mIBG – We are back on!

This entry is part 3 of 3 in the series "Radiation" --

WARNING: Science Content


As with all my posts, I try to include some thought provoking science, as well as interesting water cooler talk.  Good luck.
 
MetaIodoBenzylGuanidine

MetaIodoBenzylGuanidine


[Prologue]

For those avid followers of all of the science that I have introduced during all of this, you will recognize that this post is a rehash, but an exciting rehash.

Early on, Liam was initially slated to participate in a mIBG (MetaIodoBenzylGuanidine) trial.  The trial wasn’t supposed to happen until after the induction period of chemotherapy.  The catch is that only 80-85% of neuroblastomas absorb mIBG.  This is why fairly soon after diagnoses, while there is still a lot of cancer in concentrated pockets throughout the body, an mIBG scan is given to see if the particular variety of neuroblastoma picks it up. This is done with [123]- mIBG (see below.)

When this scan was performed on Liam back in September, there had been problems and the scan was not performed right away.  The doctors and hospital staff were having difficulty stabilizing Liam.  In fact, that first session in the hospital lasted over 21 days.  He had been started on  a fantastic chemotherapy drug called Topotecan (which is a TopoIsomerase I inhibitor that is so darn cool, it deserves its own post and I will not discuss it here.)  The problem was that Liam was spiraling out of control while he was on it. He started having trouble breathing, and he ended up with a plural effusion (yep… that was a bad couple of days. Click here for the post from that day).  After all was said and done, the mIBG scan was pushed off until he was admitted for chemo round 2.

When the [123] mIBG scan was finally performed, it came back negative. We were bummed, but the chemo seemed to be going so well that we really didn’t give it much thought. Liam was feeling better.

After 6 rounds of chemotherapy, a follow up PET scan was performed. No cancer showed up on the scan. He had a remarkable response, and we thought we were doing pretty well.  In reviewing all that had happened over the course of 6 rounds of chemo, I wondered if most of the cancer had vanished just after the first round of chemotherapy.  If it did, it would have skewed the mIBG test to a negative result.

Looking back at the sudden improvement after round 1- the plural effusion (now believed to be caused by cancer dying his lungs) and all of the immediate weight loss (now believed to be the cancer dying in his abdomen)…. he looked normal for the first time in months; I contend that the Topotecan chemotherapy made most of the cancer disappear quickly.  His response even astonished his doctors.

Now that the cancer has come back,  it was suggested by the doctors at CookChildren’s that we look one more time at the mIBG.  So, we did, and it gave a positive response to mIBG.  It can clearly be seen in the left tibia and the pelvis.

mIBG Liam 24July2015

123-mIBG Scan of Liam on 24July2015. His neuroblastoma has soaked up the mIBG compound, and due to its radioactivity is exposing the film. His trouble spots in his left leg and pelvis can clearly be seen.

So what does this mean? It means that we now have a really awesome tool in our tool chest to fight this. It won’t cure the neuroblastoma, but hopefully we can knock it down and coupled with other therapies, we can get this disease under control for Liam.  This is an option that a week ago we did not have.

[End of Prologue]

So, how does it work? It turns out that Neuroblastoma has a strong affinity for mIBG in about 85% of cases.[1] In a very high percentage, the Neuroblastoma cells will take this compound up while the normal cells will not. This is called ‘selectivity’. (i.e. the Neuroblastoma soaks this compound up selectively over normal cells).  mIBG in itself, however, doesn’t do anything. It is taken into the cell, and then is excreted from the cell at a later time.  This means that the Neuroblastoma cells are not sensitive to the compound. 

A clever and ingenious pupil of chemistry can already see what to do next.  Swapping out the Iodine atom on this compound with the radioactive version  makes this molecule very useful.


[123]-Iodine

123 Iodine will decay by electron capture to form 123 Tellurium which will then emit a Gamma ray with an energy of 159 keV. This is useful for imaging.  This is like having an x-ray performed, but rather than having an x-ray source shining high energy light through Liam, the light will be generated inside him!  Since this radioactive atom is attached to a compound which is only selective to Neuroblastoma, Gamma rays (like x-rays) will be generated only at the Neuroblastoma sites.  With the correct detector, the Neuroblastoma will light up like a Christmas tree.


[131]-Iodine

If 131 Iodine is used, different results will be observed.  131 Iodine decays in the follow two manners (statistically a 90% Beta(-) Decay and a 10% Gamma decay):

(Beta(-) Decay ~90%) {^{131}_{53}\mathrm{I}} \rightarrow \beta + \bar{\nu_e} + {^{131}_{54}\mathrm{Xe}^*}  + 606 keV 

(Gamma Decay ~10%) {^{131}_{54}\mathrm{Xe}^*}  \rightarrow {^{131}_{54}\mathrm{Xe}} + \gamma  + 364 keV

The Beta(-) decay produces a very energetic electron and an Antineutrino which have a tissue penetration of about 0.6 to 2 mm. This is enough energy to destroy cells. (i.e. a cell sized atomic bomb) So in essence, this gives a pathway for the mIBG, which is very selective to the Neuroblastoma, to blow up the cells (and leave the good cells alone).


