Asia
Hyperbaric
Centre
Who Is
This For?
This supportive protocol is for people who received radiation therapy to the pelvis — for prostate, bladder, rectal, cervical, or other gynaecological cancers — and are now experiencing its late effects on the bladder (radiation cystitis) or the rectum (radiation proctitis).
It is most appropriate for those experiencing:
Radiation cystitis: Blood in the urine (haematuria) that keeps returning, urinary urgency or frequency that disrupts daily life, or bladder pain — typically appearing six months to many years after treatment.
Radiation proctitis: Rectal bleeding (haematochezia), mucus discharge, urgency, or a constant feeling of incomplete emptying — especially when standard measures such as topical agents or argon plasma coagulation have not resolved it.
Both together: The bladder and rectum sit in the same radiation field. Many clients arrive with injury on both sides, and the protocol addresses the whole irradiated region.
A doctor's referral is required before any protocol begins. If you do not have one, we can help you coordinate with your urologist, gastroenterologist, or oncologist.
Late radiation injury follows a slow clock. Symptoms commonly surface six months to several years after treatment ends — sometimes a decade later. The evidence carries one consistent message about timing: response is best when sessions begin before bleeding becomes severe and transfusion-dependent [2] [4].
You should consider discussing hyperbaric oxygen with your specialist when:
Blood in your urine or stool has recurred after an initial episode settled — recurrence is the pattern, and it rarely reverses on its own.
Standard measures have been tried without lasting resolution — bladder instillations, topical agents, or argon plasma coagulation for rectal bleeding.
Urgency, frequency, or night-time waking is shrinking your daily life, even when bleeding is mild.
Your specialist is discussing more invasive options, and you want to try the evidence-backed conservative protocol first.
Bleeding has required transfusion, or your iron levels keep falling. Do not wait for this point — but if you are here, act now.
When to Consider HBOT
Healing the Tissue the Bleeding Comes From
Bladder and bowel linings renew themselves constantly. That renewal runs on blood supply. Radiation silently narrows and scars the microscopic vessels of the pelvis — a process called obliterative endarteritis. Years later, the lining it feeds becomes thin, fragile, and studded with abnormal surface vessels (telangiectasia) that rupture easily [1]. Bleeding is the visible sign. Underneath it is tissue that is hypovascular, hypocellular, and chronically starved of oxygen.
Stopping the bleeding vessel by vessel — cauterising each one — does not change the tissue that keeps producing them.
Inside the chamber, we change the physics. At 2.0 to 2.5 ATA, 99.5% medical-grade oxygen dissolves directly into the blood plasma, bypassing red blood cells entirely [1]. This hyper-oxygenated plasma reaches pelvic tissue that normal circulation has abandoned.
Over a course of sessions, three documented effects follow. New micro-vessels grow into the irradiated tissue (angiogenesis), restoring real circulation. The fragile lining regains the oxygen it needs to rebuild its protective barrier. And your own stem cells are mobilised to the injured region [1] [5]. The aim is not to patch this month's bleed. It is to restore the tissue that stops next year's.
The Science & Clinical Evidence
We do not make promises. The research does that. Pelvic radiation injury is one of the few areas in this field with randomized, controlled trials — the gold standard — on both the bladder and the bowel side.
For radiation cystitis, the RICH-ART trial, published in The Lancet Oncology, randomised 79 people with late radiation cystitis to hyperbaric oxygen (30–40 sessions) or standard care [2]:
40% vs 9% — the proportion regaining a good urinary quality of life (EPIC score ≥ 80) with hyperbaric oxygen versus standard care. Urinary symptom scores improved by 17.8 points versus 7.7 (P = .013). — Oscarsson et al., The Lancet Oncology, 2019 (RICH-ART) [2]
5 years — the follow-up confirming that the improvement was sustained. Most responders kept their gains long-term; a small number needed a second course. — Oscarsson et al., eClinicalMedicine, 2025 [6]
For radiation proctitis, a randomized, double-blind, placebo-controlled crossover trial — the strongest design this field has produced — compared hyperbaric oxygen against sham pressure in 120 people with refractory rectal radiation injury [3]:
88.9% vs 62.5% — the proportion of responders with hyperbaric oxygen versus sham (P = .0009). The number needed to treat was 3 — meaning every third person treated gained a benefit they would not otherwise have had. — Clarke et al., Int J Radiation Oncology Biology Physics, 2008 [3]
Real-world data supports the trials. A 10-year cohort of people with radiation proctitis reported complete resolution of bleeding in 64.6% and overall response in 94.3% [7]; a meta-analysis of 602 people with haemorrhagic radiation cystitis found partial or complete resolution in 84% [4].
Where we are honest with you: RICH-ART could not be blinded — a true sham hyperbaric session is difficult to stage — and one trial (HOT2) found no benefit when the outcome measured was broad bowel dysfunction rather than bleeding [7]. The evidence is strongest where the target is precise: bleeding, and the tissue it comes from. That is the target this protocol aims at.
