How Brachytherapy Works — the Science Without the Jargon

---

Radiation kills cancer cells by damaging their DNA so thoroughly that the cells can no longer divide. External beam radiation — EBRT and SBRT — achieves this by directing beams from outside the body toward the prostate.

Brachytherapy achieves the same goal by placing the radiation source directly inside the prostate, where it delivers its dose from within.

The internal delivery has one significant precision advantage. The radiation dose from a seed falls off rapidly with distance.

The prostate receives a very high dose while the adjacent bladder, rectum, and urethra receive substantially less than with equivalent external beam techniques.

There are two types of brachytherapy for prostate cancer. Low-dose-rate brachytherapy — LDR, also called seed implant — involves placing 70 to 120 tiny radioactive seeds permanently into the prostate.

High-dose-rate brachytherapy — HDR — uses temporary catheters through which a single high-activity source briefly moves into precise positions inside the prostate, then withdraws completely. No material remains in the body.

This guide focuses primarily on LDR seed implant, which is the more common standalone approach.

What the seeds are and how they work

LDR brachytherapy seeds are typically made of iodine-125 or palladium-103 — both low-energy radioactive isotopes. Each seed is a titanium capsule approximately 4.5 millimetres long and 0.8 millimetres in diameter.

The radiation emitted by these seeds has a very short range in tissue — the dose falls to near-zero within a centimetre. This is why the seeds must be precisely distributed throughout the prostate volume, not clustered in one area.

A physicist and radiation oncologist work together to create a treatment plan mapping exactly where each seed should sit to deliver a uniform high dose across the entire prostate gland. This planning is as clinically important as the implant procedure itself.

Iodine-125 seeds have a half-life of approximately 60 days. They deliver most of their total radiation dose over the first six months as the radioactivity decays. By approximately one year after implant, the seeds are essentially inert.

The seeds remain in the prostate permanently. They are never removed. They do not set off airport metal detectors — the titanium capsules are too small. They cause no sensation. Most men forget they are there.

Who Is a Good Candidate — and Who Is Not

---

Not every prostate cancer patient is suitable for LDR brachytherapy. The selection criteria are well defined and genuinely important — the outcome data that makes brachytherapy credible comes from populations of carefully selected patients.

Factors that make a patient a good candidate

Gleason grade: LDR brachytherapy alone — as monotherapy — is most appropriate for Grade Group 1 (Gleason 6) and Grade Group 2 (Gleason 3+4) disease. For Grade Group 3 or above, brachytherapy is used as a boost alongside external beam radiation, not as a standalone treatment.

PSA level: PSA below 10 is ideal for monotherapy brachytherapy. PSA between 10 and 20 is treatable with brachytherapy combined with short-course external beam radiation. PSA above 20 generally requires a different primary approach.

Prostate volume: This is the factor that catches many men off guard. Brachytherapy works best in prostates below approximately 50 to 60 grams in volume.

Larger prostates are technically more difficult to implant accurately — the pubic arch can obstruct needle placement. Larger prostates also tend to cause more severe post-implant urinary symptoms because they swell more after the procedure.

Men with very large prostates — above 80 grams — are generally not good candidates. Some radiation oncologists use a short course of hormone therapy beforehand to shrink a borderline prostate to a workable volume, though this adds ADT side effects to the plan.

Baseline urinary function: Men with significant pre-existing urinary symptoms — poor flow, frequency, nocturia — from benign prostatic hyperplasia are at higher risk of severe urinary obstruction after brachytherapy.

A formal urinary symptom score must be measured before brachytherapy is recommended.

Factors that make a patient unsuitable

Men who have had a previous TURP — transurethral resection of the prostate — are generally not good candidates. The TURP creates a cavity where seeds cannot be reliably retained, leading to dosimetric gaps and potentially inadequate coverage.

Men with inflammatory bowel disease involving the rectum — Crohn's disease or ulcerative colitis — are at higher risk of severe rectal complications and are generally excluded.

