SRT-- how many GY (for those who did SRT)

I may have asked this before. I just saw the radiation oncologist.

He said I would be getting 68.4 GY.

Two questions:

1) How much GY did you get?

2) Was it determined (the amount) after he did the measurements or before.

Mel

I had 70.2 Gy over 38 sessions. I'm not sure at what point the dosage was determined.

I go back to see the radiation doctor next week. It's been nearly 5 years since diagnosis and surgery, and 4 years since RT now for me. I'll probably have a blood draw tomorrow.

68 Gy for mine.
I do not know if or what he measured but he did the CT scans and worked up a plan and told me it would be 68.
I am at 2 yrs post SRT and just had another <0.04
YEA!

good luck
David

b

Here is some interesting information, from :

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2848745/

This is an interesting, extensive article. Some quotes:



"Optimal radiation dose required for patients with post-RP PSA relapse remains unknown. Most published studies used a radiation dose <70 Gy for salvage RT, due to the concern for radiation morbidity. It is plausible that a higher radiation dose may yield better treatment outcome. King suggested a dose-response relationship in salvage RT setting (85). He estimated that 66.8 Gy would give a 50% chance of achieving PSA relapse-free rate at 5 years and that the proportional gain in PSA relapse-free rate would be 3.8% per additional Gray within the steep part of the tumor control probability curve. Bernard (86) and King (76) described in their retrospective series that a higher radiation dose was associated with improved PSA relapse-free rates. In recent years, the adaptation of more sophisticated techniques in radiation delivery such as intensity-modulated radiotherapy has allowed escalating radiation dose to the target, while minimizing toxicity to the surrounding normal tissues. De Meerleer recently reported, using intensity-modulated radiotherapy, that a dose of 75 Gy could be delivered with a low risk of serious acute and late radiation toxicity in a salvage RT setting (67)."

"For salvage RT, further study is needed to address optimal radiation dose required for patients with PSA relapse. In parallel, more advanced techniques in radiation simulation and delivery need to be explored in order to minimize radiation toxicity to the surrounding normal tissues, while escalating radiation dose to the target. Another unresolved question is whether regional pelvic nodes should be irradiated along with the prostate bed, and the current RTOG 0534 study is addressing this question"

Mel

Mel,  My radiologist is using 68.4 Gy just like you.  He based my treatment on my pathology and surgical report.  The 68.4 is based on a Dana Farber Harvard Cancer Center standard treatment protocol.  He would not deviate from that protocol unless there were some underlying condition.  I am about halfway through with my treatment and have not had any SEs yet.  My equip. is just like yours and Fairwinds. 

Carlos

So Fairwind, you are undergoing a full 80 gys? They backed me down from 80 to the 72, and they used the same logic, since I had BCR so fast after surgery, they wanted to got at it like there hadn't been a surgery.

Fairwind -- along with the lupron that's pretty aggressive treatment.  how are you feeling man?

ed

 

I had 66.6 over 37 sessions. 1.8 per.

At the initial consult, I was told it may be around 66 gys and 34-35 sessions...

After my scans and such and after they determined the programming, they told me 64 gys, 32 sessions of 2 gys each, and to come in with a full/nearly full bladder.

pasayten

I had 66 Gy over 33 sessions.
When I asked why those numbers, they said that 66Gy was the standard treatment plan according to their protocols for someone in my position. I assume they have some sort of mathematical model and entered my data about post-op PSA Gleason score and pathology (eg SVI) quantity and location of tumour, and the post-op PSA record and velocity that revealed the BCR.

From the way they spoke of how they had worked out how to give "just enough, but not too much" I was left with the impression that years ago they used to give a higher dose.

I assume that radiologists have been aware that with many other types of cancers the patient is not surviving for as many years after initial treatment the way PCa guys do (and breast cancer too).
ie put bluntly I'm guessing that if you die of say lung cancer 3 years after high dose RT it is not relevant that the high dose you received might have caused another cancer had you lived for another 10/15 years, whereas if after my RT I could live for another 20 years it would be a bit unfortuante to develop another cancer after 10 years becasue they gave me too much RT. But equally I don't want the PCa to come back after only 5 years becasue they didn't give me enough. So I'm assuming they have worked out their protocols on the basis of the guys who "went before".

Alf

Great information in a very recent study by DA Kuban et al at MD Anderson released in 2010 that showed EBRT at 78Gy as better than 70Gy. You can read the study at the Prostate Cancer Info Link and at the NIH site. Probably the MD Anderson site would also have it.

I recollect that I received 78 Gy for the EBRT delivered by IMRT. As I was feeling very good throughout I asked my rad-onc why don't we do a few more. He was very clear that over 78Gy significantly increased side effects. While some get as many as 80Gy they also report much worse side effects. He also sited studies that indicated 78Gy as superior to lesser doses and that today's more modern machines (IMRT and IGRT) allows a greater sode than in the past without worse side effects and considered it as the optimal dose for me.

JNF, your post is helping make a point for me. I heard a lot about using a min. of 70 gys with IMRT to give the best possible cure rate. No one I talked to in advance, reccomended less than that.