SRT Namogram & Rads of Radiation question

Hawk · Experienced user Joined: 22 Nov 2006 Posts: 56

Here is a namogram on Memorial Slone-Ketting' Cancer Center's (MSKCC)site for determining ones odds with SRT. http://www.mskcc.org/mskcc/html/10088.cfm
Clink on "Open Calculator" in the top right area of the page.

I do not have the missing piece of data for Rads of radiation so I guessed at a range of numbers. Seems I have heard a term of Gray which I guess is 100 Rad.

Strangely, MSKCC doctors have recommended SRT for me but I only get about a 2% cancer free chance on this namogram. Either I am doing something wrong or my case is so hopeless it is humorous. (We find humor where we can) Smile

What is the "typical" rads of radiation given for SRT?
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History: PSA's 6.7 neg. biopsy - PSA 16.6 neg. biopsy - PSA's 8.2 - 8.1 - 8.7 Biopsy. 4+4 Gleason 8. Lap RP Apr 2004, age 52 All neg margins, nodes, and structures. (T2a). Post RP PSA: every 6 mo. <.1 until Feb, 08 (46 mos) PSA .1 - I then got sensitive tests (all in 2008) showing:
Feb .06 - May .09 - Jun .10 - Aug .10

Replicant · Moderator Joined: 01 Nov 2006 Posts: 244

A fairly "normal" dose these days is 70.2 Gy (commonly referred to as "grays") which is 7020 in rads.
Your mileage may vary, of course. Smile

Try putting in a number like 7020 into the nomogram.
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Replicant

Dx Feb 2006, PSA 9 @age 43
RRP Apr 2006 - Gleason 3+4, T3a, N0M0, pos margins
PSA 5/06 <0.1, 8/06 0.2, 12/06 0.6, 1/07 0.7.
Salvage radiation (IMRT) total dose 70.2 Gy, Jan-Mar 2007@ age 44
PSA 6/07 0.1, 9/07 <0.1, 12/07 <0.1, 4/08 <0.1, 11/08 <0.1
http://pcabefore50.blogspot.com

Hawk · Experienced user Joined: 22 Nov 2006 Posts: 56

Well that gives me a 35% chance of cancer free in 6 years but there are a few wording problems on this namogram.

It defines "Elevated POST RP PSA" as : the PSA BEFORE RP (I think it should say before SRT)

They then express the results for being cancer free X years after surgery (I think this should say after SRT.)

Hard to believe they don't clean this up, or maybe I am stupid and mis-reading it.
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History: PSA's 6.7 neg. biopsy - PSA 16.6 neg. biopsy - PSA's 8.2 - 8.1 - 8.7 Biopsy. 4+4 Gleason 8. Lap RP Apr 2004, age 52 All neg margins, nodes, and structures. (T2a). Post RP PSA: every 6 mo. <.1 until Feb, 08 (46 mos) PSA .1 - I then got sensitive tests (all in 2008) showing:
Feb .06 - May .09 - Jun .10 - Aug .10

Replicant · Moderator Joined: 01 Nov 2006 Posts: 244

I've emailed both MSK and Dr. Stephenson, about that wording. Also, the results seem a little pessimistic in the online nomogram compared to the pen and paper nomogram as presented in the journal article.
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Replicant

Dx Feb 2006, PSA 9 @age 43
RRP Apr 2006 - Gleason 3+4, T3a, N0M0, pos margins
PSA 5/06 <0.1, 8/06 0.2, 12/06 0.6, 1/07 0.7.
Salvage radiation (IMRT) total dose 70.2 Gy, Jan-Mar 2007@ age 44
PSA 6/07 0.1, 9/07 <0.1, 12/07 <0.1, 4/08 <0.1, 11/08 <0.1
http://pcabefore50.blogspot.com

Hawk · Experienced user Joined: 22 Nov 2006 Posts: 56

OK, I played with this namogram and found some interesting yet confusing variables. First, you get the most optimistic outlook with 6500 rads of radiation. Anything above or below this starts to incrementally reduce the odds of being cancer free in 6 years. Could one presume that more radiation would cause a secondary cancer and that is built into the calculation or are they suggesting a higher dose reduces the chance of killing the prostate cancer Confused

Interestingly my local Radiation Oncologist just today said he delivers 6480 rads which is almost imperceptibly below the optimal according to this namogram.