Men with a narrow pubic arch — which can restrict needle access to the posterior prostate — may not be technically suitable. This is assessed at the planning stage using an ultrasound assessment of pelvic anatomy.

The Procedure — What Happens Step by Step

---

Brachytherapy is performed under spinal or general anaesthesia. The entire procedure is typically complete within 90 minutes to two hours, and the patient is in a recovery room the same morning they were admitted.

Step 1 — Volume study and treatment planning

One to two weeks before the implant, a transrectal ultrasound volume study maps the exact dimensions of the prostate.

A physicist uses this data to calculate how many seeds are needed and precisely where each one should be placed to deliver a uniform dose across the entire prostate volume.

A seed placed even a few millimetres from its planned position can produce an under-dosed area. This is why the planning session is as clinically important as the implant day itself.

Step 2 — The implant

Under anaesthesia, a transrectal ultrasound probe images the prostate in real time. A template grid is placed against the perineum — the skin between the scrotum and anus.

The radiation oncologist inserts thin needles through the grid holes and into the prostate, guided by the ultrasound image. Seeds are deposited at precise positions as each needle is withdrawn.

Typically 70 to 120 seeds are implanted across 20 to 30 needle insertions. Once all seeds are in place, a fluoroscopy image confirms seed distribution. A urinary catheter is placed to manage the initial swelling around the urethra.

Step 3 — Hospital stay

Most patients spend one night in hospital. The catheter is assessed overnight. In most cases it is removed the following morning once urination is satisfactory, and the patient is discharged.

A small proportion of men — those with significant pre-procedure urinary symptoms or a large prostate — go home with the catheter in place for three to seven days while the initial swelling subsides.

This is managed with alpha-blocker medication and resolves in the vast majority of cases.

Recovery Timeline — What to Expect Week by Week

---

Brachytherapy recovery is different from surgery recovery and from EBRT recovery. There is no wound to heal and no post-surgical fatigue. What there is — is a prostate that has been punctured multiple times by needles and contains a permanent implant.

The prostate responds to this with swelling. That swelling produces urinary symptoms. Understanding this mechanism removes most of the anxiety about what recovery will feel like.

Days 1–7: The immediate post-procedure period

The perineum is sore from the needle insertions — similar to the sensation after a heavy bruise. Most men describe it as a three to four out of ten on the pain scale, well managed with paracetamol and ibuprofen.

Bruising in the perineal area is normal and resolves over ten to fourteen days. Urinary frequency and urgency begin within the first 24 to 48 hours as the prostate starts to swell.

Most international patients are comfortable returning to their serviced apartment by day two. They walk around normally, eat normally, and sleep reasonably well. The main complaint in week one is urinary — frequency, urgency, and mild discomfort passing urine.

Weeks 2–6: The peak urinary symptom period

Urinary symptoms typically worsen between two and six weeks after the implant. The radiation dose accumulates and the inflammatory response builds during this period. This is the most uncomfortable phase of brachytherapy recovery.

Urinary frequency at night — waking two to four times — is very common. A slow or interrupted urinary stream is common. Mild burning when urinating is common. These are all expected effects of radiation being delivered from within a swollen prostate.

For international patients who have returned home before this peak — which is typical, as most fly home within seven to ten days — this phase happens at home. The discharge side effect guide describes what is expected and what needs local medical attention.

Months 2–6: Gradual improvement

As the seeds decay and the prostate swelling resolves, urinary symptoms gradually improve. Most men notice significant improvement by months two to three.

The majority are at or near their pre-implant baseline by months four to six. Bowel symptoms — mild rectal urgency or looser stools — affect approximately 15 to 20 percent of men in the first three months but typically resolve by month four to six.

Radiation precautions after the implant

For the first two months, iodine-125 seeds are still actively emitting low-energy radiation. The radiation has a very short range — it is essentially shielded by your own body tissues.

