What a field day for the heat
A thousand people in the street
Singing songs and carrying signs
Mostly saying, "hooray for our side"

Monday, August 25, 2014

Things I've learned for the reboot (part 1 of I don't know how many)

X-ray radiation is nothing to be trifled with. In the past x-rays have been used for everything from killing off children's enlarged thymuses (important to your immune system, and normally enlarged in children compared to adults), as a treatment for acne, and to properly fit shoes. And there is no excuse for these issued. Clarence Dally died from his exposure to x-rays in 1904 (he was Thomas Edison's friend and glass-blower, he also was the subject of Edison's demonstration of fluoroscopy at the National Electric Light Association exhibition in 1896 and sat for 8-hours each day under the fluoroscope). X-ray radiation damage profile is mapped in what's called a Linear, Non-threshold chart which means there is no exposure level which doesn't have some risk.

We don't use much radiation in x-ray these days. With digital we use a little more than the last film technology (90s), but much less than the 70s and 80s (and you don't want to know about before that). Fluoroscopy uses a little more. If you need fluoro, be careful, ask questions, and ask if they can put the machine on "pulse". Most radiologists will only do intermittent fluoro-ing (not have the beam on all the time). CT (or CAT) scan gives you a much higher dose. If you've had recent CT scans (in the past year or two) and the doctor is asking for more, let that doctor know (especially if they hadn't ordered the earlier scans). Understand that there is no official top limit to the dose you can receive for diagnostic and therapeutic x-rays (CT included), but you should limit it as much as you can. We are happy to make copies of your scans for you if you ask. If it's a personal copy there will be a small charge, but just tell us its for your doctor (wink) or have them put it on the order. If your scan was done at an allied health care provider (in Cleveland we have University Hospitals and Cleveland Clinic) if you stay within one system, the doctors should be able to see your previous scans). Let them know one was done. Unless something has changed, they may be able to use your prior scans.

This next point is very rare, but worth noting. It is uncommon for you to have "reddening" of the skin after x-ray treatment. If after a CT scan or fluoroscopic procedure (especially catheterization or arteriorgrams) you have red skin (like a sunburn) or an ulceration, even if you think it's not where you were x-rayed, see a doctor immediately (if they weren't involved in the procedure, let them know about it). Erythema is a direct cause of 300 rem of exposure. Three-hundred rem (Roentgen equivalent man) is also the LD 50/60 number which means that of a population that experiences a 300 rem full-body dose, 50% will be dead in 60 days. With treatment, you can survive. Like I said, these days this is very, very rare, but still can occur. Immediate diagnosis and treatment is the key to surviving this. If you're having standard x-rays, even for complicated procedures (like a bone survey (not the same as "bone density" or DEXA scan) or having an l-spine/t-spine/c-spine series) you won't get anywhere near this dose unless the machine explodes over you, and even then more than likely not.

If you're under 21 keep a record of all the x-rays you've had. Go to imagegently.org, they have some helpful publications.

X-rays interact at the atomic level. We actually are concerned with which electron (well, actually their shell) we knock out of its orbit. This is also how x-rays are produced, but we'll probably cover that later. This is also what makes them dangerous, because we're changing the electrical charge on the atom (ionization). That can disrupt your organic chemistry. We're also creating a lot of free radicals (which can cause damage). Fortunately the most common effect of these, even for "direct strikes" (when we hit your DNA) is either no appreciable damage or cell sterilization (it's unable to successfully divide again).

The human body is an amazingly beautiful, complex and robust system that can handle a lot of injury and still remain functioning. Contrarily, the human body is a disgustingly smelly, simple and fragile system that the tiniest of disruptions can cause catastrophic chain-reaction failures.

Things that you might think are just annoyances, or aren't important are, in fact, exceedingly important to correct diagnosis and treatment. Say, having a shellfish or seafood allergy for instance. Yea, if you have one, never forget to tell your healthcare worker (because you're most likely actually allergic to iodine, which is in a lot of things). That pain in your toe just might be related to that pain in your back or rear you've been having. If you might have a pinched nerve in your neck your doctor will do ask you to do things you might think aren't related, like rolling your eyes around, but are actually important to the diagnosis.

Oh, and while I'm thinking of it, if you have neuropathy, it is vitally important to visually check where you have a lack of sensation. Every. Single. Day. No, you don't what to know why, just trust me on this one. Okay, well, I've seen enough necrotic toes on diabetics. You don't want to have to deal with that (and I really don't want to x-ray them, yes, your x-ray department should have spray to help clear that smell, but sometimes it doesn't work so well).

Oh, and try and keep your toenails clipped and your feet clean. I know your Mom told you to wear clean underwear, but seriously, clean feet are way, way more important to me. Okay, let's just say clean everything. Make sure you're clean. Because, damn.

X-rays don't just show your bones. We see everything. Fat. Edema. Some muscles. Major organs. So you may be x-rayed to show some of these soft-tissues (and it's a part of our protocol to show them clearly to make sure we have a good exposure). For hands and fingers, we should even see your fingernails.

