I am talking to two radiologists who have a strong difference of opinion. One radiologist tells me I should start ADT two months before I do the space OAR, markers and simulation, and then start the radiation. Another doctor tells me I should start the ADT at the same time as I do the space OAR and simulation and cat scan, which will precede the start of the radiation by maybe 2 weeks. My concern about the second doctor's protocol is that the ADT will shrink the prostate and the tumors. When the doctor does the simulation and mapping of the prostate gland and the lesions, it will subsequently contract in size, configuration and volume, even if only slightly, which may cause the radiation beams to be inaccurate and possibly damage healthy tissue or the bladder or rectum. When I ask the second doctor about this, he said that starting the ADT 2 months prior, or even a month prior, makes no difference and that there is no imperial evidence to suggest greater toxicity by starting the ADT at the same time as, or slightly after, the simulation. Does anybody have any thoughts out there before I dump the second doctor and go with someone else?
Proton Treatment - When to start the ... - Advanced Prostate...
Proton Treatment - When to start the ADT relative to simulation and CT of the prostate
Simulation is not what it sounds like. It's a CT scan to be used as a baseline map, for the RO, dosimetrist and radiation physicist to draw contours, and determine the amount of radiation. You will get tattoo dots on the side your hips where you were positioned when the CT was taken
They will do a computer simulation without you.
When doing the actual radiation, you will lay down and they will line up the tattoo dots to lasers, and get a CT immediately prior to treatment. The technician will use the that CT and adjust accordingly to the baseline CT to properly treat the prostate. If the prostate shrank, then they will adjust the treatment area.
In any case, the CT taken at the first treatment date will be verified by your RO, against the simulation before proceeding.
I agree with you completely!
Also, wouldn't it be better to give ADT a running start before RT?
Thats what Dr Cosmatos said to me!!
I just saw him today, coincidentally.
Thank you, Still in Shock. But I'm not sure that I understand. Are you saying that it doesn't matter if the prostate later shrinks after the simulation since the radiologist will recalibrate the beams every day that I do the radiation? Would it not be better for the prostate to shrink first, before the simulation, or it doesn't make a difference???
Also, when you say that I should give the ADT a running start before the radiation, do you mean, like, two weeks, or two months?
The question you raise is reasonable. When the second doctor says there is "no imperial evidence to suggest greater toxicity by starting the ADT at the same time as, or slightly after, the simulation" does he mean studies have been done on that issue that show that or that there haven't been any studies to show it does. I was on ADT first and the prostate reduced in size about 30%.
When you say your prostate shrank 30%, over what time period are you referring to?
A couple of months.
That's fast!
How did you determine that? CT scans? MRI?
I went back and checked. Pre-ADT prostate volume was 48 cm. Lupron started Oct. and a Dec. MRI showed a decrease to 39 cm. So, about 20%. However, I had HDR brachytherapy in Jan. so that may or may not have made a difference in the simulation. I'd be interested to know if HDR brachytherapy reduces or increases the prostate volume. Anybody know?
My team followed your first Drs recommendation. Starr ADT 2 months prior to RT.
In this article: ncbi.nlm.nih.gov/pmc/articl...
ADT is recommended to start 8 weeks before RT in all cases due to the evidence supporting synergy of RT and ADT.
My ADT started 8 weeks before my RT treatment which I am currently undergoing.
My 2 cents worth based upon my experience: my docs (uro, RO, and MO) recommended 2 mos ADT prior to IMRT and brachyboost and to continue ADT for a total of 9 mos. Brutal for me but that's another story. The protocol was based upon NCCN treatment guidelines that were in effect in 2018-19. I refer you to the NCCN for the latest SOC. Good luck to you.
EdinBaltimore
My husband was started on ADT shortly after learning he had Gleason 7 and was going to have to take action of some kind; it was when he met with the first (not final) RO. That first RO was the one who said, " I can give you standard SBRT, or you can explore other options, like Proton therapy - which is what I would do, if I were in your situation."
So, that first RO gavę my husband a Lupron shot, on August 13, and then my husband went to get 2nd, 3rd, 4th opinions.
The 3rd opinion was Proton treatment, which he was told would begin somewhere between months 2 and 3 of ADT, depending upon when they could schedule him in.
It began 2.5 months after his initial Lupron injection.
My prostate was 5x normal . I took ADT for several months prior to radiation (7 months) and by the time they did radiation, my prostate was normal size. The reasoning was that it would be easier for the radiation to kill the PCa cells as the target would be smaller. What I did not know is that the ADT after radiation was what counts for the optimal results so I took ADT for longer than I would normally have. See my profile for results.
I don’t think the timing of ADT matters as the fiducials are merely used to align your body on the IMRT table and the radiation tech then uses a predefined radiation mapping that delivers the appropriate dosage. I had HDT-BT/SpaceOar and four months of ADT before fiducials were placed for IMRT pelvic radiation.
Thanks, Timotur. My question is that, shouldn't the fiducials be placed, and the mapping of the prostate occur, after the prostate has shrunk from the ADT?? Or, does it not matter??
My other question is that my RT wants to start radiation 2 weeks after I start ADT. I understand that standard protocol is 2 months prior. My RT tells me that there is no evidence to suggest that 2 months is better than 2 weeks. Do you have any thoughts on this??
CB: definitely two months before to give ADT time to sensitize the PCa cells. (I started in April, had HDR-BT in June). See the link below...
In all cases, ADT should begin ~8 weeks prior to the start of prostate radiation, due to the evidence supporting synergy of RT and ADT.
ncbi.nlm.nih.gov/pmc/articl....
Actually, I believe the radiation mapping for my IMRT pelvic radiation was done with a separate MRI after the fiducials were put in. I believe the fiducials provide a consistent placement/alignment for RT but not a precise marker for the location of the prostate. It can be expected that the prostate would change size anyway during RT. The techs can see the prostate before each session-- they looked to see how full my bladder was before the treatment.
CBRD, I'm close to the same stage you are in treatment. I started ADT (Orgovyx) 3-weeks ago and have since been working to get my gel insertion scheduled. Regarding the spacing gel and ADT scheduling, I haven't read anything that says those are related. What's more certain is that ROs (at least my RO) want you to be on ADT for 2 to 3 months before initiating EBRT. It wouldn't matter if I'd been on it a year, just that it starts 2-3 months ahead of EBRT. As she explained it, lowering your testosterone begins to weaken the cancer cells, making them even more vulnerable to radiation. Yes, it also shrinks the tumors and that may wind up helping to concentrate the radiation, improving its effectiveness. Regarding its timing with the spacing gel procedure, my RO wants to start radiation within a month following. Within that time, the RO must schedule the test shoot and get the target tatoos locked in.
My problem is trying to get the spacing gel procedure scheduled this month because I learned today the urologist forgot to tell his staff and has now left for Tanzania. So my whole schedule may be out the window. Good luck with your scheduling.
My Dad was just diagnosed with Gleason 10, stage 4 PC with mets to spine. He starts ADT tomorrow and radiation oncologist said he needs to start ADT at the very least one month prior to beginning radiation. This is in Toronto, Canada.
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