Our protocols follow the session structures used in the trials above [2] [3]. The parameters are not arbitrary — they are the ones that produced the published outcomes.
Oxygen Purity: 99.5% Medical-Grade Oxygen — pharmaceutical-grade purity certified under the Pharmacy and Poisons Ordinance (Cap. 138) [8].
Chamber Pressure: 2.0 to 2.5 ATA (Atmospheres Absolute) — the pressure range used in RICH-ART and the proctitis crossover trial [2] [3].
Session Duration: 90 minutes at depth.
Frequency: Once daily, 5 days per week.
Total Course: 30 to 40 sessions — the structure used in the randomized trials. Severe or transfusion-dependent cases may require up to 60, coordinated with your specialist [2] [3] [9].
The Protocol
What To Expect
We understand that entering a hyperbaric chamber can feel unfamiliar. Our team is here to guide you through every step of the process, ensuring you feel comfortable, safe, and supported.
Step 1 — The Briefing & Preparation: Before your first session, our technician will walk you through the safety protocols. You will change into 100% cotton clothing (provided) to eliminate static risk. No electronics, watches, or oil-based cosmetics are allowed inside the chamber.
Step 2 — Pressurisation: As the chamber pressurises over 10-15 minutes, you will feel a sensation in your ears similar to descending in an airplane. Our technician will coach you on simple techniques to clear your ears. Once at depth (2.0-2.4 ATA), you will breathe 99.5% pure oxygen through a comfortable hood or mask. You can read, rest, or watch a screen during the 90-minute session.
Step 3 — Depressurisation & Next Steps: The chamber will slowly depressurise over 10-15 minutes. Once open, you can return to your normal daily activities immediately. Our technician will examine your wound site and coordinate with your primary wound care team to track your progress.
FAQ
How many sessions before I notice a difference?
Most protocols run 30 to 40 sessions. In the trials, improvement was measured at 6 to 8 months from the start — tissue repair sets the pace, not the session count [2] [3]. Many clients report fewer bleeding episodes or reduced urgency partway through the course. We review progress with you and your specialist as we go.
Will the bleeding stop completely?
That is the aim, and often the result — in the 10-year proctitis cohort, bleeding resolved completely in about two-thirds of cases and improved in most of the rest [7]. But no honest provider promises a complete stop for everyone. A minority relapse, sometimes months or years later; most of those respond to a further course [6]. What we can promise is a protocol with randomized-trial evidence behind it and transparent tracking of your response.
Can hyperbaric oxygen cause my cancer to come back?
This question matters, and the evidence answers it clearly. Systematic reviews examining this specific concern have found no indication that hyperbaric oxygen stimulates tumour growth or recurrence [10]. The protocol supports the recovery of normal tissue injured by radiation. Nothing more.
Feldmeier J, et al. Delayed Radiation Injury (Soft Tissue and Bony Necrosis). UHMS Hyperbaric Oxygen Therapy Indications, 15th Edition. Undersea and Hyperbaric Medical Society. UHMS Official Indications
Oscarsson N, Müller B, Rosén A, et al. Radiation-induced cystitis treated with hyperbaric oxygen therapy (RICH-ART): a randomised, controlled, phase 2-3 trial. Lancet Oncol. 2019;20(11):1602-1614. PubMed 31522932
Clarke RE, Tenorio LM, Hussey JR, et al. Hyperbaric oxygen treatment of chronic refractory radiation proctitis: a randomized and controlled double-blind crossover trial with long-term follow-up. Int J Radiat Oncol Biol Phys. 2008;72(1):134-143. PubMed 18342453
Cardinal J, et al. Scoping review and meta-analysis of hyperbaric oxygen therapy for radiation-induced hemorrhagic cystitis. Curr Urol. 2019;12(6):38. [UNVERIFIED — volume/issue/pages to be confirmed before publication]
Thom SR, et al. Stem cell mobilization by hyperbaric oxygen in humans is mediated by nitric oxide. Am J Physiol Heart Circ Physiol. 2006;290(4):H1378-H1386. PubMed 16199259
Oscarsson N, Rosén A, Müller B, et al. Radiation-induced cystitis treated with hyperbaric oxygen therapy (RICH-ART): long-term follow-up of a randomised, controlled, phase 2-3 trial. EClinicalMedicine. 2025;83:103214.
Moreira Monteiro A, et al. The effectiveness of hyperbaric oxygen therapy for managing radiation-induced proctitis — results of a 10-year retrospective cohort study. Front Oncol. 2023;13:1235237. Frontiers
Hong Kong e-Legislation. Pharmacy and Poisons Ordinance (Cap. 138). Cap. 138 on e-Legislation
Cooper JS, et al. Hyperbaric Treatment of Radiation Proctitis. StatPearls. 2023. NCBI Bookshelf
Feldmeier J, et al. Does hyperbaric oxygen enhance tumor growth or recurrence? A systematic review. Undersea Hyperb Med. 2003;30(1):1-24. PubMed 12841604
