Hyperbaric oxygen for the management of radionecrosis of bone and cartilage

Chondroradionecrosis of the trachea after definitive radiotherapy for cervical esophageal cancer: A case report

Chondroradionecrosis (CRN) is an infrequent phenomenon after definitive RT. The clinical manifestation is usually difficult to distinguish from that of tumor recurrence; however, clinicians should be aware of the possibility of CRN.

Therapeutic alternatives in the management of osteoradionecrosis of the jaws. Systematic review

Background

to systematically review the literature, comparing the healing of osteoradionecrosis (ORN) among the therapeutic alternatives: surgical, pharmacological and combined.

Material and Methods

The review was organized according to the PRISMA protocol with regards to the following PICO question: patients with ORN of the jaws (P=Patient); all interventions reported (I = intervention); between all therapies (C=Comparison); healing of lesions (O=outcome).

Results

Surgical treatment was the most common choice (46.3%) followed by pharmacological treatment, exclusively (25.9%) or combined (26.9%). Treatment exclusively by surgical intervention seems to be most effective option, with 51.2% of the lesions healed, OR for healing of 5.7 (CI95% 1.9-16.9, p=0.002). Only 1 case (0.9%) corresponded to low level laser therapy.

Conclusions

It seems clear that early intervention with conservative surgical combined with pharmacological methods improves the prognosis of ORN.

Key words:Osteoradionecrosis, radiotherapy bone necrosis, hyperbaric oxygen, pentoxifylline, teriparatide, low level laser therapy.

Tumor subsites and risk of osteoradionecrosis of the jaw in patients with oral cavity cancer: a national-based cohort study

PURPOSE

The association between the tumor subsites of the oral cavity and the risk of osteoradionecrosis of the jaw (ORNJ) remains unclear. We study the correlation between oral cavity tumor subsites and the risk of ORNJ in a nationwide population-based database.

METHODS

We enrolled 16,701 adult patients with oral cavity cancers who were treated with radiotherapy between 2000 and 2013. The subsites of the oral tumor, treatments of oral cavity cancers, and the timing of tooth extraction were examined for their association with ORNJ in oral cancer patients.

RESULTS

903 patients (5.40%) developed ORNJ. Of the relevant variables, pre-RT mandible surgery, tooth extraction either before or after RT, and tumor sites were associated with the risk of ORNJ. The adjusted HRs for ORNJ in the mouth floor, gums, retromolar, and buccal cancer were 2.056 (1.490-2.837), 1.909 (1.552-2.349), 1.683 (1.105-2.562), and 1.303 (1.111-1.528), respectively, compared with the risk of tongue cancer. There was no significant difference in the risk of ORNJ between the pre-RT extraction group, the during-RT extraction group, and the post-RT extraction (less than 6 months) group; the post-RT extraction (more than 6 months) group had a significantly higher risk of ORNJ.

CONCLUSIONS

This study demonstrated that oral cavity tumor subsite is an independent risk factor of ORNJ after RT. Post-RT extraction (less than 6 months) group did not carry a significantly higher risk of ORNJ compared with pre-RT extraction group or during RT extraction group.

The Role of Hyperbaric Oxygen in Head and Neck Reconstruction and Facial Cosmetic Surgery

Hyperbaric oxygen (HBO) is a treatment modality with the primary mechanism of therapy being the delivery of oxygen to hypoxic tissues. A review of HBO applications in the field of head and neck reconstruction and facial cosmetic surgery is provided. HBO can be useful in the management of radiation sequelae and treatment of compromised flaps and grafts. It may also have application in tissue compromise following cosmetic surgery and dermal fillers. We provide evidence from the available literature as well as highlight our experience in using HBO in head and neck reconstruction.

