HealingWell
Search Close Search
☰

No need to go through 38-44 IMRT treatments anymore

Support Forums
>
Prostate Cancer
✚ New Topic ✚ Reply
❬ ❬ Previous Thread |Next Thread ❭ ❭
Posted 3/21/2017 8:00 AM (GMT 0)
Yet another nail in the coffin for conventionally fractionated IMRT. I put together a table of all the recent hypofractionation studies I had in my files - it's quite a body of Level 1 evidence. It's hard to justify any doctor refusing to offer it, or any patient refusing to accept it. Better yet, why not go all the way and do it in just 5 easy SBRT treatments?

/pcnrv.blogspot.com/2017/03/no-need-to-go-through-38-44-treatments.html

Of course, this doesn't apply to salvage RT (although early trials of hypofractionated salvage RT look good), and those with high risk PC should be considering brachy boost therapy.
Posted 3/21/2017 2:15 PM (GMT 0)
Allen...thanks for the great compilation of data.
Assuming a patient selects a RO skilled at hypofractination, it seems like a no brainer.
One thing that jumped out at me was the Hypro trial.
It was the one that had the highest percentage of high risk patients and also had the highest rates of urinary and rectal toxicities.
I am interested in your thoughts on that correlation.
Many Thanks
Posted 3/21/2017 2:35 PM (GMT 0)
There are RCT's ongoing. Maybe we don't know everything about these therapies yet to change treatment standard? But waiting for RCT is not an option for those diagnosed with PCa today. confused
This one compares 26 fraction vs. 5 fractions RT:
/clinicaltrials.gov/ct2/show/NCT01794403?term=NCT01794403&rank=1

This one compare surgery vs SBRT and conventionally fractionated RT vs SBRT:
/clinicaltrials.gov/ct2/show/study/NCT01584258?term=NCT01584258&rank=1
Posted 3/21/2017 2:35 PM (GMT 0)
Most encouraging. If my slowly rising uPSA cooperates, maybe it will also be standard for salvage radiation by time I need it.

Today's NY Times has an article on this very topic (at least I think it's same). They quote an MSK radiologist:

"Dr. Michael J. Zelefsky, a radiation oncologist who treated Mr. Kolnik there, said that several years ago, 90 percent of his patients had the standard course of treatment. Now 90 percent choose the shorter course. On the basis of Sloan Kettering’s experience with several hundred men who had the intense radiation therapy over the past three years, the treatment, he said, “is emerging as a very exciting form of therapy.”"

Robert
Posted 3/21/2017 3:35 PM (GMT 0)
Great summary of so many studies.

Maybe I'm missing something, but it seems none of them compared to 79.2 Gy in 44 fractions by IGRT, a very common plan today. It would be of further interest regarding the toxicity assessments to understand the type of EBRT done for conventional fractionation. How many of those std fractionation evaluations used IGRT, with its improved accuracy? Most likely all of the hypofractionation plans used some kind of image guidance.

I'd like to see the effectiveness / toxicity comparisons for comparable treatments, say all of them image guided, and treated to a modern standard of 79.2 to 81 Gy bioequivalent with similar dose hypofractionated.

Fewer treatments would sure be attractive. My 44 sessions became something of a groundhog day experience, and I'd have welcomed a plan with fewer of them.
Posted 3/21/2017 4:28 PM (GMT 0)
Thanks Very Much !
Hero
Posted 3/21/2017 4:33 PM (GMT 0)
wish you would have posted this 6 years ago ...
Posted 3/21/2017 7:13 PM (GMT 0)
Stay Tuned-

There is an issue in the way that grade 2 urinary toxicity is counted. This is explained in the write-up of the Fox Chase trial

