Wednesday, 2015/8/26 ~ Tuesday, 2015/9/1 – Upsetting Revelations

Wednesday, 8/26

The Medical Oncologist (chemotherapy expert) in Lancaster gave me some difficult news. The radiation is going to do some things I had not anticipated fully, and the chemotherapy is going to be much worse than I understood, from what I had originally been told. He advised me to get the chemotherapy done in Los Angeles, where the radiation can be done immediately afterward, so I got an appointment to see the Medical Oncologist down there.

Apparently, the chemotherapy they will be using is more aggressive than usually used on this particular type and location of cancer, in the hope that it will combine with the radiation to make an absolutely complete cure, with no chance of recurrence. The plan is to weaken the cancer, and strengthen the healthy cells nearby, make the cancer more susceptible to the radiation while protecting the healthy cells, and to target the very short-wavelength (read narrow and accurate) X-rays very precisely, to kill the cancer but leave as much as possible of the healthy tissue alone. The radiation will scramble the DNA of the cancer cells, so they cannot reproduce or continue to regenerate. The linear accelerator is the newest and best IMRT (Intensity-Modulated Radiation Therapy) and uses Smart Arc programmed control, to adjust the beam more accurately, and offer the best chance to cure, with the least collateral damage. The radiation damage on my  neck, and the stripe through my beard where the hair doesn’t grow during the treatments are unavoidable. Of course, the chemo may make my hair fall out anyway, so a stripe through my beard will not be much of an issue.

A hypnotic video on how Linac works:
[Some of the stuff, especially after about 7:00 is specific to one manufacturer and model (Elekta Synergy) but most of it is exactly what Kaiser’s Linacs are like too.]

A deeper delve into radiation therapy equipment, which fascinated this lifelong science nerd and electronics/computer instructor:

Here’s a slide show created for the U. S. DOE Department Of Energy) to accompany a talk given on Linacs. The actual talk is not there, and it points heavily toward charged-particle therapy (which is not what I am getting) but some of the history and forecasting are enlightening:

I am having a dizzying series of appointments to see various different doctors, all of whom will be co-operating to kill the cancer without killing me… too much… The plan is to kill me mostly, but the cancer completely, and then bring me back. Think Princess Bride, when Wesley was “mostly dead.” All of these appointments are now “Down Below,” in the Los Angeles metroplex. That’s where they will be pumping me full of poison (Cisplatin) and shooting death rays through my neck and jaw.

Tuesday, 9/1

I went to UCLA dental again, to get the fluoride trays, and later that morning, to see the Medical Oncologist at the main facility in Los Angeles, to learn about diet, and a lot of other stuff to do with the chemotherapy. A couple of days later (Thursday, 9/3) I will go to have a rigid plastic web mask made to hold my head absolutely still during the irradiation, and have a PET scan done to get the most precise possible picture of where they need to irradiate, and where they can leave healthy tissue alone. It involves giving me an IV of radioactive sugar, which the cancer will gobble up greedily (much faster than healthy cells) and in that way mark the cancer very clearly for them to target the radiation treatments precisely.

I am definitely going to hate having my head clamped to the table, and may need Ativan or Valium to keep from doing something both embarrassing and dangerous. I have never dealt well with being immobilized, and in the last few years it has been worse. The day after the PET scan (Friday, 9/4) I will see the Radiation Oncologist (captain of my team) to plan the actual treatments. It will almost surely be 7 weeks of radiation, Monday through Friday, with the Cisplatin being infused intravenously three times, spaced throughout the treatment period.

Tuesday, 2015/12/15 – Even More Nuclear Physics

OK…. I confess to being a total technerd, and fascinated by the Linac (Medical Linear Accelerator) that irradiated me five days a week for seven weeks. I was also fascinated by the imaging tech. they used to diagnose me, and to plan where to send the death rays. I made such a pest of myself asking the therapists about the science, that they arranged for a Medical Physicist to talk with me and answer some of my weird questions.