Bisphosphonate-induced reactive oxygen species inhibit proliferation and migration of oral fibroblasts: A pathogenesis of bisphosphonate-related osteonecrosis of the jaw

BACKGROUND

The onset mechanism for bisphosphonate-related osteonecrosis of the jaw (BRONJ) has been reported, with a focus on bone remodeling, biofilm formation, and epithelial cell proliferation and migration. However, the involvement of stromal cells, especially fibroblasts, in the oral cavity is unclear. Therefore, this study was focused on how bisphosphonates (BPs) affect orthotopic periodontal ligament fibroblasts from the viewpoint of oxidative stress compared with ectopically obtained fibroblasts.

METHODS

Normal human periodontal ligament fibroblasts (HPdLFs) and normal human dermal fibroblasts (NHDFs) were used to gain insight into the functional differences in sensitivity and reactions to BPs. Cell growth assay, measurement of reactive oxygen species (ROS) and nitric oxide (NO) production, and wound-healing assay in vitro were performed. Maxillary first molars were extracted in C57BL/6 mice and either BP, N-acetyl-cysteine (NAC), and BP or saline were administered.

RESULTS

BP-induced IC₅₀ values were significantly lower in HPdLFs (30.6 µM) than in NHDFs (109.7 µM). BP resulted in an increase in ROS, but not NO generation in HPdLFs. BPs also inhibited proliferation and migration of HPdLFs but not NHDFs, while the addition of a ROS inhibitor, NAC, reversed those inhibitions. A BRONJ mouse model in which BP was administered and then the tooth was extracted, impaired wound healing of the socket was observed. When NAC was administered before tooth extraction, wound healing was significantly improved.

CONCLUSION

These results suggest that BP causes fibroblasts obtained from the oral cavity but not from skin to generate ROS and that the subsequent ROS-mediated inhibition of fibroblast growth and migration definitely delays wound healing, thereby contributing to BRONJ pathogenesis.

Post-transplantation laryngeal actinomycosis

A case of laryngeal actinomycosis occurred after bone marrow transplantation was reported. The patient was a 14-year-old girl who had a history of bone marrow transplantation for the treatment of acute lymphocytic leukemia 4month before the onset of the disease. She was referred to our hospital complaining persistent sore throat since 2weeks ago. Fiberscopic observation proved the presence of white tumor-like mass on her right arytenoid of the larynx. As CT image demonstrated that the mass was localized at the arytenoid region with central low-density area surrounded by granulation tissue, we underwent biopsy under local anesthesia. Excision of the mass proved it to be a soft granulation including sulfur granules. Oral administration of amoxicillin 750mg per day was initiated as a postoperative medication. On day 17, histological study confirmed that the tumor-like mass was Actinomyces granuloma, and therefore amoxicillin administration continued. The medication was effective to subside the disease and the arytenoid lesion healed on day 31. Amoxicillin was further administered until day 70 to prevent recurrence. At 6month after the biopsy, she was free from the disease.

Osteoradionecrosis of the jaws: definition, epidemiology, staging and clinical and radiological findings. A concise review

Osteoradionecrosis (ORN) of the jaws is a pernicious complication of radiation therapy for head and neck tumours. This article aims to provide an update on data related to the definition, epidemiology, staging, and clinical and radiological findings of ORN of the jaws. Using certain keywords, an electronic search was conducted spanning the period from January 1922 to April 2014 to identify the available related investigations. Pooled data were then analysed. ORN is described as exposed irradiated bone that fails to heal over a period of 3 months without evidence of persisting or recurrent tumour. The prevalence of ORN varies in the literature. Several staging or scoring systems of ORN have been proposed. Clinical findings include ulceration or necrosis of the mucosa with exposure of necrotic bone. Radiological findings are not evident in the early stages of ORN. Furthermore ORN may not be apparent in imaging even when the disease is advanced. Taking into account the severity of ORN and the difficulties in diagnosing it early and accurately, the clinician should be aware of this complex entity in order to prevent its appearance or the development of more severe complications.

Chondroradionecrosis of the larynx: 24-year University of Wisconsin experience

BACKGROUND

Chondroradionecrosis (CRN) is an uncommon but significant complication of laryngeal radiotherapy that presents a diagnostic challenge to clinicians through its similarity in presentation to cancer recurrence.

