A novel method to evaluate local control of lung cancer in stereotactic body radiation therapy (SBRT) treatment using 18f-Fdg positron emission tomography (PET)

An improved method is introduced for prediction of local tumor control following lung
stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer
(NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG
PET). A normalized background-corrected tumor maximum Standard Uptake Value
(SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of
the maximum uptake of lung tumor (SUVmax). This method minimizes the variations
associated with SUVmax and objectively demonstrates a strong correlation between the
low SUVcmax (< 2.5-3.0) and local control of post lung SBRT. The false positive rates
of both SUVmax and SUVcmax increase with inclusion of early (<6 months) PET scans,
therefore such inclusion is not recommended for assessing local tumor control of post
lung SBRT.