TLDR

Hyperbaric oxygen therapy (HBOT) has a meaningful role at every phase of radiation treatment — before, during, and after. Used before radiation, HBOT optimizes tissue oxygenation and builds resilience. During radiation, it supports tissue integrity and reduces inflammatory burden. After radiation, it is FDA-approved to treat the chronic tissue damage — osteoradionecrosis, radiation cystitis, radiation proctitis, and soft tissue radionecrosis — that can persist for months or years. At OxygenWell in Sherman Oaks and Calabasas, Dr. Beth Meneley and her team provide physician-directed, FDA-cleared HBOT at up to 2.4 ATA, accepted by Medicare and most PPO insurance plans.

Table of Contents

• How Radiation Damages Healthy Tissue
• HBOT Before Radiation: Building Tissue Resilience
• HBOT During Radiation: Protecting Healthy Tissue
• HBOT After Radiation: FDA-Approved Injury Treatment
• FDA-Approved Radiation Injuries Treated with HBOT
• The Marx Protocol: Prevention of Osteoradionecrosis
• Does HBOT Promote Cancer Growth?
• What to Expect at OxygenWell
• Start Your HBOT Consultation

How Radiation Damages Healthy Tissue — and Why That Damage Can Last for Years

Radiation therapy is one of the most effective tools in oncology. Roughly half of all cancer patients receive radiation at some point during treatment, and for many, it is curative or life-extending. But radiation does not distinguish between cancer cells and the healthy tissue surrounding them. Over time, this exposure sets off a chain of cellular and vascular changes that can manifest months — or even years — after treatment ends.

The core mechanism of radiation-induced tissue injury is progressive hypoxia. Radiation damages the small blood vessels (arterioles and capillaries) that supply oxygen to tissue. As these vessels scar and narrow over time, blood flow to the irradiated region drops. Less blood flow means less oxygen delivery. Less oxygen means impaired cellular repair, reduced collagen production, suppressed immune function, and a tissue environment that simply cannot heal itself.

This sets off a damaging cycle:

• Hypoxia leads to poor healing and cell death
• Fibrosis (scarring) stiffens and further restricts blood vessels
• Reduced blood flow deepens the hypoxia
• Tissues become more vulnerable to infection, necrosis, and breakdown

Approximately 5% of cancer patients who receive radiation develop severe late-onset toxicity. For patients with head and neck cancers, pelvic cancers, or breast cancers — where radiation fields often encompass significant volumes of healthy tissue — this risk is particularly meaningful. Common late effects include osteoradionecrosis of the jaw, radiation cystitis, radiation proctitis, and soft tissue radionecrosis.

Hyperbaric oxygen therapy directly interrupts this cycle. By delivering 100% medical-grade oxygen at 1.5–2.4 ATA of pressure, HBOT dramatically increases dissolved oxygen in the plasma — reaching tissues that oxygen-carrying red blood cells can no longer access. It stimulates angiogenesis, reduces chronic inflammation, activates fibroblasts for collagen synthesis, and supports immune function in tissue that radiation has left depleted.

The clinical question is not just whether HBOT can help radiation patients — the evidence is clear that it can. The more precise question is when to use it, and at what protocol. The answer differs substantially across the three phases of radiation care.

HBOT Before Radiation: Building Tissue Resilience

The Pre-Radiation Rationale

Radiation works in part through an oxygen-dependent mechanism. When ionizing radiation strikes DNA, the damage is "fixed" (made permanent) by reactive oxygen species. In well-oxygenated tissue, this process is more efficient. In hypoxic tissue — the core of many solid tumors — the oxygen-dependent fixation is incomplete, meaning tumor cells in the hypoxic core receive less effective radiation damage. This phenomenon is called tumor radioresistance due to hypoxia.

Pre-radiation HBOT addresses this on two fronts: it oxygenates healthy tissue to make it more resilient to the coming radiation stress, and it may improve tumor oxygenation to reduce radioresistance. Research published in the European Journal of Cancer has shown that well-oxygenated tissues are often more responsive to radiation therapy.

