HBOT Referral Guidelines for Urologists

When to Refer Patients With Radiation Cystitis, Hemorrhagic Cystitis, Pelvic Radiation Injury, Fournier Gangrene, and Compromised Urologic Reconstruction

Hyperbaric oxygen therapy, commonly abbreviated as HBOT, has a focused role within urology. Its most established urologic application is delayed radiation injury of the bladder, particularly radiation cystitis associated with hematuria, urinary frequency, urgency, dysuria, and reduced quality of life.

HBOT may also be relevant when a urologist is managing necrotizing infection, compromised reconstructive tissue, or another recognized hyperbaric condition. It is not a general treatment for lower urinary tract symptoms, recurrent urinary infection, erectile dysfunction, interstitial cystitis, postoperative discomfort, or uncomplicated surgical healing.

A useful referral identifies a specific tissue problem that increased oxygen delivery may help correct. The Undersea and Hyperbaric Medical Society recognizes delayed radiation injury involving soft tissue or bone as an accepted HBOT indication. Medicare separately covers soft tissue radionecrosis and osteoradionecrosis when HBOT is used as an adjunct to conventional treatment. (UHMS)

Radiation Cystitis Is the Primary Urologic Referral Indication

Pelvic radiation can produce progressive injury to the bladder months or years after cancer treatment. The affected tissue may become hypovascular, fibrotic, fragile, and chronically hypoxic.

Radiation cystitis may occur after treatment for:

• Prostate cancer
• Bladder cancer
• Cervical or endometrial cancer
• Rectal or anal cancer
• Other pelvic malignancies

Patients may present with:

• Microscopic or visible hematuria
• Clot retention
• Urinary frequency
• Urgency
• Dysuria
• Pelvic or bladder pain
• Reduced bladder capacity
• Incontinence
• Recurrent admissions or transfusion requirements

HBOT is intended to address the underlying radiation tissue injury rather than merely suppressing bleeding temporarily. Increased tissue oxygenation may support angiogenic signaling, capillary development, fibroblast activity, epithelial repair, and recovery of viable hypoxic tissue.

Do Not Attribute Hematuria to Radiation Without Evaluation

A previous history of pelvic radiation does not establish that new hematuria is caused by radiation cystitis.

Patients who received pelvic radiation remain at risk for urothelial malignancy and may also develop infection, stones, upper tract disease, renal pathology, prostatic bleeding, or anticoagulation-associated hemorrhage.

The 2025 AUA/SUFU microhematuria guideline identifies prior pelvic radiation as an additional urothelial cancer risk factor. It recommends risk-based evaluation, with cystoscopy and axial upper tract imaging for patients classified as high risk. (American Urological Association)

Before referring a patient for HBOT, the urologist should generally document an evaluation appropriate to the patient’s presentation and malignancy risk. This may include:

• Urinalysis and urine culture
• Complete blood count
• Renal function
• Cystoscopy
• Upper tract imaging
• Urine cytology in selected circumstances
• Biopsy of suspicious bladder lesions
• Review of anticoagulant or antiplatelet therapy

Cystoscopic findings associated with radiation injury may include telangiectasia, friable mucosa, diffuse erythema, ulceration, and bleeding from multiple surfaces. Suspicious focal lesions should be evaluated for recurrent or new malignancy rather than presumed to be radiation change.

Stabilize Severe Hemorrhage Before Outpatient Referral

A patient with active clot retention, hemodynamic instability, symptomatic anemia, obstructive uropathy, or uncontrolled gross hematuria requires immediate urologic and hospital management.

Initial treatment may include:

• Large-bore urethral catheter placement
• Manual clot evacuation
• Continuous bladder irrigation
• Cystoscopy with clot evacuation
• Fulguration of bleeding sites
• Transfusion when clinically indicated
• Reversal or adjustment of anticoagulation
• Upper tract decompression when necessary
• Angiographic embolization in selected refractory cases

HBOT is not an emergency substitute for relieving urinary obstruction or stabilizing blood loss. A bladder filled with clot still requires drainage, and a patient in hemorrhagic shock still requires resuscitation and bleeding control.

