How important is the equipment age when looking at different SRT RO's?

I would think if the equipment is calibrated regularly it would be good. More important I believe would be in the protocols being used such as IGRT/IMRT, VMAT, etc., and a good experience RO and radiation team.

The faster the machine the better and the newer machines are faster and more accurate. My SRT was done using the Varian Edge.

Bobby Mac

JNF said...
I had IMRT seven years ago. They used an Electric machine that was a few years old at the time. Excellent results as my signature shows. Choose the excellence of the technicians not the machine. All it takes to own the latest and greatest machine is good credit.

When doing SRT or ART the speed of the machine is more important because bowels are constantly moving in the prostate bed. The faster the machine the better! Less chance of radiation hitting an unintended object. Plus the newer machines are much more accurate.

JNF had a prostate to help block the radiation from the bowels. You don't have a prostate for that protection.

Bobby Mac

As long as it's a VMAT (arc) linac, it will be plenty fast. As I recall, each arc lasted about 20 seconds for me, so not a lot of time for organ movement during each arc. A little bit of random motion won't matter - it will average out over the 35 or so low dose rate treatments. The experience of the RO is more important, and so is a full bladder to anchor everything in place and lift it away from the prostate bed; and, not proceeding with treatment that day if bowels are at all distended. Other important questions concern image guidance with cone-beam CT. Some ROs use soft tissue landmarks, some use fiducials/transponders, but what they should not use are bones.

Here are some questions to ask (adapt freely):

Questions for a Salvage Radiation Interview.

1. How many patients have you treated with adjuvant/salvage radiation?
2. How has your practice of salvage treatment changed, if at all?
3. What is the probability that I need salvage treatment? Do you calculate that from a nomogram?
4. Do you think I should get a Decipher test to find my probability of metastasis in the next 5/10years? Do you know if my insurance covers it? What do you think about their PORTOS score?
5. How large a dose do you propose for the prostate bed? (should be near 70 Gy)
6. Do I need pre-treatment, concurrent or adjuvant ADT?
a. Why? 
b. What's the evidence that it's useful?
c. For how long?
7. How do you decide whether to treat the pelvic lymph nodes? 
a. If so, at what dose? (50 Gy)
b. How do you plan to prevent bowel toxicity? 
c. How will you account for the separate movement of that area and the prostate bed?
8. What do you think of doing this in fewer treatments (hypofractionation)?
9. What kind of machine do you use? (e.g., RapidArc, Tomotherapy, Vero, etc.) Why do you prefer that one?
10. What is the actual treatment time for each treatment? (faster is better)
11. What kind of image guidance do you propose? fiducials in the prostate bed? Using the fixed bones only? Soft tissue?
12. How will inter- and intra-fractional motion be compensated for?
13. What measures do you propose to spare the bladder and rectum?​ (ask about treatment margins and dose constraints)
14. ​What side effects can I reasonably expect, and how do we handle them?​(discuss in detail!)
15. What probability of a cure can I reasonably expect, given my stats? Is there a nomogram you use to come up with that?
16. How will we monitor my progress afterwards, both oncological and quality of life?
17. What's the best way for us to communicate if I have a question or issue?

TA - thanks so much for the question list, I'll definitely use it.

Thanks for everyone else who responded, appreciate all your feedback / info on this.

I just had another uPSA test ... it's still ticking up... now 0.08 ... so I think I'm going to go forward quickly with SRT at this time... not sure about HT ...

PSA velocity (reg.slope) = 0.25 ng/ml per year

PSA doubling time = 0.2 years.



Zzarth