I am 72 and in good health. My PSA is 6.4, my Gleason score is 6, and only one of 12 biopsy cores was positive. My doctor has discussed several treatments and asked me to choose. What should I know about radioactive seed implantation and proton therapy?
Quick Answer
Your results may fit a low-risk prostate-cancer pattern, but that cannot be confirmed from PSA and Gleason score alone. Modern risk assessment also considers the clinical stage, PSA density, MRI findings, the amount of cancer in the positive biopsy core, prostate size and your overall health.
If the cancer is confirmed to be low risk, current AUA/ASTRO guidance recommends active surveillance as the preferred management option for most men. This means careful monitoring rather than immediate surgery or radiation.
If you decide on radiation, brachytherapy (seed implantation) is an established treatment for appropriately selected low- or favorable-intermediate-risk disease. Proton therapy is also a radiation option, but it has not been shown to provide better cancer control or fewer side effects than other modern radiation techniques such as IMRT.
Hello Ottis,
The first thing I would change from the old way of answering this question is the order of the discussion. Before choosing between radioactive seeds and proton therapy, you need to know whether you actually need immediate treatment at all.
What Do PSA 6.4 and Gleason 6 Suggest?
A Gleason score of 3+3=6 corresponds to Grade Group 1, the lowest prostate-cancer grade group. A PSA of 6.4 ng/mL is below 10 ng/mL, and only one of 12 biopsy cores was reported as positive.
Taken together, those findings can be consistent with low-risk disease, but several details are still missing:
- your clinical T stage;
- the percentage or length of cancer in the positive biopsy core;
- your prostate volume and PSA density;
- whether a multiparametric MRI has been performed;
- whether the MRI showed any suspicious higher-grade lesion;
- the exact pathology wording; and
- whether the biopsy has been reviewed when there is diagnostic uncertainty.
These details are important because treatment should be based on your prostate-cancer stage and risk group, not PSA alone.
Could Active Surveillance Be an Option?
Yes. If your cancer is confirmed to be low risk, active surveillance should be part of the discussion before you choose surgery or radiation.
Active surveillance does not mean ignoring the cancer. It means monitoring it carefully and moving to curative treatment if there is evidence that the disease is becoming more significant.
A surveillance program may include:
- regular PSA testing;
- clinical follow-up;
- multiparametric MRI when appropriate; and
- repeat biopsy according to the surveillance protocol.
Your age of 72 does not by itself determine the decision. Overall health and estimated life expectancy matter more than chronological age alone.
What Is Prostate Seed Implantation?
“Seeding” usually refers to low-dose-rate (LDR) brachytherapy.
During this procedure, small radioactive sources are placed inside the prostate using image guidance. Because the radiation source is positioned within the gland, a high dose can be delivered to the prostate while limiting exposure to surrounding tissues.
There is also high-dose-rate (HDR) brachytherapy, in which temporary radioactive sources are placed through catheters for a controlled period and then removed.
You can read more in our detailed guide to brachytherapy for prostate cancer.
Who May Be a Good Candidate for Brachytherapy?
For men who choose radiation, current AUA/ASTRO guidance recognizes permanent LDR seed implantation and temporary HDR brachytherapy as established treatment options for appropriately selected patients with low- or favorable-intermediate-risk prostate cancer.
Suitability may depend on factors such as:
- prostate size and anatomy;
- baseline urinary symptoms;
- previous prostate procedures;
- risk category;
- pubic-arch anatomy;
- ability to undergo anesthesia; and
- the experience of the treating brachytherapy team.
What Are the Main Side Effects of Brachytherapy?
Possible effects include:
- temporary worsening of urinary frequency or urgency;
- a weaker urinary stream;
- difficulty urinating or, less commonly, urinary retention;
- rectal irritation or bowel symptoms;
- erectile dysfunction developing over time; and
- rare urethral or rectal complications.
A radiation oncologist should discuss your individual baseline urinary function before recommending seed implantation.
What Is Proton Therapy?
Proton therapy is a form of external-beam radiation therapy. Instead of using high-energy X-rays (photons), it uses charged particles called protons.
Protons have physical properties that allow radiation planners to control where much of the radiation dose is deposited. This can reduce radiation exposure to some tissues beyond the target.
That physical advantage is real, but it does not automatically mean better clinical outcomes for prostate cancer.
Is Proton Therapy Better Than IMRT?
At present, there is no good evidence that proton therapy provides superior prostate-cancer control compared with modern photon-based radiation such as intensity-modulated radiation therapy (IMRT).
AUA/ASTRO specifically advises clinicians that proton therapy can be discussed as a treatment option, but it has not been shown to be superior to other radiation modalities in either toxicity profile or cancer outcomes.
