A thin win.
How often do you find yourself having to request a second MRI for patients with brain metastases in order to have thin slices for stereotactic radiosurgery (SRS) planning? Is that really necessary? In this study, 1 mm thin slice MRIs used for Gamma Knife SRS planning were reconstructed to generate 2 mm and 3 mm slices. Using 2 mm slices for 28 patients with > 100 mets, 14% of patients had brain mets that were missed or, even worse, normal structures that were mistakenly called mets. That increased to 25% with 3 mm slices. In addition, when the size of a met is similar to slice thickness, there can be significant volume averaging that results in increased contour volume. So, yes, a second MRI is worth it. | Thrower, Adv Radiat Oncol 2021