Hyperbaric Oxygen Treatment of Chronic Refractory Radiation Proctitis: A Randomized and Controlled Double-Blind Crossover Trial With Long-Term Follow-Up

Management of radiation cystitis

Acute radiation cystitis occurs during or soon after radiation treatment. It is usually self-limiting, and is generally managed conservatively. Late radiation cystitis, on the other hand, can develop from 6 months to 20 years after radiation therapy. The main presenting symptom is hematuria, which may vary from mild to severe, life-threatening hemorrhage. Initial management includes intravenous fluid replacement, blood transfusion if indicated and transurethral catheterization with bladder washout and irrigation. Oral or parenteral agents that can be used to control hematuria include conjugated estrogens, pentosan polysulfate or WF10. Cystoscopy with laser fulguration or electrocoagulation of bleeding points is sometimes effective. Injection of botulinum toxin A in the bladder wall may relieve irritative bladder symptoms. Intravesical instillation of aluminum, placental extract, prostaglandins or formalin can also be effective. More-aggressive treatment options include selective embolization or ligation of the internal iliac arteries. Surgical options include urinary diversion by percutaneous nephrostomy or intestinal conduit, with or without cystectomy. Hyperbaric oxygen therapy (HBOT) involves the administration of 100% oxygen at higher than atmospheric pressure. The reported success rate of HBOT for radiation cystitis varies from 60% to 92%. An important multicenter, double-blind, randomized, sham-controlled trial to evaluate the effectiveness of HBOT for refractory radiation cystitis is currently being conducted.

A murine model for the study of molecular pathogenesis of radiation proctitis

PURPOSE

To establish a novel mouse brachytherapy model with which to study the role of inflammation in the pathogenesis of radiation proctitis.

METHODS AND MATERIALS

The distal rectums of BALB/c and C57BL/6 mice were irradiated with three to five fractions of 5.5 to 8 Gy. Tissues were harvested and evaluated for histopathology, using the radiation injury score (RIS). Cytokine mRNA expression was assessed using real-time PCR.

RESULTS

Fifty percent of the mice treated with 22 Gy delivered in four fractions of 5.5 Gy died as a result of anorectal stenosis and distal bowel obstruction prior to the time of scheduled sacrifice, with a latency period of 4 to 10 weeks for the BALB/c and 3 to 4 weeks for the C57BL/6 mice. The RISs were 7, 12, and 8 at 2, 6, and 11 weeks, respectively, in the BALB/c mice and was 8.7 in the C57BL/6 mice on week 6. A 100- to 300-fold increase in interleukin-1beta (IL-1beta) (p = 0.04) and IL-6 mRNA (p = 0.07) and a 5- to 6-fold increase in transforming growth factor (TGF) and tumor necrosis factor-alpha mRNA expression levels (p < 0.001 and p = 0.01) were observed at 2 to 6 weeks after radiation. Cytokine mRNA tissue expression correlated positively with radiation dose (p < 0.0001). The RIS correlated well with IL-1beta and IL-6 mRNA levels in the BALB/c mice and with IL-1beta, IL-6, and TGF mRNA levels in C57BL/6 mice. Analysis of receiver operating characteristic curve showed that IL-1beta and IL-6 have the largest area under the curve and therefore are good markers of radiation proctitis (p < 0.001).

CONCLUSIONS

Radiation-induced proctitis was associated with a dose-dependent, characteristic proinflammatory cytokine response pattern in a novel mouse model suitable for interventional studies.

Late rectal complications after prostate brachytherapy for localized prostate cancer: incidence and management

This review of the literature on late rectal complications after prostate brachytherapy indicated that it is a highly effective treatment modality for patients with clinically localized prostate cancer but can cause chronic radiation proctitis. The most common manifestation of chronic radiation proctitis was anterior rectal wall bleeding, which often occurred within the first 2 years after brachytherapy. It is interesting to note that the rates of late rectal morbidity appear to have declined over time, which may reflect improvements in implantation techniques and imaging. Rectal biopsy as part of the workup to evaluate rectal bleeding can lead to rectal fistula and the need for colostomy, a rare but major complication. The authors recommend 1) screening colonoscopy before brachytherapy for patients who have not had a screening colonoscopy within the preceding 3 years to rule out colorectal malignancies and, thus, facilitate conservative management should rectal bleeding occur; 2) lifestyle modifications during treatment to limit exposure of the rectum to radiation; and 3) conservative management for rectal bleeding that occurs within 2 years after brachytherapy. Cancer 2009. (c) 2009 American Cancer Society.

