Monday, May 5, 2008

Kevin’s Cancer Treatment for Medulloblastoma

I have been working on this for a while and this maybe still a work in progress, so there maybe changes. But hopefully it will answer some questions. - Rachel

What is medulloblastoma?

Medulloblastoma is a type of brain tumor that occurs in infants and young children. It represents about 20% of all pediatric CNS cancers. By definition, medulloblastomas occur in the cerebellum, which is the back part of the brain that controls walking, balance and fine motor coordination, among other things.

Medulloblastoma is a long name made up of three smaller words: medulla = Latin for marrow, meaning inner substance or core; blastos = Greek word for germ, meaning young, primitive, not fully developed; and oma = Greek for tumor. In other words, this is a tumor of primitive, undeveloped cells located inside the cerebellum. The patients’ average age at diagnosis ranges between five and seven years. Boys are affected more often than girls (sex ratio about 1.5:1)


Cancer
Cancer cells are natural body cells which behave abnormally (or have mutated) after which they don't preform their natural function, they just keep dividing. They can grow rapidly, causing tumors which interfere with the normal functions of the body. A single cancer cell can grow into a tumor or metastasize, sending cancer cells to other locations in the body, where they can grow into tumors. The challenge is trying to eliminate cancerous cells from our bodies. It is important to kill every one of them. Since they are a part of our body, it is difficult to target only those cells. To accomplish that task, current medical technology offers surgery, chemotherapy, and radiation therapy, and, for some, stem cell rescue.

Surgery
The first step in treating Kevin’s tumor was surgery. Immediately following the MRI Kevin was scheduled for the first of three surgeries, 2 of which he would have within 24 hours. Kevin’s tumor caused pressure to build up in his brain so much they were concerned he could have a stroke. So they placed an EVD into his head to drain the fluid that had been building up in his brain. The next surgery was a craniotomy and performed by Dr. Sood. He removed almost the entire golf ball sized tumor from Kevin’s head except for a few microscopic cells that had started to grow into his brain. After Kevin’s 2nd, 6 hour long, surgery Dr. Sood informed us pathology would confirm if it was cancer but he was pretty sure it was Medulloblastoma, a rare type of brain tumor cancer (about 350 children in the U.S. are diagnosised each year). In a week, we received the pathology report, which did confirm - unfortunately it was a Medulloblastoma, which is malignant (aka cancerous). A couple of days after surgery, Kevin received another MRI and then later he was given a spinal tap. Neither of these test detected any cancer cells in his body. Before leaving Children’s Hospital of Michigan Kevin had his 3rd surgery replacing his EVD line with a shunt and placing a port in his chest.


While Kevin was in Children’s Hospital of Michigan I started looking into the best places for Kevin to receive treatment. At the same time a women named Kathy contacted us via our family blog when our post with Kevin’s diagnosis came up in her Google search. Her son had a form of medulloblastoma and had been treated successfully at St. Jude Children’s Hospital in Memphis. Along with her and another mom/Dr. (whose daughter had the same cancer but is out east) helped me sort out which protocol would be best for Kevin. As soon as Kevin came home I contacted St. Jude and within 72 hours me, Kevin and baby Jake were on our way to Memphis for 8 weeks, we would get to come home for 3 ½ weeks then return for 4-6 months for chemo and stem cell rescue. Eric, Mike and Scotty arrived the weekend after.


Radiation
The initial treatment included the use of radiation therapy to try to destroy any tumor cells left behind after surgery. Kevin completed his radiation treatments at the end of April 2008 in St. Judes new Chili Care Center.

How Radiation Therapy Works
Radiation treatments or radiotherapy directs high-energy x-rays at targeted areas of the body to destroy tumor cells. Many brain tumors are radiosensitive, which means that the cancer cells can be destroyed by radiation therapy. The challenge to using radiation is to deliver it in such a way that it does minimal damage to healthy cells and maximum damage to tumor cells. There is also a limit to the amount of radiation an individual can receive in his or her lifetime, so doctors are careful in determining dosage and total amounts to be given.