Hyperbaric consultation may occur during the hospitalization, especially when the bleeding appears radiation related and is likely to recur. The patient does not necessarily need to remain free of all visible hematuria before consultation, but the airway, circulation, bladder drainage, and immediate hemorrhagic risk must be manageable within the receiving facility’s capabilities.

Refer Before Repeated Bleeding Causes Major Morbidity

HBOT is sometimes considered only after numerous admissions, transfusions, endoscopic procedures, and intravesical treatments. This may delay treatment until the bladder has developed advanced fibrosis, reduced capacity, fistula, or extensive irreversible injury.

Earlier referral may be reasonable when:

• Radiation cystitis has been confirmed
• Hematuria recurs after cystoscopic management
• Urinary symptoms remain clinically significant
• The patient requires repeated irrigation or hospitalization
• Bleeding is producing anemia
• Conventional treatment provides only temporary relief
• The urologist wants to preserve the bladder before more destructive intervention
• The tissue appears viable enough to undergo vascular repair

The Canadian Urological Association best practice report recommends considering HBOT relatively early after cystoscopy and fulguration have failed, noting its ability to address the underlying ischemic process and the body of evidence supporting symptom improvement. (PubMed Central (PMC))

Referral should not be postponed solely because the patient has not tried every possible intravesical agent. Treatment sequencing should account for bleeding severity, local resources, contraindications, patient preferences, and the relative durability and morbidity of available interventions.

How HBOT May Improve Radiation-Damaged Bladder Tissue

During HBOT, the patient breathes oxygen at increased atmospheric pressure. This raises arterial oxygen tension and substantially increases oxygen dissolved in plasma.

Repeated hyperoxic exposures may stimulate vascular and reparative responses in chronically hypoxic radiation-damaged tissue. The intended effects include:

• Increased oxygen diffusion into injured bladder tissue
• Promotion of neovascularization
• Support for fibroblast and epithelial activity
• Improved collagen organization
• Reduction of selected inflammatory processes
• Improved tissue resistance to recurrent bleeding
• Support for healing after cystoscopic or reconstructive intervention

The objective is not simply to constrict bleeding vessels for the duration of a treatment. Hyperoxic vasoconstriction may temporarily reduce edema or bleeding, but the longer-term therapeutic rationale involves recovery of the microvascular environment.

This distinction helps explain why treatment usually requires a series of daily sessions rather than one isolated exposure.

Evidence From the RICH-ART Trial

The RICH-ART trial was a randomized, controlled, phase 2 to 3 study conducted at five Nordic university hospitals. It enrolled patients with persistent urinary symptoms after pelvic radiation and compared HBOT with standard care.

Patients assigned to HBOT received 30 to 40 sessions at approximately 2.4 to 2.5 atmospheres absolute for 80 to 90 minutes per treatment. At follow-up, the improvement in the EPIC urinary score was significantly greater in the HBOT group than in the standard-care group. Transient grade 1 or 2 adverse events involving vision or hearing were reported during treatment. (PubMed)

The five-year RICH-ART follow-up, published in 2025, found that patient-reported improvement in urinary symptoms was sustained over five years among the followed cohort. This provides important evidence that benefit can persist beyond the immediate treatment period. (The Lancet)

These results support HBOT for appropriately selected patients with chronic radiation cystitis. They do not establish equal benefit for every severity or clinical phenotype.

Understand Who Was Not Represented in RICH-ART

The RICH-ART trial excluded several patients frequently encountered in tertiary urologic practice.

Exclusions included:

• Ongoing bleeding requiring more than 500 mL of transfused blood during the previous four weeks
• A permanent urinary catheter
• Bladder capacity below 100 mL
• A bladder fistula
• Previous HBOT for late radiation injury

The trial therefore provides strong information about symptomatic chronic radiation cystitis but less direct guidance for patients with uncontrolled transfusion-dependent hemorrhage, a severely contracted bladder, chronic catheter dependence, or fistulizing disease. (PubMed)

HBOT may still be discussed in severe cases, but expectations should be cautious. Advanced structural damage may require embolization, urinary diversion, reconstructive surgery, or cystectomy. Treatment should not be presented as a reliable method of reversing a fibrotic, nonfunctional bladder.

