SBRT v. Brachytherapy for Favorable Intermediate Risk

[StrongFives]

Hi. I'm new here. Appreciate the intelligent and supportive comments. I'm 56 yrs old, diagnosed 5 months ago with Gleason 3+4, 2/10 cores positive, MRI showed no focal tumor, PSA has dropped from 6.0 to 4.5. RO recommends AS. Is that Ok? If I treat, is SBRT as good as brachytherapy? RO says healthy tissues (urethra) get more radiation with SBRT. I know TallAllen likes SBRT. Why is it superior to brachytherapy, other than less invasive? Thanks.

[Tall_Allen]

Whether or not you're a good candidate for AS depends on some info you haven't provided. When one gets a second opinion from Epstein on the biopsy cores (which is a good idea), he will tell you the percent of the cancer in those two cores that is pattern 4. (note: this is different from the % of the core that is cancerous) If it is 40% pattern 4, you are not a good candidate for AS. If it is 5% pattern 4, you may be a good candidate. If it is something you're interested in, you may also want to look at a genomic analysis of the biopsy core (either Oncotype Dx, Prolaris, or Decipher).

Actually, I think your RO is wrong about the urethral dose - it's higher with brachytherapy - I've seen dose-volume histograms for both. The problem with ROs is that none has expertise outside of his own specialty (unless he routinely does both - which is rare).

I don't think SBRT is superior to brachytherapy monotherapy in terms of oncological results for favorable intermediate risk men in the hands of equally expert practitioners. Very similar results:

pcnrv.blogspot.com/2018/10/...

There may be some advantage to SBRT in terms of side effects:

pcnrv.blogspot.com/2016/08/...

I think high dose rate (HDR) brachytherapy may be superior to low dose rate (LDR) brachytherapy, but there has never been a prospective randomized comparison, only a retrospective study.

In my case, it came down to SBRT vs HDR brachytherapy. I had access to THE experts in both. I finally decided on SBRT on the basis of convenience and cost. It was much simpler for me to lie down on a bench 5 times for ten minutes. It is also completely non-invasive (except for the fiducials), no catheters, no anesthesia, no recovery time - as close to a cake walk as it gets.

If you have only 2 positive cores, you may be a candidate for focal ablation. I think there are too many unanswered questions right now. It is experimental and costly, but some guys prefer it.

[Gardenpests]

Agree with Tall_Allen with obtaining a 2nd opinion from Epstein. The process is quick and about $300.

My 3+4 was downgraded by Epstein to 3+3 which reclassified me as 'low risk' and provided me with a higher margin of comfort for continuing AS.

[curtisbirch]

I’m glad to get this question because I really struggled over it when I did my research and interviewed the top doctor at UCLA for HDR brachy and the top doctor for SBRT, also at UCLA. In fact, the latter is the man who invented HDR SBRT for prostrate cancer while he was at Stanford. He told me both were equal. I believed him, although the studies I read made it seem like he was being modest or not trying to sway me. This further confused me.

But if you want to compare head to head, you don’t have the 10 year studies to back up the results for SBRT. But the studies that are coming out on this treatment are super convincing. Not to mention Tall Alan, known for being highly active here, had great results with SBRT using this same doctor at UCLA. I really wanted a less intrusive treatment, because I was traumatized by the biopsy.

In other words, I thought I was leaning towards SBRT. But in the end I had an oncologist tell me simply that why would I want to send the radiation through my body when I could apply it in two short treatments with micro precision and computer mapping right on the spot? Being 50, I was worried about ED and quality of life.

I continued to struggle trying to make a choice—researching different studies to attempt to determine which treatment would be more effective with the least possible side effects. Even after my due diligence, I really didn’t see myself doing HDR brachytherapy. Even though it somehow felt more of a known quantity.

HDR brachytherapy probably felt more solid because this particular specialist, Dr Dimanes, had been treating patients this way for over 20 years and had success rates higher than the rest. Success rates on intermediate risk patients that were so high, it didn’t seem possible.

Still, in the end, It came down to how convinced I felt when interviewing both these doctors and hearing their analyses of my biopsy, second opinion on biopsy and my 3t MRI.

This is why most everyone here on this forum — whether they had RP, beam or brachy therapy — will tell you to take your time do your research then meet the doctors.

Once you are at the point you are at now where you can’t make up your mind, go in and ask as many questions possible of the doctors and try to listen to your gut. In the end the answer will come to you and it will be the right one.

