Is a Prostate Specific Antigen (PSA) level of 0.46 ng/mL normal in a patient with a history of Gleason 9 prostate cancer, treated with Androgen Deprivation Therapy (ADT), High Dose Rate (HDR) brachytherapy, and Intensity Modulated Radiation Therapy (IMRT)?

PSA of 0.46 ng/mL is Reassuring and Likely Normal After Your Treatment

A PSA of 0.46 ng/mL following ADT, HDR brachytherapy, and IMRT for Gleason 9 prostate cancer is within the expected range and does not indicate treatment failure at this stage. 1

Understanding Post-Radiation PSA Kinetics

After radiation therapy (unlike surgery), PSA does not drop to undetectable levels but instead gradually declines to a "nadir" (lowest point) over 18-36 months following treatment completion. 1 Your current PSA of 0.46 ng/mL falls well within the normal post-treatment range and does not meet any criteria for biochemical failure.

Key points about your PSA:

• PSA values between 0.1-2.0 ng/mL are commonly observed in successfully treated patients after radiation therapy 2
• The median post-treatment PSA for biochemically controlled high-risk patients is often <0.02 ng/mL, but values up to 2.0 ng/mL can still represent disease control 3, 2
• Your PSA is likely still declining toward its nadir, which may take up to 3 years to reach 1

What Defines Treatment Failure (You Don't Meet These Criteria)

The Phoenix criteria defines biochemical recurrence as nadir + 2 ng/mL. 1 This means your PSA would need to:

1. First reach its lowest point (nadir)
2. Then rise by 2.0 ng/mL above that nadir
3. Show three consecutive PSA rises to distinguish true progression from benign fluctuations 1

You have not met any of these criteria with a single PSA value of 0.46 ng/mL.

ADT Effects on PSA Interpretation

The ongoing or recent ADT complicates PSA interpretation because testosterone recovery is highly variable and can artificially suppress PSA, masking true disease status. 1 However, this works in your favor—if your PSA is 0.46 ng/mL while potentially still suppressed by ADT, this is even more reassuring.

Important caveat: A PSA nadir >0.2 ng/mL following 8 months of ADT in patients with PSADT <3 months has been associated with poor prognosis, but this applies to rapidly rising PSA, not a stable low value like yours. 4

Expected Monitoring Plan

Continue PSA monitoring every 3-4 months for the first 2 years after radiation therapy, as this represents normal post-radiation surveillance. 1 Do not pursue imaging (bone scans or CT) at this PSA level, as these have extremely low yield below 10 ng/mL. 1

Red Flags to Watch For (None Currently Present)

You should contact your oncologist immediately if you develop: 1

• Three consecutive PSA rises with PSA doubling time <6 months
• PSA rise meeting Phoenix criteria (nadir + 2 ng/mL)
• PSA >10 ng/mL
• Bone pain or other new symptoms

Your current PSA of 0.46 ng/mL does not trigger any of these concerning features and represents an appropriate treatment response for Gleason 9 disease treated with multimodal therapy.