radiation

Gavin's Story: Living with & Preparing to Evict My AN, “Frank”...but When?

admin — Wed, 19 Jan 2022 22:12:12 +0000

Gavin's Story: Living with & Preparing to Evict My AN, “Frank”...but When? admin Wed, 01/19/2022 - 17:12

Gavin Donatelli of Victoria, BC discovered he had an AN after suffering a concussion following a game of hide and seek. He was only 35 years old at the time.

Gavin Donatelli

Through a strange set of circumstances my acoustic neuroma (AN) was discovered in 2017. I previously worked for a youth criminal justice program offering an alternative to incarceration to help offenders get onto a positive life path. While playing an intense game of hide and seek tag, a favourite of both participants and staff, I was accidentally kicked in the head.

I suffered a concussion and, during the assessment of my injury, an MRI of my brain revealed that I had an AN on my left side. After hearing my diagnosis, I immediately recognized what they were talking about because

one of my parents also has an AN. However, we do not have NF2, the genetic binomial version of an AN, and I have been told that it is pure coincidence we both have ANs based on the existing research. I have also undergone genetic testing, performed by none other than a Dr. Blood, to see if she could detect genetic markers suggesting our ANs are hereditary. The testing came back saying that no genetic mutations were identified for NF2. However, an increased susceptibility to an AN wasn’t entirely ruled out. I looked it up and, if the odds of having an AN are 1 in 100,000, then by my calculations the odds of both my parent and me having an AN are 1 in 10,000,000,000. I suspect that there just hasn’t been funding to research other hereditary causes of single-side AN.

Fortunately, when my AN was discovered, it was small (11mm x 5mm), and it didn’t seem to be causing symptoms. I was told by my ENT that I would need to go for regular MRIs to monitor the size, but it would only be life threating if I lived in a remote area far from access to advanced medical care. While my ENT mentioned surgery as an option one day, he told me that “watching and waiting” was the best course of action. I decided I needed to make peace with my tumour, which I named Frank, and hoped that we could cohabitate and share the limited space in my brain for years to come. However, Frank had other plans and he has continued grow in size.

Eventually, I arranged a consultation with Dr. Vallieres, a radiation oncologist who outlined the costs and benefits. She said that this procedure carries a lower risk of losing my hearing on the left side, at least initially, no requirement to cut the balance nerve, and would allow me to have little disruption in my life. However, given my young age of 35, there could be long-term risks of developing cancer and other issues by exposing my brain to radiation. While there are no studies showing a link between these radiation procedures and developing brain cancer, these procedures are relatively new and the majority of patients with ANs are older. Therefore, there are lower risks for them using radiation because there is less potential time for negative side effects to develop in the life span of these patients. Dr. Vallieres said that given my age, which should help me recover better from the surgery, the talent of Dr. Akagami (the famed neurosurgeon in BC), and the additional risks for using radiation as a treatment, she would encourage me to consider surgery as an option. She was careful to tell me that both procedures are good choices and that ultimately, I would need to make a personal choice. I was struck by the fact that this physician was recommending a treatment option for me other than her own specialty. I really appreciated her candor and her empathetic approach to my situation.

At a subsequent consult with my ENT, my AN showed enough growth that he suggested I meet with Dr. Akagami. I saw Dr. Akagami in August of 2020. He said that both radiotherapy and surgery were viable options; however, he said the radiotherapy would provide less control of the tumour size and there is a very small risk of radiation-induced tumour growth. In addition, the radiotherapy typically provides about 15 years of control over the tumour at which point the effectiveness decreases. Since I hope to live significantly more than 15 years, this played a factor in my decision. The potential for complete loss of my hearing on my left side was more likely with surgery, but I could get lucky with a 40% chance of hearing preservation. I also understood that while there are risks to my facial nerves, chance of increased neurological deficit and other associated risks of the surgery, given my age and health, as well as the location and size of the tumour, I had a really good chance of a comprehensive recovery from the procedure. While the prospect of having brain surgery seemed daunting, I got a good feeling from Dr. Akagami and many people told me how highly skilled he is, including his ENT partner, who described his hands as “a gift from God!”