Pre-Radiation Protocol at OxygenWell

• Pressure: 1.5–2.0 ATA
• Duration: 60–90 minutes per session
• Frequency: 2–5 sessions per week
• Goal: Optimize baseline tissue oxygenation, support mitochondrial health, reduce pre-existing inflammation, and improve tissue resilience before the radiation field is established

What Pre-Radiation HBOT Accomplishes

1. Optimizes tissue oxygenation. Each HBOT session temporarily elevates tissue oxygen levels 10–15x above baseline. With a series of sessions, this primes tissues with higher baseline oxygen availability heading into radiation treatment.

2. Supports mitochondrial health. Radiation stresses mitochondria — the energy-producing organelles in every cell. HBOT increases mitochondrial ATP production and upregulates antioxidant enzymes including superoxide dismutase (SOD) and glutathione. This mitochondrial preparation reduces cellular vulnerability to radiation-induced oxidative stress.

3. Improves tissue resilience. By stimulating early angiogenesis and fibroblast activity, HBOT helps tissues enter radiation in a state of stronger vascular architecture and reduced baseline inflammation.

4. Reduces baseline inflammation. Inflammatory cytokines — CRP, IL-6, TNF-a — are elevated in many cancer patients before radiation begins. HBOT consistently reduces these markers. Entering radiation with lower systemic inflammation may reduce the severity of acute radiation side effects.

"Well-oxygenated tissues are often more responsive to radiation therapy. Pre-radiation HBOT is about giving the body the best biological starting point."
— Dr. Beth Meneley, DAOM, L.Ac., Founder of OxygenWell

HBOT During Radiation: Supporting Oxygenation and Tissue Integrity

The Case for Concurrent Use

Using HBOT concurrently with radiation therapy requires coordination with the treating oncologist and a clear understanding of timing. When done appropriately, concurrent HBOT supports ongoing tissue health during a period of cumulative radiation stress.

The primary goals during radiation are protective, not curative. HBOT during radiation helps maintain the tissue oxygenation gradient that keeps healthy cells functional while radiation does its work on the tumor. It also helps offset the progressive vascular damage that begins accumulating from the first radiation fraction.

During-Radiation Protocol at OxygenWell

• Pressure: 1.5 ATA
• Duration: 60–90 minutes per session
• Frequency: 2–5 sessions per week, as tolerated
• Goal: Maintain tissue oxygenation, reduce acute inflammatory burden, support skin and soft tissue integrity, preserve tissue resilience throughout the radiation course

What HBOT Supports During Radiation

Skin and mucosal protection. Radiation dermatitis — the inflammatory skin reaction within the radiation field — is one of the most common acute side effects. Concurrent HBOT helps maintain microcirculation in the skin, reducing the severity of acute radiation skin reactions. For head and neck cancer patients, this extends to the mucosal surfaces of the mouth and throat, where radiation mucositis can be severe and dose-limiting.

Ongoing oxygenation of healthy tissue. As radiation fractions accumulate, vascular damage progresses. HBOT sessions deliver oxygen through plasma dissolution rather than through compromised red blood cell delivery, ensuring healthy tissues adjacent to the radiation field remain adequately oxygenated.

Reduction of inflammatory burden. Each radiation fraction triggers an acute inflammatory response. HBOT downregulates TNF-a, IL-6, and other pro-inflammatory cytokines, reducing the cumulative inflammatory load over a multi-week radiation course.

Fatigue support. Radiation fatigue is a nearly universal side effect, driven in part by mitochondrial dysfunction and systemic oxidative stress. HBOT's role in improving mitochondrial ATP production and reducing oxidative stress markers may help patients maintain energy and quality of life during treatment. A 2016 meta-analysis in Support Care Cancer confirmed that HBOT improves quality of life and reduces fatigue in cancer patients.

Important note: HBOT during active radiation requires coordination with your radiation oncologist. OxygenWell works collaboratively with oncology teams to ensure timing, scheduling, and protocol selection are appropriate for each patient's specific cancer type and treatment plan.

HBOT After Radiation: FDA-Approved Treatment for Radiation Injuries

Why Post-Radiation Tissue Damage Develops

For most patients, the side effects of radiation therapy resolve within six months. For approximately 5–10%, however, the damage is progressive and irreversible without intervention. As irradiated blood vessels scar and narrow over time, tissue oxygen levels continue to fall — sometimes for years after treatment ends. The result is a spectrum of delayed radiation injuries: chronic wounds that will not close, bone that dies and fractures, bladder bleeding that recurs, and bowel inflammation that causes daily pain and urgency.

