Continued hearing loss years after radiation

[ANSydney]

Hi Paul, it would be great to meet up when you're next in Sydney. I've only been to Adelaide once, a few decades ago. Actually it was to Murray Bridge, but we did pop over to Adelaide and the Barossa Valley.

I'll have a good look at my copy of the paper when I get home tonight. My copies are useful to me as I make notes on the paper about interesting findings. Reading the abstract, it does sound like gamma knife is the best thing since sliced bread.

Geographic location is an interesting subject. The following are for tumors up to 3 cm in diameter and are based on where you live. If you live in Los Angeles, there is a 55% chance of surgery, 25% chance of radiation and 20% chance of observation. If you live in Hawaii then you have a 15% chance of surgery , 30% chance of radiosurgery and 55% chance of observation.

These figures are from https://www.ncbi.nlm.nih.gov/pubmed/27334903

If you live in Denmark or parts of England, then for a 2 cm or less sized tumor, 95% are observed.

So clearly the water where you live is the most important factor for treatment modality!

From the abovementioned paper "Despite a lack of compelling evidence supporting one treatment modality over others, many providers and institutions remain highly biased toward one particular therapy-microsurgery, radiation, or primary observation." and "Until there is clear evidence supporting one therapy over others, multidisciplinary consultation with a minimum of a neurotologist, neurosurgeon, and radiation oncologist or radiosurgeon should be offered in order to provide balanced counseling and accurate informed consent." Who do you see that is biased towards observation to get a complete picture?

Nobody can even answer the most fundamental question of what percentage of tumors grow? What have we been doing for the past 100 years?

By the way, regarding treatment options the best are robotics for microsurgery and MRI guided focused ultrasound for non-invasive surgery and objective measures for observation. We just have to wait another 5 to 10 years for the first two, which should only be done after a 2 year trial (5 MRIs) with intervention for select few cases where there is rapid growth threatening to exceed 3 cm or objective symptom progression. Given the known biases, the patient should be able to personally measure growth profile (do not rely on radiologist as they got my measurements completely wrong) and objectively record symptom progression (do not rely on memory).

[ANSydney]

MRI and CT have only been available since the 1970's. So size measurements have only been possible for the last ~40 years. So change that 100 years to 40 years. (Although the natural incidence in the population, through cadaver examination, could have been known 100 years ago.)

[ANSydney]

I've started re-reading the https://www.ncbi.nlm.nih.gov/pubmed/25434946 paper. It's long at 16 pages. Unfortunately the Kaplan-Meier plots for hearing loss (Fig. 5) do not provide the at risk numbers, which would be interesting to know in the later years. They report a very impressive 97.1% tumor control rate. However "Tumor control was defined as no need for further surgical or radiosurgical intervention after primary GKRS treatment". This is a lot easier to achieve than a no-growth criteria.

This paper was queried in a letter at http://thejns.org/doi/pdf/10.3171/2014.12.JNS142826 and stood up pretty well to scrutiny. There is also reference in the query to the paper at https://www.ncbi.nlm.nih.gov/pubmed/25415463 . So three sets of papers or letters to process. I hope to read them all again over the next few days.