What Makes Brain Tumors Radiosensitive
Rapidly dividing cells in tumors have unstable DNA (the material in the cell that tells it how to grow). This DNA is susceptible to damage from ionizing radiation. Normal cells can also be damaged, but they are more likely to repair themselves to a certain degree, though some may never be completely normal again either. The repair mechanisms of cancer cells are not very effective, so cancer cells tend (hopefully) to not grow back.

Kevin Radiation Treatments
Kevin’s radiation treatments were divided into 2 parts, which were administered daily, excluding weekends. During the first part, he was given 13 treatments to his full head and spine ("cranial-spinal radiation "). During the second part, called the "tumor boost", Kevin was given 18 treatments to the area of the brain where the tumor was removed (the posterior fossa).

After Effects of Radiation of Brain & Spine
Red or Brown discoloration of the skin.
Upset Stomach or vomiting
Hair Loss
Low Blood Counts
Decreased Growth or shorter heights than expected
Hormonal problems
Thyroid problems
Learning Difficulties (ADD, loss of IQ points, slower processing speed etc.)
Problems with Memory
Second Cancers
Damage to some brain cells close to the tumor sight, this is called necrosis
Scoliosis


What is Chemotherapy?
Healthy cells grow in a well-established pattern, and when they divide, typically an identical copy is produced. The body makes only the number of normal cells that it needs at any given time. As each normal cell matures, it loses its ability to reproduce and it is also pre-programmed to die at a specific time.

Tumor cells, on the other hand, reproduce uncontrollably and grow in an unpredictable way. Chemotherapy involves the use of drugs that damage rapidly multiplying cells, such as those found in brain tumors. There are hundreds of chemotherapy drugs and they use a variety of approaches to destroy cancer cells.

Unfortunately, some good normal cells are damaged along with the bad tumor cells. The normal cells which are most often affected are those which grow and divide rapidly, including cells in the bone marrow, hair, mouth, and intestines. Hair loss is an example of a side effect due to damage to “good” cells. Unlike tumor cells, however, normal cells do repair themselves. Each child reacts differently to each chemotherapy drug. Some children experience severe side effects, while others do not. They try, as best as possible, to manage many of these side effects by various measures.

Chemotherapeutic agents are chosen based on several characteristics of the tumor cells. A child’s doctor may select different drugs to damage the tumor cells in different parts of their life cycle or to interrupt various cell functions. The frequency of chemotherapy treatment depends on many factors and the effect of the chemo medicines on any certain child’s healthy cells can be a factor in determining frequency of the treatments.

In order to make the most progress in treating childhood brain tumors, doctors coordinate their efforts through clinical trials. Clinical trials, also called studies or protocols, involve designing a particular treatment program to treat specific types of tumors. Doctors evaluate these treatments and try to decide how to improve survival rates and reduce side effects. Each study or protocol builds on those that have gone before it.

Kevin’s treatment consists of surgery, radiation, high dose chemotherapy followed by stem cell rescue (called the SJMB03, which was written by Kevin’s Dr., Dr. Gajjar). This treatment has been in development over the last 5-12 years. Kevin has completed the surgery and radiation part of this treatment plan. The chemotherapy, which will start in May (this month), is planned to last for about 4-6 months ( and is described below) as long as when he goes back (in a little over a week) there no new tumors have started to sprout up.

High Dose Chemotherapy with Stem Cell Rescue.
As mentioned, chemotherapy drugs kill rapidly growing cells, so one of the limiting factors for the dosage of chemotherapy is how much damage it will do to healthy cells. Blood is composed of many different types of cells, each with its own function for maintaining a healthy body. All blood cells are produced by stem cells, which are a part of the bone marrow. Because they grow rapidly, stem cells are vulnerable to chemotherapy drugs and will be killed when high doses of chemotherapy are given. In order to use high doses of chemotherapy, stem cells are "harvested" from the body before chemotherapy begins, and then infused back into the body after chemotherapy is completed (i.e. they rescue the body's blood production system). Stem cell rescue allows us to use very high doses of chemotherapy drugs to attempt to destroy every cancer cell in a body. As a side effect, almost every other rapidly dividing cell is killed, leaving the body with very little resistance to infections. A few days after chemotherapy, the stem cells which have been harvested and frozen are returned to the body where they magically find their way back to the bone marrow ("engraft") and resume blood cell production. It takes a few weeks for the stem cells to produce enough white blood cells for the body to fight off infections on its own. While the blood system is regenerating, Kevin has to stay relatively isolated , with his health closely monitored and taking antibiotics, fluids, and perhaps nutrition through his lines.