These conditions are not rare complications of aggressive treatment. They are the predictable consequence of radiation physics in vulnerable tissue — and they have a well-established, FDA-approved treatment: hyperbaric oxygen therapy.

Post-Radiation HBOT Protocol at OxygenWell

• Pressure: 2.0–2.4 ATA
• Duration: 90 minutes per session
• Frequency: 5 sessions per week
• Total sessions: 20–40+ sessions (condition-dependent)
• Goal: Stimulate angiogenesis, improve oxygen delivery to chronically hypoxic tissue, support collagen production, reduce chronic inflammation, and restore tissue viability

This higher-pressure, longer-duration protocol is clinically distinct from the pre- and during-radiation protocols. The goal shifts from prevention and support to active tissue repair and regeneration.

The Mechanisms of Post-Radiation HBOT Healing

Angiogenesis. HBOT stimulates vascular endothelial growth factor (VEGF) and other angiogenic signals, triggering the growth of new capillary networks in hypoxic tissue. This is the central mechanism by which HBOT reverses the hypoxia-fibrosis-hypoxia cycle of radiation injury. New blood vessels restore the oxygen and nutrient supply that radiation depleted.

Stem cell mobilization. After approximately 10 HBOT sessions, CD34+ stem cells are mobilized from bone marrow at up to 8x baseline levels. These circulating progenitor cells home to areas of injury and contribute to tissue repair, new vessel formation, and regeneration.

Collagen synthesis. Fibroblasts — the cells responsible for producing collagen and rebuilding connective tissue — require oxygen to function. HBOT restores the oxygen environment that fibroblasts need, supporting the collagen production essential for wound closure and tissue reconstruction.

Reduction of chronic inflammation. Radiation-injured tissue carries a persistent inflammatory burden long after treatment ends. HBOT systematically reduces CRP, IL-6, TNF-a, and other markers of chronic inflammation — shifting the tissue environment from ongoing damage to active healing.

Research support: A 2025 clinically focused review published in CA: A Cancer Journal for Clinicians — one of oncology's highest-impact journals — confirmed that HBOT is effective for treating fibrosis, radiation proctitis, and radiation cystitis. A comprehensive PubMed review found Grade B and C evidence that HBOT at pressures exceeding 2 ATA reduced late-onset radiation injuries to the head and neck, bone, prostate, and bladder. [PubMed: Hyperbaric oxygen and radiation therapy: a review, 2020]

FDA-Approved Radiation Injuries Treated with HBOT

HBOT is FDA-approved for several delayed radiation injuries. At OxygenWell, these conditions are covered by Medicare and most PPO insurance plans — our billing team handles all pre-authorizations.

Osteoradionecrosis (ORN)

Osteoradionecrosis is the death of bone in a previously irradiated field. It most commonly affects the jaw (mandible) in patients who received head and neck radiation, but it can also occur in other bones. ORN presents as exposed, non-healing bone — often painful, prone to infection, and resistant to standard wound care. Without adequate oxygen, irradiated bone cannot heal, and the damage progresses.

HBOT for ORN restores the oxygen gradient that bone cells need to survive and regenerate. It stimulates angiogenesis in the periosteum (bone's outer layer), supports osteoblast activity, and reduces the bacterial burden that often accompanies exposed bone. Standard protocol: 30–40 sessions at 2.0–2.4 ATA, 90 minutes, 5x/week. HBOT is also a critical preventive measure before dental surgery in irradiated fields — see the Marx Protocol section below.

Radiation Cystitis

Radiation cystitis occurs when the bladder wall is damaged by radiation to the pelvis — most commonly after treatment for prostate, cervical, uterine, rectal, or bladder cancers. Symptoms include hematuria (blood in urine), urinary frequency, urgency, pelvic pain, and in severe cases, life-threatening hemorrhage. The damage results from the same vascular scarring and hypoxia that drives all delayed radiation injuries — in this case, affecting the highly vascularized bladder mucosa.

Multiple prospective studies report symptom improvement rates of 76–89% for radiation cystitis with HBOT. The 2025 CA: Cancer Journal for Clinicians review specifically confirmed HBOT effectiveness for radiation cystitis. At OxygenWell, this is one of our most commonly treated radiation injuries — and one with excellent outcomes. Protocol: 30–40 sessions, 2.0–2.4 ATA, 90 minutes, 5x/week.