Registry Data Support Improvement in Real-World Practice

Prospective data from the UHMS Multicenter Registry have also evaluated patient-reported outcomes after HBOT for radiation cystitis.

A 2024 Journal of Urology study examined changes in hematuria, urinary distress, and quality of life among patients treated at multiple centers. Patients underwent a median of approximately 39 sessions and reported improvements in hematuria, urinary function, and quality of life. (PubMed)

Registry data are valuable because they reflect broader clinical practice, including patients treated outside a randomized trial. They cannot fully control for selection bias, concurrent interventions, natural symptom variation, or differences among treatment protocols.

The combined evidence supports HBOT as a reasonable option for selected radiation cystitis patients while reinforcing the need for careful diagnosis and realistic outcome measurement.

Suggested Timing of Referral

Urologists should consider three broad referral pathways.

Urgent inpatient consultation may be appropriate when recurrent radiation bleeding continues after clot evacuation and stabilization, particularly if the patient is facing repeated transfusion, embolization, diversion, or cystectomy.

Early outpatient consultation may be appropriate after confirmation of radiation cystitis when hematuria or lower urinary tract symptoms remain clinically meaningful despite initial urologic treatment.

Planned perioperative consultation may be appropriate when a reconstructive operation is being considered within severely irradiated pelvic or perineal tissue and the team believes tissue oxygenation may affect healing.

Early referral does not mean that every patient will be accepted for treatment. It allows the hyperbaric physician to review the diagnosis, expected benefit, chamber safety, and timing before the disease reaches a less salvageable stage.

HBOT Protocols for Radiation Cystitis

Common protocols use approximately 2.0 to 2.5 atmospheres absolute for 80 to 120 minutes, usually once daily, five days per week.

A treatment course may include approximately 30 to 40 sessions, although the final number depends on:

• Clinical response
• Bleeding frequency
• Urinary symptom improvement
• Treatment tolerance
• The extent of radiation damage
• Planned surgery
• Recurrence during or after treatment

The RICH-ART protocol used 30 to 40 sessions at 240 to 250 kPa for 80 to 90 minutes. (PubMed)

The hyperbaric physician should prescribe the pressure, oxygen periods, air breaks, and number of treatments. The urologist should continue to monitor hematuria, catheter needs, hemoglobin, bladder function, and the possibility of another underlying diagnosis.

Coordinate HBOT With Urologic Procedures

HBOT should be integrated with urologic management rather than treated as a transfer of care.

The urologist may still need to provide:

• Repeat cystoscopy
• Clot evacuation
• Fulguration
• Catheter management
• Intravesical treatment
• Upper tract evaluation
• Management of obstruction
• Surveillance for malignancy
• Embolization referral
• Reconstructive planning

Communication is particularly important when an operation is scheduled during the treatment course. The teams should agree on whether HBOT is intended to prepare irradiated tissue before surgery, support healing afterward, or treat an established radiation injury independent of the operation.

A scheduled chamber treatment should not delay urgent cystoscopy, relief of obstruction, or control of active hemorrhage.

Pelvic Soft Tissue Radionecrosis Beyond the Bladder

Pelvic radiation injury may involve more than the bladder mucosa. Urologists may encounter:

• Perineal wounds
• Urethral tissue injury
• Pelvic soft tissue necrosis
• Nonhealing suprapubic or surgical wounds
• Radiation-damaged tissue surrounding urinary diversion
• Combined bladder and rectal injury
• Wounds involving previously irradiated genital tissue

HBOT may be considered when a documented soft tissue radionecrosis is contributing to poor healing and viable tissue remains. Medicare lists soft tissue radionecrosis as a covered condition when HBOT is used as an adjunct to conventional treatment. (Centers for Medicare & Medicaid Services)

A fistula, ureteral obstruction, urethral stricture, or severely contracted bladder should not be expected to resolve solely through HBOT. These structural problems require diagnosis-specific surgical or reconstructive management.

