PET/CT PSMA (Prostate Cancer) — Dictation, Appropriateness, and Dose for Residents

1. The Rising PSA and the PSMA PET-CT Read

It’s 3 PM. Urology is on the phone about a post-prostatectomy patient whose Prostate-Specific Antigen (PSA) just bumped to 0.6 ng/mL. They’ve ordered a PSMA PET-CT for biochemical recurrence, and it’s next on your list. You know the attending expects you to nail every avid focus — from the prostate bed to potential distant mets — while confidently dismissing the minefield of physiologic uptake in the salivary glands, kidneys, and bowel. This isn’t just a search for disease; it’s a roadmap for the patient’s next therapy, potentially qualifying them for Pluvicto.

When I was a fellow, the first few PSMA PETs felt like a high-stakes game of “spot the difference.” Is that focus in the pelvis a ureter or a node? Is that celiac ganglion uptake or a true metastatic deposit? Getting it right, and getting it right efficiently, is the job. This guide provides the structured template and clinical pearls to help you dictate these studies with confidence. For more guides and tools, check out the residents and fellows resource hub.

2. What a PET-CT PSMA Covers and What Attendings Look For

A Prostate-Specific Membrane Antigen (PSMA) PET-CT is the most sensitive tool we have for detecting prostate cancer, both for initial staging of high-risk disease and, more commonly, for localizing biochemical recurrence at very low PSA levels. The radiotracer (like Ga-68 PSMA-11 or F-18 piflufolastat) targets PSMA, a protein overexpressed on prostate cancer cells.

Your attending is looking for a comprehensive report that answers these key clinical questions:

• Local Recurrence: Is there PSMA-avid disease in the prostatectomy bed or the remaining prostate gland?
• Nodal Metastases: Are there avid pelvic, retroperitoneal, or other lymph nodes?
• Distant Metastases: Is there evidence of osseous (bone) or visceral (organ) metastatic disease?
• Theranostic Eligibility: Does the patient’s disease demonstrate sufficient PSMA avidity to be a candidate for PSMA-targeted radioligand therapy (e.g., Lu-177 PSMA-617 / Pluvicto)?

A clean, structured report that systematically addresses these points while correctly identifying physiologic uptake is the goal.

3. Radiology Report Template for PET-CT PSMA (Prostate-Specific Membrane Antigen)

This template provides a solid foundation. Remember to first master the patterns of physiologic uptake and common false positives to avoid overcalling disease. The key principles below are your guideposts.

• Detection Rate by PSA: The likelihood of finding disease rises with PSA. Expect ~30-50% detection at PSA 0.2-0.5 ng/mL, climbing to >90% for PSA >2.0 ng/mL.
• Physiologic Uptake: Intense uptake is normal in salivary and lacrimal glands, kidneys, liver, spleen, and urinary bladder/ureters. Don’t mistake these for cancer.
• Common False Positives: Be wary of autonomic ganglia (especially celiac), healing rib fractures, Paget’s disease, and inflammation. Always correlate with the CT findings.
• Theranostic Implications: Your read directly determines if a patient with metastatic castration-resistant prostate cancer (mCRPC) is eligible for Lu-177 PSMA therapy.

Technique

PROCEDURE: PET-CT PSMA from skull base to mid-thighs.

RADIOPHARMACEUTICAL: [9.0 mCi of F-18 piflufolastat (Pylarify) / X mCi of Ga-68 PSMA-11] administered intravenously.

SCAN TIMING: Imaging was performed approximately [60] minutes after radiotracer injection.

IMAGING: A low-dose, non-contrast CT was performed for attenuation correction and anatomic localization. PET images were acquired and reconstructed.

COMPARISON: [Date and type of prior study]

CLINICAL HISTORY: [Age]-year-old male with a history of prostate cancer, status post [prostatectomy/radiation therapy], with biochemical recurrence. PSA is [X.X] ng/mL. The study is for restaging.

Findings

PHYSIOLOGIC DISTRIBUTION: Normal and symmetric radiotracer uptake is seen in the salivary glands, lacrimal glands, liver, spleen, small bowel, and kidneys, with excretion into the urinary collecting systems and bladder. No unusual sites of physiologic uptake are identified.