Even more confusing is the time from surgery until your PSA hits .2 (mine is still at .1 so I have to play with that piece of data)

Everything I have read suggests the longer to bio-failure the greater the likelihood of a local recurrence. Strangely however, beginning with a recurrence, of 1 month, the more you extend the time to recurrence the worse the prognosis for SRT. Go figure. I guess I should try to accelerate my PSA rise rather than slow it. Once more I am Confused

bewildered.

PS: I wonder if the methodology or logic of this namogram is explained anywhere in terms that a lay person can digest.

PS: (With the 6500 rads I climbed another 10% to 45% cancer free in 6 years if anyone can put any faith in this namogram)
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History: PSA's 6.7 neg. biopsy - PSA 16.6 neg. biopsy - PSA's 8.2 - 8.1 - 8.7 Biopsy. 4+4 Gleason 8. Lap RP Apr 2004, age 52 All neg margins, nodes, and structures. (T2a). Post RP PSA: every 6 mo. <.1 until Feb, 08 (46 mos) PSA .1 - I then got sensitive tests (all in 2008) showing:
Feb .06 - May .09 - Jun .10 - Aug .10

Replicant · Moderator Joined: 01 Nov 2006 Posts: 244

http://www.prostatecenter.com/Tools/ASCOMultDiscipliniary.pdf

On slide 4 is the paper nomogram that is the source of the one at the Memorial Sloan Kettering site. The paper version makes more sense to me, as I have elaborated in my blog.

The slide is entitled "Nomogram Predicting 6-Year Progression-
Free Probability after Salvage Radiotherapy"

You can print out the slide (enlarging it if needed) and go through it fairly easily.

Predictions in prostate cancer are pretty rough. When a man is referred to salvage radiation, he generally has about a 50/50 chance of a "durable response". It's hard to say "cure", because you have to follow the man for decades--and in the meantime, radiation technology and techniques improve rapidly compared to what the man had.

In my case, I wanted to know where I lay in the broad spectrum of probabilities, and the nomogram helped me in that regard.

It's key to remember the maxim of "garbage in, garbage out." When I first looked at this nomogram, in a 2004 version, I saw that my chances of success were not good. However, I had bad information! My uro told me I had negative margins.

Now usually, negative margins are good to have. But when you're trying to decide if your recurrence is local, and therefore treatable by SRT, it's better to have positive margins, since they provide a local explanation for elevated PSA.

So I go into the radiation oncologist, head hanging low. He reads the cover note from my uro. "Negative margins." I nod. Then he opens the folder. "Wait a minute. You have POSITIVE margins." And he showed me. I felt like a huge load had been lifted off my shoulders. My uro had somehow gotten it into his head that I had negative margins, and had even written a post-it to that effect.

(I don't want to make it seem like surgical margins are the only relevant factor in predicting success of SRT. If you look at the nomogram you'll see there are several.)

It was still a roll of the dice, but at least the odds seemed slightly in my favor rather than heavily against.

The gamble SEEMS to have paid off. I won't say "cured" for many years, since I'm not even to the median point where most men have failed SRT (18 months to 2 years). But when I get to 5 years, I'm going to throw a little party. And another at 10. And at 15, I might start to say "salvage radiation cured me."

I'll have another PSA just before Thanksgiving. And another DRE. I wish the oncologist would drop the DRE, but he says he wouldn't be doing his job if he didn't examine his patient. What the heck. I've had so many it's getting to be about as routine as "open up and say ah."

I'm rambling. I'll stop now!
_________________
Replicant

Dx Feb 2006, PSA 9 @age 43
RRP Apr 2006 - Gleason 3+4, T3a, N0M0, pos margins
PSA 5/06 <0.1, 8/06 0.2, 12/06 0.6, 1/07 0.7.
Salvage radiation (IMRT) total dose 70.2 Gy, Jan-Mar 2007@ age 44
PSA 6/07 0.1, 9/07 <0.1, 12/07 <0.1, 4/08 <0.1, 11/08 <0.1
http://pcabefore50.blogspot.com

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