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Questions from Friday's meeting about the new STAMPEDE trial results

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Jim Marshall (not a doctor) said ...

During last Friday's phone-in meeting we discussed the latest finding from the STAMPEDE trial. Basically, men diagnosed with a few mets lived longer if they started radiotherapy at the time they started hormone therapy (ADT).

Our posting on this, including links to the published paper and a news article is here:

 

Two questions arose at the meeting:

Was the radiotherapy to the prostate or to the mets?

Would stereotactic radiotherapy be used?

 

The answers seem to be:

The radiotherapy was to the prostate (using high energy X-rays).

 

Stereotactic radiotherapy is used when very precise control is needed - head, neck and near the spine.

Stereotactic radiation was not used in this trial. At the meeting we spoke of the benefit of ordinary radiotherapy 'spilling' a little around the prostate, perhaps getting cells beginning to migrate away from the prostate.

Indeed, if you look at the extract from the paper below, you will see that it specified the amount of spread - 8mm at the rear of the prostate, 10mm elsewhere.

Radiotherapy was offered as every weekday for 4 weeks, or a higher dose one day a week for 6 weeks. It is known from other research that more, smaller doses of radiation are equivalent to fewer higher doses in effect. There is, however, a slight increase in side effects with the larger (hypofractionated) treatments.

 

... end Jim

 

"External­-beam radiotherapy to the prostate was given as one of two schedules nominated before randomisation: either 36 Gy in six consecutive weekly fractions of 6 Gy, or 55 Gy in 20 daily fractions of 2·75 Gy over 4 weeks. Radiotherapy was given with the patient supine and with a full bladder and an empty rectum. The planning target volume consisted of the prostate only, with an 8 mm margin posteriorly and a 10 mm margin elsewhere. 

Radiotherapy was to commence as soon as practicable after randomisation, and within 3–4 weeks after the last docetaxel dose."

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Charles (Chuck) Maack

SBRT (Stereotactic Body Radiation Therapy)

Compiled by Charles (Chuck) Maack – Prostate Cancer Continuing Patient, Activist, Mentor

 

This paper from the U.S. National Institute of Health October 2017 provides a pretty thorough explanation of outcomes from stereotactic body radiotherapy (SBRT):

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638714/

 

Its conclusion states: “Initial studies examining the use of SBRT in the treatment of prostate cancer have demonstrated impressive rates of biochemical recurrence-free survival and PSA response, while maintaining a relatively favorable acute toxicity profile. Doses of 8 Gy or less per fraction have lower reported rates of toxicity with similar biochemical control rates compared to higher doses per fraction. Though we are cautiously optimistic that SBRT has the potential to serve as an alternative to conventionally fractionated RT in the treatment of prostate cancer, long-term follow-up is needed in order to evaluate whether biochemical control, overall survival, and late toxicity are maintained, or improved, as compared to the current standard of care.”

 

Of toxicities mentioned, it appeared one of the primary concerns were those to the rectal wall.  With the availability now of the SpaceOAR System – a prostate-rectum hydrogel spacer application that has been determined is a relatively safe technical procedure that is well tolerated and has a high technical success rate and significantly reduces rectal radiation dose and results in long-term reductions in rectal toxicity, as well as improvements in bowel, urinary, and sexual QOL – it would appear that problem with SBRT can be avoided. See:

https://www.sciencedirect.com/science/article/pii/S009042951731213X

The conclusion in this paper reads: “These clinical trial results demonstrate that the prostate-rectum spacer application technique is safe and well tolerated, and that the space created significantly

reduces rectal injury during radiation therapy, leading to long-term clinical benefits. We believe that urologists treating newly diagnosed patients with prostate cancer appropriate for radiation therapy are well suited to perform this spacing procedure. A clinically significant reduction in radiation therapy complication rates should lead to improved patient outcomes, reduced toxicity concerns, and hopefully overall cost reductions.”

 

Urinary toxicity was also a concern, and one report above suggests catheterization during treatment may be advisable.

 

 

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Patrick Turner

I had a very swollen PG about 3 times normal volume at the time of attempted open RP in April 2010.

The cancer had come out of capsule, and docs could not proceed lest they cut away too many nerves that were obscurred from view. So they took biopsy samples, removed two lymph nodes, cut back seminal vesicles, then sewed me up.

I was then given 6 months ADT which shrunk the PG to a smaller target size for EBRT, 4 directions, 70Grey, 35 days, and later I found out that this standard treatment was 90% likely to fail because I had a Gleason 9. Maybe it works with a Gleason 5.

Anyway, ADT continued for 18mths after EBRT, and I stopped the ADT. Psa went from 0.08 to 8.0 in 6 mths, so my treatment had failed. I was put back on to ADT, until something else came along, and in 2016, Psa crept up but I had a chance to get MORE EBRT only this time it was with Stereotactic IMRT and at Epworth, and I had another 31Gy to PG. That slowed the Pca in PG, and stopped it spreading to rectum and bladder etc. By 2017, the mets which could not be seen by any scan before 2016 began to be big enough for new PsMa scans to see, and I found I was riddles with countless mets, and the last 15 weeks of Docetaxel failed because Psa went from 12 to 42 last week. I am getting Lu177 starting on 8 November. Maybe it gives me more time.

But in general, as soon as I knew the RP had failed ( because I had a low Psa for a massive amount of Pca ), I realised I'd have a battle for rest of life - I had already read many posts in Pca groups, and so many men had had and RP and Pca continued on, and the RT to the site of surgery did not always work, and unless they get ALL the cancer out with an RP, and IF it has NOT spread, maybe a man never has to worry about Pca again and all he has to do is recover from his RP. And maybe he does not have ED, and does not have incontinence, and I am not sure of the % of those diagnosed who get a nice long life after treatment. But those who have a fight many years must be a large % of those diagnosed.

Nobody mentioned BT, brachytherapy, with maybe 100 radioactive gold pellets inserted. This gives the strongest RT to PG without much damage to rectum or anything else. The SBRT I had at Epworth with a gel pad to protect rectum still caused 2 months of bad radiation colitis. But I am still fully continent. Much of what is said about RT and side effects is bullshit. 

Its either not to bad, or worse than stated.

But I coped OK with all. If the Pca has spread at time of primary treatment of Pca, the danger comes later.

Just because you get RT does not mean you'll be cured. I have known men with Gleason 5 who said they were cured with a 35 day session of standard EBRT. Just lucky I guess, but predicting how anyone will fare after RT is somewhat impossible.

I was told I'd get a cure with EBRT, and I thought the doc to be a fool, and later I was right because the initial 70gy did not do much, and it was just luck that my Pca was suppressed well with ADT.

My fight is not over, and I think my Pca will probably kill me. Just when is not known. But I am now buying time with Lu177.

Whether it works for me is unknown. Doc says it should work good because I am not a late stage patient; I am in good health apart from the Pca, and last week I cycled 270km, on day 7 to day 14 after my 5th and last chemo infusion.

If Lu177 works, it may take its time because I have many bone mets. But if I get a lower Psa by Xmas I will be happy.

Patrick Turner.  

 

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