The goal of this retrospective review was to determine the clinical relevance of one-month post-treatment imaging in the selective internal radiation therapy (SIRT) patient population by reporting the incidence of change in clinical management.Between January 2012 and January 2016, 85 patients underwent 109 SIRT treatments for either primary or secondary hepatic malignancies. There were 59 men and 26 women with a mean age of 62.4 years (range: 39-89 years). Patients' medical records were retrospectively reviewed for procedural, historical, laboratory and imaging information. The imaging study was considered to have changed patients' clinical management if it resulted in the addition of a new procedure, canceling of a planned procedure or change in systemic therapy.The one-month post-treatment imaging findings led to management changes in 10 of 109 (9.2%) of treatments. When evaluated by cancer type, 2/61 (3.3%) hepatocellular carcinoma (HCC) treatments had management changed while 8/48 (16.7%) non-HCC treatments underwent management change (P=0.03). This difference was also significant at multivariate analysis (P=0.03; odds ratio: 0.17 [0.03-082]).Management is rarely changed by one-month post-SIRT imaging in patients with HCC and thus is likely unwarranted. Conversely, in non-HCC patients, one month post-SIRT imaging led to a significant percentage of clinical management changes suggesting that one month imaging in this setting is likely warranted.