HEAD AND NECK: No PSMA-avid suspicious lesions.

CHEST: No PSMA-avid mediastinal, hilar, or axillary lymphadenopathy. No PSMA-avid suspicious osseous or pulmonary lesions.

ABDOMEN AND PELVIS:
Prostate Bed/Prostate: [No focal PSMA-avid lesion in the prostatectomy bed. OR: There is a focal PSMA-avid lesion in the prostatectomy bed measuring X x Y cm with SUVmax of Z, suspicious for local recurrence.]

Pelvic Lymph Nodes: [No PSMA-avid pelvic lymphadenopathy. OR: There is a PSMA-avid left external iliac lymph node measuring X mm with SUVmax of Z.]

Retroperitoneal/Abdominal Lymph Nodes: [No PSMA-avid retroperitoneal or abdominal lymphadenopathy.]

Liver/Spleen/Adrenals: No PSMA-avid suspicious visceral lesions.

Bowel/Mesentery: No PSMA-avid suspicious lesions.

OSSEOUS STRUCTURES: [No PSMA-avid suspicious osseous metastatic disease. OR: There are multiple PSMA-avid osseous lesions involving the [T7 vertebral body, right iliac bone, left 5th rib] consistent with metastatic disease.]

OTHER FINDINGS: [Incidental non-avid findings on the CT portion of the exam, e.g., renal cyst, hiatal hernia.]

Impression

1. Evidence of PSMA-avid metastatic disease involving [e.g., pelvic lymph nodes and multiple osseous structures], as detailed above. The findings are consistent with metastatic prostate cancer.

2. [If applicable] A PSMA-avid focus in the prostatectomy bed is suspicious for local recurrence.

3. No other sites of PSMA-avid disease to suggest distant metastatic prostate cancer.

4. The patient’s sites of disease demonstrate PSMA avidity, suggesting potential candidacy for PSMA-targeted radioligand therapy.

4. Free Template Sources for Other Modalities

Building a personal library of high-quality templates is a key part of residency. Beyond this guide, two great free repositories exist that are worth bookmarking. They are maintained by radiologists for radiologists and cover a huge range of modalities and subspecialties.

• RadReport.org: Curated by the RSNA, this is one of the most comprehensive and widely used free template libraries available.
• Radiology Templates (AU): An excellent, well-organized library maintained by Australian radiologists with a clean interface and practical templates.

5. The Next-Level Move: From Free-Form Dictation to Structured Report

A solid template is your starting point, but the real challenge is integrating positive findings on the fly without breaking your flow. Instead of toggling between your dictation window and a template, you can dictate the positive findings in free form and let an AI tool handle the structuring. GigHz Precision AI is designed for this workflow. You can simply dictate, “There’s a PSMA-avid left external iliac node with an SUVmax of 8.5 and a focal avid lesion in the prostatectomy bed,” and the tool generates a clean, structured report using pre-loaded ACR and SIR templates. It helps streamline the reporting process, ensuring all key elements are included in the correct format, which makes your reports clear and your attendings happy.

6. When Should You Order a PET-CT PSMA? ACR Appropriateness Criteria

Knowing when a study is indicated is as important as reading it correctly. The American College of Radiology (ACR) provides evidence-based guidelines to help clinicians choose the right test for the right reason.

For the clinical scenario of a rising PSA after treatment, the ACR Appropriateness Criteria on Post-Treatment Follow-up of Prostate Cancer rates PSMA PET-CT as “Usually Appropriate.” It has become the standard of care for detecting sites of disease in patients with biochemical recurrence, especially at low PSA levels where other imaging modalities are often negative.

