Suivi par imagerie IRM, mais sans traitement
||Les options de base pour un neurinome de l'acoustique sont :
- la neurochirurgie,
- la radio-chirurgie,
- l'observation clinique, sans traitement.
Avant de faire son choix, il est important de connaître toutes ses options. Lisez d'abord la page décrivant toutes les options de traitement. La présente page concerne ceux qui envisagent l'observation sans traitement (wait and watch en anglais = attendre et voir). D'autres pages de ce site concernent ceux qui font le choix de la chirurgie et de la radio-chirurgie. Il est fortement conseillé de les lire toutes avant de prendre une décision.
Les raisons de choisir l'observation plutôt que le traitement
- Statistiquement, environ 40% des neurinomes accompagnés de symptômes légers semblent arrêter spontanément leur croissance. Des études dans les pays scandinaves, ou chaque décès est suivi d'une autopsie, montrent que la grande majorité des neurinomes n'atteignent jamais le stade des symptômes cliniques, et passent donc inaperçus.
- Tout traitement médical pour les neurinomes, que ce soit chirurgie ou radiations, comporte des risques. La grande majorité des neurinomes sont à croissance très lente et les cas de neurinomes cancéreux sont rarissimes ou inéxistants. Il est donc logique d'attendre au moins 6 mois après le premier diagnostique pour faire un deuxième examen IRM. Cela permettra de vérifier le taux de croissance dans votre cas particulier. Si ce taux de croissance est nul il est envisageable de ne jamais subir d'intervention médicale.
- Avec le temps, qui sait, d'autres options que la chirurgie et les radiations seront peut-être découvertes.
Introductory comments about waiting and watching.
Waiting & watching is not procrastination. ANs are typically slow growing and non-cancerous, so the patient has plenty of time to do research in most cases. As the cure for ANs can be worse than the complaint, research is a good idea.
While waiting & watching during research makes perfect sense, once the decision for treatment has been made it is usually foolish to put it off any longer. Only when research shows that medical treatment might never be needed should waiting & watching become a permanent strategy.
- The first thing to decide for wait & watchers is: "what will trigger my decision to seek treatment". One thing that should trigger it is the size of the tumor. It is generally thought that surgery on tumors larger than 2 cm carry more risks of hearing loss and facial paralysis. Tumors larger than 3 cm may no longer be suitable for radiation treatment. So if a tumor is close to these levels, and growing, medical treatment should be the preferred option.
- Another thing that should trigger the decision is a change in symptoms. Most AN sufferers discover their tumor when they start losing hearing in one ear, or develop tinnitus (1), or start losing balance, or, in rare cases, start feeling numbness in the face. If any of these symptoms get noticeably worse, it can be a sign to stop waiting and seek treatment.
Two basic wait & watch options:
- Pre-treatment research
Acoustic neuromas on average grow at rates close to 2 mm per year. They are never cancerous so they do not invade other tissues. However, treatment by physicians who are not experts in acoustic neuromas can lead to very undesirable consequences. Hence, a period of several months of watching & waiting to seriously research the various treatment options is recommended for almost all AN patients. A good plan is to wait for a second MRI test, about 6 months after the first, to establish the real growth rate. That is time enough to seriously research the options.
Of course, there are a few exceptions to this rule.
- In the past, patients sometimes waited until their tumor was large before consulting. Symptoms at diagnosis could be as severe as facial numbness or partial facial paralysis. This almost never happens now. With the advent of MRI imaging acoustic neuromas are usually diagnosed when they are still small and present few symptoms. However, there are still cases where the tumor is discovered late and may be threatening to do serious damage to surrounding nerves and brain structures. In such cases, waiting may be a bad choice. Consult with several doctors before you decide urgent treatment is required.
- There are rare cases reported where the growth rate of the tumor is much higher than the average. Possible causes can include pregnancy or head trauma, such as a car accident. If rapid growth is suspected, obviously waiting is not a good option. Again, several doctors should be consulted to make sure that rapid growth is real.
- Decision not to seek medical treatment
Some patients decide that the tumor may never need to be medically treated. This is called "conservative management". An MRI test is done at regular intervals (initially 6 months, then maybe every year or every 2 years). Any change in symptoms is closely monitored and considered as important as any change in size, if not more so. If the change is significant, the decision to stop waiting and seek treatment can be taken.
Some studies show that about 40% of acoustic neuromas do not grow after diagnosis. A typical case is a patient over 60 years of age at the time of diagnosis, with rather mild symptoms and a small tumor. For instance, a recent Italian study shows that 8 selected patients over 65 with tumors extending less than 1cm into the CPA were followed for 5 years with conservative management only. "At the 5-year follow-up, no tumor growth was seen in six of the eight patients in the observation group. The other two patients exhibited a tumor growth rate of less than 2 mm per year, and their tumors still protruded less than 1 cm into the cerebellopontine angle. Therefore, neither of these patients required surgical intervention."
Although there may be many cases other than the elderly where the tumor will not grow, the danger of conservative management is wishful thinking. Acoustic neuroma surgery is no picnic, but treatment is preferable to letting the tumor grow and the symptoms worsen.
Very clear goals should be set to trigger an end to the wait & watch period. To avoid the natural tendency to put treatment off for too long, the patient should consult frequently with his doctors and not make the decision alone.
Waiting and watching carries the risk that hearing will be irretrievably lost. Generally speaking, none of the treatment options give much hope of improved hearing, so what is lost will probably stay lost. Another danger is the constant stress of knowing that there is an untreated tumor which might stay dormant for a while and then start growing again.
www.anausa.org The Acoustic Neuroma Association (USA). There is a lot of useful information on this site and a guest book as well as a very active mailing list for patients.
www.ANSeattle.org The Seattle (WA) Acoustic Neuroma Group - SANG.
www.anarchive.org The AN Patient Archive site, full of information and patients' stories.