This mIBG scan that was performed today only involved 123 Iodine for gamma ray imaging (see above images). This indicates all of the places that the Neuroblastoma is, with a few exceptions. There are false readings in some of the places like the thyroid (which regulates Iodine containing compounds).    In the coming weeks, it’ll be time to bring out the [131] Iodine and give this cancer the radioactive punch it deserves.

  1. According to NationWideChildrens.org “…Roughly 80-85% of neuroblastomas will absorb MIBG. There are really 2 ways in which MIBG treatment is used. In both methods, the MIBG chemical is attached to an iodine molecule that has been made radioactive. The radioactivity can be either a low-dose or a high-dose…. ”

Cancer is Wood

This entry is part 8 of 10 in the series "Liam's Battle" --

Fred and I met in the fall of 1995 at Southwest Texas University (now Texas State University). I was a 17 year old freshman and he was a senior. We met at the first chemistry club meeting. He told me I had cold hands (he asked to shake my hand after I was elected secretary of the new club), and I later told my roommate that I had met a really nice guy but he was way too old for me. A Friday night group movie night (planned by Fred just to have a way to ask me out without asking me out on a one on one date), a Saturday night group outing to listen to music and dance at Nephews (I walked down to the square in San Marcos to check to make sure I could actually get into the venue), and a Sunday morning “date” to attend church and Sunday school together, and I was smitten.

A year and a half later, we had been already been engaged to be married for 7 months and the plan was to wed when I graduated (scheduled for May 1998…I was on the “I took a bunch of AP classes in high school and am willing to work through the summers to complete this degree” program); however, Fred and I wanted to move the wedding up and start our happily ever after. My parents wanted me to finish school. So, Fred and I flew out to northern Virginia for Spring Break to discuss the possible change in plans.

My parents were preparing to put their house on the market. (My dad had been reassigned to Fort Sill, OK.) Unlike the previous trip that Fred had taken to visit my parents, the tenor of this visit did not involve sight seeing or national monument visitation. This trip involved a lot of work…together.

We stacked firewood. And my dad watched our interaction. The temperatures fell. And then dropped below freezing. And dad asked (told) us to power wash the large wooden deck. This was a task that neither Fred nor I had ever done before-alone or together, in good weather or bad. But we tackled it together and managed to enjoy a rather miserable time together. We took turns, we encouraged one another, we laughed, we borrowed a joke from the sitcom “Boy Meets World” that we still use, “This is the opposite of fun. This is wood.” And my dad watched.

At the end of Fred’s trip, my parents had a clean deck, we had the memory of a lifetime, and my dad gave his blessing for us to move our wedding to August of 1997…even though I wasn’t done with school, my sister was getting ready to finish high school/start college, and they were selling their home and moving halfway across the U.S.

What I didn’t fully appreciate at the time, but am starting to appreciate more fully after 17 years of marriage, is that character is revealed as well as developed during times of conflict. My dad had already figured that out and was resourceful in using tasks that needed to be accomplished to see how Fred and I would work together in challenging times.

Our first year of marriage was a borderline disaster, but we endured the conflict that arises when one person has a schedule crammed too full of graduation requirements and the other is waiting for said person to graduate. We endured all of the frustrations that go along with learning to share a life (and small apartment) with someone else. We endured the transition to graduate school and my realization that I didn’t want a Ph.D. because I knew I would feel compelled to use it in a job outside of the home once I had earned it. We endured 5 years of a commuting marriage when I took a job at Portland Community College, while Fred finished his degree in Eugene. (I had an apartment in Portland and lived there during the week and came “home” to Fred on the weekends.)

We endured the stillbirth of our first child, a daughter who we had named, talked to, hoped for, and love deeply. We have endured the wonder, blessing, sleeplessness, and general nuttiness that parenting 4 kids can entail. We endured a chemical pregnancy and a miscarriage.

We have walked an interesting journey together and we continue to grow together as two become one flesh, a head and a body learning to serve each other as we respect, love, and cherbish (we both mispronounced “cherish” in our wedding vows) each other (Ephesians 5).

We celebrated our 17th wedding anniversary by indoor skydiving, a surprise my sweet husband knew I would love. We laughed and made memories as we experienced the wonder of being supported by a force we could not see, but could definitely feel. We cheered for each other as we learned how to relax into the wind. We compared sore muscles after our brief flights.

And on August 17, 2014, the day after our 17th wedding anniversary, our sweet two-year-old Liam was diagnosed with Neuroblastoma. It is a horrible disease and the treatment for it seems cruel and unusual in many ways. Honestly, at first I felt like we were in free fall. But as we continue to endure and walk this journey together, I have come to realize that just like when we were skydiving indoors, we are being supported by an invisible force. We can’t see it, but we can definitely feel it. This is an opportunity for our character to be revealed and shaped. It is an opportunity for us to grow together as a couple as well as for our family to be unified.