Sensible precautions are recommended for close contact with pregnant women and young children for the first two months only. Avoid sitting a child under ten years old on your lap for more than 30 minutes at a time.

Maintain about one metre of distance from pregnant women during extended seated contact. These restrictions are modest and do not prevent normal social and family life. After two months, no precautions are necessary.

Brachytherapy Cost in India vs USA vs UK

---

LDR seed brachytherapy in India costs USD 4,000 to 7,500 at a JCI or NABH-accredited hospital. This includes the treatment planning session, seeds, anaesthesia, theatre, and the one-night hospital stay.

In the United States, the same procedure costs USD 15,000 to 30,000. In the United Kingdom privately, it costs GBP 10,000 to 18,000.

The seeds themselves — the iodine-125 capsules — are manufactured internationally and purchased at the same global price by hospitals in every country.

The cost difference reflects the same structural factors that make all Indian hospital procedures cheaper: lower labour costs and lower overhead, not lower quality standards or equipment.

Procedure	India	USA	UK (private)
LDR seed brachytherapy	$4,000–7,500	$15,000–30,000	GBP 10,000–18,000
HDR brachytherapy boost	$3,000–5,500	$12,000–25,000	GBP 8,000–15,000
EBRT + HDR boost combined	$7,000–12,000	$40,000–80,000	GBP 20,000–38,000
SBRT 5 sessions (comparison)	$5,000–9,000	$25,000–50,000	GBP 12,000–20,000

Total trip cost for international patients

The total episode cost for a brachytherapy trip to India — procedure, one night of hospital stay, seven to ten days of accommodation at USD 50 per night, and return flights from the UK or UAE — typically runs USD 6,000 to 11,000.

Brachytherapy's seven-to-ten-day India stay is the most compact of any prostate cancer radiation treatment episode.

Compare this to conventional EBRT, which requires four to eight weeks in India, or robotic prostatectomy, which typically requires three to four weeks before it is safe to fly home. For a working man with family responsibilities, that time difference is significant.

Cancer Control Outcomes — How Brachytherapy Compares

---

For correctly selected patients with low-to-intermediate-risk localised prostate cancer, LDR brachytherapy produces long-term cancer control outcomes equivalent to radical prostatectomy and external beam radiation.

Ten-year biochemical recurrence-free survival — the proportion of men whose PSA stays below the threshold that indicates recurrence — is 90 to 95 percent for Grade Group 1 and 2 disease treated with brachytherapy monotherapy at high-volume centres.

This is directly comparable to the outcomes reported by high-volume robotic prostatectomy and SBRT programmes for the same patient populations. The prostate cancer-specific mortality for low-risk disease treated with brachytherapy at fifteen years is below 2 percent.

For favourable intermediate-risk disease, prostate cancer-specific mortality is below 5 percent at fifteen years. These are outcomes consistent with cure in the vast majority of appropriately selected patients.

The honest comparison between treatment options

For low-to-intermediate-risk localised prostate cancer, no single treatment — surgery, EBRT, SBRT, or brachytherapy — has demonstrated superior long-term cancer-specific survival over the others in head-to-head comparison.

The choice between them is driven by side effect preferences, patient anatomy, logistical factors, and local availability — not by one treatment being definitively more effective than another.

Where brachytherapy has shown a specific advantage in some published data is in biochemical relapse rates for low-risk disease compared to EBRT.

The very high local dose delivered from directly inside the prostate appears particularly effective at eradicating tumours that might otherwise be underdosed by external beams.

Where brachytherapy falls behind surgery in the decision-making is in the salvage options if cancer recurs. If cancer recurs after prostatectomy, salvage radiation to the prostate bed is relatively straightforward.

If cancer recurs after brachytherapy, re-irradiation or salvage surgery is technically very demanding, though salvage HIFU and focal treatments are increasingly used at specialist centres.

Frequently Asked Questions

---