cervix hdr fractionation

[Reaganite]

Got an interesting referral...lady with IIB cervix Ca who was treated with chemo-RT (EBRT to 45 Gy) at an outside facility and who for reasons I won't go in to, presented to me for the HDR component of her treatment. She completed her EBRT in 6 weeks (had a week break d/t unrelated condition) and now presents to me 2 weeks after completion of EBRT. So basically already at the 56 day deal. How would you fractionate the HDR? What's the shortest regimen you'd give?

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[Gfunk6]

6 Gy x 5 fractions is the standard after 45 Gy.

In residency, my Gyn attending did 7 Gy x 4 fractions routinely which is equivalent in terms of BED calcs. ABS recommends < 7.5 Gy per fraction due to concerns over late toxicity.

Personally I would do 7 Gy x 4.

 

[Palex80]

We give 4x7Gy to high-risk-CTV and 4x5Gy to intermediate-risk-CTV. Two fractions per week.

 

[Neuronix]

Agreed completely with Gfunk and Palex.

I have seen one alternative in this specific case when the patient is from far away, is up against the 8 week window, and/or there are concerns about them not completing treatment due to social reasons. That is: 5 x 5Gy BID (prescribed to HR-CTV, >6 hours between treatments) in a single implant/admission if you're using interstitial coverage. 4 x 7 Gy BID over 2 days would also be reasonable for T&O only or limited interstitial coverage, preferably spaced ~12 hours apart per fraction.

 

[Tanner]

Got an interesting referral...lady with IIB cervix Ca who was treated with chemo-RT (EBRT to 45 Gy) at an outside facility and who for reasons I won't go in to, presented to me for the HDR component of her treatment. She completed her EBRT in 6 weeks (had a week break d/t unrelated condition) and now presents to me 2 weeks after completion of EBRT. So basically already at the 56 day deal. How would you fractionate the HDR? What's the shortest regimen you'd give?

What did your pelvic exam reveal- specifically what was the post-EBRT tumor response?

 

[user_name]

Canadian regimen is 8 Gy x 3 to Pt A I believe. My training institution did this as I recall. Try McGill in your search.

Found a link: http://www.ncbi.nlm.nih.gov/pubmed/15863152

 

[seper]

I'd still do 6 Gy X 5 twice per week, starting right away to speed things up.
If you do 8 Gy X 3, you may have to do it one week apart.

 

[RadRadRad]

I agree with Seper (6Gy x 5 or 5.8Gy x 5 or 5.5Gy x 5...this is a whole diffferent discussion).
I think 7Gy x 4 in 2 wks is also reasonable.

Completing treatment in 56 days is ideal, but I dont think you should feel obligated/pressured to do something too different from normal (like doing all fractions in 2 days..even though interstitial cases may be done this way) b/c of external factors. U don't want to be in a situation of trying to justify if there is a high grade toxicity.

 

[Neuronix]

Where do you all get 56 days from? I thought it should be 49 days...

http://www.ncbi.nlm.nih.gov/pubmed/7635767/?

 

[medgator]

Where do you all get 56 days from? I thought it should be 49 days...

http://www.ncbi.nlm.nih.gov/pubmed/7635767/?

1995..... I think that was before routine chemoradiation wasnt it?

http://www.ncbi.nlm.nih.gov/m/pubmed/22806897/

 

[Radonc90]

Old thread but important thread...

- The paper that @Neuronix posted above is from C. Perez (Washington Univ) during RT alone era (no concurrent chemo) and LDR.
Pezer recommended overall Tx time < 49 days (7 weeks).

- The latest ABS compendium for brachytherapy was last updated in 2019:

Compendium of fractionation choices for gynecologic HDR brachytherapydAn American Brachytherapy Society Task Group Report

https://www.americanbrachytherapy.org/ABS/document-server/?cfp=ABS/assets/File/public/consensus-statements/Brachy2.pdf

On page 3, excerpts:
"...Point A-based prescription. Treatment with EBRT (with or without concomitant chemotherapy) and brachytherapy should be completed in less than 7-8 weeks as better local tumor control and survival can be expected (11,12). Some institutions interdigitate HDR brachytherapy with EBRT to shorten the total treatment duration, but this can only be carried out if adequate dose can be given to the residual disease. The most recent ABS consensus guidelines for HDR definitive brachytherapy for cervix cancer are from 2012 (8)..."

- So for 2022, when the vast majority of pts receive concurrent chemo, I am OK with overall Tx time of 49 days to 56 days. Basically, let's say the EBRT is 45 Gy and completed in 5 weeks (assuming no interruption), then you have 2-3 weeks to do the HDR implants. If you do 2 HDR procedures/week, and assuming you do 3-5 fractions (max = 5 HDR appliactions) then you should be fine.