It was around this time that my mother did some research and discovered the Acoustic Neuroma Association of Canada (ANAC). Right when I really needed a lifeline, ANAC was there for me. I joined their support group and took comfort in the advice, community and collective wisdom they offered me. ANAC shared a list of top doctors I could contact for a second opinion and sent newsletters with the latest medical information. ANAC connected me with other people in similar circumstances who could share their experiences with the various treatment options, and gave me helpful tips for recovery and living with an AN. Carole Humphries, the Executive Director of ANAC, has been so kind and helpful. Carole has been a strong advocate and support for me, going above and beyond to let me know I’m not alone in this struggle.

I decided to have surgery and got my name on Dr. Akagami’s waitlist in September 2020. I was told that, given my tumour size, I would likely be on the wait list for about a year before I would have my surgery. This was a long time to wait, but I mentally prepared what I like to think of as my “ armour”. I started exercising more, I stopped drinking, and I started doing additional exercises to enhance my balance to prepare for when they cut my balance nerve on my left side to remove the AN. In the spring of 2021, I met with a new ENT who informed me that my AN hadn’t grown in the latest MRI. At ANAC’s AGM this past summer, I learned that tumours can potentially stop growing because they outrun their blood supply.

In May of 2021 my partner and I had been lucky enough to welcome our first child into our lives! Our son Ozzie has been such a blessing during COVID and a real inspiration to help me prepare and plan for recovery from the surgery. I did start wondering if I might be able to “watch and wait” again if my tumour had indeed stopped growing. I emailed Dr. Akagami and learned my ENT had incorrectly assessed my tumour which was in fact still growing at about the same pace. This was really hard news to take. I had been mentally preparing for surgery and the sliver of hope my tumour had stopped growing had weakened my resolve, I think in part because I’m now a parent and worried about how I will care for my son post-surgery.

My MRI in September 2021 showed that my tumour continues to grow, is 16mm by 14 mm, and I am definitely experiencing symptoms. My surgery has been postponed from September 2021 until at least the new year, because of the strain on our healthcare system caused by this pandemic. Nurses are burning out and retiring, and access to operating room time has been limited. This delay is disheartening since now I do not know when I will be able to get this tumour out of my head or if my symptoms will significantly increase before it’s removed.

British Columbia, like many other places worldwide, has seen a spike in the number of COVID cases and number of unvaccinated people in ICUs during the current 4th wave. Hospitals are being pushed to the brink and are having to cancel or delay all kinds of surgeries and medical procedures. This has forced people like me to wait longer for urgent medical procedures and suffer through symptoms.

My hope is that those who are unvaccinated will listen to the advice from the consensus of global medical experts and get vaccinated to bring this pandemic to an end. At the very least, I encourage you to speak with your local health care provider about your concerns and refrain from sharing anecdotal information about COVID-19 vaccines that is unsupported by scientific evidence. My quality of life depends on people getting vaccinated so that I can access the healthcare intervention I need.

radiation

surgery

Answers to Your Questions About Radiation

admin — Fri, 28 Feb 2020 20:54:02 +0000

Answers to Your Questions About Radiation admin Fri, 02/28/2020 - 15:54

David Roberge, head of radiation oncology, works in a new “superhospital” in downtown Montreal -- the “CHUM” or “Centre Hospitalier de l’Université de Montréal”. He has been performing radiosurgery for more than 15 years. Dr. Roberge currently treats patients using the latest version of the “Cyberknife” (since it installed the first Canadian Cyberknife in 2009, this is CHUM’s third iteration of this robotic device) and works with a team including a neurosurgeon, ENT surgeon, neuro-radiologists and audiologists. He gives us his opinion regarding five common questions about acoustic neuroma radiation treatments.

1. Once a patient has chosen to defer treatment, what should trigger the decision to proceed with radiation?

As with many decisions in the management of acoustic neuromas, the answer is “it depends”. The decision can be different for each patient — taking into account the size of the tumour, the age and general health condition of the patient, and the patient’s symptoms, goals and preferences.

In general, triggers for treatment can be tumour growth or new/ progressive symptoms. The dilemma will often be similar to the dilemma faced at the time of diagnosis — should I have treatment now or should I wait? On one hand, long-term outcomes (especially hearing) will be best in those patients with good cranial nerve function at the time of treatment (injury caused by the tumour during observation will often be permanent) but on the other hand, treatment itself can cause injury to the cranial nerves.

The rare circumstances where treatment “must” be performed are those where the tumour is causing symptoms by compression of the brainstem or there is a blockage of outflow of cerebrospinal fluid (hydrocephalus). Treatment should also strongly be considered for tumours with rapid growth.

