method uses small amounts of radioactivity, similar to PET scans, and is generally well-tolerated by patients. It is important to consult a healthcare provider to understand potential risks and benefits. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the RefleXion Medical Radiotherapy System (RMRS) because it offers a novel approach to imaging prostate cancer using a combination of PET-CT and a targeted radiotherapy system. Unlike traditional imaging methods, RMRS allows for real-time targeting of cancer cells, potentially leading to more precise and effective treatment. The integration of [18F]-rhPSMA PET-CT facilitates better visualization of cancerous tissues by using a specific radioactive tracer, flotufolastat F-18, which binds to prostate-specific membrane antigens. This innovative approach could improve the accuracy of prostate cancer treatment planning and monitoring, offering hope for more personalized and effective patient care.

What evidence suggests that this PET-CT imaging technique is effective for prostate cancer?

Research has shown that the RefleXion Medical Radiotherapy System (RMRS), which participants in this trial will experience, might help detect prostate cancer using PET-CT scans. Studies indicate that the RefleXion X1 platform can visualize prostate cancer tumors by using a special tracer called 18F-rhPSMA. This tracer is absorbed by prostate cancer cells, making them visible on the scans. Early results suggest that this system could guide radiotherapy by using signals from the cancer itself. This approach aims to enhance how doctors find and target prostate cancer during treatment. ^{2 4 6 7 8}

Who Is on the Research Team?

Jeffrey Wong

Principal Investigator

City of Hope Medical Center

Are You a Good Fit for This Trial?

This trial is for adults over 21 with prostate cancer who have already had a standard PET-CT scan showing active cancer spots. They must be able to undergo an additional RMRS PET scan on the same day and provide informed consent.

Inclusion Criteria

I am 21 years old or older.

Able to get same day X1 RMRS PET

My PET scan shows active cancer spots.

Exclusion Criteria

Known psychiatric or substance abuse disorder that would interfere with conduct of the study

Patient weight exceeding the weight limit (450 pounds) outlined per X1 RMRS specifications sheet

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Imaging

Participants receive SOC flotufolastat F-18 gallium IV and undergo PET-CT on study, followed by X1 RMRS PET-CT imaging-only session 120 minutes post-injection

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after imaging session

Up to 72 hours

1 visit (in-person or virtual)

What Are the Treatments Tested in This Trial?

Interventions

• RefleXion Medical Radiotherapy System (RMRS)

Trial Overview The study tests how well a new type of PET-CT imaging using [18F]-rhPSMA works compared to the current method. It's part of research to improve real-time, targeted radiation therapy planning and delivery in prostate cancer treatment.

How Is the Trial Designed?

Group I: Device Feasibility ([18F]-rhPSMA PET-CT, X1 RMRS PET-CT) Experimental Treatment 4 Interventions

Patients receive SOC flotufolastat F-18 gallium IV and undergo PET-CT on study. Patients then undergo X1 RMRS PET-CT imaging-only session 120 minutes post-injection.

Who Is Running the Clinical Trial?

City of Hope Medical Center

Lead Sponsor

Trials

614

Recruited

1,924,000+

National Cancer Institute (NCI)

Collaborator

Trials

14,080

Recruited

41,180,000+

Published Research Related to This Trial

In a study of 114 patients with biochemical recurrence of prostate cancer after radical prostatectomy, 18F-fluciclovine PET/CT imaging identified cancerous lesions in 42% of cases, significantly impacting treatment decisions.

The imaging results led to management changes in nearly half of the patients, with 32% altering their overall treatment approach, highlighting the importance of this imaging technique in guiding salvage radiation therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

18F-Fluciclovine Positron Emission Tomography in Men With Biochemical Recurrence of Prostate Cancer After Radical Prostatectomy and Planning to Undergo Salvage Radiation Therapy: Results from LOCATE. Solanki, AA., Savir-Baruch, B., Liauw, SL., et al.[2021]

In a study of 18 patients with metastatic castration-resistant prostate cancer (mCRPC) on enzalutamide, 18F-sodium fluoride (NaF) PET imaging revealed that not all new findings indicated treatment failure, suggesting a complex relationship between imaging results and disease progression.