METHODS

Two hundred ninety-four patients underwent primary, adjuvant, or salvage radiation for laryngeal cancer from 1991 to 2015 at the University of Wisconsin. Medical records were reviewed to identify and characterize patients with a diagnosis of CRN.

RESULTS

Of the 294 patients, 7 cases (2.4%) of CRN were identified. Development of CRN was associated with the presence of cartilage invasion by tumor (p = .038) and ongoing alcohol use postradiotherapy (p = .036). Additionally, a trend between development of CRN and ongoing smoking postradiotherapy was observed (p = .067).

CONCLUSION

The diagnosis of CRN is challenging, and the likelihood of successful resolution is modest. A high premium should be placed on efforts directed at prevention, such as tobacco and alcohol cessation. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1189-1194, 2017.

Anti-inflammatory effects of hyperbaric oxygen on irradiated laryngeal tissues

INTRODUCTION

To manage the complications of irradiation of head and neck tissue is a challenging issue for the otolaryngologist. Definitive treatment of these complications is still controversial. Recently, hyperbaric oxygen therapy is promising option for these complications.

OBJECTIVE

In this study, we used biochemical and histopathological methods to investigate the efficacy of hyperbaric oxygen against the inflammatory effects of radiotherapy in blood and laryngeal tissues when radiotherapy and hyperbaric oxygen are administered on the same day.

METHODS

Thirty-two Wistar Albino rats were divided into four groups. The control group was given no treatment, the hyperbaric oxygen group was given only hyperbaric oxygen therapy, the radiotherapy group was given only radiotherapy, and the radiotherapy plus hyperbaric oxygen group was given both treatments on the same day.

RESULTS

Histopathological and biochemical evaluations of specimens were performed. Serum tumor necrosis factor-α, interleukin-1β, and tissue inflammation levels were significantly higher in the radiotherapy group than in the radiotherapy plus hyperbaric oxygen group, whereas interleukin-10 was higher in the radiotherapy plus hyperbaric oxygen group.

CONCLUSION

When radiotherapy and hyperbaric oxygen are administered on the same day, inflammatory cytokines and tissue inflammation can be reduced in an early period of radiation injury.

Diagnostic Features and Management Strategy of a Refractory Case of Osteoradionecrosis of the Mandible: Case Report and Review of Literature

INTRODUCTION

Osteoradionecrosis of the jaws produces a considerable amount of esthetic as well as functional deficits seriously affecting quality of life of the patient. Cases are often notoriously difficult to treat and manage owing to associated comorbidities of the patient, post irradiation fibrosis and decreased vascularity at the site, which complicates free tissue flap and graft transfer, that subsequently succumb to failure. Hyperbaric oxygen therapy (HBOT), in which 100 % oxygen is administered by mask under 2.4 atm pressure, in a hyperbaric oxygen chamber, helps by increasing local vascularity.

AIM AND METHODS

It was the aim of this study to show that a particularly refractory, compromised and challenging case of osteoradionecrosis can be managed successfully even without HBOT, by mandibular segmental resection followed by reconstruction using a titanium reconstruction plate enveloped within a pedicled Pectoralis Major Myocutaneous flap.

RESULT

Post operative recovery of the patient was excellent with good functional and esthetic rehabilitation of the patient with and practically nil donor site morbidity.

CONCLUSION

It is important to have a thorough knowledge of the clinical, radiographic, histopathologic, CT and MRI features of osteoradionecrosis of the jaws in order to make a quick and accurate confirmatory diagnosis and to overcome possible diagnostic dilemmas. The strategy of reconstruction of a large mandibular defect using a bridging titanium plate sandwiched by a healthy vascularized myocutaneous flap, following ablative surgery for ORN, has proved to be a safe and reliable option for composite mandibular defects, with gratifying long term functional and cosmetic results.