In my practice, I find it useful to take the time to decide up front what the trigger for treatment will be. This will decrease anxiety at each subsequent MRI. Those triggers can be a growth rate (more than 2mm/year), a size (2cm) or a decrease in hearing.

2. When is radiation not a viable option?

There may be reasons related to the tumour or the patient who favors surgery over radiation. Size used to be an important consideration but, as years go by, the evidence for the safety of radiation to treat larger tumours is accumulating. Each clinic will have a different comfort level in treating tumours greater than 3 or even 4 cm with radiation. Independent of exact size, when the goal is to relieve pressure on brain structures or restore flow of cerebrospinal fluid, radiation is not the appropriate treatment.

There are occasional cases where, even for a trained neuro-radiologist, the diagnosis of acoustic neuroma is uncertain. In these cases, it may be best to perform surgery to treat the tumour and confirm the diagnosis.

There are diseases and genetic profiles which make an individual more sensitive to radiation. Luckily these are rare and those syndromes which lead to the highest risk of radiation injury (Ataxia Telangiectasia, Fanconi Anemia, or Nijmegen Breakage Syndrome) have other manifestations which should bring them to attention. It is important for the medical team to review the entire medical history, including apparently unrelated conditions, prior to recommending radiation. There is a budding industry of tests which purport to quantify radiation sensitivity, but these are almost never used and are probably better suited to situations where more of the body would receive radiation (such as the treatment of breast or prostate cancer). It is normal to be more reluctant to use radiation in children as they will have more years ahead of them to develop radiation-induced tumours. This will be weighed in the decision but as the absolute risk of a radiation-induced tumour will remain very small, radiosurgery can still be considered for children.

There are fewer and fewer patients who cannot undergo MRI imaging as most surgical material is now made to be MRI safe and protocols are developed to allow imaging of patients with many types of pacemakers. I also find that patients suffering from claustrophobia can almost always undergo MRI on new devices with larger bore sizes — sometimes with medication or psychological support. In extreme cases, sedation by an anesthetist can be a last resort. There do remain cases in which MRI cannot be safely obtained. In those cases, radiotherapy can still be performed but will not be ideal as targeting will be done with less precise CT imaging.

3. Under what conditions is it possible to repeat radiation?

The risks of radiation will be greater when it is repeated, and the efficacy will likely be less. As the doses of radiation used for acoustic neuroma are modest, it is often safe to repeat treatment once. Although time does allow for repair of radiation damage to normal brain, this repair is never complete, and the radiation doses will be additive.

The main concern when contemplating a second radiation treatment is so called “pseudoprogression”. It is common for a tumour to enlarge and then shrink on its own in the first years after radiation. Because of this, it almost never makes sense to radiate again in the first 2-3 years after an initial radiation treatment.

4. When is radiation done following surgery?

Tumours are not always completely removed at surgery. Sometimes this is intentional in order to preserve nerve function. The indication and timing of radiation after surgery will depend on several factors including how much tumour is left, what nerve function remains after surgery and how fast the tumour was growing prior to surgery. It is my personal preference to let the patient recover a few months and offer radiation up-front when the tumour was rapidly growing prior to surgery but wait until the first sign of regrowth for most other patients.

5. Are there any statistics about the demographics of patients undergoing radiation?

As the Canadian Cancer Registry has not included benign brain tumours, it is difficult to have good data in Canada. In the US, the most significant demographic factor in predicting whether or not a patient had radiation for an acoustic neuroma was where that patient lived. You were most likely to have radiation if you lived in New Mexico and tenfold less likely to have radiation if you lived in Utah. I would not be surprised if we found significant analogous regional difference in Canada.

Dr David Roberge

Dr. David Roberge is a full professor in the division of Radiology/Radiation-oncology/Nuclear Medicine at the University of Montreal. Dr. Roberge is also editor of the journal of the Canadian Association of Radiation Oncology and reviews manuscripts for more than 25 journals. More recently, he has focused on technology in radiation oncology with an interest in advanced CT imaging.

