Three ways for protecting your brain from acoustic neuroma

There are three treatment procedures to protect your brain from acoustic neuroma over the decades, but none of them is ideal.

The bigger a tumor becomes, the more difficult the treatment is. Hence, early diagnosis and early treatment are essential for your cure. The three treatment options are available.

1. conservative management

2. stereotactic radiation therapy, and

3. conventional surgical treatment.

In addition, a multidisciplinary approach that combines two of these options, based on the complete understanding of the advantages and disadvantages of each, as part of a 10–20 year plan is a new strategy for the next decade. By comparing each long-term result, the treatment of first choice becomes clear for your specific medical condition.

Evidence-based treatment selection for acoustic neuroma

Procedure 1. Conservative management

Conservative management consists of two things. One is to repeat magnetic resonance imagings at a certain period of time (6-12 months) and the other is to repeat both neurological examination and 3 hearing tests at the same intervals. So that we can find any change of tumor size as well as facial and hearing functions.

Evidence for conservative management.

One long-term cohort follow-up study report has been published based on large-scale clinical trials in Canada (third column in the table). In this study, 72 patients with acoustic tumors underwent conservative observation with a mean follow-up period of 7 years.

Tumors of the internal auditory canal (IAC type) had an average growth rate of 0 mm / year, whereas cerebellopontine angle tumors (CPA type) had an average growth rate of 1.3 mm / year.

Those cases that needed additional treatment as a result of tumor growth or aggravated symptoms had an average tumor growth rate of 3.1 mm / year.

Patients with both IAC-type and CPA-type tumors showed a decline in pure-tone average (PTA) of 5 db / year and a decline in speech discrimination score (SDS) of 6% / year.

The loss of hearing increased with each year of conservative observation.

(Clinical Otolaryngol 2004 29, 505–514. Raut et al.)

Procedure 2. Stereotactic radioosurgery

Stereotactic radiosurgery, without a skin incision, are used to deliver adequate irradiation to a tumor. They are precisely designed to deliver highly compact and focused irradiation, to prevent the growth of the tumor.

Mrs .E.K. 体験談1. Testimonial

Mrs. Kagawa is a middle aged lady, a master of calligrapher teaching penmanship for many years at her own class. She has had hearing difficulty since 4years ago. She was diagnosed to have a quarter inch sized acoustic neuroma at that time at University hospital. Her physician recommended to have stereotactic radiosurgery (gamma knife) and she agreed to proceed with it subsequently. She did maintain her excellent facial movement as well as her hearing for the first 3 years. Since a year ago, she did experience some facial twitching as well as further decline of hearing ability on the affected side. Recent brain MRI did show tumor regrowth even 3 years after the treatment. Now she has strong fear of how she can deal with this difficult situation since she did already undergo radiation therapy. She did hear about the risk of cancer transformation after radiation therapy. She is now looking for any hope to solve this situation.


I am now particularly anxious about her facial movement since I have been informed that any treatment after gamma knife is tremendously difficult so that the risk of hurting my facial motion is quite high. Now I came to see Dr. Nakatomi looking for any information about the treatment after gamma knife.”

She did undergo my surgery and was very successful. Her tumor was totally out, her hearing was maintained at the same level. .

In order to achieve adequate effects, stereotactic radiation treatment takes 12–24 months; the tumor does not respond immediately to treatment, rather there is a gradual increase in the probability of a certain reduction of the tumor size or a cessation of the tumor growth over time.


Evidence for stereotactic radiosurgery.

Physicians at the Mayo Clinic (Rochester, United States), together with whom Dr. Nakatomi personally treated patients, reported on a series of 288 cases (fourth column in the table) demonstrating the efficacy of stereotactic radiosurgery.

Among these cases, the risk of hearing loss was around 40%, the risk of facial nerve palsy was 5%, and malignant transformation was observed with a probability of 1 / 1,200.