New perspectives on the conservative management of osteoradionecrosis of the mandible: A literature review

Over the last decades, several therapeutic options were considered in the treatment of the osteoradionecrosis (ORN) of the mandible, including supportive measures, ultrasound therapy, corticosteroids, hyperbaric oxygen, surgical resection with reconstruction, and, more recently, drugs capable of reversing the fibroatrophic process. Once established, the ORN does not spontaneously disappear and a standard treatment has not yet been defined. The clear clinical effectiveness of hyperbaric oxygen therapy (HBOT) varies according to the literature and there are some economic/logistic issues to be considered; the triplet tocopherol/pentoxifylline/clodronate demands greater evidence from randomized clinical trials and also resilience from the patient, given the long treatment duration and its possible side effects. Controversy around the ideal treatment of the initial stage ORN of the mandible persists. More rigorous randomized prospective trials are essential. The purpose of this article was to review the relevant literature on the physiopathology of ORN of the mandible and discuss the new perspectives of its conservative treatment. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.

[Osteoradionecrosis of the sternoclavicular joint]

BACKGROUND/OBJECTIVE

Osteoradionecrosis is a rare, but feared, late complication after radiotherapy of the head and neck region. Its localization to the sternoclavicular joint has rarely been described so far.

MATERIALS AND METHODS

Data are from a retrospective study that included all patients admitted to the authors' clinic with osteoradionecrosis of the sternoclavicular joint during the last 5 years. Therapy and outcome were evaluated and compared to the established literature.

RESULTS

Over the past 5 years, 2 patients have been treated for pronounced osteoradionecrosis of the sternoclavicular joint. Both patients had received postoperative radiotherapy for tumors of the neck and chest, and presented with lesions involving the clavicle and the sternum. After eliminating the suspicion of recurrent cancer, both radiologic imaging and histopathologic evaluation confirmed an infection. Aggressive debridement with partial claviculectomy, partial sternectomy, and reconstruction using a pectoralis flap lead to the patients' recovery.

CONCLUSION

Osteoradionecrosis does not only affect bone, but also the surrounding soft tissue. Due to the changes associated with previous radiotherapy, osteoradionecrosis should always be treated with radical debridement of the infected area, followed by flap reconstruction using unaffected tissue. The prognosis for the patient is then good.

PATIENT'S PERSPECTIVE ON HYPERBARIC OXYGEN TREATMENT OF OSTEORADIONECROSIS

Osteoradionecrosis (ORN) is a known complication to radiation therapy for head and neck cancer with a prevalence of 5–7% among radiated patients. Treatment might include dental surgery and reconstruction of the jawbone as well as hyperbaric oxygen treatment (HBOT). HBOT takes place in a closed compartment where patients are breathing 100% oxygen under pressure for 90 minutes once a day every weekday for 6 weeks. In Denmark, HBOT is available at two facilities with very different organizational set-ups.

Clinical Assessment and Treatment of the Dysfunctional Larynx after Radiation

Objective

To review the pathophysiology of early and late radiation-related tissue changes, methods to differentiate these changes from disease recurrence, and treatment of these changes in the irradiated larynx.

Data Sources

Peer-reviewed publications.

Review Methods

PubMed database search.

Conclusions/Implications for Practice

Early and late radiation-related changes in the larynx manifest variably between individual patients. Severe radiation-related tissue changes in the larynx and recurrent malignancy share many clinical characteristics, and the presence of malignancy must be considered in these patients. Positron emission tomography may help select patients who need operative biopsy to rule out recurrence. In patients with a cancer-free but dysfunctional larynx, both surgical and nonsurgical treatment options, including hyperbaric oxygen, are available for attempted salvage. Further investigation is needed before hyperbaric oxygen can be considered standard-of-care treatment for these patients.