CHUM radiation oncology has positioned itself as a leader in the theoretical and clinical investigation of dual energy CT imaging in radiation treatment planning due to his leadership. Dr. Roberge’s vision is to develop at CHUM new treatment paradigms and optimal implementations of modern radiotherapy technologies.

radiation

Radiation Therapy for Acoustic Neuromas: All You Need to Know

admin — Tue, 04 Dec 2018 20:38:28 +0000

Radiation Therapy for Acoustic Neuromas: All You Need to Know admin Tue, 12/04/2018 - 15:38

Acoustic neuromas (AN) are benign tumours of the inner ear nerve that can be observed or treated effectively with radiation or surgery. Tumours that are growing over time should receive treatment, of which radiation therapy (RT) is an effective option. Radiation therapy is a non-invasive method of treating acoustic neuromas. Radiotherapy relies on high-energy x-rays that penetrate the head and skull to target the tumour while avoiding surrounding normal body structures. These x-rays damage the DNA of the tumour cells, causing them to stop growing. There are two main methods to deliver RT for acoustic neuromas, stereotactic radiosurgery (SRS) or fractionated irradiation.

What is stereotactic radiosurgery (SRS)?

SRS is defined by the use of a single, high-dose treatment aimed at a target in the head. SRS typically relies on the use of a rigid, stereotactic frame that is anchored to the outside of the skull using three or four metal pins (Figure 1). The stereotactic frame is a piece of hardware that reduces the patient’s head movement to ensure a very high precision of treatment.

SRS can be delivered through a number of technologies, including cobalt-based systems (also known as Gamma Knife, Perfexion, or Icon), CyberKnife, or a linear accelerator (trade names include, but are not limited to, RapidArc, TrueBeam, Versa). SRS is prescribed by a radiation oncologist and a neurosurgeon, who work closely with a physics and therapist team.

Fig 1. Stereotactic frame for SRS

Image credit

A typical workflow is as follows: A patient undergoing SRS obtains a high-resolution MRI and CT of their tumour. The stereotactic frame is applied by a neurosurgeon on the morning of the treatment with local anesthetic (freezing) at the pin sites. A dedicated team consisting of a medical physicist, neurosurgeon, radiation oncologist, and therapists create a personalized radiation plan. The frame (and the patient) is docked to the radiation machine, and the treatment begins. Treatment length can range from 20 -120 minutes. After treatment, the frame is removed, and the patient is taken home the same day by a companion.

What is fractionated radiotherapy?

The term “fractionated” refers to the fact that this form of radiation is delivered over a course of 25-30 treatments (5-6 weeks). Fractionated radiation is almost always delivered using a linear accelerator. Patients are immobilized using a plastic mask, so a stereotactic frame is not necessary. Each daily treatment takes 5 -15 minutes per day, and patients can attend outpatient appointments at the cancer centre unaccompanied. Patients typically feel well before and after treatments and can continue normal daily activities without restrictions.

Fig. 2 Fractionated Radiotherapy

Figure 2. Green lines show moderate radiation dose, whereas yellow lines show high radiation dose. (Left) Stereotactic radiosurgery (gamma knife/Perfexion) plan. (Right) Fractionated radiation plan (linear accelerator). Image credit: D. Tsang

How to choose between radiation treatments?

Factors that affect the choice between radiation treatment type include the tumour size and availability of SRS. In patients with small tumours, SRS offers a more focused, precise radiation plan. This is because the method of immobilization for SRS is more rigid through use of a stereotactic frame. SRS is very precise, which reduces the volume of normal brain tissues that receive a low-to-moderate dose of radiation (Figure 2).

For larger tumours, SRS is not feasible because a single high dose of radiation can cause more side effects in the setting of a large treatment volume. Thus, larger tumours are usually referred for surgery or fractionated irradiation.

How effective is radiation therapy?

Both SRS and fractionated radiation work very well, with long-term tumour control rates greater than 90%. Both treatments work equally well at controlling acoustic neuromas.

For more statistics, visit:
Article by Lo et al. 2018: https://doi.org/10.1016/j.ijrobp.2017.09.024Article by Persson et al. 2017: https://dx.doi.org/10.1007/s00701-017-3164-6

What are some side effects of radiation therapy?

These can include: fatigue, headache, rash, hair loss (partial), hearing loss and ringing in the ears (tinnitus). Very rarely, patients can get seizures, facial weakness or numbness, brain swelling/ normal pressure hydrocephalus, or other brain tumours after radiation treatment. The risk of hearing loss, facial weakness or facial numbness does not differ between SRS or fractionated radiation.

How does radiation differ from surgery?