The dynamic nature of NaF PET scans may help identify cases of oligoprogression, where only a few lesions progress, allowing for targeted interventions rather than changing overall treatment strategies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Quantitative Analysis of Serial Positron Emission Tomography Imaging in Men with Metastatic Castration-resistant Prostate Cancer Treated with Enzalutamide. Gandhy, SU., Karzai, FH., Bilusic, M., et al.[2023]

Recent studies highlight the effectiveness of PET/MR imaging in diagnosing and monitoring prostate cancer, providing a more comprehensive view of the disease compared to traditional imaging methods.

PET/MR imaging may offer potential advantages in treatment planning and assessing treatment response in prostate cancer patients, although further research is needed to establish its full clinical utility.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Molecular research in urology 2014: update on PET/MR imaging of the prostate. Wetter, A.[2021]

The study developed a human prostate stem cell antigen knock-in mouse model to evaluate the effectiveness of anti-PSCA immuno-PET imaging, which can help distinguish between indolent and aggressive prostate cancer.

The smaller [89Zr]A2cDb tracer demonstrated superior tumor targeting and faster clearance compared to the larger [124I]A11 Mb, providing clearer imaging of prostate cancer with minimal background interference, thus enhancing the potential for accurate diagnosis and monitoring of treatment response.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[89Zr]A2cDb Immuno-PET of Prostate Cancer in a Human Prostate Stem Cell Antigen Knock-in (hPSCA KI) Syngeneic Model. Zettlitz, KA., Tsai, WK., Knowles, SM., et al.[2021]

In a study analyzing 2025 portal images and 23 CT scans from prostate cancer patients, off-line position verification using implanted gold markers significantly reduced systematic errors in treatment positioning to below 1 mm, enhancing treatment accuracy.

However, relying solely on bony anatomy for position verification can sometimes increase systematic errors for individual patients, indicating that while it may reduce population-level uncertainty, it may not be effective for every patient due to organ motion.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of megavoltage position verification for prostate irradiation based on bony anatomy and implanted fiducials. Nederveen, AJ., Dehnad, H., van der Heide, UA., et al.[2019]

In a study of 4,363 men with low-risk prostate cancer, combined radiation therapy was found to be significantly more toxic than brachytherapy alone, leading to higher rates of genitourinary incontinence, obstruction, and erectile dysfunction.

Compared to external beam radiation therapy (EBRT) alone, combined therapy also resulted in increased gastrointestinal bleeding and other toxicities, suggesting that EBRT may offer protective benefits against these side effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The burden of overtreatment: comparison of toxicity between single and combined modality radiation therapy among low risk prostate cancer patients. Jiang, R., Tomaszewski, JJ., Ward, KC., et al.[2015]

PET imaging is crucial for diagnosing and managing various cancers, including prostate cancer, by providing detailed insights into disease extent.

The development of novel PET tracers aims to improve the detection of extraprostatic and micrometastatic disease, which are often missed by standard imaging techniques, potentially leading to better personalized treatment strategies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

PET and Radiation Therapy Planning and Delivery for Prostate Cancer. Vapiwala, N., Lin, A.[2016]

In a study of 224 patients with localized prostate cancer, endorectal MRI findings, particularly the status of extracapsular extension (ECE), were significant predictors of biochemical relapse after external beam radiation therapy (EBRT).

Patients with no ECE had a 5-year PSA relapse rate of only 7%, while those with bilateral ECE had a much higher rate of 48%, highlighting the importance of MRI in assessing cancer progression risk.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Predicting post-external beam radiation therapy PSA relapse of prostate cancer using pretreatment MRI. Fuchsjäger, MH., Pucar, D., Zelefsky, MJ., et al.[2021]

Prostate cancer is the most common type of cancer affecting the urinary system in men, and its biological diversity makes diagnosis and treatment challenging.

Positron emission tomography/computed tomography (PET/CT) is highlighted as a valuable noninvasive imaging tool that can enhance the diagnosis and understanding of prostate cancer biology, with various new radiopharmaceuticals being developed for this purpose.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Positron emission tomography for molecular imaging of prostate cancer]. Shen, GH., Zhang, WJ., Jia, ZY., et al.[2018]

In a study of 50 post-radical prostatectomy patients, image-guided radiation therapy (IGRT) using cone-beam computed tomography (CBCT) showed smaller total errors and prostate bed motion compared to traditional kV planar imaging, suggesting better localization accuracy.