Key alternatives and their roles include:

• FDG PET-CT: Usually not appropriate for early biochemical recurrence, as most prostate cancers are not highly FDG-avid. It’s reserved for later-stage, dedifferentiated disease that may have lost PSMA expression.
• F-18 Fluciclovine PET (Axumin): An older agent that may be appropriate but has lower sensitivity and detection rates than PSMA PET, particularly at PSA levels below 2.0 ng/mL.
• Bone Scan + CT: Historically used, but now considered less sensitive than PSMA PET for detecting osseous metastases. PSMA PET often identifies bone mets earlier and with greater certainty.
• mp-MRI of the Prostate: Usually appropriate for evaluating the prostate bed for local recurrence but cannot assess for distant nodal or metastatic disease.

7. How Much Radiation Does a PET-CT PSMA Deliver?

Patients often ask about radiation dose, and it’s our job to provide an accurate and contextualized answer. A PSMA PET-CT scan involves two sources of radiation: the injected radiotracer and the low-dose CT scan used for localization.

The total estimated effective dose from a PSMA PET-CT is typically in the range of 7-12 mSv. This is comparable to a few years of natural background radiation, which we all receive just by living on Earth. This dose level is similar to other common nuclear medicine and CT studies and is considered appropriate given the critical clinical information the scan provides for managing prostate cancer.

The CT portion is performed at a low dose, optimized for attenuation correction and anatomic correlation rather than full diagnostic quality, which helps keep the total radiation exposure as low as reasonably achievable.

8. PET-CT PSMA Imaging Protocol — Phases, Contrast, and Key Parameters

A successful PSMA PET-CT depends on meticulous protocoling. Unlike FDG PET, there is no fasting requirement, but patient hydration and bladder voiding are critical for clearing urinary activity from the pelvis, which can otherwise obscure the prostate bed.

The table below outlines a typical protocol. Note that some institutions administer a low dose of a diuretic (furosemide) at the time of injection to enhance urinary washout and improve pelvic visualization.

A common protocol pitfall relates to the choice of radiotracer. F-18 based agents have a longer half-life (~110 min) compared to Ga-68 (~68 min), which simplifies logistics and allows for more flexible scheduling. However, Ga-68 can be produced on-site with a generator. For evaluating the pelvis, F-18 PSMA-1007 is a useful alternative as it has primarily biliary excretion, resulting in very low urinary activity that might otherwise obscure a subtle recurrence in the prostate bed.

9. The 3-Months-Free Offer for Residents and Fellows

3+ months free for radiology residents and fellows

Look like a rockstar on your reports — dictate positive findings in free form, and the AI generates a structured report using ACR + SIR templates with the appropriate clinical decision support firing automatically. This is your chance to try the full platform, on us.

All we ask is feedback so we can keep improving the product for trainees. The signup is simple. No credit card, no long forms. To apply, just provide these three items:

1. Your PGY year (e.g., PGY-2, PGY-4)
2. Your training type (radiology residency or specific fellowship)
3. Your training program / hospital name

Ready to give it a try? Apply for the residents free-access program and we’ll get you set up.

10. Frequently Asked Questions

Is GigHz Precision AI HIPAA-compliant?

Yes. The platform is designed for de-identified workflows by default. You dictate findings, and the tool structures them without requiring Protected Health Information (PHI). It operates securely within compliance standards.

Do I need my hospital’s IT department to set this up?

No. It’s a browser-based tool that requires no local installation. You can use it on any hospital workstation, your personal laptop, or even the call-room iPad. There’s nothing for IT to install or approve.

How does this work with PowerScribe or other dictation systems?

It works alongside your existing dictation system. Most residents dictate their findings into the GigHz platform, let the AI generate the structured report, and then copy-paste the final, clean text into PowerScribe. It’s a simple copy-paste workflow.

Can I use this on my phone or iPad?

Yes, the platform is web-based and responsive, so it works on modern browsers on desktops, laptops, tablets, and phones. This is especially useful for reviewing templates or checking criteria on the go.

Can I customize the templates?

Yes. While the system comes pre-loaded with ACR and society-recommended templates, you can create, modify, and save your own versions to match your personal preferences or your institution’s specific requirements.

What happens after my residency or fellowship ends?

The free access is for trainees. After you graduate, you can choose to subscribe to a paid plan for practicing radiologists. There’s no obligation, and your free access will simply expire at the end of the offer period if you choose not to continue.