Fox Chase said...
For the protocol definition of GU toxicity, an increase of greater than once-daily use of tamsulosin 0.4 mg (dominant alpha blocker used) is coded as a grade 2 reaction. The overall (crude) incidences of grade 0, 1, 2, and 3 worst late GU reactions were 2.0%, 50.3%, 44.4%, and 3.3% for CIMRT versus 3.4%, 51.7%, 40.9%, and 4.0% for HIMRT. Liberal use of an alpha blocker during RT is common practice and substantially influences the incidence of grade ≥ 2 toxicity. The 5-year cumulative risks of grade ≥ 2 GU adverse effects were 37.9% (95% CI, 29.7% to 46.1%) for CIMRT and 39.1% (95% CI, 30.6% to 47.4%) for HIMRT (Fig 3D). The coding criteria were modified such that any alpha blocker use and occasional non-narcotic medication for dysuria were coded as grade 1 . The revised plot (Fig 3E) shows that grade ≥ 2 reactions are much less when considered this way. The 5-year revised cumulative risks of grade ≥ 2 late GU adverse effects for the CIMRT and HIMRT patients were 13.4% (95% CI, 8.0% to 20.1%) and 21.5% (95% CI, 14.4% to 29.6%) with no overall difference (P = .16).

So, most of the trials reported 2 flomax/day as grade 1, whereas HYPRO reported it as grade 2. I think this has been cleared up in the new RTOG grading criteria. But when those trials were started, the grading standard was different.

I agree that the toxicity on the HYPRO study was an outlier. Some have suggested that they did not set dose constraints to organs at risk tightly enough. I believe it was the one with the highest biologically effective dose in the hypofractionated arm, and very careful IGRT becomes particularly important with such high doses.
Posted 3/21/2017 7:17 PM (GMT 0)
Redwing-

78 Gy in 39 fractions is actually a higher biologically effective dose than 79.2 Gy in 44 fractions.
Posted 3/21/2017 7:53 PM (GMT 0)

Tall Allen said...
Redwing-

78 Gy in 39 fractions is actually a higher biologically effective dose than 79.2 Gy in 44 fractions.

Ok, understood. Would those all have been done with image guidance, like the hypofractionated would be?
Posted 3/21/2017 10:10 PM (GMT 0)
You have to look at each study, but in general, fiducial placement was part of the plan in both arms. In general, both arms were treated with the same equipment. Cleveland Clinic was the exception - they used 3D-CRT for conventional fractionation, and IMRT for the hypofractionation.
Posted 3/22/2017 12:56 AM (GMT 0)
Interesting also to note the big variation in toxicity between the various trials too. I realise there are many variables at play, but still. For example, the lowest 2+ urinary toxicity of all results is 1%, the highest 41%.

<D
Posted 3/22/2017 1:15 AM (GMT 0)
Grading toxicity is always dicey. There are different grading criteria (like CTACAE v4.0) that change over time, and different clinical trials use different criteria. They are also dependent on good patient/doctor communication. I assume grade 0 and 1 are interchangeable - sometimes patients don't bother doctors over mild symptoms. I often just report grade 3 or higher when I have the info because I can be reasonably sure the doctor will hear about those. Within a given clinical trial, it's reasonable to assume the same doctors are grading the same for all their patients, so comparisons can be made. It's when you try to compare different trials that interobserver variation becomes problematic.

When I can get it, I much prefer it when they report "patient-reported outcomes" on a validated questionnaire (like EPIC). Then, it's much more reasonable to compare different clinical trials. All patients were asked the same questions in the same way, and the outcomes are quantifiable.
Posted 3/22/2017 1:26 AM (GMT 0)
TA: Why does this not necessarily apply to SRT or when having it in conjunction with brachy boost?
Posted 3/22/2017 1:33 AM (GMT 0)
MichaelT-

Because those weren't types of treatments and patients examined in any of those clinical trials.

We don't yet have the outcomes of any randomized trials of hypofractionated salvage radiation:

/pcnrv.blogspot.com/2016/08/can-salvage-radiation-therapy-be-safely.html

And you've seen what I have on brachy boost therapy in high-risk patients.

There are all kinds of radiological considerations that are different.
Posted 3/22/2017 3:41 AM (GMT 0)
Thanks TA. One of my brothers did seven weeks of IMRT back in 2011, a year before I was diagnosed. He was vision impaired and couldn't drive, his wife was a college professor and they were managing their four school-age kids so the duration wasn't particularly easy for them. Nice to have some more manageable options now...
✚ New Topic ✚ Reply