Treatment algorithm

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ONGOING

small tumor (Koos grades 1-2)

1st line – observation

Back
ONGOING
|
small tumor (Koos grades 1-2)
1st line – 

observation

Small, asymptomatic tumors with normal cranial nerve function can be monitored by observation. Observation is also considered the first option in patients with small tumors with complete hearing loss.

Clinical observation is recommended if no growth appears on serial scans. At 6 months from presentation, patients who are being observed only should have an MRI, followed by yearly scans for several subsequent years, then scans every 2 years.[58]​ In select cases, patients with smaller growing tumors may still be observed if reliable follow-up can be assured.[57]

2nd line – focused radiation or surgery

Back
ONGOING
|
small tumor (Koos grades 1-2)
2nd line – 

focused radiation or surgery

Some patients with normal cranial nerve function may opt for focused radiation or surgery, but these treatments can deteriorate the nerve function and are usually not recommended.[13]

If tumor growth is apparent on serial scans, focused radiation or surgery is usually recommended. The choice depends on local physician expertise and patient preference.[73][74]

Surgery is completed with a number of approaches tailored to the patient's tumor size and degree of hearing loss, and to the surgeon's experience. In general, a middle fossa approach is completed through an incision that begins in front of the tragus of the affected ear and extends superiorly onto the temporal scalp. A 5 x 5 cm craniotomy is made above the ear, essentially centered on the ear canal. This approach is typically reserved for smaller tumors confined to the internal auditory canal when hearing preservation is attempted.[64]​ The translabyrinthine approach is performed through an incision behind the ear, working through the mastoid portion of the temporal bone, and does not preserve hearing because the inner ear is opened when, as the name suggests, the labyrinthine bone is drilled away. Thus, this approach is often used for patients who already have poor hearing or sometimes in cases where hearing preservation is unlikely, such as with large tumors.[64] The retrosigmoid approach is completed through an incision behind the ear allowing a craniotomy or craniectomy inferior to the transverse sinus and posterior to the sigmoid sinus.[64] This approach can be used for any sized tumor, with or without the intent of hearing preservation. Almost always, the posterior aspect of the internal auditory canal must be removed with a high-speed drill to access the component of the tumor extending into this area.[65][66][67]​ Intraoperative neurophysiologic monitoring of cranial nerves, in particular the facial nerve, is considered standard of care. Monitoring of cranial nerves has changed the nature and success of surgery in terms of cranial nerve morbidity.[68][69][70][71]

Consider – salvage radiation or surgery

Back
ONGOING
|
small tumor (Koos grades 1-2)
Consider – 

salvage radiation or surgery

Treatment recommended for SOME patients in selected patient group

In approximately 5% to 10% of patients who opt for radiation therapy, tumors may grow despite treatment and may require salvage surgery.[72] Similarly, in patients selected for upfront surgical treatment, tumor recurrence may occur during follow-up, especially if less than a gross total resection is performed, and then may require follow-up salvage radiation. Generally speaking, if a person fails initial radiation treatment, then surgery is pursued. If a tumor recurs after surgery, then radiation is pursued.

Recurrence after microsurgical resection of small tumors is approximately 1% to 3% but may be slightly higher in cases of attempted hearing preservation.

medium tumor (Koos grades 3-4, tumor size <3 cm)

1st line – focused radiation or surgery

Back
ONGOING
|
medium tumor (Koos grades 3-4, tumor size <3 cm)
1st line – 

focused radiation or surgery

A majority of patients with medium-sized tumors may have vestibular/cochlear symptoms.[13] Upfront treatment with radiosurgery or microsurgery is typically recommended for such tumors, and long-term observation is usually not considered. The reason for this paradigm is that treatment outcomes are primarily driven by tumor size, and tumors >1.5 cm risk poorer outcomes if further growth occurs.[57]​ Stereotactic radiation carries lower risk than surgery. Nevertheless, surgery ensures complete resection of the tumor.[13]