We will ask you very personal questions (especially if you're female). We don't do this to embarrass you, we're trying to protect you. If you may be pregnant, you really need to say so. If it's been more than 28-30 days since your last cycle, we may ask for a pregnancy test. If you are female, you're x-ray technologist (the person who takes the x-ray) should ask you directly about this unless you're coming from the ER/ED and had a pregnancy test already, or you're older than 50 or so (everybody's department has a different cut-off, if you're older than 45 I'll ask if you've gone through menopause).

If you know you have something in you, or you have situs inversus, or had things removed, let your technologist know. Don't leave it as a surprise for us, we get enough presents as it is. Fortunately one patient did let me know he had his patella removed before I took a sunrise (without a patella, there's no need for a sunrise view).

And while we're at it, try and keep track of your prothesis, okay? No, really, if I ask if you've had a hip replacement or surgery, you think you'd remember that. You'd be wrong about it, too. If you have permanent metal in you limbs, back, neck, or head, let us know. We have to show all of it on the x-ray and if you don't tell us you have a 12 inch plate along your distal ulna, we may need to retake 3 of the 4 views of your wrist to include it. Let us know. We're here to help.

No, x-rays won't bother your phone, but it has to be out of the x-ray (so don't leave it in your pocket). I have funny stories about these, but I can't share them here. Let's just say some of you have your phone in weird places, okay.

If you have a doctor's order to limit your movement (say, like a recent pacemaker implantation), let us know that as well. With HIPAA we don't see all of your history, only the doctor's order and their diagnosis to support that order. Also, your doctor (or their assistant) may have lied to us (or the insurance) or not told us the full story, so you gotta let us know. For example, with that pacemaker, you shouldn't be raising your left arm above your shoulder, but your doctor is doing a 2 view chest x-ray to check for pneumonia. All the order says is "pneumonia", not "possible complication from surgery to implant pacemaker". And if it's been long enough that you're no longer in the sling, I may ask you to raise that arm up to take the lateral. You shouldn't do that. Let me know and let me know why (not just, "it's stiff").


Phiala said...

Yeah, I don't want to even think about it.

2014 will have at least:
3 regular CT scans
2 CT scans to get the RT set up
28 doses of RT, guided by CT scans

I know it's all in the service of not dying, but I wish the requirements of not dying were less likely to kill me.

Steve Buchheit said...

I thought about including something about your situation, but didn't want to get deep into fractionalization. I also figured you (and your oncologist) would be on the lookout for ulcerations and erythema.

Folks who don't know, that's way too much radiation for the normal person. However, in Phiala's case, they are intentionally trying to kill tissues. It's also my guess (but I'm pretty sure I'm correct) that the hospital's Radiation Safety Officer, Medical Physicist, and Dosimetrist are all calculating the exact dosages she has been receiving (both on the front end and the back end). Also, the CTs are to make sure the RT beam is going exactly where programmed (i forget the actual variance on it, but IIRC it's less than millimeters).

The good thing is RT has come a long way even in the last decade. The bad thing is it's still a hellalotta dose of radiation (even when broken up over several treatments).

Phiala said...

Oh yes: while receiving RT, I saw a nurse, PA, and radiation oncologist every week, as well as having bloodwork to ensure that everything was okay.

And everything is very carefully calibrated and measured and dosed. I could tell you how much radiation I got from the radiation therapy, but that paperwork is at home.

You probably already know how it works, but if it would amuse you to point people at it I wrote up a bit about how RT happens, including the difference between the 3D and IMRT methods. (IMRT is amazingly nifty!)

I hope that after this year I will be able to go a long, long time with only periodic CT scans for follow-up.

Incidentally, I have peripheral neuropathy, but not complete numbness, so I'm unlikely to hurt myself and not realize it. I'm still being careful, of course.

Steve Buchheit said...

I missed you were having IMRT treatments. That's some serious cutting edge stuff (also some high intensity beams, I'll have to look for more information because at the intensities the accelerator can make, AFAIK the beam just wouldn't even care you were there - you don't have enough atomic mass to attenuate it, unless you've been dosing the tumor with gold or iridium or some such). I mean at those energies (10mV) you're talking pair-production (splitting neutrons into electrons and positrons - aka anti-matter or technically an anti-electron, I know you know this, but just so we don't leave everyone else behind). Your atoms don't have enough heft to even to do Bremsstrahlung reactions at that level (I might be wrong on that, I'd have to check the physics).

I should probably note putting in intensity curves and exactly why we use the energies we use in diagnostic x-rays.

Also, after this, I'm sure your doctors are going to be very reluctant to order CTs for anything else.

Phiala said...

There was much arguing with my insurance company, but I eventually ended up with IMRT.

I looked up the doses last night. I had 3 treatments of standard 3D radiation at 180 cGY per does, and 25 IMRT treatments at 190 cGY per dose, for a total of 52 GY.

The dose per IMRT isn't that much greater, but it's more carefully targeted and distributed more around the body: the 3d model used three bursts of radiation at different angles; the IMRT is continuously adjusted while circling the pelvis.

And I'm now scheduled for a CT on Friday. (Mmmm barium contrast.)

All this radiation has certainly increased my risk of developing a secondary cancer in a few decades ENORMOUSLY. If it lets me live a few decades I'll worry about it then.