Autonomic dysfunction from pancreatic cancer?

[ramsesthenice]

Had an interesting one worth sharing. Had a 70 something female present with an unresectable pancreatic cancer encasing the celiac and several primary branches. They wanted to give her chemo but she had severe positional hypotension and syncopal episodes. It was attributed to celiac compression and I was asked to consider SBRT to try to palliate these symptoms so she could maybe be a chemo candidate. I don't know about anyone else, but I have never heard of using SBRT for this particular indication in pancreatic cancer. From a physiologic perspective it made sense and she had pain so SBRT was reasonable from that perspective. I was very clear with everyone that I didn't know what to expect as far as palliating her hypotension and syncope. I gave 50/5 and let it get pretty hot in the GTV. Finished 10 days ago and she hasn't had any hyoptensive or syncopal episodes in a week. Pain is better too.

I am glad it worked in this case but I am curious if anyone has ever seen this before and had a similar experience (or not).

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[FrostyHammer]

Had an interesting one worth sharing. Had a 70 something female present with an unresectable pancreatic cancer encasing the celiac and several primary branches. They wanted to give her chemo but she had severe positional hypotension and syncopal episodes. It was attributed to celiac compression and I was asked to consider SBRT to try to palliate these symptoms so she could maybe be a chemo candidate. I don't know about anyone else, but I have never heard of using SBRT for this particular indication in pancreatic cancer. From a physiologic perspective it made sense and she had pain so SBRT was reasonable from that perspective. I was very clear with everyone that I didn't know what to expect as far as palliating her hypotension and syncope. I gave 50/5 and let it get pretty hot in the GTV. Finished 10 days ago and she hasn't had any hyoptensive or syncopal episodes in a week. Pain is better too.

I am glad it worked in this case but I am curious if anyone has ever seen this before and had a similar experience (or not).

What is your bowel constraint with 50/5 or do you just let that area of the volume be cold?

 

[RadOncDoc21]

Fake news, radiation doesn’t work. If anything it was the idea of immunotherapy that made the symptoms improve.

 

[ramsesthenice]

What is your bowel constraint with 50/5 or do you just let that area of the volume be cold?

I use the same SBRT constraints regardless of the RX dose. For 5 fractions I limit the stomach/duodenum max to 34 and try to limit the V30 Gy to a few ccs. This particular lesion was a body lesion and was able to get 90% PTV coverage at Rx dose. When going to 50 I will typically accept down to 50% coverage as long as we can get >95% above 34 Gy.

 

[ramsesthenice]

What is your bowel constraint with 50/5 or do you just let that area of the volume be cold?

Also, dose escalated SBRT is a lot easier when there is vascular encasement because the tumors tend to be fixed. I personally find that head lesions without vascular encasement are harder to get to higher doses because of respiratory motion. Compression frequently makes things worse by smashing everything together.

 

[GI_RadOnc]

Nope, never had that one in the last 100 pancreatic cancer patients I had. That's really an interesting case with the hypotension and syncopal episodes!

 

[evilbooyaa]

I didn't think that the parasympathetic/sympathetic functions of the celiac plexus/nerve system would be related to systemic sympathetic/para-sympathetic signagling in the sense of causing autonomic dysfunction in relation to systemic hypotension/bradycardia/etc.- mostly just gut related (peristalsis)?

I suppose IF celiac plexus dysfunction could cause systemic autonomic dysfunction relating to unstable vitals, then that COULD be caused by a tumor as described given the location, and PERHAPS ablative radiation would relieve the pressure on the nerves and allow for resolution of those symptoms.

Perhaps (IMO more likely), she had significant pain (pain from celiac involvement well documented, given h/o celiac plexus block to improve pain in this scenario) and was taking significant medications for it, some of which could cause pre-syncopal episodes, as well as increased somnolence leading to decreased oral intake, potentially leading to the orthostatic hypotension described.

When you hear hoofbeats, think horses not zebras, IMO.

 

[ramsesthenice]

I didn't think that the parasympathetic/sympathetic functions of the celiac plexus/nerve system would be related to systemic sympathetic/para-sympathetic signagling in the sense of causing autonomic dysfunction in relation to systemic hypotension/bradycardia/etc.- mostly just gut related (peristalsis)?

I suppose IF celiac plexus dysfunction could cause systemic autonomic dysfunction relating to unstable vitals, then that COULD be caused by a tumor as described given the location, and PERHAPS ablative radiation would relieve the pressure on the nerves and allow for resolution of those symptoms.

Perhaps (IMO more likely), she had significant pain (pain from celiac involvement well documented, given h/o celiac plexus block to improve pain in this scenario) and was taking significant medications for it, some of which could cause pre-syncopal episodes, as well as increased somnolence leading to decreased oral intake, potentially leading to the orthostatic hypotension described.

When you hear hoofbeats, think horses not zebras, IMO.

Don't disagree with anything you said. My thought when first reading this case (prior to consult) was that she was vasovagaling secondary to pain. My knowledge of intricate physiology related to peripheral CNS autonomic innervation is not exactly profound (as in it sucks). However, her pain was not severe and she was only taking tylenol so the latter scenario, though generally plausible, probably wasn't the case. I don't honestly know what to make of it. Which is why I reached out see if anyone else had ever heard of anything like this. It was a first for me. Honestly, its a little weird to get pain relief this fast from SBRT either. But the hypotension was quantifiable (they kept her in house) and clearly did improve. May just be a case of better to be lucky than to be good.

 

[Lamount]

There are some data to suggest that it is mediated by decreased vagal activity and that this may be due to systemic inflammatory cytokines like CRP (i.e. a paraneoplastic syndrome)... If this is the case, RT could help as it may facilitate cytoreduction.

Interesting case...

 

[elementaryschooleconomics]

If it was mostly positional hypotension/syncope, perhaps it was pressing on vasculature in just the unfortunately "right" way to compromise venous return/decrease preload? Was she a small lady? I could see decreased PO intake 2/2 pain coupled with mass effect on vasculature supplemented by frail/small substrate leading to this...super interesting, thanks for sharing.

 

[evilbooyaa]

Don't disagree with anything you said. My thought when first reading this case (prior to consult) was that she was vasovagaling secondary to pain. My knowledge of intricate physiology related to peripheral CNS autonomic innervation is not exactly profound (as in it sucks). However, her pain was not severe and she was only taking tylenol so the latter scenario, though generally plausible, probably wasn't the case. I don't honestly know what to make of it. Which is why I reached out see if anyone else had ever heard of anything like this. It was a first for me. Honestly, its a little weird to get pain relief this fast from SBRT either. But the hypotension was quantifiable (they kept her in house) and clearly did improve. May just be a case of better to be lucky than to be good.

I agree that mild pain on tylenol makes my scenario a bit less likely. Maybe it's b/c of resolution of a paraneoplastic syndrome. Maybe it's directly due to resolution of ganglion impingement. Maybe it's Maybelline.

 

[ramsesthenice]

I agree that mild pain on tylenol makes my scenario a bit less likely. Maybe it's b/c of resolution of a paraneoplastic syndrome. Maybe it's directly due to resolution of ganglion impingement. Maybe it's Maybelline.

Maybe the hamster powering our linacs was running really fast those days 🙂

 

[Palex80]

There are some data to suggest that it is mediated by decreased vagal activity and that this may be due to systemic inflammatory cytokines like CRP (i.e. a paraneoplastic syndrome)... If this is the case, RT could help as it may facilitate cytoreduction.

Interesting case...

So treat it with 6 x 0.5 Gy ?
🙂