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4. Osteoradionecrosis of the Jaw and Hyperbaric Oxygen
Hyperbaric Medicine Research is supporting LHM Healthcare with two ongoing multicenter trials into the clinical effectiveness of HBOT for this condition.
A. The Hopon Trial and the B. The DAHANCA Trial
The most serious side effect of radiotherapy is something called osteoradionecrosis, or ORN for short. This is a condition affecting jaw bones that received radiotherapy in the process of treating cancer of the head and neck. The bones can be damaged by the radiotherapy and do not heal as well as other tissues, because they have a limited blood supply. And the worst case scenario for this particular condition is where the bone dies completely.
It affects patients who have been successfully treated for head and neck cancer and can occur any time after radiotherapy – even 20 years later in some cases. While it can arise spontaneously, it usually develops following dental work, particularly tooth extractions or inserting implants. Loss of bone can lead to patients suffering jaw fractures, experiencing a lot of pain, or having holes (sinuses) appearing in their faces where the jaw bone has collapsed.
Because more people are developing, and surviving, head and neck cancer, we are seeing an increasing number of people with these long term side effects. We think around one in 10 patients who received radiotherapy to the head and neck develops ORN, but we need research to find out exactly how many patients are affected. And for many of these patients, treating ORN is worse than the original cancer treatment. So, as doctors, it is something we are desperately keen to avoid for our patients.
The idea behind the HOPON trial began in the US during 1970s and involved the use of hyperbaric oxygen treatment. People are put in a chamber for a period of time each day, where the oxygen is at higher pressure than in air we normally breathe. It had previously been used in diving accidents, carbon monoxide poisoning and for people with wound healing problems.
The theory was that the increased oxygen re-invigorates damaged tissues and helps them heal quicker. And therefore might help repair jaw bones damaged by radiotherapy, preventing severe side effects from developing after dental surgery in cancer survivors.
A clinical trial was carried out in the early 1980s in Florida. Patients who had been given radiotherapy and later needed dental work were having significantly reduced risk of developing ORN when they receive hyperbaric oxygen therapy before and shortly after their dental procedures. But that original study was a small trial. The time had now come to prove one way or the other if hyperbaric oxygen treatment works in preventing ORN in most patients. And that is the principle behind the HOPON trial.
NEW: Greenlight Approval for DAHANCA 21 Study at LHM Healthcare granted on 17th August 2016
In this study patients who had radiation to the head and neck and then unfortunately developed damage to the jaw bone, called Osteoradionecrosis, will be randomised to have standard treatment with antibiotics and supportive treatment or Hyperbaric treatment with supportive treatment and their surgery to remove the injured jaw bone.
Both these studies are managed primarily by maxillofacial and head and neck surgeons with the assistance of Hyperbaric treatment centres.
Click here for more information on Osteoradionecrosis > (hidden)
Osteoradionecrosis of the mandible or jaw (ORN) is an unfortunate side effect seen in survivors of cancer of the head and Neck. It is bone necrosis (death of bone) secondary to irradiation given to kill cancer cells and in addition can be due to superimposed infection. Although modern radio therapeutic doses and targeting have improved over the years it still occurs because the radiation used invariably not only destroys the cancerous cell but will destroy normal cells and blood vessels as well. Damage to the blood vessels deprives the bone and soft tissues of the oxygen and nutrients necessary for a normal functioning of cells.
Due to the slow onset of the radiation induced damage this can be a protracted effect with the eventual bone necrosis seen after a latent periods of years after the original cancer.
This condition can be extremely debilitating, physically disfiguring and painful. It can manifest as ulceration of the mucosa (tissue) overlying the lining of the mouth and bone. these ulcers can become deeper and more destructive over time, leading to a tendency for the bone to break and not heal as normal bone would.
Speech and eating can be severely affected and cause physical and psychological detrimental effects in a population of patients ranging from all aspects of life and age groups.
Patients needing further surgery either to remove teeth that have decayed or died as a result of the radiation used or for non-healing fractures are at high risk of suffering from non-healing wounds and repeated wound breakdown. Attempts to cover the resulting defects either within the mouth or outside of the jaw can be technically challenging and fail due to the inability of the local tissues to undergoing a normal wound healing process.
Hyperbaric oxygen has been used for over 30 years to try and mitigate theses effects and to try and reset the ‘radiation clock’ in this unfortunate group of cancer survivors that are often at the end of conventional strategies for wound healing and left to cope with a painful, debilitating and disabling condition.
HBOT ids both used to prevent the development of ORN and to try and repair damage from established ORN as well.
This calls for a multidisciplinary approach and team effort.
The aim of our charity will be to raise awareness of this debilitating condition in the general public, patients being treated for heads and neck cancers, allied healthcare professionals and medical and surgical teams involved in treating these patients.
Over the years the incidence seemed to have declined and we have witnessed a reduction in the number of cases referred to us, however we feel that in other units of the international hyperbaric community have not seen this and on the contrary seem to have evolved practices that enable administration of HBOT to their patients as part of established referral pathways and strategies.
Further aims of our charity are to provide not only funding to ‘kick-start ‘ research into these conditions but also to enable a form of expertise and advice open to any individual with an interest to ameliorate the suffering of this heterogeneous patient population. We envisage a broad spectrum of available expertise not only into the setting up of research but publication of advice, reassurance and a general rallying point for patients, relatives and healthcare professionals all coming together to further our understanding and treatment of their often overlooked debilitating process. This is to reassure patients that they are not on their own left to fend for themselves and labelled with an incurable and debilitating condition but to be reassured that there is a caring community out there striving to help to improve their lot and to offer advice, reassurance and care, whist at the same time strives to enhance our understanding of the underlying disease and to explore novel approaches to treatment and prevention of this latent tissue damage to manifest itself with all the complications suffered.