CT scan of the lungs is the regularly used scan to detect pulmonary metastases and to record their changes. CT scan is usually done for a staging - to find out if patient is present with the metastatic or localized stage of sarcoma and then every 3 month during the first two years of the follow up after the resection of the primary tumor if there were no lung metastases at the presentation. CT scan is also used for the follow up after the surgery/ablation/radiation treatment for the lung mets to check on it results, but there are the limitations as CT scan findings are not specific - it just finds the nodule but can not judge what it this nodule - the necrotic scar after the surgery or ablation, the live tumor nodule or the radiation induced necrosis, some times there are other accidental findings after the earlier happened lung conditions as pneumonia or viral/bacterial infection. To distinguish in between these findings a few consecutive lung scans are compared and if there is a growth the nodule is considered to be a metastases, if not then they still will be watched over as a suspicious nodules as there are well known cases of temporary stability ranging from a few month up to a few years of ASPS lung mets. The other CT scan limitation is the size - nodules smaller then 1-2 mm can stay undetected until they grow pass this size so the real number of the nodules can be very much different from the one detected - by dozens.
CT scan can be copied on the CD disk by the request of the patient and a copy few consecutive scans on the same disk is needed for the consultation reg. possible surgery/ablation/radiation treatment when you get a second opinion outside of your regular clinic.
lungs CT scan
deviation of the lung mets volume and center position (CT)
From the proceedings of the ASTRO 48 Annual meeting:
http://astro2006.abstractsnet.com/pdfs/ ... t_2492.pdf
Abstract ID:
2492
Tumor and Normal Tissue Motion in the Thorax during Respiration: Analysis of Volumetric and Positional Variations using 4D CT
"Average maximum variations in volume size during respiration were between 9.0% and 22.3% for the gross tumor volume
average maximum 3D centroid displacement of 8.0 mm for gross tumor volume"
The practical implications of the article for the CT scans results interpretation: changes up to 22 % in the volume of the lung met which corresponds with the change of the diameter up to 7 % could be a normal motion deviation of the lung met, and the finding of the new met in proximity of the 8 mm to the old location could be the shifted old met.
http://astro2006.abstractsnet.com/pdfs/ ... t_2492.pdf
Abstract ID:
2492
Tumor and Normal Tissue Motion in the Thorax during Respiration: Analysis of Volumetric and Positional Variations using 4D CT
"Average maximum variations in volume size during respiration were between 9.0% and 22.3% for the gross tumor volume
average maximum 3D centroid displacement of 8.0 mm for gross tumor volume"
The practical implications of the article for the CT scans results interpretation: changes up to 22 % in the volume of the lung met which corresponds with the change of the diameter up to 7 % could be a normal motion deviation of the lung met, and the finding of the new met in proximity of the 8 mm to the old location could be the shifted old met.