I was happy that the Dr. Alexander confirmed what I had learned through my research and that he was on the same page with what I was thinking. What the radiation oncology department at Brigham and Womens can offer is either stereotactic radiosurgery (SRS), or Intensity Modulated Radiation Therapy (IMRT).
SRS, also known as Gamma Knife or Cyber Knife involves a 1 day outpatient treatment that involves higher levels of radiation exposure at one time. The benefit of this clearly is that it is over after one day. However, SRS is not appropriate for tumors that are located where Charlie's tumor is because it is on the optic nerve. In order to keep his vision safe, the level of radiation must be lower than what is involved in SRS.
IMRT is the radiation at Brigham and Womens that Charles could do. IMRT allows doctors to customize the radiation dose by modulating, or varying, the amount of radiation given to different parts of the treatment area. This modulation is done in highly accurate, three-dimensional detail, according to the shape, size, and location of the tumor. IMRT uses a linear accelerator equipped with a multi-leaf collimator to shape the radiation beams and vary their intensity. This allows the radiation to be very precisely targeted to the tumor or area at risk, while minimizing the radiation to normal surrounding organs.
The risks to this radiation is that in order to irradiate his tumor, radiation would be exposed to his optic chiasm, which is the area where the optic nerves meet. Too much radiation could involve the complete and total loss of his sight. I'm not entirely sure how likely that would be, they didn't give odds on that. In addition, the other risk to radiation is the possibility that the radiation exposure could result in cancer in the long term. We all know that exposure to radiation can cause cancer, and while the odds are low, there is definitelty a risk to consider in choosing any type of radiation. If Charles was 60+, they wouldn't hesitate to use radiation, but because he is so young, he has much more opportunity to develop radiation related cancer. Dr. Alexander, the radiation oncologist definitely wanted to get across that this is not ideal for Charles and while it may work, there are definite risks involved.
However, Dr. Alexander eagerly recommended Proton Beam radiation at Mass General Hospital. In my research, I had pretty much figured that if Charles was indeed not eligible for SRS, then Proton Beam would be a better option than IMRT. While similar, Proton Beam radiation allows for more precision and less radiation exposure to healthy tissue. If Charles does have radiation at any point, it is most likely going to be Proton Beam. There are only 9 centers in the country that have Proton Beam technology, and we are fortunate enough to live an hour away from one of them!
What Is Proton Beam Therapy?
The characteristics of proton beam therapy enable physicians to deliver higher, more conformed doses to tumor volume while almost completely sparing normal healthy tissue.
Protons are hydrogen atoms whose electrons have been removed. Proton beam therapy uses a special machine called a cyclotron or synchrotron to energize protons. Protons are extracted from the cyclotron or synchrotron and directed with magnetic fields to the tumor. The depth of penetration of the protons is related to their energy and can be precisely controlled to match the location of the tumor.
Protons deliver the majority of their energy at a very narrow area within the body. This unique dose delivery property of protons is known as the Bragg Peak. We can manipulate the Bragg Peak area to deliver the desired radiation dose to the tumor itself without any exit dose beyond the tumor. Conventional external beam radiation therapy uses photons or x-rays that enter and exit through the body. The special properties of protons generally reduce the radiation dose to the uninvolved normal tissues surrounding the tumor.
Principles of Proton Beam Therapy
Irregularly shaped lesions located near critical structures, tumors in children, and large tumors near any critical organ are well suited for proton beam therapy. Protons have a physical advantage over gamma rays and x-rays when it comes to sparing normal tissues. Protons deposit most of their radiation energy in what is known as the Bragg Peak, which occurs at the point of greatest penetration of the protons in tissue. The exact depth to which protons penetrate, and at which the Bragg Peak occurs, is dependent on the energy or modulation of the proton beam. This energy can be very precisely controlled to place the Bragg Peak within a tumor or other tissues that are targeted to receive the radiation dose. Because the protons are absorbed at this point, normal tissues beyond the target receive very little or no radiation. Proton energy can be adjusted to match the depth of the target with a sharp drop in dose beyond the Bragg Peak.
Tumors can have very irregular shapes and can be located close to critical organs. Every patient’s tumor shape, size and location are unique. Patient specific hardware, which helps sculpt the proton beam, is customized to maximize the dose to the tumor while minimizing the dose to normal structures. The shaping of the proton beam can also be controlled by magnetically scanning across the tumor volume. Aiming proton beams, each with customized field shaping, from various directions further ensures that the dose to normal tissues is reduced as much as possible, therefore reducing the risk of treatment related complications.
Charles' other option besides Proton Beam radiation is another surgery. Charles really doesn't want to go through surgery again. He hates having to stay in hospitals and the recovery was hard on him. Yes, it went well in the fact that he didn't have any complications other than his sight, but it was still hard to go through and he really doesn't want to go through it again. Dr. Golby said that if he were to do surgery, she would have him go to Dr. Ossama Al-Mefty, who Dr. Alexander called "a magician", he said "there are surgeons, and then there is this guy, he's a magician". He specializes in exactly what Charles has- a skull base meningioma. Apparently, he would do the best job. Dr. Golby said that he was the best doctor for this in the world.
HOWEVER, Dr. Golby does not believe that Dr. Al-Mefty would be able to get all of the tumor out. If he can't get all of the tumor out, Charles may likely have to go through radiation anyway, either immediately after surgery, or after some time. Since his tumor reproduces more rapidly than the average Grade I tumor, it would be more likely to grow again if not all of the tumor is removed. So Dr. Golby thinks that if he has to have radiation anyway, then why go through surgery a second time in addition. However, if there is a chance that all of the tumor could be removed, then we should consider it. Based on what Dr. Alexander said about radiation, surgery might be a better option because of the risk that the radiation will render him completely blind. Even though Charles said that he could make it as "The Blind Chef" no one wants that to happen. We will have to get a lot of information from Mass General on the risks related with the Proton Beam radiation. In addition, we will see what Dr. Al-Mefty has to say.
I think it's a good idea to really pay attention to any negatives that each doctor say about their own specialty. Dr. Alexander's concerns about radiation are something I take very seriously, however Dr. Golby's opinion on surgery are also very important. The appointment with Dr. Alexander was good in that it narrowed it down to two possibilities - Proton Beam at Mass General, or Surgery with Dr. Al-Mefty at Brigham & Womens. We will have to meet with them to know what to decide on.
When I was researching after the appointment with Dr. Golby, I really got held up on the concept of Charles getting cancer in the long term after irradiating the tumor. This is especially painful to think about because I can't help but think of Jeremy and everything that he and his family have gone through due to his brain cancer. Charles and I love each other so much, and whatever will give us the best chance to have a long, happy, healthy life together, is what he will decide to do. It definitely didn't lessen my concern about cancer meeting
with Dr. Alexander because he thought it was something to definitely consider in the decision. Even if the risk is low, he put a lot of emphasis on the fact that having surgery is not going to do anything to possibly cause cancer in 15 years.
Before meeting with Dr. Alexander, Charles didn't really want to consider surgery, but now he said that he will, so we will meet with them and see where we go from there.
Please let me know if you have any questions or if it seems like I left something out. Since it's been a few days, I very well likely did.
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