Tumor growth after Stereotactic Radiation Surgery - 1288406

hlw22
Posts:11

How likely is it for a lung nodule to continue to grow after stereotactic radiation surgery, and if so, why does it?
Thank you.

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catdander
Posts:

HI,

Although stbr can be very effective for most people it's not 100% effective in killing 100% of cancer cells. If not all cells are killed then growth continues. With that said radiation continues to work for weeks after treatment has stopped. Another important piece to know is radiation causes a lot of inflammation that looks like cancer on a scan. Most doctors don't take scans within 3 months of radiation because it's somewhere between difficult to impossible to discern inflammation from cancer.

I'll look for specific numbers of efficacy rates.

All best,
Janine

hlw22
Posts: 11

Janine,

Many thanks for your response. I am on the East Coast and have gone to a hospital that has a few of the coveted proton machines (not used for me) and has a radiation oncologist whose publications are quantitatively and qualitatively mind-blowing to me. The percentages of effectiveness, I was told, are clearly in the plus range you mention. I had two lung nodules, not near any organs, and the largest was 15 mm.

If I may, questions bound into and relevant to my topic: I read somewhere that 3 months is the general waiting period to determine if treatment is working, but what is the longest period of time before it can be determined if treatment is working and how unusual would that time be? What might be the standard -- 3 -4 months? 3-6 months? How do they finally know if they "got it all"? Again, thank you for your straight forward, clear answers. hlw

JimC
Posts: 2753

Hi hlw,

Radiation kills cancer cells by damaging their DNA, so it can take some time for the radiated cells to succumb to it. I think that depending on the amount of scarring caused by the radiation, you could look at 3-6 months as the point when you should be able to see what effect the radiation has had, although despite a clean-appearing scan you can't really say that every last cancer cell is gone. That's the reason for follow-up scans after that period of time.

JimC
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cards7up
Posts: 636

This is a hard one, I know because I lived it. I also had two nodules, 1.2 cm and 2.3 cm. One in upper and lower right lobes. I decided on SBRT and chemo. They kept a good eye on the lower right lobe as you also end up with scar tissue, so it's hard to distinguish if that growth is behind the scar tissue. I had a local recurrence 2.5 yrs. after original treatment in the LRL. As I mentioned, it was behind the scar tissue and had grown to 5.2 cm and invaded the pleura. This is when they were able to see it. It was a hard biopsy due to the scar tissue but it was done. I then had surgery and chemo. Now at the 3 year mark on the 29th for surgery.
So there is no right or wrong answer, it has to show itself before it can be biopsied.
Take care, Judy

hlw22
Posts: 11

Thanks Judy for sharing your experience. I will be certain to ask questions about the amount of scar tissue I have and its relationship to the actual nodule--can or is it hiding it. I go back in November for another scan, only this time instead of a PET/CT, I will get the CT chest with iv contrast along with a basic Metabolic Panel.
Before radiation, the nodule was 12x15mm with maximum SUV of 2.5. Now it is 15/17 with maximum SUV of 4.6. Something is going on there! I can't have surgery or chemo, so I don't know whether they can do anything. But then, I thought the same thing before I discovered stereotactic radiation. I am remain hopeful and a bit anxious, but I have too much to do to dwell to long on the unknown. Hope you are now feeling well. Helen

JimC
Posts: 2753

Hi hlw,

Not only can scar tissue obscure the true size or even presence of a nodule, the inflammation caused by radiation can also light up on a PET scan, so the SUV seen in the latest scan doesn't necessarily reflect cancer activity. It will be good for you to get a CT with contrast, and hopefully that will show a good response to treatment.

JimC
Forum moderator

JimC
Posts: 2753

Judy,

Congratulations on reaching the three-year mark! Hoping for many more years of clean scans!

JimC
Forum moderator

hlw22
Posts: 11

Dear Jim C,
Thanks for your encouraging information. Always the replies help because they do not sugar coat the answers. Clarity matters! Helen