Fournier Gangrene Requires Surgery Before Chamber Treatment

Fournier gangrene is a necrotizing soft tissue infection involving the perineum, genitalia, or lower abdominal wall. It is a surgical emergency.

Management requires:

• Immediate resuscitation
• Broad-spectrum antimicrobial therapy
• Urgent and extensive debridement
• Repeated operative inspection
• Critical care
• Management of diabetes, renal dysfunction, and shock

HBOT may be considered as an adjunct when it can be delivered without delaying initial or repeat debridement. Medicare covers progressive necrotizing infections, including necrotizing fasciitis, within its national HBOT policy. (Centers for Medicare & Medicaid Services)

A patient should not be transferred away from timely surgical care solely to reach a chamber. Referral is most appropriate when source control has started, the patient can be transported safely, and the receiving hospital can maintain the required surgical and critical-care capability.

Compromised Urologic Grafts and Flaps

Urologists involved in genital, perineal, urethral, or urinary reconstruction may encounter compromised tissue after grafting or flap placement.

Possible referral scenarios include:

• A threatened skin graft after genital reconstruction
• A compromised perineal flap
• Ischemic tissue following urethral reconstruction
• Reconstruction within a heavily irradiated field
• Tissue loss after debridement of Fournier gangrene
• A threatened flap covering urinary or pelvic structures

The operating surgeon must first evaluate for hematoma, seroma, infection, excessive tension, arterial insufficiency, venous congestion, or mechanical disruption.

HBOT is not indicated for a graft or flap that is healing normally. Medicare covers preparation and preservation of compromised skin grafts, specifically distinguishing this use from primary management of ordinary wounds. (Centers for Medicare & Medicaid Services)

The hyperbaric referral should describe the operation, tissue used, vascular status, signs of compromise, corrective procedures already performed, and the specific reconstruction being preserved.

Non-Radiation Hemorrhagic Cystitis

Hemorrhagic cystitis can also follow:

• Cyclophosphamide or ifosfamide
• Hematopoietic stem cell transplantation
• BK virus
• Adenovirus
• Other infectious or chemical injuries

The evidence for HBOT in these settings is substantially less established than the evidence for radiation cystitis. A 2024 retrospective report described HBOT alongside conventional supportive treatment in 16 patients with late-onset hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation, but this small nonrandomized study cannot define standard practice. (PubMed)

Referral may be discussed for an exceptional refractory case, but the urologist should clearly identify the cause and recognize that:

• The indication may be investigational
• Insurance coverage may not apply
• Infection-directed or hematologic treatment remains essential
• The expected benefit is less certain
• The protocol may not be standardized

Non-radiation cystitis should not be coded or documented as soft tissue radionecrosis merely to obtain coverage.

Conditions That Do Not Routinely Warrant HBOT Referral

HBOT is not established as routine care for:

• Interstitial cystitis or bladder pain syndrome
• Chronic prostatitis or chronic pelvic pain
• Recurrent uncomplicated urinary tract infection
• Overactive bladder
• Stress or urge incontinence
• Benign prostatic hyperplasia
• Erectile dysfunction
• Peyronie disease
• Uncomplicated postoperative healing
• Routine recovery after prostatectomy
• An uncomplicated urethral reconstruction
• A healthy graft or flap
• General pelvic inflammation

The presence of pelvic pain, urinary frequency, or poor wound healing does not automatically indicate radiation tissue necrosis or another oxygen-responsive condition.

A hyperbaric physician may still provide consultation when the diagnosis is uncertain, but referral should not promise treatment before eligibility has been assessed.

Information to Include With the Referral

A complete referral reduces delays and helps the hyperbaric team assess medical necessity.