Surgery is completed with a number of approaches tailored to the patient's tumor size and degree of hearing loss, and to the surgeon's experience. In general, a middle fossa approach is completed through an incision that begins in front of the tragus of the affected ear and extends superiorly onto the temporal scalp. A 5 x 5 cm craniotomy is made above the ear, essentially centered on the ear canal. This approach is typically reserved for smaller tumors confined to the internal auditory canal when hearing preservation is attempted.[64]​ The translabyrinthine approach is performed through an incision behind the ear, working through the mastoid portion of the temporal bone, and does not preserve hearing because the inner ear is opened when, as the name suggests, the labyrinthine bone is drilled away. Thus, this approach is often used for patients who already have poor hearing or sometimes in cases where hearing preservation is unlikely, such as with large tumors.[64] The retrosigmoid approach is completed through an incision behind the ear allowing a craniotomy or craniectomy inferior to the transverse sinus and posterior to the sigmoid sinus.[64] This approach can be used for any sized tumor, with or without the intent of hearing preservation. Almost always, the posterior aspect of the internal auditory canal must be removed with a high-speed drill to access the component of the tumor extending into this area.[65][66][67]​ Intraoperative neurophysiologic monitoring of cranial nerves, in particular the facial nerve, is considered standard of care. Monitoring of cranial nerves has changed the nature and success of surgery in terms of cranial nerve morbidity.[68][69][70][71]

Consider – salvage radiation or surgery

Back
ONGOING
|
medium tumor (Koos grades 3-4, tumor size <3 cm)
Consider – 

salvage radiation or surgery

Treatment recommended for SOME patients in selected patient group

In approximately 5% to 10% of patients who opt for radiation therapy, tumors may grow despite treatment and may require salvage surgery.[72] Similarly, in patients selected for upfront surgical treatment, tumor recurrence may occur during follow-up, especially if less than a gross total resection is performed, and then may require follow-up salvage radiation. Generally speaking, if a person fails initial radiation treatment, then surgery is pursued. If a tumor recurs after surgery, then radiation is pursued.

large tumor (Koos grade 4, tumor size >3 cm)

1st line – surgery

Back
ONGOING
|
large tumor (Koos grade 4, tumor size >3 cm)
1st line – 

surgery

With or without tumor growth on serial scans, surgery is recommended owing to the large size and potential damage to adjacent structures and resulting functional deficits. Surgery is recommended in most centers in preference to radiation, because of improvement in mass effect symptoms offered by surgery over radiation.[66][75]​​ Surgery to preserve hearing is not offered by most surgeons as the mass effect of such a large tumor often has already caused damage to hearing structures, although if the patient has useful hearing prior to surgery, a hearing preservation attempt is a reasonable undertaking, albeit not likely to succeed.​[53][67]​​ Surgery should focus on improving or maintaining quality of life and attempting to preserve the nerve function.[76]

Patients with large tumors may have modest brainstem compression and may present with facial nerve paresis and gait ataxia. Decompression of the brainstem and stretched cranial nerves is vital in such cases, and thus surgery is the preferred treatment option.

Surgery is completed with a number of approaches tailored to the patient's tumor size and degree of hearing loss, and to the surgeon's experience. In general, a middle fossa approach is completed through an incision that begins in front of the tragus of the affected ear and extends superiorly onto the temporal scalp. A 5 x 5 cm craniotomy is made above the ear, essentially centered on the ear canal. This approach is typically reserved for smaller tumors confined to the internal auditory canal when hearing preservation is attempted.[64]​ The translabyrinthine approach is performed through an incision behind the ear, working through the mastoid portion of the temporal bone, and does not preserve hearing because the inner ear is opened when, as the name suggests, the labyrinthine bone is drilled away. Thus, this approach is often used for patients who already have poor hearing or sometimes in cases where hearing preservation is unlikely, such as with large tumors.[64] The retrosigmoid approach is completed through an incision behind the ear allowing a craniotomy or craniectomy inferior to the transverse sinus and posterior to the sigmoid sinus.[64] This approach can be used for any sized tumor, with or without the intent of hearing preservation. Almost always, the posterior aspect of the internal auditory canal must be removed with a high-speed drill to access the component of the tumor extending into this area.[65][66][67]​ Intraoperative neurophysiologic monitoring of cranial nerves, in particular the facial nerve, is considered standard of care. Monitoring of cranial nerves has changed the nature and success of surgery in terms of cranial nerve morbidity.[68][69][70][71]

Consider – radiation or observation

Back
ONGOING
|
large tumor (Koos grade 4, tumor size >3 cm)
Consider – 

radiation or observation

Treatment recommended for SOME patients in selected patient group

As complete resection may lead to deterioration of cranial nerve function, incomplete resection of the tumor followed by radiation or observation is recommended.[13]

back arrow

Choose a patient group to see our recommendations

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer

Use of this content is subject to our disclaimer