Surgery is sometimes preferred for patients with large tumours, tumours that are pushing on surrounding organs (brain or brainstem), patients with symptoms, those whose hearing may already be lost, or younger patients. Radiation is sometimes preferred for patients with intact hearing, smaller tumours, or for whom surgery is not possible or safe (due to other medical conditions).

The recovery from surgery takes longer (in the range of many weeks), whereas the recovery from radiation is shorter (in the range of a short number of days). There is no one factor that predisposes one to choose a specific treatment over another. Patients should speak with their doctors to discuss what is best for them.

What is the follow-up plan after radiation?

Because acoustic neuromas are very slow-growing tumours, they do not always shrink after radiation. In fact, some acoustic neuromas swell slightly after treatment, and then stop growing or shrink over time. The goal of the treatment is to stop the tumour from growing. Most tumours remain stable after time, without any growth or shrinkage. A minority will shrink slightly with time, over the course of many years.

After radiation treatment, your doctor will usually arrange for a follow-up MRI and clinic visit 6 months after treatment, then annually. After 5 years, your follow-up will stretch out to every 2 years. After 10 years, you may be discharged from follow-up, or receive MRIs every 2-3 years. Your doctor may order audiograms to check your hearing and offer hearing aids if needed.

If you have any questions about whether radiation is a suitable treatment for your acoustic neuroma, contact your doctor and ask her or him about this option.

Dr Derek Tsang

Dr. Derek Tsang, MSc, MD, FRCSC is a fellowship-trained and board-certified radiation oncologist. He is an Assistant Professor of Radiation Oncology at the University Toronto. Dr. Tsang works at Princess Margaret Cancer Centre and Toronto Western Hospital at University Health Network in Toronto and at the Hospital for Sick Children. He holds a Master’s degree in clinical epidemiology from the Harvard T.H. Chan School of Public Health. Dr. Tsang treats primary central nervous system and paediatric tumours.

Dr Nasim Sarhan

Nasim Sarhan, MD. Having graduated in Jordan in 2010, Dr. Sarhan undertook specialty training in radiation oncology at King Hussein Cancer Center where he was a consultant for three years. He currently is doing his fellowship at PMH in CNS, Stereotactic Radiosurgery and paediatric tumours.

radiation

Marilyn's Acoustic Neuroma Journal: Options and Treatment

joanne — Tue, 10 Apr 2018 16:37:11 +0000

Marilyn's Acoustic Neuroma Journal: Options and Treatment joanne Tue, 04/10/2018 - 12:37

Marilyn Sharples, North Vancouver, BC (This is an edited version of experience I shared with ANAC's BC Chapter on October 21, 2017).

Marilyn Sharples

Reflecting on the last eighteen years of my life, I go back to the beginning of my journey. In 1999, I was studying ASL, American Sign Language, and Deaf Culture at college. It was a lifelong dream to be able to converse fluently with the deaf. I had grown up with a deaf brother and we had only communicated using drawings for fifty-five years.

Nearing the end of the spring term, I experienced balance issues, fatigue, nausea, dizziness, ear ringing, diminished hearing and a feeling of fullness in my left ear, room spinning and trouble walking without support. I wrestled with questions and especially “FEAR”- fear of the unknown. I needed answers!

I was diagnosed with benign positional vertigo (BPV) because of acute labyrinthitis by Dr Michael Smith, ENT in North Vancouver. I went to a Balance and Dizziness Disorder (BADD) meeting to learn coping skills. I was still dizzy. Back to Dr Smith. He arranged a Cat Scan immediately and found my little friend – a 1.5cm diameter mass in the left cerebellopontine angle, that contains cerebrospinal fluid, arachnoid tissue, cranial nerves, and associated vessels, which is consistent with an acoustic neuroma. Now I could plan!!

I met with Dr Michael Boyd who outlined three options considering my symptoms:

1. Wait and Scan
As my tumour was small, a follow-up MRI would be done one year later.

2. Surgery
I still had functional hearing in my left ear. Prior to surgery, I would need a full examination of the brain stem evoked potentials and full audiogram assessment including speech discrimination to give a better estimation of possible hearing salvage. Dr Boyd quoted me a 50-50 chance with the posterior fossa approach. He felt the tumor was not ideal for a middle fossa approach as my tumor went to the apex of the canal. In such circumstances, hearing is a bit more difficult to preserve. Nevertheless, he thought removing the tumor was a viable option.

