Correct!
1. 18FDG – PET scan shows multiple foci of metabolically active lymphoid tissue
The anterior segment right upper lobe nodular opacity again does not show metabolic activity greater than mediastinal blood pool background, and no evidence of recurrent metabolic activity in the mediastinum or left supraclavicular zone- the sites of presentation of the patient’s original lymphoproliferative disorder in the thorax- is present. The 18FDG – PET scan shows multiple foci of metabolically active lymphoid tissue, particularly in the bilateral peribronchial regions; these foci of tracer activity have been present and stable over a number of years.
Five years after the initial lymphoma diagnosis, a new p53 mutation was discovered and the patient underwent repeat 18FDG – PET scan (Figure 7) and enhanced CT.
Figure 7. Axial 18FDG – PET performed 5 years after initial lymphoma diagnosis shows continued metabolic activity in the bilateral peribronchial regions as well as elevated tracer utilization in the left pelvis, the later suggesting recurrent lymphoma. The right upper lobe anterior segment nodule shows metabolic activity that does not exceed mediastinal blood pool.
The repeat 18FDG – PET is compared with the prior 18FDG – PET studies in Figure 8.
Figure 8. Comparison of anterior segment nodule tracer uptake over time. (A) 18FDG – PET scan at initial lymphoma diagnosis. (B) 18FDG – PET scan at restaging 1 year after initial lymphoma diagnosis. (C) 18FDG – PET scan at restaging 2 years after initial lymphoma diagnosis. (D) 18FDG – PET scan at restaging nearly 5 years following initial lymphoma diagnosis. The anterior segment right upper lobe nodule does not show tracer accumulation greater than mediastinal blood pool at any time point.
Which of the following represents an appropriate interpretation for the repeat 18FDG – PET scan (Figure 7) and the comparison to previous 18FDG – PET studies (Figure 8)? (Click on the correct answer to be directed to the eigth of 12 pages)