I alaready posted about the PET in September:

I published some of the actual imagery from my scans here:

I now have some clarification about PET. Here is some of the expanded information Dr. X gave me, with a few extra details his guidance led me to dig up::

The annihilation of the electron and positron generates two gamma rays, each about 0.5MV (half a Million Volts equivalent energy) that travel in opposite directions, on a line through the locus of the collision. Some of the rays hit a ring of phosphor crystals, making them glow. That light is picked up by very sensitive photocells, and analysis of which crystals get hit gives the computer a line along which the annihilation occurred. The computer records hundreds of millions of these lines, and uses the points at which they cross to tell where the radioactive marker is. Adding information on the TOF (Time Of Flight) of the rays can improve the accuracy, but is not in common use yet. So far, we just can’t measure the delays of the rays (picoseconds) traveling at the speed of light, accurately enough to make much use of the information. You can read more on TOF:

Now more on the LINAC:

The following will make better sense if you have read what I already wrote about the Medical Linear Accelerator on 9//1:

…and on 10/9:

Now Dr. X has helped me understand it even better, and here is some of that new information and clarity:

As I lay on my back on the couch, the therapists would sometimes tell each other to move me “ten millimeters more X,” or “just nudge him down a little on the Y axis.” I realized that they were referring to the directions of movement in Cartesian co-ordinates, with the abscissa (Y axis) being vertical to me (from my head to my toe) and the Ordinate (X axis) across my body, from one shoulder to the other. Of course, I had to ask if the Z axis was from my front to my back, but the therapists didn’t seem to understand, so I asked Dr. X later on. Indeed, that is how the Z axis is defined. I drew a picture to illustrate:


Of course, with me lying on my back, the whole thing rotated like this:


The coronal plane is perpendicular to the Z axis, and the coronal slices of a scan (CT, MRI, or PET) will be parallel to that plane. Imagery is most often “viewed” from the front of the subject (coronal) from below the subject’s feet (axial) or from their Left side (Sagittal) depending on which plane one selects.

This means that as one lies in a scanner or the Linac, these are the axes:


The imaginary line down the center of my body is called the Axial Isocenter. It is the one they most oft3en refer to, so they sometimes do not specify “axial.” The Linac gantry rotates around this axis, and the beam remains centered on the Isocenter as the gantry rotates. The standard radius of most medical linacs is 100cm, from the target to the Isocenter. The target is a piece of Tungsten the electrons hit to generate the X-rays, and it’s up inside the treatment head. For tumors on the skin or only slightly below it, the target is replaced by a scattering foil (very thin aluminum or copper) and the electron beam itself is directed to the treatment area.

Clinac_isocenter_960x500Here is a sketch of the basic configuration of the Varian Clinac that delivered the radiation therapy to my tumors:VarianKlystronLinacAfter the electrons are accelerated in the waveguide, some Linacs use a magnetic slalom path to further focus the beam.  This video shows such a beam path:

Varian Linacs, like the Clinac that was used on me, instead use a single 270° Achromatic bending magnet (dipole) to bend and focus the beam, as seen in these illustrations:



In the 270° turn through the dipole, the beam is narrowed to a millimeter (1/26 inch, or 0.0393701 inch) in diameter.

The electron beam velocity (near light speed) determines the energy level of the rays produced. I got 6MV (MegaVolt) X-rays (photons), because my tumor was not deep inside my body, but not at the surface either. The Clinac can also produce a 15MV photon beam for tumors deeper inside the body. The system can also do digital X-ray imaging, at either 6MV, or 12KVP (KiloVolt Peak)

To make sure the right amount of radiation is delivered, the computer uses two ion chambers in the beam path between the dipole and the final collimator. The first one tells the computer when the dose has been administered, and the second one can sense if the first one has failed, and cause an emergency shut down.

Prior to each patient getting their first dose of radiation, the mapcheck array is used to align the system and adjust the dosage to match their specific treatment plan. The mapcheck array has 475 diodes as sensors, sending dosage information to the computer in real time.

If you’ve read this far, then you are a true TechnoGeek like me. Congratulations, for the geek shall inherit the earth.

Monday, 2016/04/25 ~ 2016/05/04– Second Tumor Board & Third PET

Monday, 2016/04/25 – Second Tumor Board & Third PET

I was amazed at how quickly after I received Dr. Mc’s news I was scheduled for my second tumor board.  There is seldom any reason to ask for a second opinion after a tumor board, because it represents the findings of half a dozen extremely competent doctors in various allied specialties, plus the consultation of more experts, such as radiologists and medical physicists. I went to be examined one more time, including the laryngoscope, to discuss my signs and symptoms with various doctors, and hear their diagnosis and recommendations. Charlotte took me down there, and stayed with me throughout, and posed some questions I did not think to ask.  After the investigative phase came the deliberations for about an hour, and then they called me into a pleasant office with a computer and comfortable furniture. On the way, we stopped by the exam room where they had scoped me earlier, and showed me the video of the exam.  It showed a bulge at the back of my throat (in the nasopharynx region) which indicated some sort of growth or swelling there.

It was just Dr. I and Dr. K this time, and Charlotte and I had a good long session with them.