I had more than 60 % of my cores showing 3+3 (not to mention a fraction of 3+4 that showed on the biopsy second opinion). This made certain doctors put me in a high risk intermediate category. Those doctors were suggesting dual treatments that just seemed out of the question of a 50 yr old concerned with quality of life. That checked another box for me as to why HDR brachy monotherapy might be the way to go. Monotherapy whether it’s LDR or HDR brachytherapy can be proven, through convincing studies, to outperform dual treatment for my risk level.

In the end, there really was no choice for me but to go with HDR brachy. I ended up going to a student of Dr Dimanes who works through my health plan, Kaiser Santa Clara, called Dr. Wang. I would highly recommend him. The treatment was very easy when i think of the biopsy. The catheters used for the treatment are highly un-intrusive and I have seen no side effects a year and a few months out of treatment.

You, showing a smaller quantity at 20%, and also being a potential watchful waiting candidate, might feel very confident with SBRT as the way to go. I have no doubt it could be a great treatment for you like HDR brachy was for me. Ask Tall Alan how it went for him. But if you really want to know the answer, I would seriously consider both of these treatments all the way to the bitter end. Then after going through your own process, decide on the one that feels right for you.

Also if you haven’t done it already, get the second opinion on your biopsy from Johns Hopkins and have a 3t MRI done. I’ll give you a doctor’s name out of Cornell Weil imaging who should read your MRI for you. You need to have the right doctor reading your MRI to make sure it is used the right way in your treatment plan.

Best of luck —let us know where you end up and how it goes!

[Ant_Imony]

I was in a similar class of cancer gleason 3+4, 2c and considered SBRT / Cyber knife as the results are very good. However as I am 52 - two separate oncologists put me off it due to distant radiation cancer risks. SBRT is very effective - but does increase risk of long range cancers.

Therefore I went with LDR Brachy - the local unit does real time placement - and their biochem control results for intermediate grade cancers at 6 years were 95% so up with SBRT. I understand HDR also gets very good results.

[rocketman42]

I had a 3+4 and decided to go with SBRT at MSKCC and have had good results with minimal side effects. Not sure where you're located but if you are near NYC then I would urge to see Dr. Michael Zelefsky at MSKCC...he is terrific and is well renowned for both Brachy and SBRT.

Good luck.

[OldTiredSailor]

I have a basic question about radiation therapy that you very experienced men might help me with. A year ago I chose RALP due to what my very experienced medical oncologist/retired open RP surgeon felt were "several puzzling inconsistencies" in my 12-core TRUS biopsy and my 3T mpMRI results.

My MRI was PIRADS 3 was only "Equivocal" with an "subtle area of T2 signal hypointensity"

The post-surgery pathology report showed my G7 (3+4) was bi-lateral at the apex rather than ONLY in the left lobe as indicated by both the biopsy and the MRI.

Additionally, the G7 tumor was 7 cc NOT the 0.35cc identified by the MRI and the TRUS imaging during the biopsy. (Tumor was 20 times the diagnosed size!)

And, there was a focal 2mm G6 extraprostatic extension despite the MRI clearly showing there was NO EPE.

And finally, my prostate was 37 cc NOT the 18 cc size specifically described by both the biopsy and the MRI.

IF - I had chosen radiation therapy as my primary treatment - would those discrepancies in size and location have led to an ineffective RT treatment plan?

Can any of the RT treatments compensate for not really knowing the size and location of the tumor tissue?

[Tall_Allen]

I just wanted to correct some misconceptions in a few posts, seemingly caused by consulting with medical oncologists for localized PC, which I think is a bad idea. It is not their field and they know less about it than I do, and certainly less than expert practitioners.

The misconception is the exposure of outside tissues to radiation from HDR brachytherapy (HDR-BT) vs SBRT. They are much the same. Whether radiation starts from the inside out or the outside in, it still hits other tissues. When the ROs treat patients with HDR-BT, they insert the radioactive Ir-192 robotically from a shielded room because the radiation penetrates outward. With SBRT, the beams originate from multiple directions, and it is only where the beams converge (remember Ghostbusters?) that there is enough dose to affect tissue. I sometimes tell patients to draw an asterisk with 6 lines; if you draw it starting at the center with 6 lines outward, or if you draw 6 lines meeting at the center, the asterisk looks exactly the same. In fact, when Dr King first used SBRT for prostate cancer in 2003, he modeled it on the dosimetry of HDR-BT. (There are differences in dose homogeneity.) Both SBRT and HDR-BT are planned with small margins of a few millimeters outside of the prostate, and they both have sub-mm accuracy.

