Keytruda for Adenocarcinoma (NSCLC), first PET-CT result

Mon, 10/22/2018 - 09:27

Hello friends,

My mom, (aged 77, Adenocarcinoma NSCLC, Stage 4, EGFR and ALK negative)  was diagnosed in 2014, underwent VATS and pleurodesis, followed by 6 cycles of Carboplatin & Alimta, Alimta maintenance, Tarceva (for just a couple of months) and is now on Keytruda for her stage 4, lung cancer treatment.  Her PDL-1 expression was over 70%.

The following is her first PET-CT result following 4 cycles of Keytruda (really 3 cycles as the 4th infusion was less than a week before the scan).   I'm looking for assistance to understand this report and possible options as we set up time with her oncologist to discuss her recommendations.

Thanks as always!


  • Mixed response to therapy compared to previous study 6/21/2018
  • There is slight decrease in the scattered intense FDG uptake noted along the thickened pleura and in a dominant lung nodule in the left lower lobe.  Many of the pleural based lesions demonstrate some calcifications, query: prior pleurodesis?
  • The bilateral, supraclavicular lymph nodes, right paratracheal, left hilar lymph nodes, left para-aortic and left retrocrural lymph nodes are no longer measurable without any FDG uptake.  The findings are compatible with favorable response.
  • Interval new widespread foci of intense FDG uptake noted throughout the visualized bones in predominantly sclerotic lesions.  The findings are compatible with progression of metasis to the bones.  

JanineT Forum …

Hi Simone,

It sounds like your mom could be responding to immunotherapy. The "query" I would think means that the pleural thickening might be due to her previous pleurodesis; it's not uncommon. All of the nodules listed as not seen except for uptake means that they can no longer be seen by the CT, a very good thing. It's important to understand that the SUV/FDGuptake hasn't been shown to be a good predictor of how to best proceed with treatment and it has been extensively tested. The gold standard of treatment decision making in stage IV followup is still CT and clinical workup/doctor's exam.--------If the only evidence of progression is higher FDG uptake most oncologists will read that as no progression but only response. As a matter of fact most oncologists and probably all lung cancer specialists use CT scans without PET for followup scanning. With your mom's scans you didn't mention any progression shown by CT but only by PET uptake. The reason most oncologists don't use PET is so they won't feel pressure to change treatment because of rising uptake (SUV). As I stated earlier clinical trials have not shown that additional information provided by PET improves outcomes and that's the goal.---- (My husband's onc used PET/CT for his followup for a year or more and rejected my thoughts on using CT only but it wasn't a battle I needed to fight so I let it be.)-----Too most often when a scan shows mixed response and the patient has not declined she will stay the course for at least one more cycle. -----Following is a link to 5 videos on immunotherapy, the 3rd one at 27 minutes shows a discussion on the rare occurrence of "Psudoprogression". Importantly they talk about letting patients stay on immunotherapy if there CT shows a few mm of progression and no new symptoms, this is similar to how many oncs feel about any stage IV treatments not just the rare possibility of psudoprogression.…

I hope this helps some and I look forward to hearing how the appointment goes.
Best of luck,

In reply to by JanineT Forum …


Thank you Janine! I appreciate your detailed and swift response so much! I am not sure why the PET CT was ordered and am hopeful the oncologist will stay the course, especially since my mom's performance status continues to be very good. I am wondering if the onc might add something for the spread seen in the bones? I'll be sure to share back. Cant thank you enough.

Jim C Forum Mo…

Hi Semone, As Janine stated, if some increase in FDG uptake is all that is seen in the bones, that's not solid evidence of progression, and it wouldn't necessarily suggest a change in treatment. And in general it's very difficult to measure progression using bone metastases, so I would agree that staying the course would be a quite reasonable option. Congratulations on the overall very positive update! Jim C Forum Moderator


Thank you very much Jim and Janine! 

I spoke with the NP at the oncologist's office and was told that the onc wants to continue Keytruda.  She also wants to add monthly injections of Xgeva.  They are interpreting the result as progression of bone metastases.  While I am grateful that Keytruda is being continued, I am wondering if the Xgeva is being added too hastily.  I hope the side effects / added level of treatment works for my mom.  Any feedback on this situation and how well tolerated Xgeva tends to be?  Thanks again! 

JanineT Forum …



As is described in your first post new multifocal scloratic lesions with high FDG uptake probably does signal bone metastases.  However oncs normally don’t want to change treatments just yet because there are only so many other options for treatment, so you’d want to stay on one treatment as long as possible before moving on.  Adding xgava doesn’t fit that scenario and it has a good track record of keeping bone mets at bay. So it’s probably a good direction for your mom and she can always stop treatment if the side effects are too toxic.  Several years ago there was talk that the drug may have long lasting efficacy after stopping treatment but trials to prove or disprove aren’t done (there’s little to motivate pharma co to spend research dollars to find out if you can take less of a drug) but it's helpful to know that if you need to stop that treatment it may continue to work. 

A thorough dental exam and dental work should be done before starting xgava.  One of the rare side effects is degeneration of the jaw bone and most often happens in people with dental problems or dental work done while on the drug.  The following link explains this in more detail.

I hope your mom does very well moving forward.  

All best,