Successful hyperbaric oxygen therapy for laryngeal radionecrosis after chemoradiotherapy for mesopharyngeal cancer: case report and literature review

Laryngeal radionecrosis is one of the most troublesome late complications of radiotherapy, because it is frequently resistant to treatment and laryngectomy is required in the worst case. Here, we report a case of laryngeal radionecrosis, successfully treated by use of hyperbaric oxygen (HBO) therapy, in which laryngectomy was avoided. A 67-year-old male received radical chemoradiotherapy (CRT) for mesopharyngeal cancer, which included radiotherapy with a total dose of 71.4 Gy/38 Fr and chemotherapy with CDDP + S-1. He developed dyspnea and throat pain 9 months after completion of CRT. Laryngoscopy revealed vocal cord impairment because of severe laryngeal edema. He was diagnosed as having laryngeal radionecrosis and initially received conservative therapy combined with antibiotics, steroids, and prostaglandins. Because his dyspnea was persistent despite this treatment, HBO therapy was administered 20 times, and resulted in complete remission of the dyspnea. HBO therapy, therefore, is regarded as an effective conservative therapeutic option for laryngeal radionecrosis.

Standardized analysis of mandibular osteoradionecrosis in a rat model

OBJECTIVE

To develop a rat model of mandibular osteoradionecrosis(ORN) that uses novel micro-computed tomography bone volume analysis and detailed histology to provide a more effective, quantifiable, and standardized way to study ORN in vivo.

STUDY DESIGN

Animal model.

SETTING

Academic medical center.

SUBJECTS AND METHODS

Modifications to our previously published rat model of mandibular ORN were done to develop an ideal protocol consisting of 10 rats (6 experimental and 4 controls) with their left middle mandibular molar removed 7 days after either 20 Gy high dose rate brachytherapy or sham irradiation. Rats were sacrificed 21 days after extraction for landmark defined bone volume and histologic analysis.

RESULTS

A standardized method of quantification was achieved in all samples. The radiated group (XRT) had a mean bone volume/total volume (BV/TV) of 13.8% compared to 65.9% for controls (P < .001). There were increases in osteoclasts and fibrosis, decreases in osteoblasts,and less bone in radiated samples with a mean (SD)of 5.91 (3.77) osteoclasts/high-powered field (HPF) and 4.00(1.83) osteoblasts/HPF in XRT samples compared to 1.08(1.08) osteoclasts/HPF and 22.49 (6.00) osteoblasts/HPF for controls (P <.001).

CONCLUSION

Our updated model continues to be clinically analogous to human mandibular ORN and improves the radiologic and histologic analysis of bony defects, providing a method for quantification of bone loss. Further cell-specific staining, including immunohistochemistry, can be used with this model to study potential cellular mechanisms of mandibular ORN and test any future therapeutic options.

Possible application of hyperbaric oxygen technology in the management of urogenital and renal diseases

The purpose of this report is to explore possible therapeutic use of hyperbaric oxygen (HBO(2)) technology on renal and urogenital diseases. HBO(2) reduces inflammation, immunity and inflammatory cytokines, stimulates wound repair and angioneogenesis, maintains tissue oxygenation, increases antioxidant enzymes and heals tissue hypoxia and radionecrosis. A literature review of peer-reviewed articles that address HBO(2), genitourological diseases, renal disease, and dialysis was performed. The paper reviews complications of renal diseases, dialysis, clinical applications of HBO(2), and effect of HBO(2) on renal and urogenital diseases. HBO(2) was used successfully to treat calcific uraemic arteriolopathy, and in many cases of acute renal failure. This technique is particularly useful in the treatment of intractable haemorrhagic cystitis secondary to pelvic radiation therapy and Fournier's gangrene. Clearly HBO(2) might play a role in the management of urogenital diseases, urinary bladder dysfunction and diseases, testicular pathology, renal diseases, and post-traumatic ischaemic injury and/or impaired wound healing and infections. The possible role of HBO(2) for autoimmune diseases, uraemic osteodystrophy or neuropathy due to chronic renal diseases is discussed. The clinical application of this technology is expanding and the various biological influences of HBO(2) encourage testing its possible benefit in renal and urological diseases.