Now, LDR-BT is a little different. The radiation is shorter range and the same degree of shielding is not required. However, the radiation decays slowly and during that time it is a constant source of irritation to nearby tissues, especially the urethra. It is because it is so short range, that it cannot be used as a monotherapy (as SBRT or HDR-BT can) for unfavorable risk PC when there is significant risk of penetration outside of the prostate - LDR-BT does not curatively treat any margin outside the prostate.

So none of these spare organs at risk completely, but they are all pretty good.

I also do not buy into any age limits for any radiation therapy (or AS, for that matter).

[Adf2529 in reply to Tall_Allen]

Thanks.

[Ant_Imony in reply to Tall_Allen]

Hi Tall Allen - can you please explain why you dont buy the age limits for radiation if there are other options. I am merely saying what 2 different consultants in the UK told me. I investigated studies into this and there is an increased risk of distant cancers. Happy if you have evidence otherwise. As i say - I would have gone with SBRT otherwise. Thx

[Tall_Allen in reply to Ant_Imony]

It is true that the risk of a second primary cancer increases as a percent, but the absolute risk is nonetheless minuscule. Read this:

pcnrv.blogspot.com/2016/08/...

As you can see, the real risk is on the order of 7 in a thousand, if that. With SBRT or IMRT, it's probably even less because of the sub-mm accuracy. Here's a discussion on how the radiation technique affects the risk:

pcnrv.blogspot.com/2016/08/...

The absolute risk is probably comparable to the risk that surgery will spread the cancer.

[curtisbirch]

I think it's a good point that you bring up about SBRT being so targeted based on the nature of the beam reaching it's full potential when it hits its target. Why I was so close to choosing this treatment. One of the cool things about it is that there actually is a target inserted into the area before treatment. Dr. King, out of UCLA, invented SBRT using HDR dosimetry while at Stanford and is someone you can believe in when he explains exactly how it works in person, much as its explained above. It was a huge thing for me that King wasn't confident with SBRT HDR as a mono treatment for my quantity of cancer --6 or 7 cores out of 12 (3+3 Gleason that was upgraded to 3+4 after Epstein gave me a second opinion on my biopsy and found 2-5% of Gleason 4 in two of the cores). I think later down the road they will have more research to support SBRT as a mono treatment for someone like me. However, King wanted me to also take six months of ADT along with SBRT. There was also uncertainty at that time about my MRI, 2which give some doctors concern about extra capsular extension (that would be later attributed to camera shake by Dr. Margoles out of Cornell Weil imaging, who I highly recommend for anyone who has concerns about their MRI).

On the other end of the spectrum from King, and other doctors who felt adamant about dual therapy for me, was Dr Dimanes, a HDR brachy mono therapy specialist also out of UCLA. Dimanes was very certain, based on the hour plus he spent giving me an ultra sound, and other examinations, that I was a middle of the road intermediate risk and HDR brachy mono therapy was an ideal fit. He also had decades of experience and had won awards for his diagnostics. Not to mention, crazy high success rates using HDR brachy mono therapy for all type of intermediate risk patients.

My gut told me HDR brachy was the right approach for me but I was not thrilled by the idea of the treatment's invasiveness. In the end, I couldn't ignore that I felt more confident going that way. Not to mention, it would be two short treatments instead of five+ with SBRT. I also did like the idea of a localized treatment rather than beaming something through my body. But like it's been said, there may be no risk with SBRT causing more collateral damage to healthy tissue than HDR brachy. So do your research and make sure you are comfortable with what you find and the kinds of answers the doctors give you.

It's interesting to note that Dr. King was the first doctor to tell me that RP, HDR brachy and SBRT (with HDR dosimetry) were all equally effective treatments. When you look at it that way, it really comes down to which one you are more comfortable with after going through the long, soul searching process of researching, interviewing doctors and listening to your gut. I do believe for 50 year olds who are concerned with ED there is good logic as to why you could believe you have far better odds with RT vs. RP. As I mentioned, King explained how ED medications could be used to help keep blood flowing through that area as a preventative treatment. My doctor who ended up doing my HDR brachy treatment, Dr. Wang out of Kaiser Santa Clara,, also supported that approach along with keeping sexually active. I subscribed wholeheartedly to that plan -- Why not, right? : ) -- and I believe it helped tremendously. I have not had any side effects and I'm 14-15 months out of treatment. I also remember, after getting finished with my final treatment, thinking that I couldn't believe how non-invasive the whole process had been. In the end, I couldn't have imagined going through surgery, which brings a far higher risk of serious side effects, to get essentially the same results.

[Bigmls7890 in reply to curtisbirch]

What about your ejaculate and seminal fluid levels

[Bigmls7890 in reply to curtisbirch]

Do you have any retrograde ejaculation or painful orgasm?