Include:

• The suspected hyperbaric diagnosis
• The clinical objective
• Cancer and radiation history
• Radiation field, dose, and treatment dates when available
• Hematuria onset and severity
• Transfusion and hospitalization history
• Cystoscopy findings
• Pathology and cytology
• Upper tract imaging
• Urine culture results
• Previous fulguration or intravesical therapy
• Current catheter or irrigation requirements
• Bladder capacity when known
• Presence of fistula, obstruction, or hydronephrosis
• Anticoagulant and antiplatelet therapy
• Planned urologic procedures

For compromised reconstruction, include the operative report, current photographs, perfusion findings, and details of any surgical revision.

For Fournier gangrene, direct physician-to-physician communication should address debridement status, hemodynamics, ventilatory support, planned return to the operating room, and whether the receiving center can manage the patient’s acuity.

Hyperbaric Safety Screening

The hyperbaric team will conduct its own evaluation, but the urologist should identify factors that may affect treatment.

Relevant issues include:

• Known or suspected pneumothorax
• Severe pulmonary air trapping
• Uncontrolled seizure disorder
• Ear or sinus disease
• Heart failure or significant fluid overload
• Unstable cardiovascular status
• Implanted medical devices
• Insulin or glucose-lowering treatment
• Severe claustrophobia
• Mechanical ventilation
• Continuous infusions
• Pregnancy

Catheters, drainage bags, nephrostomy tubes, ostomy appliances, dressings, and implanted devices require chamber-specific planning. The need for a urinary catheter does not automatically preclude HBOT, but the tubing and collection system must be managed safely during compression and decompression.

Coverage and Documentation

Medicare covers HBOT for soft tissue radionecrosis and osteoradionecrosis when used as an adjunct to conventional treatment. It also covers progressive necrotizing infection and preservation of compromised skin grafts. (Centers for Medicare & Medicaid Services)

Radiation cystitis is typically treated under the soft tissue radionecrosis category when the diagnosis and treatment rationale are documented appropriately.

The medical record should establish:

• Previous therapeutic radiation exposure
• Delayed tissue injury within the radiation field
• Symptoms and objective findings
• Exclusion of recurrent malignancy and other causes when appropriate
• Conventional treatment already provided
• The clinical objective of HBOT
• Ongoing response and medical necessity

Commercial payer policies, prior-authorization requirements, and accepted diagnosis codes vary. The hyperbaric center should verify the patient’s specific benefits rather than assuming that all radiation-associated urinary symptoms qualify.

Measure Outcomes That Matter to Urologic Care

The treatment plan should define what improvement would justify continuing HBOT.

Possible outcomes include:

• Resolution or reduction of visible hematuria
• Fewer clot-retention episodes
• Reduced transfusion requirement
• Improved urinary frequency or urgency
• Reduced dysuria
• Improved patient-reported urinary function
• Fewer hospital admissions
• Successful healing of irradiated tissue
• Preservation of a graft or flap
• Avoidance or postponement of diversion or cystectomy

Improvement should be evaluated over time rather than judged solely by urine appearance on one treatment day.

Some patients experience partial improvement rather than complete resolution. A reduction in hospitalization, transfusion, or procedural burden may still be clinically meaningful.

Continue Urologic Follow-Up After HBOT

Completion of HBOT does not eliminate the need for urologic surveillance.

Patients may require follow-up for:

• Recurrent hematuria
• Malignancy surveillance
• Bladder capacity and storage symptoms
• Upper tract obstruction
• Infection
• Catheter dependence
• Incontinence
• Fistula
• Late reconstructive needs

Symptoms may recur, and selected patients may be considered for additional HBOT after reassessment. The five-year RICH-ART findings indicate that improvement can remain durable, but not every patient maintains complete symptom control indefinitely. (The Lancet)

The best referrals occur after the urologist has confirmed or strongly characterized the disease process, addressed immediate threats, and identified a clear treatment objective. For radiation cystitis, referral should occur before repeated bleeding and fibrosis leave the bladder with little recoverable function.

HBOT is most effective as part of coordinated urologic care. It can support vascular recovery in radiation-damaged tissue, but it cannot replace clot evacuation, cancer evaluation, infection treatment, reconstruction, diversion, or other definitive management when those interventions are required.