Osteoradionecrosis: an update

Osteoradionecrosis (ORN) of the mandible is the most serious and severe side effect of combined treatment of head and neck tumors. A new theory for the pathogenesis of ORN has been proposed relating it to a fibro-atrophic mechanism including free radical formation, endothelial dysfunction, inflammation, microvascular thrombosis leading to bone and tissue necrosis. Risk factors mainly include radiation related risk factors, surgery and, tobacco and alcohol abuse. Removing of diseased teeth after and even probably after radiotherapy is generally considered the main risk factor in ORN. Conversely, steroid use before or after radiation may have a protective effect related to the inhibition of the initial inflammatory phase of ORN. Prevention of ORN is still based on the preventive extractions of decayed or periodontally compromised teeth before radiotherapy. Based on the current understanding of ORN pathophysiology, new preventive and therapeutic protocols have been suggested for mild to moderate stages. Free tissue surgical transfers is the treatment of choice of severe, extensive and long established ORN.

Prolonged Success With a Covered Endovascular Stent After Emergent Use in Radiation-Induced Subclavian Artery Blowout: A Case Report

Radiation-induced damage to the bone, soft tissues, and vasculature represents the unfortunate consequences of radiation therapy for the treatment of malignant tumors. Complications arising from irradiation are frequently challenging to manage and may be life threatening. A case is presented of a patient with a longstanding clavicular osteoradionecrosis with an acute massive hemorrhage after rupture of the subclavian artery and subsequent management with endovascular stent placement. With over 2 years' follow-up, vascular patency was maintained with no further bleeding episodes in this surgically high-risk patient.

Surgical treatment of osteoradionecrosis of the temporal bone in patients with nasopharyngeal carcinoma

Objective:

To investigate methods of treating diffuse osteoradionecrosis of the temporal bone in cases of nasopharyngeal carcinoma, following radiotherapy.

Study design:

Retrospective.

Methods:

Fourteen post-irradiation nasopharyngeal carcinoma patients (n = 14 ears) with diffuse osteoradionecrosis received surgical treatment from March 1994 to May 2005. The patients underwent radical mastoidectomy (five ears), extensive radical mastoidectomy (one ear), or radical mastoidectomy and obliteration with local vascularised fascia flaps (eight ears).

Results:

Six ears fully recovered; two ears were still infectious but sequestrum had not re-formed; five ears (50 per cent) still had repeated suppuration and did not epithelialise; and one ear had local re-formation of sequestrum requiring periodic dressing changes.

Conclusion:

Diffuse osteoradionecrosis of the temporal bone following radiotherapy for nasopharyngeal carcinoma is difficult to treat surgically. The main objective of surgery is to facilitate drainage and to prevent complications. Radical mastoidectomy and obliteration with local vascularised flaps is an effective method.

Osteoradionecrosis prevention myths

PURPOSE

To critically analyze controversial osteoradionecrosis (ORN) prevention techniques, including preradiation extractions of healthy or restorable teeth and the use of prophylactic antibiotics or hyperbaric oxygen (HBO) treatments for preradiation and postradiation extractions.

METHODS

The author reviewed ORN studies found on PubMed and in other article references, including studies on overall ORN incidence and pre- and postradiation incidence, with and without prophylactic HBO or antibiotics.

RESULTS

Owing in part to more efficient radiation techniques, the incidence of ORN has been declining in radiation patients over the last 2 decades, but the prevention of ORN remains controversial. A review of the available literature does not support the preradiation extraction of restorable or healthy teeth. There is also insufficient evidence to support the use of prophylactic HBO treatments or prophylactic antibiotics before extractions or other oral surgical procedures in radiation patients.

CONCLUSIONS

To prevent ORN, irradiated dental patients should maintain a high level of oral health. A preradiation referral for a dental evaluation and close collaboration by a multidisciplinary team can be invaluable for radiation patients. As with most other dental patients, restorable and healthy teeth should be retained in irradiated patients. The use of prophylactic HBO or antibiotics should be reconsidered for preradiation and postradiation extractions.