- On the comment above re 3 fractions.
It was first pioneered by McGill, the first ever article on HDR for cervix (they started this HDR program in 1984, way before any centers in Canada or USA) to publish in RedJ circa (RT alone bc data for concurrent chemo came later in the late 1990s). If you take this set of data from McGill, add about 10-12% to the survival figures and you should get modern outcome data...

* Data from 1984-1989 (n= 187 during 5 yr-period, high-volume center!)

DEFINE_ME

* McGill data updated in 2005 in Gyn Onc; data from 1984 and 1997, n = 282:

Long-term results of high-dose rate brachytherapy in cervix cancer using a small number of fractions

To evaluate the long-term treatment outcome of patients with carcinoma of the cervix treated with high dose rate brachytherapy (HDRB) using a small nu…

www.sciencedirect.com

Kind of funny ABS comments saying "resource-poor countries" comment...

- Anyway, for 2022, I am OK with 8 Gy x 3, 7 Gy x 4, or 6 Gy x 5.
If one is too old to remember anything, a memory aid is 3-4-5-6-7-8...lol.

- I have done 8 Gy x 3 for over 15-20 yrs, it works very well.

 

[evilbooyaa]

A nearly 9 year necrobump on Cervix fractionation... wowza. I usually do 6Gy x 5 but can push for 7Gy x 4 at first fraction to see if anatomy is favorable. Total package time < 56 deals in chemoRT era is ideal.

 

[taserlaser]

OR time is at a premium where I’m at. 8 x 3 unless something extraordinary. New brachy RO where I’m at has been successful at getting time for 4 insertions though so that may change for us

 

[seper]

no need to go over 4 fractions anymore for cervical brachytherapy, with new imaging and devices

 

[evilbooyaa]

no need to go over 4 fractions anymore for cervical brachytherapy, with new imaging and devices

OR time is at a premium where I’m at. 8 x 3 unless something extraordinary. New brachy RO where I’m at has been successful at getting time for 4 insertions though so that may change for us

Benefits of fractionating to increase therapeutic window between EQD2 a/b 10 and EQD2 a/b 3 continue to exist. While it's not going to make me increase the number of procedures above 5 for T&Os, that's still my standard based on my patient population.

It's not necessary for all patients, but certainly there are anatmoical challenges. I understand in resource-poor environments or places where no insertion can occur in department (say with Anesthesia support) that any brachy is better than no brachy, but I favor sticking with 5Fx if I'm going to go above rectum or sigmoid EQD2 a/b3 65 or bladder EQD2 a/b3 75.

I usually see c/rT2B or higher disease though, so YMMV.

What do you two accept as EQD2 for bladder and rectum?

 

[Palex80]

Our most common issue for prefering more fractions are actually not rectum/sigma or bladder constraints, but issues with small bowel.
Every now and then we have a patient with small bowel loop directly behind the uterus lying quite low in the pelvis. That's usually a fixed loop that has already received the full dose of the EBRT when covering the nodes and lies directly next to the uterus. No matter what we try in terms of bladder filling, it won't fix the issue since that loop is behind the uterus. Without an MRI, one can easily mistake these loops for sigma, but unfortunately they do exist. A couple of times per year it also happens with prostate cancer patients, where small bowel loops may appear lying directly on top of the seminal vesicles.

If you are trying to cover your cervix target with 4-5 Gy, you are going to end up with >3 Gy on those small bowel loops.

4 x 3 Gy = 12 Gy + 45-50 Gy from the EBRT part --> Doses around 60 Gy for the small bowel (especially in less mobile loops) make me feel uncomfortable.

 

[Irradi8or]

OR time is at a premium where I’m at. 8 x 3 unless something extraordinary. New brachy RO where I’m at has been successful at getting time for 4 insertions though so that may change for us

I do it routinely in a freestanding setting w conscious sedation - in case that’s an option for you

 

[taserlaser]

Benefits of fractionating to increase therapeutic window between EQD2 a/b 10 and EQD2 a/b 3 continue to exist. While it's not going to make me increase the number of procedures above 5 for T&Os, that's still my standard based on my patient population.

It's not necessary for all patients, but certainly there are anatmoical challenges. I understand in resource-poor environments or places where no insertion can occur in department (say with Anesthesia support) that any brachy is better than no brachy, but I favor sticking with 5Fx if I'm going to go above rectum or sigmoid EQD2 a/b3 65 or bladder EQD2 a/b3 75.

I usually see c/rT2B or higher disease though, so YMMV.

What do you two accept as EQD2 for bladder and rectum?

Sorry, I don‘t treat gyne regularly in the past few years (though aware they do 8 Gy x 3 for the most part). I don’t have those constraints burned into my brain past ABR orals haha and wouldn’t go by what i use. Usually abided by gec-estro/embrace(2) planning constraints though iirc