IMPORTANT: It is important anyone, siblings & family, coming to Memphis to help MUST wash hands almost obsessively in order to try to keep Kevin from any infection. If you are coming to help and feel the slightest hint of a cold it would be best for you not to be in the same room or near as him or Jake. We will find other ways for you to help that doesn’t involve care of the kids. Do not let Kevin push or touch button or handles in public (even the hospital) like elevator buttons or restroom door handles during these 4-6 months. Kevin MUST wear his mask outside of the apartment at ALL times.


Stem cell mobilization and harvest
Under normal conditions, stem cells reside in the bone marrow where they can be harvested by poking a pelvic bone needle into the pelvic bone and extracting them. An easier and less painful way to harvest them is by attempting to force them into the bloodstream ("mobilization") where they can then be extracted directly from the blood using a centrifuge. In order to encourage Kevin’s stem cells to move out of his bone marrow and into his blood, a medicine to encourage stem cell growth (a "GCSF") will be used. Starting on May 16th will be given a dose of the GCSF every day for a week or so. During the week of May 19th Kevin’s blood will be tested to see if it is feasible to extract stem cells. Radiation treatments make it more difficult to mobilize the stem cells into the blood, so the fact that Kevin had radiotherapy decreases the likelihood that stem cells can be harvested from his blood. If they can't be harvested from his blood, they will be harvested from his pelvic bones with a needle. Harvesting stem cells from the bones takes place in a surgical suite under anesthesia and Kevin will be uncomfortable for a couple days afterwards. Kevin is scheduled for surgery on May 20th to remove his current port and to put in what they call a Hickman catheter line.

Kevin's Chemotherapy
“High-dose chemotherapy and autologous stem cell transplantation (SCT): Six weeks after the completion of radiotherapy, patients receive high-dose chemotherapy comprising vincristine IV followed by cisplatin IV over 6 hours on day -4 and cyclophosphamide IV over 1 hour on days -3 and -2. Patients undergo autologous SCT on day 0. Patients receive filgrastim (G-CSF) subcutaneously beginning on day 1 and continuing until blood counts recover. Patients receive vincristine IV on day 6. High-dose chemotherapy and autologous SCT repeat every 4 weeks for 3 additional courses in the absence of unacceptable toxicity.” – taken from http://www.cancer.gov/clinicaltrials/SJCRH-SJMB03#Outline_CDR0000367486

On the evening of May 22, 2008 Kevin will be admitted to the hospital the 1st of 4 monthly rounds of the high dose chemo/stem cell rescue procedure. That evening they will start IV fluids and the following day is -4.
Day Chemotherapy

-4 Cisplatin, amifostine, and vincristine
-3 Cyclophosphamide and mesna
-2 Cyclophosphamide and mesna
-1 No chemotherapy - day of rest
0 Stem cell transplantation, he will be given a his infusion of stem cells
+1 G-CSF starts (stimulates stem cell production)
+6 Vincristine, G-CSF continues

Next: Kevin will leave the hospital and his blood counts will take a week to drop to zero. He may have to go back in the hospital during this time if he develops any type of a fever. While his blood counts are low he will not be able to go to crowded places (school, malls, movies, etc.). We will need to be extra cautious and make sure everything is clean around him, that he wears his mask, and he and everyone around him wash there hands ALL the time and it is important that his caregivers are well also. Once the doctors feel Kev is well enough (about 4 weeks) he will be readmitted to the hospital and he will go through another cycle of high dose chemo/stem cell rescue procedure until he has completed a total of 4 rounds of high dose chemo/stem cell rescue procedure. During all of this Kevin will probably require blood transfusions and platelets. Kevin’s blood type is A negative (refer to below, A Short Course in Hematology).