Radiation Proctitis

Radiation proctitis affects the rectum and sigmoid colon following pelvic radiation. It can cause rectal bleeding, urgency, tenesmus (a persistent feeling of needing to defecate), bowel urgency, and significant quality-of-life impairment. Like cystitis, it results from hypoxia-driven vascular damage to the rectal mucosa.

Research consistently demonstrates HBOT response rates of 80%+ for radiation proctitis. The angiogenic and anti-inflammatory effects of HBOT restore mucosal blood flow and support tissue healing in the damaged rectum. Protocol: 30–40 sessions, 2.0–2.4 ATA, 90 minutes, 5x/week. Medicare and PPO insurance typically cover this indication.

Soft Tissue Radionecrosis (STNR)

Soft tissue radionecrosis is the necrosis of soft tissue — muscle, subcutaneous fat, fascia, or skin — within a previously irradiated field. It presents as non-healing wounds, ulcerations, or necrotic areas that fail to respond to conventional wound care. The hypoxic, fibrotic tissue environment created by radiation prevents the normal wound healing cascade from proceeding.

HBOT is FDA-approved for STNR and provides the physiological foundation for healing: restored oxygenation, new capillary networks, activated fibroblasts, and reduced inflammatory burden. Protocol: 20–40 sessions, 2.0–2.4 ATA, 90 minutes, 5x/week. See our related article on radiation tissue injuries and HBOT for a deeper clinical review.

The Marx Protocol: Preventing Osteoradionecrosis Before Dental Surgery

One of the most well-established and clinically important applications of HBOT in radiation oncology is the Marx Protocol — a peri-surgical HBOT regimen designed to prevent osteoradionecrosis in patients who need dental procedures after head and neck radiation.

The Clinical Problem

Patients who have received radiation to the head and neck — for oral cancers, throat cancers, thyroid cancers, and others — face a serious risk when they need tooth extractions, implants, or other dental surgery. The irradiated jawbone has compromised vascularity and reduced capacity to heal. Surgical trauma to this tissue can trigger ORN — a condition where the bone cannot repair itself, leading to exposed, infected, and potentially progressive bone death.

Before the Marx Protocol, the incidence of ORN after dental extractions in irradiated fields was approximately 29.9%. Robert Marx, DDS, a pioneer in hyperbaric medicine, developed a peri-surgical HBOT protocol that changed this outcome dramatically.

The Protocol

• Pre-surgical: 20 HBOT sessions (2.0–2.5 ATA, 90 minutes) before oral surgery
• Surgery: Conservative, atraumatic oral surgical technique
• Post-surgical: 10 HBOT sessions (2.0–2.5 ATA, 90 minutes) after surgery

The Outcome

The Marx Protocol reduced the incidence of ORN after dental extractions in irradiated fields from 29.9% to 5.4% — an 82% reduction in a devastating complication. This outcome has been replicated in subsequent studies and is now endorsed by the Undersea and Hyperbaric Medical Society (UHMS) and recognized by Medicare and most PPO insurance plans.

At OxygenWell's Calabasas location, we work closely with oral surgeons — including providers at Calabasas Medicine directly across the street — to coordinate Marx Protocol HBOT around planned dental procedures. Pre-authorization for this indication is handled entirely by our billing team.

Citation: Marx RE et al. Undersea Hyperb Med. 1985.

Does Hyperbaric Oxygen Therapy Promote Cancer Growth?

This is the question that many cancer patients — and their oncologists — ask before pursuing HBOT. It deserves a direct, evidence-based answer.

The Concern

The historical concern arose from the observation that HBOT promotes angiogenesis (new blood vessel growth) and cell proliferation in wound healing. If these same effects applied to tumors, HBOT could theoretically stimulate cancer growth. Early case reports in the 1960s raised this possibility.

What the Evidence Shows

Current evidence does not show that HBOT promotes cancer growth or recurrence.

Two systematic reviews — widely cited in the hyperbaric medicine literature — examined all available clinical data, animal studies, and cell culture studies on HBOT and cancer. Both concluded that the available evidence does not support a cancer-promoting effect. A landmark review by Feldmeier et al. specifically addressed this question and found no evidence that HBOT promotes malignancy recurrence or new tumor growth. [PubMed: Hyperbaric oxygen: does it promote growth or recurrence of malignancy?]

