Bill Posted October 5, 2004 Share Posted October 5, 2004 Has anybody ever been told anything by their oncologists regarding the accuracy of tumor measurements ? When I voiced concern to my wife's rad onc that the primary tumor in her left lung had grown from 2.0 cm. to ~ 2.5 cm. ( based on her last 2 chest CT scan reports ) he said not to place much importance on a 0.5 cm. change. He said that several factors can cause a tumor's measurement to vary from one scan to the next whether there's been any actual change in size or not. He mentioned such things as the view ( or slice ) that the radiologist looks at and measures as well positioning and stretching, etc. in the tumor area during the scan. BTW, he also said that it's not unusual for scans and / or radiologists to miss very small lung nodules. Quote Link to comment Share on other sites More sharing options...
chloesmom Posted October 5, 2004 Share Posted October 5, 2004 Bill, I think that sounds like a good explanation. I know that my x-ray and CT prior to surgery said 2.5, but when it was removed the path report said 3.1. It was only a little over 3 weeks from CT to surgery, so I don't think it had that kind of significant growth. I think that it's all about the view, the slice, and distortion. I also have been told that they measure your tumor in it's largest dimension. What if the x-ray or CT didn't depict the largest dimension and some part of it was shielded from view of the machine???? And this one was a better picture? That sounds logical to me. I also know that these films are open to interpretation from different people. The only reason my chest x-ray was followed up on was because I had a history of breast cancer. Otherwise, I'd not have had that close scrutiny. Makes me scared just thinking of what would have happened. I hope this helps. Cindy Quote Link to comment Share on other sites More sharing options...
cindi o'h Posted October 5, 2004 Share Posted October 5, 2004 Bill, That was also a conern that I had in my early experience with NSCLC. Each time the CT scan, exposed at various facilities and read by various radiologists, seemed to have a great variance in measurements at 3 month intervals. When I asked the oncologist for an explanation, he said that the tumor can appear to change even from day to day and cited inflammation/fluid as an example of what can change the appearance of the tumour on a film. He said that there is a normal variance that is acceptable to him. He cited the numbers to me. I think, if I remember correctly, it was anything under 1cm. But, don't qoute me on that. Good luck. Cindi o'h Quote Link to comment Share on other sites More sharing options...
-Cheryl- Posted October 6, 2004 Share Posted October 6, 2004 Bill, My onc described the varying changes in size like trying to take a picture of an orange, dependent on where you slice the diameter will vary. Cheryl Quote Link to comment Share on other sites More sharing options...
Lisa O Posted October 6, 2004 Share Posted October 6, 2004 I have gotten the same information as Cheryl..... except with tennis balls instead of oranges... Quote Link to comment Share on other sites More sharing options...
Fay A. Posted October 6, 2004 Share Posted October 6, 2004 Another thing to remember is to check the resolution used on each scan. I few years ago I was astounded to find that when the reports indicated "...decrease in size..." the Radiologist had actually changed the resolution used by several millimeters. This was at a Comprehensive Cancer Center, and I was involved in a clinical trial where accurate results on response-whether it was decrease/increase/stability-was crucial. Quote Link to comment Share on other sites More sharing options...
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