3. Stereotactic radiation
This option offered an advantage of a decreased risk of hearing loss and facial nerve injury, However, not zero. He felt because of my age the potential for delayed effects from stereotactic radiation was less of an issue. He felt this was a reasonable alternative.

None of these alternatives would alter my balance. In fact, surgical intervention would likely make it transiently worse because of the loss of any residual vestibular nerve function.

However, Dr Boyd felt I would gradually compensate and my dizziness and balance would improve with time with any of the treatment options.

Dr Boyd handed me an ANAC pamphlet and sent us on our way. I needed to reach out to Evalyn Hrybko, ANAC Chapter Leader who kindly identified others to connect with. Everyone had a story and filled me with valuable information. My husband and I attended meetings and met wonderful caring and concerned people. I was no longer alone.

Because my husband is a journalist, we commenced research at the kitchen table. We poured through material on stereotactic radiation, fractionated versus one shot. We read everything about machines, LINAC, Gamma Knife, Cyber Knife, and the Lars Leksell frame. We became more and more confused. We called hospitals all over America. Our scribbler was filled with names and places (Toronto, Pennsylvania, Alabama, Cleveland, Rhode Island, California, and Washington). Could we afford to go to the States for treatment? Was the Gamma Knife indeed better? So many questions.

We were relentless in our search to do the right thing. We contacted a neighbour who studied at Stanford and was a Director of Engineering Physics, Associate Professor and Biophysics Associate at UBC and Director of the Michael Smith Lab Platform and Genome BC Technology Development Platform. Dr Marziali came right to our kitchen table. He reviewed all our research and simply said that the LINAC was a good machine. He had worked with it and assured us that the LINAC pinpointed with the same accuracy as the Gamma Knife. He also felt the fractionated approach with the LINAC gave the healthy tissue more chance of recovery between treatments.

I was on my way.... I met with Dr Michael McKenzie, radiation oncologist, at Vancouver Cancer Clinic who advised me that I was a candidate for stereotactic fractionated treatment on the LINAC 2 machine. We accepted the rationale that this treatment would result in the highest killing of tumor cells with the lowest effect on normal brain cells. There also would be less risk to the facial nerve, and importantly, a high probability of preservation of my hearing. The treatment itself would involve twenty-five visits over six to seven weeks.

A subsequent MRI indicated my tumour measured 1.7 cm. which included the tail. As my appointment did not come up for eight months, I busied myself with a night school course in Advanced ASL. I walked every day, had massages, avoided salt and never looked up. We attended ANAC chapter meetings. By mid-May, the dizziness was back with a vengeance.

July 2000 found me in the “Mould Room” for the 45-minute mask construction. The technicians built a mouth prosthesis to hold my external mask firmly in place during my treatments. The mask itself consists of a Delrin kind of meshed plastic. A rectangular piece was heated and then quickly molded to the back of my head. Similarly, another piece was heated and molded to the front of my face. It felt extremely warm, but it did not burn. The back and the front pieces clipped together at two points on each side of my head. Breathing through the mask was not a problem. The final step was to add more cement to attach the prosthesis to the bottom of the face mask. Once this dried, the sides of the mask were unsnapped. The technicians worked quickly and were very reassuring throughout the entire process.

I went for a CAT Scan wearing my newly constructed mask. A box was placed over my entirely masked head that would be marked precisely with sight markings on my tumour. It felt dark and awkward, but the staff worked quickly to slide me and all the apparatus into the CT machine. The task was completed in 20 minutes. The image files were on their way for radiotherapy treatment planning. Later that same day I had another MRI without my mask. I do recommend that one keep eyes closed during an MRI. I've had over 10!

CT Machine

Two weeks later, my LINAC treatments began. I was ushered into the radiation room. Lying on my back, I positioned myself on to the back half of my mask that was cradled between my upright arms. I was then handed the front half to put on by first placing the prosthesis in my mouth. When the buckle points were aligned, the technicians snapped the two halves together. This required super human finger strength due to the snug fit. Next, they put the sight marking box over my head and fastened it to the metal frame holding the mask. The ultraviolet lights were dimmed so that the technicians could see the projected red sight lines lined up accurately to the LINAC.

