ASCO 2016

[Palex80]

ASCO is in process right now. Did you guys find any interesting abstracts?

A couple I found interesting:

http://abstract.asco.org/176/AbstView_176_162108.html
It seems non-1p/19q-codeleted °III gliomas will also be getting chemo additionally to RT in the future.

http://abstract.asco.org/176/AbstView_176_166735.html
Hormomes for intermediate risk prostate cancer even in the era of dose escalation seem to be beneficial. The EORTC 22991 trial, recently published in JCO, showed the same.

http://abstract.asco.org/176/AbstView_176_171256.html
Interesting. Serous papillary uterine cancer needs vaginal cuff brachytherapy... I haven't be doing that so far, since most of the patients get tons of adjuvant chemo in my clinic +/- percutaneous RT for node-positive disease. Maybe I should push for more vaginal cuff brachytherapy?

http://abstract.asco.org/176/AbstView_176_165387.html
SCLC-LD is equally well treated with 60 Gy once per day or 45 Gy bid.
Personally I find the 5% (non-significant) overall survival benefit at 2 years in favor of the bid scheme interesting, although it seems to be downplayed by the authors. I haven't seen the survival curves either, maybe they cross? Was the trial powered to detect small differences in OS?

Your thoughts?

---

Members don't see this ad.

 

[mavrik13]

I thought this one was very interesting - comparison between WBRT and salvage SRS in 1-4 brain mets with resection. Seems very different than local clinical practice. Looking forward to reading the final article.

http://abstracts.asco.org/176/AbstView_176_166949.html

 

[Gfunk6]

SCLC-LD is equally well treated with 60 Gy once per day or 45 Gy bid.
Personally I find the 5% (non-significant) overall survival benefit at 2 years in favor of the bid scheme interesting, although it seems to be downplayed by the authors. I haven't seen the survival curves either, maybe they cross? Was the trial powered to detect small differences in OS?

Well, the CALGB trial is testing qday dose escalation to 70 Gy, so that may possibly improve OS compared to 45 Gy bid.

 

[Palex80]

I thought this one was very interesting - comparison between WBRT and salvage SRS in 1-4 brain mets with resection. Seems very different than local clinical practice. Looking forward to reading the final article.

http://abstracts.asco.org/176/AbstView_176_166949.html

Indeed, interesting trial. I wonder what they did with the patients recurring with multiple mets in the "salvage SRS" group. Did they "salvage SRS" 7 metastatic sites if the patient came back with 7 new mets? The time frame of 4 months as PFS in the "salvage SES"is also very interesting and can help you discuss options with the patient.
More details would be interesting. Judging from the numbers, this trial is probably underpowered to detect small differences in outcomes.

 

[Palex80]

Well, the CALGB trial is testing qday dose escalation to 70 Gy, so that may possibly improve OS compared to 45 Gy bid.

Tiny patients series from Hiroshima claiming dose escalation is feasible and probably better than 45 Gy bid.
http://meetinglibrary.asco.org/content/161478-176
Japanese abstract, so it must be viewed with caution. My experience tells me, that Japanese publications often take toxicity very lightly. 🙂 ooops, that wasn't nice...

 

[medgator]

Well, the CALGB trial is testing qday dose escalation to 70 Gy, so that may possibly improve OS compared to 45 Gy bid.

The abstract palex quoted is actually going to 66 Gy, my preferred dose for SCLC, good to know there is at least equivalence.

For those of us covering multiple centers and for certain patients, BID just isn't feasible

 

[Phantom1]

Radiobiologically BID for SCLC makes sense, its really interesting to see this comparison. Logistically I think most people end up doing QD for SCLC, but I offer/recommend BID if a motivated patient with good PFS is willing to come in twice a day. My gut feeling is that for certain sites a more "continuous" or hyper fractionated approach truly does result in slightly better outcomes.. for example 6 days a week XRT, or BID. Clearly treatment breaks or split course are really bad and published outcomes are inferior. Data on concomitant boosts towards end of treatment is also interesting, and mostly negative as far as I'm aware. Such interesting tumor biology and radiobiology... Get your dose in smoothly without breaks or incidents!

 

[medgator]

Radiobiologically BID for SCLC makes sense, its really interesting to see this comparison. Logistically I think most people end up doing QD for SCLC, but I offer/recommend BID if a motivated patient with good PFS is willing to come in twice a day. My gut feeling is that for certain sites a more "continuous" or hyper fractionated approach truly does result in slightly better outcomes.. for example 6 days a week XRT, or BID. Clearly treatment breaks or split course are really bad and published outcomes are inferior. Data on concomitant boosts towards end of treatment is also interesting, and mostly negative as far as I'm aware. Such interesting tumor biology and radiobiology... Get your dose in smoothly without breaks or incidents!

The esophagitis when I've done it in the past seemed to be a lot more, made me concerned for those patients with a ton of weight loss already coming in to treatment.

