External Beam Radiation Therapy (EBRT)
External Beam Radiation Therapy is a common and effective treatment for prostate cancer. It uses highly targeted beams of radiation from outside the body to destroy cancer cells while sparing as much healthy tissue as possible.
It is a curative treatment, suitable for a wide range of men—from low-risk to high-risk disease, and sometimes used after surgery if cancer cells remain or return.
How EBRT Works
During EBRT, a machine called a linear accelerator directs radiation at the prostate (and sometimes nearby lymph nodes). Treatments are painless and done as short daily sessions.
Advances in imaging and computer-guided delivery allow doctors to target the tumour with millimetre precision.
Types of EBRT Used Today
• IMRT (Intensity-Modulated Radiation Therapy)
Most common. Shapes radiation beams around the prostate while protecting nearby organs.
• IGRT (Image-Guided Radiation Therapy)
Uses daily imaging or implanted markers to ensure the prostate is in the exact right position before each treatment.
• SBRT / SABR (Stereotactic Body Radiation Therapy)
Very high-precision, higher-dose treatments delivered in only 5 sessions (instead of 20–39). Often used for low- to intermediate-risk cancer or in some recurrence cases.
• Proton Therapy
Less common in Canada; uses proton beams instead of X-rays. Not widely available and not clearly superior in most cases.
What Treatment Is Like
Usually Monday–Friday appointments
Each session lasts 10–20 minutes
You lie on a table; the machine moves around you without touching
No hospitalization required
You can drive yourself to and from treatment
Most men can continue regular activities, including work and exercise, during treatment.
Possible Side Effects
Short-Term (during or shortly after treatment)
Increased urinary frequency or urgency
Burning when urinating
Fatigue
Loose stools or mild bowel irritation
Temporary erectile changes
These often improve within weeks to a few months.
Long-Term (months to years later)
Persistent urinary changes
Occasional bowel changes (rare with modern techniques)
Erectile dysfunction (risk increases over time)
With pelvic node radiation: slightly higher bowel and fatigue effects
Most long-term effects are manageable, and modern radiation techniques have significantly reduced risks.
Who May Benefit from EBRT
Low- or intermediate-risk cancer (alternative to surgery)
High-risk cancer (often combined with androgen deprivation therapy / hormone therapy)
Men who prefer non-surgical options
Men not ideal candidates for surgery
After surgery if PSA rises (salvage radiation)
Role of Hormone Therapy (ADT)
In higher-risk cancers, EBRT is often combined with hormone therapy for 6 months to 3 years to improve outcomes.
Not all men need ADT; low-risk patients receiving SBRT or standard EBRT typically do not.
Why Men Choose EBRT
Non-invasive
Highly effective
Outpatient treatment with minimal downtime
Comparable cure rates to surgery
Avoids surgical risks like incontinence
Talking to others who’ve undergone EBRT, such as those in PROSTAID Calgary’s support community, often helps men understand what daily treatment is truly like.
✔ a caregiver-focused explanation