Multimodality surgical and hyperbaric management of mandibular osteoradionecrosis

PURPOSE

To elucidate long-term outcomes in 65 consecutive patients meeting a uniform definition of mandibular osteoradionecrosis (ORN) treated with multimodality therapy including hyperbaric oxygen (HBO).

METHODS AND MATERIALS

Pretreatment, post-treatment and long-term follow-up of mandibular lesions with exposed bone were ranked by a systematic review of medical records and patient telephone calls. The ranking system was based on lesion diameter and number plus disease progression. Changes from pretreatment to post-treatment and follow-up were analyzed by Wilcoxon signed-rank tests. Improved wound survival, measured by time to relapse, defined as any less favorable rank after HBO treatment, was assessed by Kaplan-Meier analysis.

RESULTS

In all, 57 cases (88%) resolved or improved by lesion grade or progression and evolution criteria after HBO (p < 0.001). Four patients healed before surgery after HBO alone. Of 57 patients who experienced improvement, 41 had failed previous nonmultimodality therapy for 3 months and 26 for 6 months or more. A total of 43 patients were eligible for time-to-relapse survival analysis. Healing or improvement lasted a mean duration of 86.1 months (95% confidence interval [95% CI], 64.0-108.2) in nonsmokers (n = 20) vs. 15.8 months (95% CI, 8.4-23.2) in smokers (n = 14) versus 24.2 months (95% CI, 15.2-33.2) in patients with recurrent cancer (n = 9) (p = 0.002 by the log-rank method).

CONCLUSIONS

Multimodality therapy using HBO is effective for ORN when less intensive therapies have failed. Although the healing rate in similarly affected patients not treated with HBO is unknown, the improvements seen with peri-operative HBO were durable provided that the patients remained cancer free and abstained from smoking.

Hyperbaric treatment for children with autism: a multicenter, randomized, double-blind, controlled trial

Background

Several uncontrolled studies of hyperbaric treatment in children with autism have reported clinical improvements; however, this treatment has not been evaluated to date with a controlled study. We performed a multicenter, randomized, double-blind, controlled trial to assess the efficacy of hyperbaric treatment in children with autism.

Methods

62 children with autism recruited from 6 centers, ages 2–7 years (mean 4.92 ± 1.21), were randomly assigned to 40 hourly treatments of either hyperbaric treatment at 1.3 atmosphere (atm) and 24% oxygen ("treatment group", n = 33) or slightly pressurized room air at 1.03 atm and 21% oxygen ("control group", n = 29). Outcome measures included Clinical Global Impression (CGI) scale, Aberrant Behavior Checklist (ABC), and Autism Treatment Evaluation Checklist (ATEC).

Results

After 40 sessions, mean physician CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0008), receptive language (p < 0.0001), social interaction (p = 0.0473), and eye contact (p = 0.0102); 9/30 children (30%) in the treatment group were rated as "very much improved" or "much improved" compared to 2/26 (8%) of controls (p = 0.0471); 24/30 (80%) in the treatment group improved compared to 10/26 (38%) of controls (p = 0.0024). Mean parental CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0336), receptive language (p = 0.0168), and eye contact (p = 0.0322). On the ABC, significant improvements were observed in the treatment group in total score, irritability, stereotypy, hyperactivity, and speech (p < 0.03 for each), but not in the control group. In the treatment group compared to the control group, mean changes on the ABC total score and subscales were similar except a greater number of children improved in irritability (p = 0.0311). On the ATEC, sensory/cognitive awareness significantly improved (p = 0.0367) in the treatment group compared to the control group. Post-hoc analysis indicated that children over age 5 and children with lower initial autism severity had the most robust improvements. Hyperbaric treatment was safe and well-tolerated.

Conclusion

Children with autism who received hyperbaric treatment at 1.3 atm and 24% oxygen for 40 hourly sessions had significant improvements in overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to children who received slightly pressurized room air.