 

[RadOncDoc21]

Radiobiologically BID for SCLC makes sense, its really interesting to see this comparison. Logistically I think most people end up doing QD for SCLC, but I offer/recommend BID if a motivated patient with good PFS is willing to come in twice a day. My gut feeling is that for certain sites a more "continuous" or hyper fractionated approach truly does result in slightly better outcomes.. for example 6 days a week XRT, or BID. Clearly treatment breaks or split course are really bad and published outcomes are inferior. Data on concomitant boosts towards end of treatment is also interesting, and mostly negative as far as I'm aware. Such interesting tumor biology and radiobiology... Get your dose in smoothly without breaks or incidents!

I wonder if chemo might trump the radiobiological benefit... Similar to head and neck.

 

[medgator]

I wonder if chemo might trump the radiobiological benefit... Similar to head and neck.

It would trump it a lot more in sclc. Radiation alone, even if altered Fx would essentially be palliative in small cell, you need the chemo to treat what is essentially a systemic disease at presentation.

H&N, outside of perhaps nasopharynx, can get pretty locoregionally advanced before it spreads below the clavicles, not so in sclc

 

[RadOncDoc21]

It would trump it a lot more in sclc. Radiation alone, even if altered Fx would essentially be palliative in small cell, you need the chemo to treat what is essentially a systemic disease at presentation.

H&N, outside of perhaps nasopharynx, can get pretty locoregionally advanced before it spreads below the clavicles, not so in sclc

Yes very true, I've seen large tumors shrink to almost nothing with chemo alone for small cell. Of course it usually always comes back in some form but still definitely more sensitive.

 

[ramsesthenice]

The esophagitis when I've done it in the past seemed to be a lot more, made me concerned for those patients with a ton of weight loss already coming in to treatment.

Just went to the presentation I think the esophagitis issue is one interesting thing Missed on the med oncs. They got better survival than Turisi with BID fractionation but much less severe esophagitis. As best I can put together, this is because they PET staged everybody and did not do ENI. I have always treated bilateral mediastinum as per Turisi and gotten roaring esophagitis. New data suggests maybe this isn't necessary with well staged patients? With reduced volumes BID may not be more acutely toxic than once daily.

Also, moderator asked the study PI if they planned to compare BID to TID

She didn't have much to say to that.

 

[medgator]

Just went to the presentation I think the esophagitis issue is one interesting thing Missed on the med oncs. They got better survival than Turisi with BID fractionation but much less severe esophagitis. As best I can put together, this is because they PET staged everybody and did not do ENI. I have always treated bilateral mediastinum as per Turisi and gotten roaring esophagitis. New data suggests maybe this isn't necessary with well staged patients? With reduced volumes BID may not be more acutely toxic than once daily.

Also, moderator asked the study PI if they planned to compare BID to TID

She didn't have much to say to that.

While the ENI issue seems to be settled in NSCLC (I think), SCLC still has its ENI proponents. The 3-arm RTOG/CALGB trial calls for ENI in the initial phase of treatment going to 44 Gy IIRC. I personally don't treat Turrisi fields, the volumes are already pretty ridiculous in many cases without it, and in many patients, I have to re-scan to account for shrinkage of the big volumes after a few weeks of treatment.

 

[Palex80]

We don't do ENI either anymore in my clinic, with the exception of supraclavicular fossa if level 2 is involved. There's sone datasupporting that you can do that in PET-staged patients, mainly from the De Ruysscher group in the Netherlands.

Besides volumes, it's certainly also a matter of technique. With 3D the esophagus was often "sacrified" to spare the lungs. 45 Gy with bid is alot of dose for the mucosa. With IMRT you can drop this and if level 7 is not involved, esophagus is often not in the PTV. I ask my planners to stay under 40 Gy and it helps in my opinion.

Last but not least: adaptive planning. Although not part of the study presented, if you start RT with the first or second cycle of chemo you will se tumor volume changes in quite some patients if you look at the CBCTs and can replan if you want to, for example after 30 Gy (2 weeks) of Turrisi, if you want to. That can also reduce dose to the esophagus.

 

[RadOncDoc21]

We don't do ENI either anymore in my clinic, with the exception of supraclavicular fossa if level 2 is involved. There's sone datasupporting that you can do that in PET-staged patients, mainly from the De Ruysscher group in the Netherlands.

Besides volumes, it's certainly also a matter of technique. With 3D the esophagus was often "sacrified" to spare the lungs. 45 Gy with bid is alot of dose for the mucosa. With IMRT you can drop this and if level 7 is not involved, esophagus is often not in the PTV. I ask my planners to stay under 40 Gy and it helps in my opinion.

Last but not least: adaptive planning. Although not part of the study presented, if you start RT with the first or second cycle of chemo you will se tumor volume changes in quite some patients if you look at the CBCTs and can replan if you want to, for example after 30 Gy (2 weeks) of Turrisi, if you want to. That can also reduce dose to the esophagus.