Even after the radiation treatment, 10–15% of patients showed subsequent tumor growth that required surgery. Most physicians reported that surgery after stereotactic radiosurgery was difficult to perform due to the strong adhesions between the nerves and the tumor capsule.

Although this might appear to be an attractive and less-invasive treatment at first glance, it has limited efficacy for larger tumors (3 cm or more in size).

At present, many physicians recommend stereotactic radiation therapy only for patients with high-risk medical conditions that make the use of general anesthesia difficult.

(Neurosurgery 2006 58 (2), 241–248. Pollock et al.)

Procedure 3. Conventional surgery

Evidence for conventional surgical treatment.

During the past 21 years, at the Nordstadt hospital, 1800 patients were given acoustic tumor surgery using the retrosigmoid approach. All the procedure were performed by Professor M.Samii.

In total, 1765 cases (98%) achieved gross total resection. Subtotal removal (90- 95% removal) or partial removal (less than 90 %) were done in 35 cases.

In 95% of cases the facial nerve was preserved in continuity.

Of these excellent functional facial nerve preservation was achieved in 85%. The other 15% of the patients lost clinical facial function.

Among 1800 ears with a tumor resected at the corresponding auditory nerve, there were 1315 with some auditory function present before operation.

Out of 1315 cases with preoperative hearing function some auditory function was successfully preserved in 529 (hearing preservation rate, 40.2%).

684 cases had normal or good hearing preoperatively.

Out of 684, 366 cases (effective hearing preservation rate, 54%) maintained normal of good hearing postoperatively.

(Neurochirurugie, 2002. 48, (6), 461-470)

Summary. Comparison of 3 procedures.

According to those 3 large volume studies, we can clearly elucidate several conclusions from the different viewpoint.

In the aspect of acoustic neuroma cure, cure should be defined as to end the disease condition by the treatment. In this sense, convensitonal surgery is superior to radiosurgery and conservative management.

In the aspect of preserving facial nerve function, concervative mangement is best and followed by radiosurgery (4% risk). Conventional surgery had significant risk (15%) of facial paralysis.

In the aspect of maintaining effective hearing, radiosurgery is superior to conventional surgery and concervative management.

Thus we can clearly conclude there have been a lot of controversies in choosing the treatment procedure, because there has been no “ideal” procedure that can take the tumor out maximally and maintain both facial nerve function and effective hearing simultaneously.

Now we are ready to reveal our new MBMI surgery which solved all the problems and disadvantages of conventional treatments.

We can say with utmost sincerity and humility, this is indeed the ideal treatment for acoustic neuroma.

Procedure 4. Nakatomi’s MBMI surgery

Here we present the actual result of our new Nakatomi’s MBMI surgery along with the conventional treatments. Although the details of new MBMI surgery is still secret, we will show you several important concepts of MBMI in the following article. Do not miss it.

Conservative
o
bservation
(Toronto; 72 cases over 6 years)

Stereotactc radiosurgery
(Mayo Clinic;
288 cases / 3 years)

Conventional Surgery
(Nordstadt hospital;
1800 cases / 22 years)

Nakatomi’s MBMI (monitoring-based minimally invasive ) Surgery 105 cases over 3.5 years

Degree of tumor removal (size)

Remained constant in 42% and 39% increased in 39%

Reduced in 85% and remained unchanged in 15%; Risk of cancer formation, 1 / 1,200

Gross Total Romoval; 98%, Subtotal Removal; 2%

Gross-Near Total Removal; 89%, Subtotal Removal (92-95%); 11%.

Currently achieves 98-95% removal in all cases

Facial nerve function

No paralysis in all.

paralysis not recoverable

No or weak paralysis in 85%.

15% lost facial function.

No paralysis or near normal in 99%, reduced function in 1%.

Auditory function

Most cases gradually deteriorated Recovery was difficult

Effective hearing maintained in 63% and deterioration in 37% with no recovery

Effective hearing maintained in 54% and deterioration in 46%

Effective hearing maintained in 80% and measurable hearing maintained in 90% in MBMI- surgery