I sort of let myself get misguided along the tracks to address long term dental issues.

One primary cause, one side effect, and two primary effects.

Direct radiation hitting teeth and bone structure. Main effect is to the jawbone and you can lead to ORN, a bone disease.

Direct radiation also damages salivary glands that reduce saliva output and causes dry mouth. Tooth decay advances quicker due to the lack of saliva that helps kill bacteria that promote formation of carries and cavities.

Also, prior teeth conditions, medical conditions, current co-moridities, medications, illegal drug use, diet, chemo, and as we know, radiation, and it's dosage amount, fractions, field of radiation, bilateray or ipsilaterally, dosage to structure (salivary gland are usually dosed under 30Gy to partially recover), all factor in tooth decay and or to accelerate it. You ever see what crystal meth does to these addicts teeth?

[quote]salivary gland are usually dosed under 30Gy[/quote]
As I never got to the dosimetrist, I was not able to learn more about the treatment plan as it translates into guidance of the radiation beam over the targeted areas.

The further I got was seeing the work the RO had done to map the areas he wanted to hit. The actual beam contouring and general painting of the other areas in the target zones was not fully understood.

The RO did make the comment that they would dose all areas as it was the most complete way to maximize the cancer kill. I pointed out to him since all the cancer was no the right and nothing was evident across the midline to go easy on the parotid glands on the left, minimizing saliva issues. His response was the priority was to dose to kill then secondary objectives would be entertained such as saving gland function.

One other thing is the target of 70gy total dosage. Given that the actual radiation is variable from zone to zone in a given session and from session to session, these must be general or computed averages.

Maybe something like 30gy to the parotids is reasonable as an average. From everything I have read thus far dosing at 30gy as a general target is far below what is considered effective. There are trials underway to deescalate to 60gy but nothing in the range of 30 for HNC.

From my readings, and I only read about SCCHN, mainly oropharyngeal, Oral Cancer, dosing above 30Gy will totally destroy the salivary glands, but could be wrong, and will not recover, as other vital structures have limiting toxicity dosing like the brain stem, spinal cord, brachial plexus nerve, so they don't get the full 70Gy. It depends if the salivary glands were involved with cancer, suspected, that would need higher dosage, but it's usually 26Gy to the salivary glands. It doesn't appear it's steady over the course of treatment, according to my colored "cumulative dose volume histogram" which has the dose, ratio of total structure volume (%), and relative dose (%), and have other colored copies of the CT, fields in plans in different positions. I can see my left, cancerous side, field was much larger. It's pretty cool if you can get copies.

Wow. I'm going to ask to see mine if I can. What cool information to have! As always, thanks Paul.

The other good thing with having copies, is if you go to another CCC, I did, they want to see them. Although, they can eventually get copies, once authorization is signed, it will just add more time to do so, which some may not be able to afford.

The rad treatment details sound cool. All I saw was a couple static images that the RO showed me where he had outlined the primary target. It was a snapshot so no interval images nor could I see any dosing info.

I'm assuming the commonly referenced dosage of 70gy implies the cumulative dosage administered during this plan to the primary target areas. Is that what your documents show, that 70gy is the max or is that some sort of average where some areas might be subjected to more than that amount for some sessions of the plan?

Do you think there is output from the planning software that could be put on a disc to view visually like the CT and PET series?

It would be unbelievable if it could do 3d rotation showing the targeted dosing and contouring and also show the changes from session to session. Putting all that on a disc would be quite a feat. I know from the CT/PET series it made the network and poor PC in the doctor office choke for breath.

It was hopeless running the imaging programs from the disc I got. Copying it all to the hard drive and running from there worked much faster. Still, on a high end PC it still took a few to get rolling. LOTS of data.

I'm not sure if I obtained a CD from radiation, I may have, and I sent everything to MSK. Six month later. They finally returned my 400 page documents, 13 discs to me, but I don't know what was removed, kept, if any, and was mixed up.

I looked at my PET/CT, which looked like a Christmas tree, and my first time thought cancer was everywhere lol. I can't make heads or tails if them, but the doctors are happy when I have a copy.

I still can't figure the whole thing out. The primary tumor, I believe is referred to as the PTV, Primary Tumor Volume, which has max, min and mean dose in % on the set-up center image. The cumulative dose volume histogram has about 10 structures with the coverage, volume, min dose, max dose, mean dose, modal dose, median dose, one which appears went up to 75Gy, and is in %. On my treatment plan report it has the dose prescription,

Target Volume Ptv70
Prescribed dose % 100%
Fractions F1
Prescribed dose 7000.0 cGy (200.0Cgy/fractions)
Dose at primary ref point 70000cGy (200.0cGy/fractions)
Number of fractions. 35

Plus- bunch of other fields

[quote]Target Volume Ptv70
Prescribed dose % 100%
Fractions F1
Prescribed dose 7000.0 cGy (200.0Cgy/fractions)
Dose at primary ref point 70000cGy (200.0cGy/fractions)
Number of fractions. 35
[/quote]

Of course you and I are just pretending we have a clue what any of this really means.

One can point out associations and draw logical conclusions. I'd bet they are better than random guesses.

First thing I notice is you typed Dose at 70,000 cGY. I think you would be dead long ago or have an electric grid connected to you to provide power to NYC. 7,000 perhaps?

What seems is there is one set dose (200cGy) for each fraction. Initially I assumed same dosage for each fraction but hear something that indicated that fractions might change during the course of treatment. The details here indicate constant dosage for all fractions.

I'll assume the "primary ref point" is the spot placed by the RO, likely the center of the primary tumor. All figures indicate dosing does not exceed 200 per session or 7000 in total.

I'll be in the pile of other figures is secondary locations to get rads as well as the contouring profiles and the general painting of the remaining targeted area(s).

Not to forget how we got here, sorry for taking this thread hopelessly OT, but coming back to dental care and the fact saliva does a lot to keep teeth healthy.

Parotid and saliva glands are rarely primary tumors. Some here longer may have come across an instance by in my year here I have no recollection of any primary in the parotid.

Clearly, the technology is advanced enough to not directly place any radiation on these structures. The question is this done and there is sufficient overspray from the radiation sent to other areas as directed by the plan or are all areas dosed at some lower level just to ensure total coverage and cancer annihilation.

The discussion with my RO clearly indicated my treatment plan was going to paint some dose on everything in the broader target zone. One of his replies to me was a question something like, "Don't you want to do all you can to get as much as you can?" I interpreted his statement that it was safer to dose areas not directly identified as cancer bearing but could be where microscopic cancers could be hiding. Blast them now rather than risk some lose one might grow and bite later. I totally agreed.

The ENT, MO and surgeon were all pro treating aggressively in my case. I'm sure age and heath and other factors were inputs to their recommendation but that is how I would want it anyway.

links to pet/ct pet/ct2 video of my files.

The second is revealing in that it becomes obvious where the term "lighting up" on the PET comes from!

I don't know about pretending, but I know very little, and even more so with any regards to the physics. I just have no interest in any math, expect my montly check lol. Yes, it was a typo 7000.0cGy vs 70000cGy. Although rare, there were a few here that had MEC cancer, muecopidermoid Carcinoma, which is cancer of the salivary glands, but kind of expected when oral cancer foundation is the name of site, and seen more of these cancers on another head and neck cancer Blog. Pretty cool you posted a X-rayed YouTube video. You better watch out you don't start a following, and goes viral with their idea of the most perfect Chistmas tree