Why choose standard radiation over SBRT

First, SBRT has about (I think) an 11-12 year track record, it’s a newer technology. For some, that’s not enough. Personally, when I was diagnosed it had a 7 year history which wasn’t enough for me. If it was now, I’d choose it.
Second, for higher Gleason grades, I believe, and someone will correct me if I am wrong, it has not proven to be as effective as it is with G6 and low G7(3+4)

Other than that, to me it would be a no brainer.

All prior comments are on target. Let me just point out that EBRT can also be done at higher intensity with fewer sessions. There are studies to 'prove' this concept.
Not as lucrative to the medical world...

SBRT can be performed on most every, if not all, linac machines that performs IMRT. It is not special technology.

The question is extremely valid. For most men considering mono-therapy IMRT, I would certainly suggest SBRT. But I would also suggest considering HDR Brachytherapy. A much longer track record (from 1981) and likely one and done as to the number of procedures.

I like the seed idea (if that is what HDR is) more then SBRT but doctor said my prostate is to big.

My experience this time around was based on the ORIOLE study.

I first got an axumin PET scan that showed I had 3 mets in my pelvis - cancerous lymph nodes 1.2, 1.3 and 1.4 cm in diameter. These are/were 3 soft tissue mets in close proximity to each other and all near the original tumor site. As that area had not been radiated during my initial radiation treatments 8 years ago they were fair game for a good whack.

I first got an MRI and CAT scan to precisely locate and map out their locations and size in 3-D. The RO wrote a program for the radiation delivery. An Intensity Modulated X-Ray machine with a LINAC accelerator in the gantry arm was the delivery device. This time around I looked at everything, questioned everyone concerned and studied up on the whole setup and delivery. That included a good hard look-see and go-over of the power source in the back room behind the gantry setup and a detailed examination of the gantry head modulator assembly. (Yes, I was a bit of a nuisance.)

The whole process ran 6 weeks, just ended Thursday last week. For the first month or so I got a relatively low dose of X-Rays over all of my pelvic lymph nodes - salvage radiation therapy. The last week and a half I got a serious 'spot' treatment of those 3 mets - IMRT. How do I know? I watched and listened to the machine as it did its thing around my body on the table. The gantry head did not pause in its output and hovered over 3 areas of my pelvic assembly instead of running a continuous route with a lower intermittent output as it had been previously. I got 2 new tattoos that were under 2 clear plastic stickers with big cross-hairs on them in Sharpie. The operators also used the 4 tattoos from my original radiation treatments. Every session started with a CAT scan to assure correct placement.

Side effects thus far are a skanky feeling in my guts and stomach and some diarrhea. My appetite is a bit off and I have some bladder discomfort as well as some serious fatigue. The RO warned me that my small intestine would get some side-scatter as would the top of my bladder. He stressed these would be minor and short-lived however. I stayed on the Eligard + Xtandi chems throughout and will remain on those for the rest of this year. I get to quit them Jan 1, 2022. Then it will be a continuation of those 3 month blood tests for at least 3 years to watch the PSA as the chems wear off. Since it will have been about 2 years and 2 months on them, it will likely be about 2 years and 2 months after I quit them to see of this treatment has worked. That puts me out to early 2025 though, a good kick of the can down the road if nothing else and a "cure" if this has worked.

62gal said...
I like the seed idea (if that is what HDR is) more then SBRT but doctor said my prostate is to big.

As JNF pointed out, HDR Brachy doesn't leave seeds in like LDR Brachy does and may be better suited to larger prostates. But...if you are really interested in LDR Brachy...the prostate can be shrunk to accommodate the procedure. And LDR Brachy, when performed on a suitable patients, is pretty much the least invasive option available with generally minimal side effects. When and if you need treatment you probably should speak to experts in LDR Brachy, HDR Brachy and SBRT so you are well educated on your options. And, to your original point, the long process of IMRT would be after those other three options for me..

Jim

Thanks everyone for your info. Hopefully I will never need it. But if I was a young man surgery would be the way I would go.

Two points about SBRT.

1) If your PCa should be turn out to be high-risk. From

Stereotactic Body Radiotherapy for High-Risk Prostate Cancer: A Systematic Review (2021)

"Conclusion: At this point, SBRT with or without pelvic ENI cannot be considered the standard of care in HR PCA, due to missing level 1 evidence. Treatment may be offered to selected patients at specialized centers with access to high-precision RT. While concomitant ADT is the current standard of care, the necessary duration of ADT in combination with SBRT remains unclear. Ideally, all eligible patients should be enrolled in clinical trials."

[Emphasis mine; ENI = elective nodal irradiation]

2) For all risk groups: See this MSK study: Predictors for Post-treatment Biopsy Outcomes after Prostate Stereotactic Body Radiotherapy (2021)

that I also posted in a separate thread with evidence that the current standard dosages used in SBRT may not be enough for oncological control.

"SBRT dose levels of 35–37.5 Gy of SBRT were associated with a higher likelihood of a positive post-treatment biopsy at 2 years.

Conclusion
Based on two-year post-SBRT biopsies, excellent tumor control was achieved when dose levels of 40 Gy or higher were used. Standard SBRT dose levels of 35–37.5 Gy were associated with a higher likelihood of a positive post-treatment biopsy. Two-year positive post-treatment biopsies pre-dated the development of PSA failure in the majority of patients."

[Emphasis mine]

Djin