Long term effect of Radiation on hearing

[Pablo]

So I'm six month after FSR. My six month hearing test shows a significant hearing loss in the high frequencies (4,000 HZ and up). I have read that radiation affects mostly high frequencies so I'm currently assuming that the hearing loss is due to radiation and not to the tumor growing (my last MRI shows no size changes before MRI, or it's even slightly smaller [ but this is arguable]).

I was wondering if anybody has some information as to by when should be expected the full long term effect of radiation in hearing after treatment , I mean nerve cells start dying  after treatment, but I assume the effect is no immediate. Is six or seven month a reasonable time to believe that no  further hearing loss will be present in the near future? Has someone been checking this?

 I use this link to perform hearing tests on a monthly basis, it is very usful and it is free.

http://www.digital-recordings.com/hearing-test/ht-products.html

Thanks in advance for any info about this.

Pablo

[Lorenzo]

Hi Pablo, My own experience showed a 5% loss from before treatment bringing me down to 75% hearing loss in total. This showed up at the six months audiology test. It hasn't changed since, two years post treatment.
Ciao, Lorenzo

[Pablo]

Thanks Lorenzo for your response. It looks like that hearing is impacted after treatment after all. I had about 35 dB lost in the high frequency range but now it is 55 dB. For some reason mid freqs haven't been affected so much. Your case seems very extreme, sorry to hear that. I guess everyone has to pay with hearing loss no matter what type of treatment you go through. I hope others can also share similar information as well.
Ciao
Pablo

[Lorenzo]

HI Pablo, Well, not that extreme. I had 70% loss before treatment, now I have 75%, so gone down by 5%. Not that bad. Either way, it's useless now. Wasn't really my reason for going the CK route, I just didn't want to get surgery. Felt more comfortable with radiosurgery.
Ciao
Lorenzo

[Pablo]

Sorry I misinterpreted your explanation (as showing 5% loss, I thought you were 95% hearing before treatment ).
Agree, it's not bad at all.
Thank you for clarifying this for me.

[Lorenzo]

No problem Pablo.
Ciao, Lorenzo

[ppearl214]

Hi Pablo.

Prior to my CK treatment, my hearing was at the bottom of the "normal" range in my left (AN) ear.  Issue with low tones. Voice recognition was still at 100%

Last hearing test done (October, 2006), showed my left ear hearing had sunk just below the "normal" range, with continuing issues with low tones (was still fine with high pitch tones), Voice recognition was at 96%.  Lost total decibles (did I spell that right?) 10-15db.

Was quoted by CK docs that total hearing loss, post radiation, should be 5%-7% of what hearing was at time of treatment (averages quoted as each individual is different).

Phyl

[Dealy]

Pablo- Since you and I are similiar in treatment protocol and size wise-however you are not an NF2-my hearing went at 6 months to 90% at 55 DB range. This is down from 96% from the start of FSR. A paper that accompanied my treatment protocol given to me by Johns Hopkins indicated that hearing loss for those with good hearing to start with usually shows a deficit within the first 6 to 10 months out. Then it can take up to 3 years or up to 5 years to stabalize. This is not true for NF2's like me.  I still did not find out why my voice and sounds resonate. Dr. at JHH indicated this is probably(notice it did not say it is) due to the neurotic changes in the tumor death. So I guess that is the extent of my answer that I am going to get. Thanks-Ron

[Pablo]

Thanks so much guys for all the useful information. This is exactly what I was looking for. It sounds like (temporary I hope) hearing loss right after radiation is very common. I was concerned about my particular treatment has been somehow a failure.

Dealy: One clarification I need from you: when you said that hearing stabilizes after 3 or 5  years, you mean this is the time expected for hearing to go back to where it was right before the treatment?

Thanks again.
Pablo
 

[ppearl214]

Hi Pablo,

it is my understanding that whatever your hearing is when it finally stabilizes will be your level of hearing. Hearing, from my understanding, does not improve or go back to what is was before (although I've heard numerous/different things on this.... but....) ... hoping someone can chime in with proof on that, but that was my understanding..."what you see (hear) is what you get".... my hearing has not improved (now pushing 10 mos post-treatment) and it's my understanding that whatever hearing I have left will be it.