Despite the differences in imaging methods, the rates of acute gastrointestinal and genitourinary toxicity were similar between the two groups, indicating that both techniques are safe for patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of daily cone-beam computed tomography and kilovoltage planar imaging for target localization in prostate cancer patients following radical prostatectomy. Simpson, DR., Einck, JP., Nath, SK., et al.[2016]

Choline PET/CT is an effective noninvasive tool for restaging prostate cancer patients with rising prostate-specific antigen levels after treatment, but it is not recommended for initial diagnosis or staging due to limitations in assessing intraprostatic tumors and small lymph node involvement.

While choline PET/CT is well-established, further research is needed to clarify the clinical roles of PET/CT using acetate and fluoride tracers in prostate cancer imaging.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The role of PET/computed tomography scan in the management of prostate cancer. Picchio, M., Giovannini, E., Messa, C.[2015]

In a study of 740 prostate cancer patients with a median follow-up of 10 years, salvage radiation therapy (SRT) after radical prostatectomy (RP) was associated with increased rates of rectal symptoms (relative risk 1.7-6.5) and mild increases in urinary symptoms (relative risk 1.2-1.4).

Overall, the majority of men experienced acceptable side effects from SRT, but a subset did report severe issues, particularly rectal bleeding, highlighting the need for careful monitoring of long-term side effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A comparison of side-effects and quality-of-life in patients operated on for prostate cancer with and without salvage radiation therapy. Braide, K., Kindblom, J., Lindencrona, U., et al.[2022]

Whole-pelvis (WP) intensity modulated radiation therapy (IMRT) for prostate cancer after prostatectomy resulted in significantly higher acute gastrointestinal (GI) toxicity compared to prostate-bed (PB) IMRT, with 61% of WP patients experiencing Grade 2 GI toxicity versus 29% in the PB group.

Despite the increased radiation exposure to the bladder and rectum in the WP group, there were no significant differences in acute genitourinary (GU) toxicity or late GI and GU toxicity between the two groups, suggesting that while WP IMRT has higher immediate GI side effects, it does not lead to increased long-term complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparative toxicity and dosimetric profile of whole-pelvis versus prostate bed-only intensity-modulated radiation therapy after prostatectomy. Deville, C., Vapiwala, N., Hwang, WT., et al.[2012]

Citations

1. reflexion.com reflexion.com/scintix-therapy/

RADIOTHERAPY JUST Leveled Up We're lighting up cancer. By combining radiotherapy and PET-CT in a novel way, we can find and treat cancer using its own emissions.

2. reflexion.com reflexion.com/press-releases/reflexion-highlights-clinical-study-results-for-future-prostate-cancer-treatment/

RefleXion Highlights Clinical Study Results for Future ... The prospective PyL imaging study established that tumors arising from prostate cancer could be visualized on the RefleXion® X1 platform using ...

3. reflexion.com reflexion.com/press-releases/reflexion-showcases-expanding-clinical-evidence-for-scintix-therapy-in-15-scientific-presentations-at-astro-2025-including-first-reported-outcomes/

RefleXion Showcases Expanding Clinical Evidence for ... A first-in-human pilot study demonstrates potential feasibility of PSMA-directed SCINTIX therapy in patients with prostate cancer.

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12340358/

Expanding SCINTIX Biology-Guided Radiotherapy Beyond ... The RefleXion X1 system offers both conventional imaging guidance treatment (IGRT mode) and BgRT (SCINTIX delivery mode). Patient Data ...

5. clinicaltrials.gov clinicaltrials.gov/study/NCT05470699

RefleXion PET/CT Imaging Performance in Patients With ... This clinical trial examines RefleXion Medical Radiotherapy System (RMRS) ... RMRS to detect lesions (primary and metastatic) in patients with prostate cancer.

6. accessdata.fda.gov accessdata.fda.gov/cdrh_docs/reviews/DEN220014.pdf

RefleXion Medical Radiotherapy System (RMRS) The PET system is comprised of two PET detector arcs mounted on the ring gantry that rotate with the system to generate complete tomographic ...

7. reflexion.com reflexion.com/scientific-evidence/

Scientific Evidence Dosimetric feasibility of dose-painting radiotherapy for targeting hypoxia in prostate cancer on a novel ring gantry radiotherapy system. Show Authors. K ...

8. cdn.clinicaltrials.gov cdn.clinicaltrials.gov/large-docs/47/NCT04788147/Prot_SAP_001.pdf

Clinical Study Protocol RefleXion Medical Performance ... The RefleXion Medical Radiotherapy System (RMRS) is a hybrid imaging-therapy system that is designed to facilitate delivery of biology-guided radiotherapy ...