More recent research has further clarified the picture. Hypoxia — the low-oxygen state that HBOT corrects — is itself a driver of cancer progression. Hypoxic tumors are more aggressive, more treatment-resistant, and more prone to metastasis. The tumor microenvironment under hypoxia upregulates HIF-1a, a transcription factor that promotes tumor survival and invasion. Restoring oxygen may actually inhibit several of these hypoxia-driven oncogenic pathways.

A 2023 review in Frontiers in Oncology explored how HBOT modulates the tumor microenvironment to support immune function and improve the efficacy of immunotherapy — further evidence that oxygen supports, rather than undermines, the body's anti-tumor capacity. [Frontiers in Oncology: HBOT and tumor microenvironment, 2023]

The current position of the Undersea and Hyperbaric Medical Society (UHMS): HBOT is not contraindicated in cancer patients, and the fear that it promotes tumor growth is not supported by clinical evidence.

"Oxygenated tissues are often more responsive to radiation therapy. The concern that HBOT promotes cancer growth has been studied extensively — and the evidence consistently does not support it."
— Dr. Beth Meneley, DAOM, L.Ac.

As with all integrative oncology decisions, HBOT for cancer patients at OxygenWell is coordinated with the treating oncology team. We do not position HBOT as a standalone cancer treatment — it is a powerful adjunct that supports the body's healing terrain at every stage of cancer care.

For a comprehensive overview of HBOT in oncology, see our article on Hyperbaric Oxygen Therapy for Cancer Patients: A Metabolic Approach.

Protocol Summary: HBOT Across All Three Phases of Radiation Care

Phase Pressure Duration Frequency Primary Goals Before Radiation 1.5–2.0 ATA 60–90 min 2–5x/week Optimize oxygenation, mitochondrial prep, reduce baseline inflammation, improve tissue resilience During Radiation 1.5 ATA 60–90 min 2–5x/week as tolerated Maintain oxygenation, reduce acute inflammation, protect skin/mucosa, support energy After Radiation (injury treatment) 2.0–2.4 ATA 90 min 5x/week Stimulate angiogenesis, treat ORN/cystitis/proctitis/STNR, reduce chronic inflammation, restore tissue viability Marx Protocol (ORN prevention) 2.0–2.5 ATA 90 min Daily 20 pre-op + 10 post-op sessions before/after dental surgery in irradiated fields

Frequently Asked Questions

Can you do hyperbaric oxygen therapy during radiation treatment?

Yes — with oncologist coordination. Concurrent HBOT at 1.5 ATA, 60–90 minutes, 2–5x/week as tolerated can support tissue oxygenation, reduce inflammatory burden, and help maintain skin and mucosal integrity during a radiation course. Timing and scheduling are coordinated with your radiation oncology team. OxygenWell works collaboratively with treating oncologists to ensure appropriate concurrent use.

How soon after radiation can you start HBOT for injuries?

Delayed radiation injuries can appear anywhere from six months to several years after radiation ends. HBOT can be beneficial at any point in the development of these injuries — earlier is generally better, as treatment before advanced fibrosis sets in tends to yield better outcomes. However, patients with long-standing radiation injuries have also responded to HBOT. There is no fixed cutoff, and OxygenWell evaluates each patient individually.

How many sessions of HBOT does it take to treat radiation injury?

The standard protocol for radiation injuries — osteoradionecrosis, radiation cystitis, radiation proctitis, and soft tissue radionecrosis — is 20–40 sessions, 5x/week, 90 minutes at 2.0–2.4 ATA. Some complex cases require 40+ sessions. Insurance typically authorizes 30–40 sessions for most radiation injury indications, with the option for additional sessions if clinical progress warrants.

Is HBOT safe for cancer patients?

Current evidence does not show that HBOT promotes cancer growth. Two systematic reviews have specifically examined this question and found no support for a cancer-promoting effect. HBOT is not a contraindicated modality in cancer patients, and the UHMS does not list active malignancy as a contraindication. However, there are specific chemotherapy drug interactions (most notably bleomycin and doxorubicin) that require precautions. OxygenWell coordinates all HBOT for cancer patients with their treating oncology team.