The box was removed, and the room lights turned up. The machine, the cot and I were in position for the first beam. Everyone left the room and the heavy door was closed. Outside, the technicians had a control panel and screens to view my image. Beams of radiation were shot. The beam makes a loud, droning noise, each lasting about twelve seconds. I felt nothing as the tumour was being treated. There is a flag available to hold in case of trouble. After five sequences, they returned to unsnap my mask. My bed was lowered, and I abandoned “ship”. Set up times varied from fifteen to forty minutes to ensure the accuracy of the beams. I sometimes counted to help me overcome claustrophobia. It was critical to remain still.

I met with my radiation physician once a week at the clinic. At my final visit, he advised that the effects of the radiation would peak over the following two weeks. My impression is that I suffered few side effects from the LINAC treatment.

The first weekend I recall some nausea but did not warrant medication. I found eating soon after each treatment kept my tummy comfortable. After session #18, patches of hair, the size of a loonie fell out in the shower. However, my hair regrew back within 5 weeks. I began to feel tired by the end of the series of treatments. Early in the sessions, I thought my hearing cleared but the old plugged feeling returned. I continued to feel some dizziness in bed at night. My follow-up audiograms and MRI's continued every six months for two years.

My hearing remained unchanged. The hearing in my left ear was diminished as it was prior to treatment. Also, there was no change in the tumour. However, the next MRI indicated the tumour shrank from 1.7 cm. to 1.5 cm. Shrinkage occurred on all sides. Follow-up appointments changed to yearly. On another positive note, I felt more energetic and my balance problems had lessened. At my annual appointment in 2004, Dr McKenzie shared positive reports about both hearing assessments and tumour appearance. I had no dizziness, loss of balance or untoward symptoms. My appointments were shifted to two-year intervals.

By 2010, Dr McKenzie rewarded me with the report “no new growth” and signs of tumor shrinkage. He said he never wanted me to come back.

That, my friends, is my story. As I reviewed the data, I was reminded how fortunate I am. How blessed to have help along the journey. These tumours take away your hearing, in exchange for tinnitus, imbalance, confusion, fatigue, pain, and dizziness. However, as human beings, we can be resilient, we can adapt, we can learn new ways of coping, and we can offer support to each other.

I now volunteer as intervenor with a deaf, blind lady using my ASL. She teaches me hard lessons about patience but gives me so much joy in living. I love my three beautiful daughters and my son who hangs my mask in his Band Room in Victoria. And my nine grandchildren and two great-grandchildren. Two years ago, I was fitted with red hearing aids in both ears. I guess it was time...even though I have no tumor in my right ear!

Addendum

The Vancouver Cancer Clinic LINAC machine was adapted for brain tumors in 1997. The LINAC 2 machine has since been replaced twice as it has a 10-year lifespan. It is now called the TRUE BEAM S10X. (x-ray)

Salvage Surgery After Radiation Therapy for Acoustic Neuromas

admin — Fri, 06 Apr 2018 22:09:54 +0000

Salvage Surgery After Radiation Therapy for Acoustic Neuromas admin Fri, 04/06/2018 - 18:09

Some of the questions patients with an acoustic neuroma not uncommonly ask are about the issue of salvage surgery after failed radiotherapy: "What happens if the tumour grows despite radiation therapy?" "Is the tumour harder to remove?" "What will happen to my facial nerve/function?" The pertinence of these questions is reflected in the fact that it is a subject of interest written about in the medical literature and discussed at annual scientific conferences.

As outlined in the Acoustic Neuroma Clinical Care Pathway on the new ANAC website, many factors influence the individualized management of a patient with an acoustic neuroma. That being said, many small-to-medium-sized tumours for which treatment is recommended can be appropriate for either surgery or radiation therapy.

Many in this situation would argue that there is what is called “clinical equipoise” between surgery and radiation therapy, meaning one option has not been adequately shown to be better or inferior to the other. Beyond physician measured outcomes of tumour recurrence, hearing, facial function, etc., several studies have shown that the quality of life in acoustic neuroma patients who undergo either surgery or radiation therapy is very similar. In many cases, the decision to pursue radiation therapy over surgery can come down to patient preference.

The principle goal of radiation therapy is referred to as “tumour control” which means either an arrest of tumour growth or actual tumour shrinkage. When calculating treatment failure after radiation therapy, it is important to discriminate from transient increases in tumour size which can be part of the radiation response and is termed “pseudoprogression.” This occurs ~20% of the time and generally between 6-24 months following radiotherapy. In most of these cases, the tumour enlargement is self-limited and either stabilizes or the tumour subsequently shrinks. Although the mechanism by which this occurs is not completely understood, it rarely represents a situation of uncontrolled growth requiring salvage treatment.