Vasculature deprivation--induced osteonecrosis of the rat femoral head as a model for therapeutic trials

Experimental Osteonecrosis

The authors' experience with experimentally produced femoral capital osteonecrosis in rats is reviewed: incising the periosteum at the base of the neck of the femur and cutting the ligamentum teres leads to coagulation necrosis of the epiphysis. The necrotic debris is substituted by fibrous tissue concomitantly with resorption of the dead soft and hard tissues by macrophages and osteoclasts, respectively. Progressively, the formerly necrotic epiphysis is repopulated by hematopoietic-fatty tissue, and replaced by architecturally abnormal and biomechanically weak bone. The femoral heads lose their smooth-surfaced hemispherical shape in the wake of the load transfer through the hip joint such that, together with regressive changes of the joint cartilage and inflammatory-hyperplastic changes of the articular membrane, an osteoarthritis-like disorder ensues.

Therapeutic Choices

Diverse therapeutic options are studied to satisfy the different opinions concerning the significance of diverse etiological and pathogenic mechanisms: 1. Exposure to hyperbaric oxygen. 2. Exposure to hyperbaric oxygen and non-weight bearing on the operated hip. 3. Medication with enoxaparin. 4. Reduction of intraosseous hypertension, putting to use a procedure aimed at core decompression, namely drilling a channel through the femoral head. 5. Medication with vascular endothelial growth factor with a view to accelerating revascularization. 6. Medication with zoledronic acid to decrease osteoclastic productivity such that the remodeling of the femoral head is slowed.

Glucocorticoid-related osteonecrosis appears to be apoptosis-related, thus differing from the vessel-deprivation-induced tissue coagulation found in idiopathic osteonecrosis. The quantities of TNF-α, RANK-ligand and osteoprotegerin are raised in glucocorticoid-treated osteoblasts so that the differentiation of osteoclasts is blocked. Moreover, the osteoblasts and osteocytes of the femoral cortex mostly undergo apoptosis after a lengthy period of glucocorticoid medication.

Major healing of refractory mandible osteoradionecrosis after treatment combining pentoxifylline and tocopherol: a phase II trial

BACKGROUND

Osteoradionecrosis (ORN) is a nonhealing wound of the bone that is difficult to manage. Is a treatment combining pentoxifylline (PTX) and tocopherol (vitamin E) boosted by clodronate effective in reversing this fibronecrotic process?

METHODS

Eighteen consecutive patients previously irradiated for head and neck cancer had exteriorized mandible ORN. Length of exposed bone (L) was 13.4 +/- 8 mm, and the mean subjective objective medical management and analytic evaluation of injury (SOMA) score was 12.6 +/- 4.9. Between June 1995 and January 2002, all 18 were given a daily oral combination of 800 mg of PTX and 1000 IU of vitamin E for 6 to 24 months. In addition, the last eight patients who were the worst cases were given 1600 mg/day clodronate 5 days a week.

RESULTS

The treatment was well tolerated. All patients improved at 6 months, with 84% mean L and 67% mean SOMA score reductions. Sixteen (89%) of 18 patients achieved complete recovery, 14 in 5 +/- 2.6 months. The remaining two patients exhibited a 75% response at 6 months.

CONCLUSION

PTX-vitamin E boosted by clodronate is an effective treatment of mandibular ORN that induces mucosal and bone healing in a median period of 6 months.

Hyperbaric oxygen therapy in the treatment of radio-induced lesions in normal tissues: a literature review

Late complications are one of the major factors limiting radiotherapy treatment, and their treatment is not codified. Hyperbaric oxygen (HBO) has been used in combination with radiotherapy for over half a century, either to maximise its effectiveness or in an attempt to treat late complications. In this latter case, retrospective trials and case reports are prevailing in literature. This prompted European Society for Therapeutic Radiotherapy and Oncology and European Committee for Hyperbaric Medicine to organise a consensus conference in October 2001, dealing with the HBO indications on radiotherapy for the treatment and prevention of late complications. This updated literature review is part of the documents the jury based its opinion on. A systematic search was done on literature from 1960 to 2004, by only taking into account the articles that appeared in peer review journals. Hyperbaric oxygen treatment involving complications to the head and neck, pelvis and nervous system, and the prevention of complications after surgery in irradiated tissues have been studied. Despite the small number of controlled trials, it may be indicated for the treatment of mandibular osteoradionecrosis in combination with surgery, haemorrhagic cystitis resistant to conventional treatments and the prevention of osteoradionecrosis after dental extraction, whose level of evidence seems to be the most significant though randomised trials are still necessary. The other treatment methods are also outlined for each location.

