My sister had a lung exray in the start of her diagnosis of cancer of tonsils in Feb 2002. It had metasticized to one lymph node on right side. She had radiation for 6 weeks twice daily(ended on Apr 27, 2002) and was checked just last week and was told that she was cancer free. Of course she has to be checked again in 3 months. I don't think they did an exray on her lungs last week. Should they? And is an exray and ct scan the same?

While it is not impossible for a lung metastasis to develop in the time span treatment takes, it isn't likely that one has since that first check. An x-ray and a CAT scan are similar but different. Computerized tomography still uses radiation to reveal what is going on, but instead of one image, it produces a series of images in layers, around 3mm apart. This gives the radiologist a series of cross-section "slices" through the area to examine; in some respects this could be considered a 3 dimensional view of things. CT