Just like power washing the deck in freezing temperatures, we are in a situation that neither Fred nor I have experienced before, we are tackling it together, and managing to enjoy a rather miserable time.

Our audience has grown. We are blessed to have our family here to help.  My dad has a front row seat to this adventure as the long term substitute in our homeschool this year.  My mom is wearing many hats as she shuttles kids, cooks, cleans, runs errands, etc.  My sister and brother-in-law (and their girls) are walking along side of us, watching, supporting, teaching. And our children are watching how we handle this situation, growing, and learning some character lessons early in life.  We are enjoying an extended family support system orchestrated by a God who listened to our prayers to relocate to Texas for six years before allowing us to move to within 2 miles of my parents and sister to a job that was a perfect fit for Fred’s skill set and personality type. We have been blessed and humbled with an army of people praying for us and our son, people providing meals, people sending care packages and encouragement, people showing us God’s love.

Cancer is the opposite of fun. Cancer is wood. And yet, it is fueling a refining fire. We are not the people or parents that we were before our son was diagnosed. We are still imperfect, flawed, and human; however, we are calling on the name of the Lord and we testify that He is our God (Zechariah 13:9). He is faithful and just to cleanse us of all unrighteousness (1 John 1:9). And He promises to use all things for the good of those who love Him…so that we can be conformed to the likeness of his Son (Romans 8:28-29). May our faith be proved genuine and result in praise, glory, and honor for Jesus Christ (1 Peter 1:7).

A Mass. A Tumor. Cancer. Metastasis.

This entry is part 2 of 10 in the series "Liam's Battle" --

In the early hours of 17 Aug 2014, moments after I had the news in hand that there was an unwelcome mass in my son that had been the cause for all of his distress, the social worker came in. My immediate thought was, “Oh great! I get to endure the questioning that comes with all of the bruising and the black eye that my son has.”  I braced myself for the line of questioning that should accompany any child that shows up at a hospital with a black eye and bruising on his body, the apparent knowledge of the mass inside my son still rattling around the inside of my brain not really certain on which brain cell it should land.

I started to formulate a preemptive strike against the social worker.  I knew that I had no idea how the bruising got there; but how could I encase this in language that would allow her to believe that I had really not done it?

I started to speak, but then I decided not to.  Instead I stood there frozen while she came in and introduced herself.

“Do you have any questions for me?” She asked.

“Like what?” I asked, now on about my fifth iteration of my almost believable yet true story.

“Well, sometimes parents need to talk after a diagnosis of cancer is revealed, and we just want to make sure that you are OK.”  She said.

‘Cancer.’ This word started rattling around with the word ‘mass’. They really didn’t register quite yet. Cancer. The only childhood cancer that I could think of at this point was Leukemia. I didn’t know much about it, but it seemed that the odds of survival were pretty good for it. Of course, I had no data to support that claim, but I believed myself anyway.

“No, I think I’m OK.” I told her. I felt fairly relieved that I had not been asked to explain the bruising.

“OK, well, if you need to talk, just have the nurse page me.”

“Sure.”  I said having felt the victory of dodging the bruising question.

It wasn’t long after the social worker came in that I was meeting with the oncologist Dr. Tanya Watt. As I would come to find out later that day, she is the doctor at Children’s Medical Center that specializes in Nuerobalstoma.  I was assured that I was in the best hands possible.

“Right now, it is important to stabilize Liam. It’s likely that he has Neuroblastoma, based on where the cancer is in his body. It has likely spread to his bone marrow and started to compromise his blood production…” She said.

Wait, did she say ‘Spread’? I thought we were talking about a mass on the adrenal gland?  Wait! Spreading is bad!

The words: Tumor.  Mass.  Cancer.  Bone Marrow.  Spread. They all congealed in a place in my brain that controls the pit in the bottom of my stomach.  The fight or flight response now activated, I thought (and possibly said out loud), “Ohhhhh Crap.  Crap. Crap Crap Crap Crap Crap!” –Why had I been so foolish and not brought him in sooner? Had I really missed all of the signs leading us to this point?

The oncologist said,   “I want you to realize that you did the right thing by bringing him in. I realize that in the first twenty-four hours of a diagnoses like this, all the parent hears is ‘Cancer’, but I want you to realize that this is not your fault. You did not do anything to cause this.” She said with certainty. “I’ll be managing your case, so I’ll come talk to you once you are upstairs on the oncology floor.  Do you have any questions for me right now?”

“Yeah.” I remember stammering. “What type of cancer did you say this was likely to be?”

“Neuroblastoma. N-e-u-r….  Here let me write it down for you.”  She pulled a napkin from the counter and wrote it down. “I know that you are going to look this up, but try not to freak yourself out before we have a chance to talk,” she said. And with that, she left the ER patient room.

“We need to start an IV.” A nurse said entering the room.

“Sure.” I said. Picking up the phone to call Jenn. Synapses were starting to fire. I knew I needed my wife here with me.