마지막 업데이트: 8월 28, 2026

Radiotherapy to the pelvis — for prostate, cervical, rectal or bladder cancer — cannot spare everything in its path. The bladder sits in the middle of that field, and in a minority of patients the radiation leaves behind fragile, poorly-supplied tissue with abnormal blood vessels that bleed.

It affects roughly one in twenty people treated, and the timing is characteristic: sometimes within three to six months, but frequently years later — often around a decade after treatment finished, by which time the connection is easily missed.

The most important point on this page

The earlier version of this article moved from a history of radiotherapy straight to treating radiation cystitis. That step must not be skipped, because radiotherapy is itself a risk factor for a later bladder cancer.

Someone bleeding ten years after pelvic radiation has three possible explanations, not one: radiation damage to the bladder, a new cancer caused by the radiation, or the original cancer returning. They cannot be told apart by the history.

So the assessment is the same one anybody with visible blood in the urine receives — imaging of the kidneys and ureters, and a look inside the bladder — before the bleeding is attributed to radiation. Radiation cystitis is a diagnosis reached by exclusion, not one assumed from the history. See blood in the urine 그리고 유연한 방광경 검사.

Pelvic radiotherapy, which can leave long-term damage to the bladder wall
The bladder sits inside the radiation field — and the consequences can appear a decade later.

Controlling active bleeding

One caution worth knowing: drugs that promote clotting are sometimes used, and they carry a real risk of forming clots inside the bladder that then cannot be passed. This is a decision for the treating team rather than something to request.

Treating the underlying damage

Hyperbaric oxygen

The problem is essentially that irradiated tissue is starved of oxygen and cannot repair itself. Breathing oxygen at increased pressure raises the amount dissolved in the tissue enough to allow new blood vessels to form and healing to occur. It has the best evidence of anything on this list, with high response rates reported and better results the earlier it is started.

What the earlier version did not say is what it asks of the patient. This is not a single treatment: it is typically thirty to forty sessions, each lasting about two hours, on consecutive weekdays over several weeks. It requires a chamber, which not every city has. There are ear pressure problems, temporary short-sightedness that reverses, and it is unsuitable for some lung conditions and for people who cannot tolerate enclosed spaces.

Reported success figures of the order of nine in ten come from relatively small series in selected patients. The direction is reliable; the decimal place is not, and the commitment is real.

Hyperbaric oxygen chamber used to treat radiation-induced bladder injury
Effective — and a course of thirty or more sessions, which is worth knowing before starting.

Oral and bladder treatments

Surgery, and a correction

Where everything fails and bleeding is life-limiting, the bladder is removed and the urine diverted. The earlier version described this as creating a neobladder connected to the abdominal wall. Those are two different operations and the description has been corrected: a neobladder is an internal reservoir joined to the urethra, with no stoma, while a diversion to the abdominal wall is a conduit or a continent cutaneous reservoir.

Either is major surgery, and it is more difficult and carries a higher complication rate than usual because it is performed in tissue that has been irradiated and heals poorly. It is genuinely a last resort — which is why the earlier options are worth persisting with.

Two further things that help throughout: stopping smoking, which impairs the healing of irradiated tissue and independently raises bladder cancer risk, and keeping fluid intake up so that clots are less likely to form.

Symptoms that need attention the same day

In an emergency in Thailand, call 1669.

방사선 방광염에 대한 자주 묻는 질문

I had radiotherapy years ago and now there is blood in my urine. Is that radiation cystitis?

It may be, and it must not be assumed. Radiotherapy itself raises the risk of a later bladder cancer, and the original cancer can also return, so bleeding is investigated with imaging of the kidneys and ureters and a look inside the bladder before it is attributed to radiation damage. Radiation cystitis is a diagnosis of exclusion.

How long after radiotherapy can it appear?

Sometimes within three to six months, but often much later — commonly around a decade afterwards, which is long enough that patients and doctors may not connect the two.

What does hyperbaric oxygen involve?

Breathing oxygen at increased pressure to raise oxygen delivery to tissue that radiation has left poorly supplied, allowing repair. It has the best evidence of the available treatments and works better the earlier it is started — but it typically means thirty to forty sessions of about two hours each over several weeks, needs a chamber, and is unsuitable for some lung conditions or for those who cannot tolerate enclosed spaces.

Are there risks with the oral medication?

Pentosan polysulfate has been associated with a form of retinal damage affecting central vision after prolonged use, which may not fully reverse. Anyone taking it long term should have eye checks and report any change in vision. This was not mentioned in the earlier version of this article.

Will I need my bladder removed?

Very unlikely. It is reserved for bleeding that resists everything else, and it is more difficult and riskier than usual because irradiated tissue heals poorly — which is why the earlier treatments are worth persisting with even when progress is slow.

Arranging a consultation

Dr. Soarawee Weerasopone sees patients at 방콕 병원 본사 and at Samitivej Sriracha Hospital in Chonburi on 088-022-1445. Bring the details of your radiotherapy — what was treated, when, and where — together with any previous cystoscopy or imaging, and a list of your medicines including any blood thinner.

Bangkok Hospital Telemedicine is available for patients who cannot attend in person, including international patients — arrange it in advance by email to the Urology department at bhquro@bdms.co.th. Samitivej Sriracha is in-person only. Enquiries about cost and about hyperbaric chamber availability are answered by the hospital, not by this website. Heavy bleeding or clot retention goes to an emergency department, not to email.

고지 사항: This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters, and is intended for education only. It is not medical advice, diagnosis or a prescription for any individual, and no advice, diagnosis or prescription is given through personal messaging channels or social media. Dr. Soarawee operates no public social media account; any account offering private consultation in his name is fraudulent. In an emergency in Thailand, call 1669.

의학적으로 작성 및 검토됨: 소아라위 위라소폰 박사(폼 박사) - 방콕 병원 본부 소속 비뇨기과 전문의, 2016년부터 비뇨기과 진료 중. 펠로우십: 로봇 수술, 창궁 기념 병원, 대만(2019) · 참관: 내시경 비뇨기과, 준텐도 대학 병원, 도쿄(2022) · 연구원 및 임상 참관: 베일러 의과대학 스콧 비뇨기과, 미국(2025~2026).

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