Brachytherapy vs Proton Therapy
| Feature | Brachytherapy | Proton Therapy |
|---|---|---|
| Type of radiation | Radiation source placed inside or temporarily within the prostate | External-beam radiation using protons |
| Treatment setting | Implant procedure; LDR seeds remain permanently, while HDR sources are temporary | External treatments delivered at a proton center |
| Evidence in localized disease | Established option for appropriately selected localized disease | Valid radiation option, but not proven superior to modern photon therapy |
| Main practical issue | Requires an invasive implantation procedure and suitable urinary/anatomic profile | Requires access to a proton facility and can be more expensive |
| Potential side effects | Urinary irritation/retention, erectile dysfunction, bowel effects | Urinary, bowel and sexual effects similar in principle to other external radiation approaches |
How Would I Approach Your Decision?
With the information you have provided, I would not begin by asking, “Seeds or protons?” I would ask your urologist and radiation oncologist these questions first:
- Am I definitely in the low-risk group?
- What is my clinical T stage?
- What percentage of the positive biopsy core contained cancer?
- What is my PSA density?
- Do I need or already have a prostate MRI?
- Am I a good candidate for active surveillance?
- If I choose radiation, why would you recommend brachytherapy, IMRT, SBRT or proton therapy specifically for me?
- What are the expected urinary, sexual and bowel side effects of each option in my case?
Getting both a urologist’s and radiation oncologist’s perspective can be particularly useful before making an irreversible treatment decision.
Your PSA of 6.4, Gleason 6 / Grade Group 1 result and one positive biopsy core sound potentially favorable, but I would first confirm the complete risk classification before choosing treatment.
If this is truly low-risk localized prostate cancer, active surveillance deserves a serious discussion and is the preferred approach for most men under current guidance.
If you prefer definitive radiation treatment, brachytherapy is a well-established option for appropriately selected low-risk patients. Proton therapy is also available, but current evidence does not establish it as superior to modern photon radiation for either cancer control or side effects.
Dr. Albana Greca, MD, MMedSc
Family Physician / General Practitioner
Founder & Lead Medical Author, Prostate Treatment Options
Fiducial Markers Before Prostate Radiation
How important is it to have fiducial markers placed before receiving radiation therapy?
Quick Answer
Fiducial markers can be very useful for image-guided prostate radiation therapy (IGRT). They act as visible reference points that help the radiation team locate the prostate accurately before treatment.
However, not every modern radiation system requires implanted fiducial markers. Some centers can localize the prostate using cone-beam CT, MRI-guided systems or other image-guidance technology. Whether markers are needed depends on the radiation technique and equipment used by your center.
What Are Fiducial Markers?
Fiducial markers are tiny radiopaque markers, often made of gold, that are placed in the prostate before certain forms of external-beam radiation therapy.
The prostate can move slightly from day to day because of changes in bladder and rectal filling. Fiducial markers provide reference points that allow the treatment team to verify prostate position before radiation is delivered.
Major cancer centers describe these markers as helping the team line up radiation beams consistently and target the prostate while reducing unnecessary exposure to nearby normal tissue.
How Are They Inserted?
Markers can be placed through a transperineal or transrectal approach, depending on the center. Ultrasound guidance is commonly used.
The procedure is similar in some respects to other image-guided prostate needle procedures, but the details, infection precautions and anesthesia vary by technique and institution.
Are Fiducial Markers Mandatory?
No. The key requirement is accurate image guidance and target localization, not necessarily a particular type of marker.
AUA/ASTRO recommends use of available target localization, normal-tissue avoidance and image-guidance procedures to optimize external-beam radiation treatment. Fiducial markers are one established way to achieve this.
What Are the Risks?
Marker placement is generally a minor procedure, but possible risks include:
- temporary discomfort;
- minor bleeding;
- blood in the urine or semen;
- infection; and
- rare marker migration or other procedural complications.
Your radiation oncology team can explain whether the benefit of markers applies to the exact treatment platform they use.
Fiducial markers are useful for many forms of prostate image-guided radiotherapy because they help the treatment team verify the prostate’s position before delivering radiation. But they are not automatically required for every modern radiation system.
Rather than asking only whether markers are necessary, ask your radiation oncologist: “How will you confirm the exact prostate position before each treatment?” That is the important safety and accuracy question.
Dr. Albana Greca, MD, MMedSc
Family Physician / General Practitioner
Medical References
American Urological Association / American Society for Radiation Oncology. Clinically Localized Prostate Cancer Guideline.
National Cancer Institute. Prostate Cancer Treatment (PDQ).
American Society for Radiation Oncology. Proton Beam Therapy for Prostate Cancer Position Statement.
Memorial Sloan Kettering Cancer Center. Prostate fiducial marker placement and image-guided radiation patient guidance.
Last evidence update: September 2026.