Mo's Treatments
Unlike many diseases, which involve germs, cancer cells are natural body cells which behave abnormally.  They don't perform any beneficial functions and 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 in trying to eliminate cancerous cells from our bodies is that we need to kill every one of them - however, since they are a part of our body, it is difficult to target only those cells.  To accomplish that task, current medical technology offers us surgery, chemotherapy, and radiation therapy (also called radiotherapy), and a number of other treatments which are classified as biologic response modifiers.

The first step in treating Mo's tumor was surgery.  Once we discovered his tumor, he was scheduled for surgery asap, which turned out to be the next morning.  Thankfully, the tumor was completly removed.  Later in the week, we received the pathology report, which determined what type of tumor he had - unfortuately it was a Medulloblastoma, which is malignant.  The day after surgery, Mo received another MRI and then about ten days later he was given a spinal tap.  Thankfully, neither of these test detected any cancer cells in his body.  The results of these tests influenced the initial treatments which included both the chemotherapy and radiotherapy.
Over the course of July and August 2003, we discovered that Mo's tumor was growing again.  This is a recurrence.  Fortunately, it was only growing in a single place, and the entire mass (which was very small), was removed with a second surgery.  Again, after surgery Mo  Because of the recurrence, we changed Mo's chemotherapy to a treatment which allows him to be given different chemotherapy medicines at higher doses (described below).


Healthy cells grow in a well-established pattern, and when they divide, 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.  Many of these side effects can be managed by various control 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 a 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.
Mo's initial treatment consisted of radiation and low-dose chemotherapy.  The treatment has been developed over the last 10-15 years.  He completed the radiation part of the treatment, and part of the chemotherapy.  The chemotherapy was planned to last for about 15 months, which would have ended in Feb. of 2004.  Because his particular tumor did not respond completely to radiation and low-dose chemotherapy, the chemotherapy treatments were switched to a treatment which uses high dose chemotherapy followed by stem cell rescue (described below).

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, the patient has to stay in a relatively isolated ward in the hospital, with his health closely monitored and taking IV antibiotics, fluids, and nutrition.

Mo's treatments are as follows (dates are approximate):
1. 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 Mo's stem cells to move out of his bone marrow and into his blood, a combination of chemotherapy along with a medicine to encourage stem cell growth (a "growth factor") are used.  On 9/18 Mo was given a dose of chemotherapy and he is being given the growth factor every day for a week or so.  During the week of 9/29 Mo'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 Mo 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 Mo would be uncomfortable for a couple days afterwards.
2. Chemotherapy
  On 10/13 Mo will be admitted to the hospital for the high dose chemo/stem cell rescue procedure.
Day 1: he will just settle in.
Day 2 - 4: he will be given a single chemotherapy medicine.
Day 5-7: he will b:e given two other chemotherapy drugs.
Day 8-10: he will be given a rest.
  3. Stem cell rescue
    Day 11: his stem cells will be put back into his body ("infused").  They will find their way back to the bone marrow and start producing blood cells.
Next 4-5 weeks: Mo's blood counts will continue to drop for a week or so, then they will recover.  He will remain in the hospital during this time where his health will be carefully monitored.  He will require quite a bit of medication (as well as IV fluids and nutrition) during the first few weeks after the reintroduction of his stem cells.
Next couple of months: When his blood counts are high enough, he will be able to come back home, but he will not be able to go to crowded places (school, malls, movies, etc.) until his resistance to disease is pretty much back to normal - this will probably take a couple of months.

Pheresis Catheter Illustration. Taken from the web and modified.
Mo's catheter is actually on his left side.

For this part of his treatment, Mo 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, Mo has a pheresis catheter implanted under his skin in his chest.  The pheresis 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 Mo receives fluids, the medical staff will use the pheresis catheter, which is much better than trying to stick an IV needle into his veins every time.

Biologic Response Modifiers
We are also considering the use of a "differentiating agent" which is a medicine classified as a biologic response modifier.  This drug, which is related to hair growth and acne medicines, is used to try to force cancer cells to "differentiate", which is to transform themselves into normal types of tissue rather than remaining in their primitive state and multiplying rapidly. I will describe this further if we end up using it.


Mo'd initial treatment included the use of radiation therapy to try to destroy any tumor cells left behind after surgery.  He completed his radiation treatments at the end of February, 2003.

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 can repair themselves. The repair mechanisms of cancer cells are not very effective, so cancer cells tend to not grow back.

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

Radiation is administered with a linear accelerator.  The linear accelerator can be rotated to deliver the radiation from various angles to carefully and precisely target the area of the body receiving the radiation, thus minimizing "scatter", which is exposure to areas of the body which don't need to be irradiated.   The treatments required Mo to lie on a bench and remain as still as possible, sometimes when he was very uncomfortable.

One of the linear accelerators Mo used at the University of Wisconsin Hospital.  On the bed are the foam body mold and plastic-mesh head mold which were used to help him maintain his position during the cranial-spinal treatments.

The IMRT setup can control the position of the x-ray beam to within one-tenth of a mm and one-tenth of a degree!
The treatments were very carefully planned to focus the radiation on the target areas of Mo's body.  During the 2nd part of his treatment (the boost to the tumor bed), his doctors used IMRT, a technique which allows them to deliver the radiation with an accuracy of about 1/2 of a millimeter, minimizing exposure to other areas of his brain.  For the IMRT, the doctors used MRI and CT scans to create a 3 dimensional map of part of his brain, and then used a device which allowed them to conduct real-time tracking of the location of Mo's brain relative to the X-ray beam during treatments.  In order to take advantage of this technique, Mo had to lie very still, as even a yawn or a sneeze would change his position on the machine!


Shiminski-Maher, Cullen, Sansalone, Childhood Brain and Spinal Cord Tumors, O'Reilly - Sebastopol, CA, Jan. 2002.

Blood and Marrow Stem Cell Transplantation, The Leukemia and Lymphoma Society - White Plains, NY

Further Reading:
For anyone wanting more insight than is being provided on our website, there is a lot of info on the web. As a recommendation, you might look at Understanding and Coping with Your Child's Brain Tumor, which is published by the National Brain Tumor Foundation.  It requires the Acrobat Reader, which probably already on your computer (it should open automatically if you click the link).  It is well written and not-too-technical.  In particular, there are sections on chemo and radiation.

Dr. Roger Packer is, one of the world's foremost experts on medulloblastoma.  He developed the initial radiation/chemotherapy protocol that Maurice, and most other medulloblastoma patients undergo.  There is a reasonably non-technical paper about medulloblastoma, written by Dr. Packer, here.