In high volume centers of excellence with published long-term results, the proportion of patients with acoustic neuromas who truly fail radiation therapy necessitating “salvage surgery” is typically well under 10% and probably closer to 5%. One should account for several factors when interpreting this data, the most important being the size (specifically the volume) of tumour being irradiated. Other variables include the rate of tumour growth prior to radiation (if growing at all), and the type and dose of radiation being delivered. Nevertheless, the majority of patients with acoustic neuromas that were deemed appropriate for radiotherapy will achieve tumour control. But in the unlikely event that radiotherapy fails, what then?

To date there are a few published studies of salvage surgery for previously irradiated acoustic neuromas. The timing of tumour recurrence after radiotherapy was very variable and occurred at any time, including after a period of long-term (>5 to 10 year) stability. Observations noted at the time of surgery for post-radiation tumours include increased scarring at the interface between the tumour and the facial nerve, increased irritability of the facial nerve during dissection and a firmer tumour consistency. The extent of resection is more likely to be incomplete compared to series of sporadic (i.e. not previously irradiated) cases, in part due to the practice of some surgeons to purposely not aim for a complete resection. The results of post-operative facial nerve function are di cult to interpret because of variability in individual surgeon expertise however, a general relationship between attempts to achieve a gross total resection and more severe post-operative facial nerve dysfunction can be appreciated. Interestingly, a consistent finding is that the rate of recurrence in cases with incomplete resection is very low. For example, in one series of 73 patients with previously irradiated acoustic neuromas, there were no recurrences in those patients who underwent incomplete resection after a mean of 5.7 years of follow-up.

My personal experience is that previously irradiated tumours are heterogenous in consistency, with some areas of tumour looking very typical (i.e. virgin) without significant scarring and can be removed much like non-irradiated tumours. In other areas, the tumour is more rm or fused to the surrounding tissues, including sometimes to the facial nerve or brainstem. As a result, completely removing a previously irradiated tumour can be more challenging.

Many surgeons (including myself) will rely very heavily on intra-operative monitoring of the facial nerve. This refers to placing electrodes at the time of surgery to measure the reaction of the facial muscles to stimulation over the course of the operation. Several techniques for stimulating and monitoring the facial nerve are possible and some allow verification of function of the nerve and not just irritability or anatomic continuity of the nerve, neither of which are particularly accurate in predicting post-operative facial nerve function. Facial nerve monitoring is especially useful to me in previously irradiated acoustic neuromas, where the usual visual or tactile “cues” the surgeon uses to safely dissect around the facial nerve are disrupted. If the facial nerve monitoring reaches a specific threshold beyond which post-operative facial weakness is likely, then I am likely to stop removing the tumour and leave a small residual if necessary. As mentioned above, we have relatively good data that shows that even if a small volume of tumour is left behind, it is likely not to grow, and by proceeding based on the intra-operative monitoring data, the patients’ facial nerve function can be preserved.

In summary, radiotherapy is a very reasonable option for many small-to medium-sized acoustic neuromas, and most patients who need to undergo treatment will have good results. Tumour growth after radiotherapy is generally uncommon. Surgical resection of previously irradiated acoustic neuromas is more challenging as described above. Besides surgeon experience and expertise, intra-operative monitoring of the facial nerve is an important adjunct to ensure maximal safe resection. Leaving some tumour along the facial nerve probably occurs more frequently compared to non-irradiated cases; however, most studies concur that the residual tumour is unlikely to recur. When patients ask me about salvage surgery in the event radiotherapy doesn’t work, and despite the challenges described above, I respond that most people will still do well in that scenario and I would not worry about that when deciding which upfront treatment to pursue.

Dr Di Maio

Salvatore Di Maio is a skull base neurosurgeon and assistant professor at the Jewish General Hospital in Montreal, Quebec. He attended medical school at McGill University and completed his neurosurgical training at the University of British Columbia. He also received in-residency training in endoscopic skull base surgery under Paolo Cappabianca in Naples, Italy, and a clinical fellowship in skull base and cerebrovascular surgery with Dr. Laligam Sekhar at the University of Washington in Seattle, USA.

Dr. Di Maio specializes in open and minimally invasive procedures for skull base tumours, meningiomas, acoustic neuromas, pituitary tumours, and neuro-oncology.

surgery

radiation