The news was very upsetting.  The specific type and strain of cancer I have is particularly susceptible to photonic radiotherapy, not generally very fast growing, and usually cured by the regimen I underwent last fall.  For it to resurface, and to be faster-growing than before, was a rare occurrence.  The MRI showed the experts a different picture than was expected.  It, along with the PET and CT scans, showed a tumor which had grown quickly outward at first, then slowed a bit and turned inward, but was now heading for some very critical structures.  The parotid gland is a pyramid-shaped thing, with the base against the inside of the jaw, and the apex pointing inward, toward the throat.  At first, the base grew, and interfered with jaw function, and caused pain and swelling in that region.    Then the thing surprised us.  It turned inward, growing at the apex, toward my carotid artery, esophagus, and vagus nerve.  It had compromised the vagus nerve, which paralyzed my right vocal fold.  This was bad news, but there was more.  On the PET scans, there was a faint shift in color in a couple of spots separate from the parotid, closer to my pharynx, which indicated increased uptake of the radioactive fluoride sugar they used as contrast, as a marker.  I have not obtained the new PET scan, but in this MRI image, we are looking up from my body, toward the top of my head, and the squiggle next to the tumor is part of my right earlobe.  Gadolinium was used for contrast.

annotated MRI of problem areas in recurrence
Parotid’s Progress

PET depends on the radioactive decay of Fluorine-18, attached to glucose, to show where sugar is being used most.  The brain uses a LOT of sugar, because it cannot burn fats or other carbs. Active muscles do as well, and there are dozens of other things that can present false positives, but cancer is one thing that uses only sugar, and tends to draw the glucose to itself, showing up as hot spots on a PET scan.

In light of the swelling at the back of my pharynx, these tiny, vague spots took on a sinister aspect. For more on the PET scan, read this earlier post:
Bottom line: my particular type of cancer should have succumbed to the combination of poison and death rays, but two things may have happened to let it live.  In trying to spare my parotid gland, the radiation may have missed a cancerous lymph node inside the gland, which did not show up on previous scans.  That is the most cogent explanation for the swelling parotid.  Another problem, not as sure, but logically surmised, is that some of the cancerous tissue in the high-dose area may have survived the radiation, and it may have included a cancerous stem cell.  It is the stem cell which, once cancerous, creates the clones that spread.  Not having the third dose of chemo may have facilitated that, but we cannot be sure.  If there is still tumor growth in that area, then it is more dangerous than the parotid tumor.

I found a very good slide show that summarizes a tremendous amount of information on cancer, what it is and how it works, at:

What to do:  another PET, chemo, immunotherapy, and clinical trials of new drugs.  I had the PET scan (with concurrent CT to improve the accuracy) Thursday evening, 2016/04/28, to evaluate the extent and nature of new growth. I will be seeing a medonc (medical oncologist) and we will discuss three possible strategies to deal with this persistent pest.   One thing is to do more chemotherapy, and if it shows any effect, add radiation to finish up the job… BUT the margin needed to assure eradication of the tumors would cut into my carotid unless the tumor(s) shrink from the chemo first.  Another hopeful avenue is immunotherapy.  Instead of killing the immune system as conventional chemo does, it boosts the natural defenses of my body so they can selectively kill the cancer. Strides are being made in immunotherapy, though success may cost Big Pharma billions of lost income from conventional chemo drugs.  It has only been successful with a few types of cancer, and the science is still developing, but it is almost surely the best way to cure cancer, when it is effective.  There are also other drugs and procedures undergoing testing, that hold a lot of promise, and if I get accepted to a clinical trial of one or more of those, it offers some chance of a cure, or at least an improvement.

Thursday, 2016/04/28 – 3rd PET scan

I wish I didn’t know so much about this stuff.  The company that contracts with Kaiser to do their PET scans in Panorama City bought a brand new motorhome and scanner, this time a Siemens instead of GE.  It’s faster than the old one, and produces better images too.  I held pretty still, and didn’t freak out… much.  Had to work to keep my breathing under control, and to stay as still as possible, but the techs said we got a really good scan.  Now I can look forward to some information on Monday, but nothing much until then.  Just holding on from one day to the next now.

Wednesday, 2016/05/04

Two doctors (Dr. K, a radonc, and Dr. S, my head/neck surgeon) called me about the PET scan. Bad news both times. The cancer has returned and is more aggressive than before. The mets are not restricted to the parotid. Some are right in the original area where my right tonsil was removed, and the radiation was the strongest. This confirms that surgery and radiation would be pretty useless at present, and chemo and/or immunotherapy are the best hope of turning this thing around. I’ll see the medonc Monday, 2016/05/09.  Meanwhile, I am fine-tuning my nutrition with probiotics and anti-oxidants and other things which aid my immune system.