Tumor oxygen dynamics with respect to growth and respiratory challenge: investigation of the Dunning prostate R3327-HI tumor

We recently described a novel approach to measuring regional tumor oxygen tension using (19)F nuclear magnetic resonance echo planar imaging relaxometry (FREDOM) of hexafluorobenzene. We have now applied this technique to evaluate in detail the oxygen tension dynamics in the relatively slowly growing, moderately well-differentiated Dunning prostate R3327 HI rat tumor with respect to tumor growth and respiratory challenge. Seven individual tumors were assessed repeatedly over a period of 5 weeks ( approximately 4 volume doubling times). For small tumors (<1 cm(3)), the mean pO(2) ranged from 28 to 44 Torr under baseline conditions, decreasing to less than 10 Torr when the tumors reached 5 to 6 cm(3), with a strong inverse correlation between the baseline tumor oxygen tension and the tumor size. The hypoxic fraction (defined as the percentage of the voxels with pO(2) <10 Torr) increased significantly with tumor growth. Administration of oxygen or carbogen produced a significant increase (P < 0.0001) in tumor oxygenation at all stages of tumor growth. Most interestingly, even regions of these tumors that were initially poorly oxygenated responded rapidly, and significantly, to respiratory intervention, in contrast to the behavior of the faster-growing rat prostate tumors investigated previously.

Treatment of experimental avascular necrosis of the femoral head with hyperbaric oxygen in rats: histological evaluation of the femoral heads during the early phase of the reparative process

The healing of vascular deprivation-induced necrosis of the femoral head of rats exposed to hyperbaric oxygen was compared with that in untreated rats. The amount of necrotic bone, extent of osteoneogenesis, degree of remodeling, and changes of the articular cartilage were histologically graded on a semiquantitative scale of 0 to 3+. On the 2nd, 7th, and 21st postoperative days, there were no differences between the two groups. Newly formed appositional and intramembranous bone was more abundant and remodeling was more advanced in the femoral heads of the hyperbaric oxygen-treated than untreated rats sacrificed on the 42nd postoperative day; also there was less necrotic debris in the femoral heads of the treated rats. There were no differences in the severity of the degenerative changes of the articular cartilage of the treated and untreated rats. Exposure of rats to hyperbaric oxygen does not preserve tissue viability after all arteries supplying the femoral head are severed. Yet, resulting in an increased oxygen tension of the tissues, it seems to provide the optimal settings for reparative processes. The results suggest that hyperoxygenation-mediated relief of ischemia enhances the fibroblastic, angioblastic, osteoblastic, and osteoclastic activities such that healing of the rats' necrotic femoral heads is expedited.

Systematic management of osteoradionecrosis in the head and neck

OBJECTIVES

Osteoradionecrosis is one of the most serious and devastating complications of radiotherapy. The proper management of osteoradionecrosis is currently undetermined. The objective of this study is to evaluate the treatment results of a systematic approach to osteoradionecrosis.

STUDY DESIGN

A prospective study of a systematic approach to osteoradionecrosis in the head and neck area was undertaken.

METHODS

From July 1993 to June 1998, 33 cases of osteoradionecrosis in the head and neck area were treated using a systematic approach that combined sequestrectomy and hyperbaric oxygen therapy.

RESULTS

Seven (21%) had recurrent cancer. The control rate of the other 26 osteoradionecrosis cases was 77% (20/26).

CONCLUSIONS

Persistent osteoradionecrosis, despite diligent radical treatment, raises the suspicion of recurrent cancer. Extensive osteoradionecrosis with a multiple discharging fistula, a large area of exposed necrotic bone, or a coexistent fracture should be treated primarily with radical sequestrectomy and microvascular free flap reconstruction. Surgery still plays a major role in controlling osteoradionecrosis, and hyperbaric oxygen therapy is adjuvant.