Help me translate medical-ese? EBRT plan.

[Jpburns]

I decided on radiation, and spent over an hour talking with radiation oncologist about treatment. Afterwards, I got access to his notes, and wonder if anyone could help me decipher his clinical notes. Not essential, but am curious about what all this means.

“EBRT using photons – plan is for 50.4 to whole Pelvis, ~55 to PSMA PET positive LN, and 70 Gy to prostate+SV, all delivered simultaneously using 28 fractions, using daily CBCT.”

I can tell he’s dosing 3 targets (pelvis generally, lymph nodes, and prostate) but what are the units specified? Does “fractions” mean sessions?

Thanks in advance.

[witantric]

The number is total radiation intensity. It will be divided into 28 roughly equal fractions. Think of 70 as the total dosage and each session will give fraction of that.

[Jpburns in reply to witantric]

Thanks. That’s helpful.

[Tall_Allen]

50.4Gy in 28 treatments is the dose that will be given to the whole pelvic area, including the pelvic lymph node area and prostate. On top of that, 5Gy extra will be given to those LNs identified by the PSMA PET scan, and 20 Gy extra will be delivered to the prostate and seminal vesicles. Cone Beam CT (CBCT) will be used at the start of each treatment to precisely align the beams.

Grey (Gy) is the amount of absorbed radiation per kg of tissue.

Fractions means treatments or sessions. Your plan is "hypofractionated"= done in fewer sessions that used to be done. That boosts the biological effective dose higher than what it would've been with normal fractionation (in 44 sessions).

[Jpburns in reply to Tall_Allen]

Thank you. This is great information.

[Brad70 in reply to Jpburns]

If 4 gy of radiation was delivered in one dose to your entire body it would be lethal. So, 70 over time to your prostate has some real cancer killing power.

[Mike58]

TA has pretty well given you the answer to your question. But out of curiosity, I copied and pasted your RO's notes into ChatGPT and asked it to give me a simple explanation.

Here's what came back

Certainly! Let's break down the notes from your radiation oncologist in simpler terms:

EBRT using photons: This refers to External Beam Radiation Therapy (EBRT) using a type of energy called photons. It's a common method of delivering radiation to treat cancer.

Plan for 50.4 to whole pelvis: This means that the radiation dose planned for the entire pelvic area is 50.4 Gray (Gy). Gray is a unit of measurement for radiation dose.

~55 to PSMA PET positive LN: Approximately 55 Gy of radiation is planned for the lymph nodes that were found to be positive on the PSMA PET scan. PSMA PET is a type of imaging used to detect prostate cancer.

70 Gy to prostate+SV: The prostate gland and the seminal vesicles (SV) will receive a radiation dose of 70 Gy. This is the primary target area for treating prostate cancer.

All delivered simultaneously using 28 fractions: The radiation doses mentioned above will be delivered all at once during each treatment session. This will be done over a course of 28 treatment sessions, called fractions.

Using daily CBCT: CBCT stands for Cone Beam Computed Tomography, a type of imaging used to guide radiation treatment. This means that before each treatment session, a CBCT scan will be done to ensure accurate delivery of radiation to the intended areas.

In simpler terms, your radiologist's notes outline a plan for radiation therapy to treat prostate cancer. Different doses of radiation will be delivered to different areas (pelvis, lymph nodes, prostate, seminal vesicles) over several treatment sessions, all monitored closely with daily imaging.

I'm pretty impressed with GPT. It is pretty handy.

[Jpburns in reply to Mike58]

That’s great! Thanks!

I do notice a typo, I think.

It says: “The radiation doses mentioned above will be delivered all at once during each treatment session.” I think it should have been: “… mentioned above WON’T be delivered…” since these are cumulative doses over the course of treatment, right?

If I got that dose all at once, my goose would literally be cooked.

AI needs some better copy editors.

[Mike58 in reply to Jpburns]

Yes you are correct. AI doesn’t always get it right 🤪

[Jpburns in reply to Mike58]

It’ll be interesting when AI starts generating treatment plans. Lots of roasted people. But maybe that’s their plan?

[Mike58 in reply to Jpburns]

Apparently, AI can learn from either its mistakes or its bad wording. So I put it to the test with the following -

ME: Your statement - "All delivered simultaneously using 28 fractions: The radiation doses mentioned above will be delivered all at once during each treatment session." is confusing and makes it sound like the combined radiation dose will be delivered all at once - can you reword this to be more correct?

ChatGPT's reply -

Apologies for the confusion. Let me clarify:

"All delivered simultaneously using 28 fractions" means that during each treatment session, the planned radiation doses for the pelvis, lymph nodes, prostate, and seminal vesicles will all be administered together. However, this delivery occurs over multiple treatment sessions, not all at once. Each session consists of a fraction of the total planned radiation dose.

So, a more accurate rewording would be:

"The planned radiation doses for the pelvis, lymph nodes, prostate, and seminal vesicles will be administered together in each treatment session, with a total of 28 treatment sessions scheduled."

I find the entire AI platform fascinating but there are times you do need to correct it. Every time we do that it is getting super smarter. look-out here comes "HAL from space odyssey 2001"

[Atlpapa in reply to Mike58]

I like the way TA broke it down because he mentioned an extra 20 to the prostate, whereas AI stated 50 to the pelvic area and 70 to the prostate. The prostate is in the pelvic area so it was confusing whether that was a double dose for 120.

[Mgtd]

Good luck with your radiation. I had a similar treatment plan. Eight months post procedure my PSA is not detectable. Life has returned to normal. I am on the 3 month plan for follow up. Every 3 months I alternate between the MO and RO and each monitors my PSA and blood work. They share information so I do not need to get multiple blood draws.

Go on a very light soluble diet and drink plenty of water prior to each session. The diet prescribed was given to me by the dietitian. Suggest keeping a box of Imodium on hand just in case.

Not sure how active you are but I left radiation and stopped at the gym for some resistance training and it made big difference in my fatigue factor. I did take a short nap in the afternoon for about 30 minutes or so.

[babychi]

The very best of outcomes to you. We are 6 years since EBRT. Follow advice here. Be kind to yourself. Rest, exercise and eat and drink what the RO team advises. Post treatment we gave up booze, started a new life based on nutrition and exercise and travel. See the world before you leave it is our motto. So far all as it should be.👍🏻💜