I actually started doing adaptive planning for all my lungs. I had one guy with a 7 cm NSCLC melt down to almost nothing after 45 Gy. I also had a 3 cm tumor turn into bone mets, so for each case it did save some unnecessary dose to normal structures.

 

[seper]

I would not rush with such interpretation of the UPSC abstract. We have to see in the final paper about what % got EBRT or combination of BCT and EBRT.

ASCO is in process right now. Did you guys find any interesting abstracts?

A couple I found interesting:

http://abstract.asco.org/176/AbstView_176_162108.html
It seems non-1p/19q-codeleted °III gliomas will also be getting chemo additionally to RT in the future.

http://abstract.asco.org/176/AbstView_176_166735.html
Hormomes for intermediate risk prostate cancer even in the era of dose escalation seem to be beneficial. The EORTC 22991 trial, recently published in JCO, showed the same.

http://abstract.asco.org/176/AbstView_176_171256.html
Interesting. Serous papillary uterine cancer needs vaginal cuff brachytherapy... I haven't be doing that so far, since most of the patients get tons of adjuvant chemo in my clinic +/- percutaneous RT for node-positive disease. Maybe I should push for more vaginal cuff brachytherapy?

http://abstract.asco.org/176/AbstView_176_165387.html
SCLC-LD is equally well treated with 60 Gy once per day or 45 Gy bid.
Personally I find the 5% (non-significant) overall survival benefit at 2 years in favor of the bid scheme interesting, although it seems to be downplayed by the authors. I haven't seen the survival curves either, maybe they cross? Was the trial powered to detect small differences in OS?

Your thoughts?

 

[thaddeus]

I thought this one was very interesting - comparison between WBRT and salvage SRS in 1-4 brain mets with resection. Seems very different than local clinical practice. Looking forward to reading the final article.

http://abstracts.asco.org/176/AbstView_176_166949.html

I was at this session - it was kind of an odd study. Patients with 1-4 mets had surgery for the largest met, then were randomized to adjuvant WBRT vs SRS for any remaining mets (if >1 initially) and for any additional subsequent two mets. Importantly, the resection cavity didn't get any adjuvant RT in the SRS arm I think they had limits on the total number of SRS treatments and the total number of lesions treated before switching to WBRT, but can't remember the numbers. No OS difference between the groups, but there was a suggestion of a survival benefit to WBRT in RPA I patients. Seems to me that standard of care is RT to the cavity (either SRS, hypofractionated course or WBRT), so I can't see anyone in the US taking this approach....

 

[thaddeus]

This was by far the most important rad onc-related study I saw at ASCO:

http://abstract.asco.org/176/AbstView_176_163254.html

Patients over 65 with GBM randomized to RT alone (Roa, 40/15) or RT (40/15) with concurrent and adjuvant TMZ. Significant OS benefit for TMZ, especially in MGMT methylated patients. Study is important because Stupp included only patients <70, with uncertain benefit in the 65-70 group. Seems like this should change standard of care for elderly patients.

 

[Phantom1]

We don't do ENI either anymore in my clinic, with the exception of supraclavicular fossa if level 2 is involved. There's sone datasupporting that you can do that in PET-staged patients, mainly from the De Ruysscher group in the Netherlands.

Besides volumes, it's certainly also a matter of technique. With 3D the esophagus was often "sacrified" to spare the lungs. 45 Gy with bid is alot of dose for the mucosa. With IMRT you can drop this and if level 7 is not involved, esophagus is often not in the PTV. I ask my planners to stay under 40 Gy and it helps in my opinion.

Last but not least: adaptive planning. Although not part of the study presented, if you start RT with the first or second cycle of chemo you will se tumor volume changes in quite some patients if you look at the CBCTs and can replan if you want to, for example after 30 Gy (2 weeks) of Turrisi, if you want to. That can also reduce dose to the esophagus.

Agree, esophagitis is minimized when you don't treat massive Tourrisi fields, but likely still more than QD for equivalent fields. I don't do full ENI, but I do treat 1 LN station above and below involved disease, most often end up covering LN station 7 and ipsilateral station 4...

 

[Palex80]

Agree, esophagitis is minimized when you don't treat massive Tourrisi fields, but likely still more than QD for equivalent fields.

This is however a matter of total dose given to the patient.

45 Gy twice per day may not be more toxic than 66 Gy once per day, as the quoted study mentions.
After all you are giving 21 Gy "more" with once per day fractionation, which "arithmetically" is alot of "dose" for the hyperfractionation/acceleration to make up for in terms of mucosa damage.
The original Turrisi trial tested 45 Gy in both arms, leading to massively more esophagitis in the bid group. People have been worrying since, but in the end Turrisi was testing two different dose levels from the radiobiological point of view, so it was logical for the more aggressive group to produce more side effects.