Does Medicare cover HBOT for radiation injuries?

Yes. Medicare covers HBOT for all four FDA-approved delayed radiation injuries: osteoradionecrosis, radiation cystitis, radiation proctitis, and soft tissue radionecrosis. The Marx Protocol for ORN prevention is also a covered indication. Most PPO insurance plans follow Medicare coverage guidelines for these indications. OxygenWell's billing team handles all pre-authorizations.

What is the Marx Protocol?

The Marx Protocol is a peri-surgical HBOT regimen: 20 sessions before oral surgery and 10 sessions after, used in patients who need dental procedures after head and neck radiation. It reduced the incidence of osteoradionecrosis after dental extractions in irradiated fields from 29.9% to 5.4% in landmark research by Dr. Robert Marx (1985). It is FDA-approved, Medicare covered, and routinely used at OxygenWell for patients with a history of head and neck radiation who need dental work.

What to Expect at OxygenWell for Radiation-Related HBOT

The Intake Process

Every new patient begins with a comprehensive medical evaluation with our clinical team. For radiation-related HBOT, this includes a review of your radiation history (field location, total dose, number of fractions, time since treatment), current symptoms, relevant imaging, and coordination with your oncology and surgical teams. OxygenWell's physician-directed care model ensures that your HBOT protocol is calibrated to your specific condition and treatment history.

The Chambers

OxygenWell uses monoplace hard-shell hyperbaric chambers — the Fortius 420 — rated to 2.4 ATA and grounded for electrical safety. Patients breathe 100% medical-grade oxygen through a non-rebreather mask throughout the session. These are not the soft "mild hyperbaric" bags sold commercially — they are medical-grade, FDA-cleared equipment delivering the therapeutic pressures that clinical evidence supports.

Your Care Team

Sessions are supervised by Certified Hyperbaric Technicians (CHTs), most of whom are EMT-certified. A Physician Assistant is on-site most weekday hours. Dr. Meneley provides medical oversight and protocol direction for every patient. Insurance pre-authorizations for all FDA-approved indications — including radiation injuries — are handled entirely by our dedicated billing team.

Insurance and Medicare Coverage

HBOT for all four FDA-approved delayed radiation injuries — osteoradionecrosis, radiation cystitis, radiation proctitis, and soft tissue radionecrosis — is covered by Medicare and most PPO insurance plans. The Marx Protocol for ORN prevention is also a covered indication. OxygenWell handles all pre-authorization paperwork. For a complete guide to insurance coverage, see: Does Medicare Cover Hyperbaric Oxygen Therapy?

Extended Hours

OxygenWell offers evening and weekend hours — a rare advantage among hyperbaric centers in Los Angeles. Radiation patients often have demanding treatment schedules, and extended availability is a meaningful clinical convenience.

OxygenWell: Physician-Directed HBOT for Radiation Patients in Los Angeles

OxygenWell is a physician-owned hyperbaric oxygen therapy and regenerative medicine center serving Sherman Oaks and Calabasas. Founded by Dr. Beth Meneley, DAOM, L.Ac., with 25+ years in integrative medicine and 12+ years dedicated to hyperbaric medicine, OxygenWell has conducted 50,000+ HBOT sessions with some of the most complex medical cases in Los Angeles.

For radiation patients, OxygenWell offers:

• FDA-cleared chambers rated to 2.4 ATA — the therapeutic pressure range that clinical evidence supports for radiation injuries
• 100% medical-grade oxygen delivery via high-flow medical systems (not oxygen concentrators)
• Physician-directed protocol design coordinated with your oncology team
• Medicare and PPO insurance accepted — billing team handles all pre-authorizations
• Evening and weekend hours to accommodate oncology treatment schedules
• Two convenient Los Angeles locations: Sherman Oaks and Calabasas

Call us at (818) 661-0939 to schedule your consultation. Our clinical team will review your radiation history, coordinate with your oncology providers, and design a protocol built around your specific needs and goals.

Dr. Beth Meneley, DAOM, L.Ac. is the Founder of OxygenWell and an integrative oncology expert with 25+ years in integrative medicine, 12+ years dedicated to hyperbaric medicine in Los Angeles, and 50,000+ supervised HBOT sessions. California law requires hyperbaric facilities to be physician-owned — a distinction OxygenWell was founded on.