Retrospective analysis identified 39 patients that were treated with SBRT for lung tumors close to the heart. Patients were grouped according to whether or not they had changes in cardiac FDG-PET uptake within the planned SBRT field.
At a median follow-up interval of 39 months (range, 6-81 months), nine patients (23%) showed increased cardiac FDG uptake associated with the heart V20. Of the 19 patients who received 20 Gy to 猢? cm3 of the heart, nine (47%) developed increased FDG uptake (vs. 0% for the 20 patients who received 20 Gy to <5 cm3) (P = 0.0004), all within the 20-Gy isodose line. Patients with hypercholesterolemia prior to SBRT were also more likely to show increased cardiac FDG uptake (P = 0.0190).
Increased FDG uptake in the heart after SBRT was observed when the 20 Gy isodose line exceeded 5 cm3 of the heart.