For this part of his treatment, Kevin will require medicines, fluids, nutrition, contrast dyes, and blood to be administered intravenously. In order to avoid the pain and stress of inserting needles into his veins for each of these procedures, Kevin will have a Hickman catheter implanted under his skin in his chest. The Hickman catheter consists of a two-chambered tube (divided longitudinally down the middle) which runs from one of the major ateries of the heart out of his chest where it divides into two lumens . Each time Kevin receives fluids, the medical staff will use the Hickman catheter, which is much better than trying to stick an IV needle into his veins every time.

During chemo Kevin maybe put on a low bacteria diet. Please ask to see the list of things Kevin can eat before offering him any food during this time or please check with one of his parents. This is very important because not following the doctor prescribed diet can cause Kevin to come down very sick, or cost him his life.

A Short Course in Hematology
Our blood is made up of two components: liquid and solid. The liquid part of the blood is called plasma. The solid part is made up of cells. There are essentially three types of cells in the blood:
1. Red blood cells - bring oxygen to our tissues.
2. Platelets - help the blood clot, the stop bleeding.
3. White blood cells (WBC) or Leukocytes- identify, attack, and destroy infection and cancerous cells. The white blood cell system is very complex. T-cells are a type of WBC which regulate immune responses. CD4 cells are a type of T-cell (they are also called helper T-cells) that co-ordinate the immune system's response to certain micro-organisms such as viruses.

For more information about blood counts click - Blood Counts -


Central Nervous System Problems
Chemotherapy may cause temporary confusion and depression, which should go away once treatment is completed.
Other central nervous system side effects can include:
  • Anemia
    The doctor will monitor your child's blood counts to check for anemia (low levels of red blood cells, which are made in the bone marrow and carry oxygen throughout the body). Red blood cell transfusions may be necessary.
  • Blood Clotting Problems
  • Chemotherapy drugs may inhibit the body's ability to produce platelets, which help blood to clot. Your child may bleed or bruise easily because of a reduction in platelets (called thrombocytopenia). Platelet transfusions can be given to treat low counts.
  • Increased Risk of Infection
  • Chemo may cause a reduction in white blood cells, which are part of the immune system and help the body to fight infection. Therefore, your child is more vulnerable to developing infections during and after chemo.

Infection precautions: Remind kids and caregivers to wash their hands before eating, after using the bathroom, and after touching animals. Friends or family members with contagious illnesses (such as a cold, the flu, or chickenpox) should refrain from visiting. Try to avoid crowds and children who have received certain vaccines, such as chickenpox or oral polio — these are live-virus vaccines and can spread disease to kids with low blood cell counts. Your child also shouldn't receive immunizations without your doctor's OK. And to prevent food-borne infection, your child shouldn't eat raw fish, seafood, meat, or uncooked eggs.

• Long-Term Side Effects
Chemotherapy can cause long-term side effects (sometimes called late or after effects), depending on the type and dose of chemotherapy and whether it was combined with radiation. These effects may involve any organ, including the heart, lungs, brain, kidneys, liver, thyroid gland, and reproductive organs. Some types of chemotherapy drugs may also increase the risk of cancer later in life. Receiving chemo during childhood also may place some kids at risk for delayed growth and cognitive development, depending on the child's age, the type of drug used, the dosage, and whether chemotherapy was used in addition to radiation therapy.



I also recommend, "Long-Term Survivors of Childhood Cancer: The Late Effects of Therapy"

4 comments:

Janine said...

Wow. Do you feel like you took a crash course medical school? What a great mom you are.

Lani said...

Thanks for the info - I'm amazed!! You need to be a doctor (just in your spare time), You are great parents!

Willardson Family said...

I don't know how you hold it together!! Gary's sister had a brain tumor when she was pregnant with her second child. This is such a hard thing you are always hoping you are doing the right thing. We are praying for you!! Let me know what toy I can send Kevin that he hasn't gotten! My kids would love to send him something!!

Laura P said...

Thanks for all the easy to understand info. It is alot to grasp, but, you obviously have done the research you need to help Kevin. Still praying...