Anyone have different info/back up on that?  Will be curious myself....

Thanks,
Phyl

[Pablo]

Phyl,
My radiosurgeon has published some long term results of FSR with regards to hearing preservation (after 5 to 7 years from treatment). The data shows that about 80% of patients maintain or even improve their hearing they had before the treatment. The rest of course is additional hearing loss.

On the other hand  there is a very intersting article called " Annual rate of hearing loss falls after fractionated stereotactic irradiation for vestibular schwannoma"  , Touru Sakamoto, Hiroki Shirat, Norihito Takeichi and others. (I'm quoting the name of the article and authors  in case you have access to these type of things , or if you're interested I could mail it to you. The purpose of the work was to investigate the rate of hearing loss in a population before and after irradiation to determine the effect of irradiation on hearing impairment. The conclusion of their research was (very summarized) that the mean annual rate of hearing loss was higher before irradiation, and hearing loss slowed rather than accelerated after irradiation. Although hearing loss after the treatment was usually permanent, FSR was suggested to be effective to lower the rate of hearing loss. The hearing loss speed data was as follows: pre FSR: about 19 dB/year average, first year after treatment 11 dB/year and after the 3rd year the hearing loss approaches to 0 db/year (stops) (THis is for pure tone tests).  This basically is in alignment with what was reported in this thread on hearing stabilization . The research was done for tumors  size ranging between 3 mm to 29 mm. It's also noted that the hearing loss after FSR during the first couple of years is mainly due to the fact that the tumor doesn't shrink fast enough to produce pressure relief on the nerve and thus stopping the hearing loss  since three years is too long for the nerve to heal after compression.

Even with my almost 3 cm AN my hearing was pretty stable and quite good before treatment so I was wondering what would happen only due to the effect of the radiation itself.

Regards
Pablo

[Dealy]

Pablo- There is a person on this site that had FSR back in 2000 with Lederman who had a 3.0CM. Goes by the handle of Ramair. He had 2.5 weeks of FSR. Results at 2 yearas he reports it-tumor shrinks more-hearing better. 3 years-about the same- At 5 years-tumor same size and hearing stablized. This pretty well typifies what can happen and as Phyl says it will never go back to pre-FSR unless one has a miracle. So whatever you loose seems with what you get stuck with at the end. By the way-another NF2 who had FSR in 2000 at JHH on a one week protocol told me that the resonation sound ceased after 1.5 year mark-however total hearing went down to 40% at 5 years. That is why I shied away from GK or CK after reading that amount of radiation on the hearing nerve was way to much for that nerve to handle and repair from. However-the argument is the other way that FSR is not enough rads to kill the tumor off as contributed by Byron on this site who had FSR in 1999-5 sessions and tumor regrew after 6years or so, We have some on this site that happened with CK also-so I guess their is no 100%. You are really never out of the woods-always looking over your shoulder. Thanks-Ron

[Pablo]

Thanks Ron for the info. By the way the statement of FSR specifically  being ineffective in the long term because of low rads is very argueable based on several papers reporting growth control in long term (7 years +). There may be exceptions as always but those exceptions occur also on single dose treatment as well. Also tumor re-growth is not a specific issue of radiosurgery, there are also re-growth cases even after surgery.   
Those papers also indicate that this type of tumor is very susceptible to radiation so that fact drove the interest for the development of HFSR to minimize nerves functional damage. CK (or GK)  and FSR seem to have the same stats as to growth control  in long term (papers indicate that there is no stat difference between tumor control of FSR or CK, both seem to be equally effective in growth control, the difference is on the effect on surrounding tissue).

Going back to the hearing loss discussion, I understand from the data you show that hearing loss after treatment is permanent and accumulative and myself  seven months after treatement should expect additional hearing loss for the first two - three years.

Thanks again. I guess this info is what I was looking for (but not what I was hoping for  ).

Pablo