Trial Registration

clinicaltrials.gov NCT00335790

Hyperbaric oxygen stimulates vasculogenic stem cell growth and differentiation in vivo

We hypothesized that oxidative stress from hyperbaric oxygen (HBO(2), 2.8 ATA for 90 min daily) exerts a trophic effect on vasculogenic stem cells. In a mouse model, circulating stem/progenitor cell (SPC) recruitment and differentiation in subcutaneous Matrigel were stimulated by HBO(2) and by a physiological oxidative stressor, lactate. In combination, HBO(2) and lactate had additive effects. Vascular channels lined by CD34(+) SPCs were identified. HBO(2) and lactate accelerated channel development, cell differentiation based on surface marker expression, and cell cycle entry. CD34(+) SPCs exhibited increases in thioredoxin-1 (Trx1), Trx reductase, hypoxia-inducible factors (HIF)-1, -2, and -3, phosphorylated mitogen-activated protein kinases, vascular endothelial growth factor, and stromal cell-derived factor-1. Cell recruitment to Matrigel and protein synthesis responses were abrogated by N-acetyl cysteine, dithioerythritol, oxamate, apocynin, U-0126, neutralizing anti-vascular endothelial growth factor, or anti-stromal cell-derived factor-1 antibodies, and small inhibitory RNA to Trx reductase, lactate dehydrogenase, gp91(phox), HIF-1 or -2, and in mice conditionally null for HIF-1 in myeloid cells. By causing an oxidative stress, HBO(2) activates a physiological redox-active autocrine loop in SPCs that stimulates vasculogenesis. Thioredoxin system activation leads to elevations in HIF-1 and -2, followed by synthesis of HIF-dependent growth factors. HIF-3 has a negative impact on SPCs.

Oxidative stress is fundamental to hyperbaric oxygen therapy

The goal of this review is to outline advances addressing the role that reactive species of oxygen and nitrogen play in therapeutic mechanisms of hyperbaric oxygen. The review will be organized around major categories of problems or processes where controlled clinical trials have demonstrated clinical efficacy for hyperbaric oxygen therapy. Reactive species are now recognized to play a major role in cell signal transduction cascades, and the discussion will focus on how hyperbaric oxygen acts through these pathways to mediate wound healing and ameliorate postischemic and inflammatory injuries.

Hyperbaric oxygen therapy for late radiation tissue injury

BACKGROUND

Cancer is a significant global health problem. Radiotherapy is a treatment for many cancers and about 50% of patients having radiotherapy with be long-term survivors. Some will experience LRTI developing months or years later. HBOT has been suggested for LRTI based upon the ability to improve the blood supply to these tissues. It is postulated that HBOT may result in both healing of tissues and the prevention of problems following surgery.

OBJECTIVES

To assess the benefits and harms of HBOT for treating or preventing LRTI.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) Issue 3, 2004, MEDLINE, EMBASE, CINAHL and DORCTHIM (hyperbaric RCT register) in September 2004.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the effect of HBOT versus no HBOT on LRTI prevention or healing.

DATA COLLECTION AND ANALYSIS

Three reviewers independently evaluated the quality of the relevant trials using the guidelines of the Cochrane Handbook Clarke 2003) and extracted the data from the included trials.

MAIN RESULTS

Six trials contributed to this review (447 participants). For pooled analyses, investigation of heterogeneity suggested important variability between trials. From single studies there was a significantly improved chance of healing following HBOT for radiation proctitis (relative risk (RR) 2.7, 95% confidence Interval (CI) 1.2 to 6.0, P = 0.02, numbers needed to treat (NNT) = 3), and following both surgical flaps (RR 8.7, 95% CI 2.7 to 27.5, P = 0.0002, NNT = 4) and hemimandibulectomy (RR 1.4, 95% CI 1.1 to 1.8, P = 0.001, NNT = 5). There was also a significantly improved probability of healing irradiated tooth sockets following dental extraction (RR 1.4, 95% CI 1.1 to 1.7, P = 0.009, NNT = 4). There was no evidence of benefit in clinical outcomes with established radiation injury to neural tissue, and no data reported on the use of HBOT to treat other manifestations of LRTI. These trials did not report adverse effects.

AUTHORS' CONCLUSIONS

These small trials suggest that for people with LRTI affecting tissues of the head, neck, anus and rectum, HBOT is associated with improved outcome. HBOT also appears to reduce the chance of osteoradionecrosis following tooth extraction in an irradiated field. There was no such evidence of any important clinical effect on neurological tissues. The application of HBOT to selected patients and tissues may be justified. Further research is required to establish the optimum patient selection and timing of any therapy. An economic evaluation should be also be undertaken. There is no useful information from this review regarding the efficacy or effectiveness of HBOT for other tissues.