Early 30-Minute Dynamic FDG-PET Acquisition Could Halve Lung Scan Times

By MedImaging International staff writers
Posted on 14 Mar 2024

Image: PET/CT of a 60-year-old male patient with clinical suspicion of lung cancer (Photo courtesy of EJNMMI Physics)

F-18 FDG-PET scans are a way to look inside the body using a special dye, and these scans can be either static or dynamic. Static scans happen 60 minutes after the dye is administered into the body, showing where the dye collects using something called standard uptake values (SUVs). This method is popular but sometimes cannot tell the difference between cancerous lung spots and non-cancerous ones, like inflammation. On the other hand, dynamic PET scans take pictures over a longer time and let doctors measure "kinetic rate constants," which are details about how the dye moves in spots over time. This method is usually better at spotting cancer accurately but takes longer, which can be hard for patients who get anxious or can't stay still for long. Now, a new study has found that carrying out dynamic PET scans in just 30 minutes, instead of the usual 65 minutes, could work just as well for checking lung lesions, making it easier for patients.

Using image reconstruction analysis, nuclear medicine researchers from the Chinese Academy of Medical Sciences (Shenzhen, China) examined if shorter, 30-minute dynamic scans were just as good in terms of picture quality and how well they could tell apart benign and malignant lung lesions. They looked at 146 patients who had 181 lung lesions, and used software to turn the scans into 28 frames, showing the dye's movement over 30 minutes or 65 minutes. Experts looking at the images found that the shorter, 30-minute scans were just as good as the longer ones. They also found that using both short and long scan times, they could accurately identify cancerous lung lesions 82% of the time. However, the challenge with using dynamic FDG-PET more widely in clinics is the long time it takes to do these scans, and finding the best time to get these images for different medical needs is still something that needs to be worked out.

“In terms of image quality, our study found that the quality of Ki-30 min images is as good as that of Ki-65 min images by visual quality assessment,” stated the researchers. “This study indicates that an early 30-minute dynamic FDG-PET acquisition appears to be sufficient to provide quantitative images with good-quality and accurate Ki values for the assessment of lung lesions.”

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Chinese Academy of Medical Sciences