e19574 Background: Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) was recognised by the WHO in 2016 as a rare sub-type of peripheral T-cell, non-Hodgkin lymphoma (NHL), characterized by an indolent clinical course and excellent prognosis. Little evidence exists on the role of post-treatment imaging surveillance with variable practices across the world. Recent UK guidelines recommend that routine surveillance imaging should not be offered to BIA-ALCL patients, in line with national/international recommendations for other NHLs. The aim of this study was to quantify the direct economic costs (DEC) of post-treatment BIA-ALCL routine radiological surveillance at our institution compared to the DEC if UK guidelines were followed. Methods: Following IRB approval a retrospective analysis of a prospectively maintained database of BIA-ALCL patients at The Royal Marsden Hospital was performed. DECs were estimated using current (2020) NHS tariffs for radiological investigations. Imaging undertaken for symptomatic problems/non-BIA-ALCL related concerns was excluded. Results: Eleven patients [median age: 49 years (IQR 45-52)] were treated for BIA-ALCL between 2015-2020 following cosmetic augmentation (n = 6) or breast reconstruction (n = 5). Median time from first implant surgery to BIA-ALCL diagnosis was 11 years (IQR 8-12). Patients presented with effusion (n = 7), mass (n = 2) or effusion and mass (n = 2). One patient had neoadjuvant CHOP/brentuximab, all 11 had explantation with en bloc total capsulectomy, 1 had adjuvant CHOP. Median follow-up was 38 months (IQR 12-47) with no local or distant relapses. Two patients did not have any radiological surveillance and 1 had follow-up elsewhere. The remaining 8 patients had a combination of PET/CT (n = 10), CT (n = 2), breast ultrasound (n = 6), mammogram (n = 4) and breast MRI (n = 1) as routine imaging follow-up not guided by clinical concerns. This represents evolving practice at our institution as the UK guidelines were published in 2021. Total cost of routine imaging surveillance was £10,396 ($14,396) with median cost of £1,953 ($2,705) per patient [IQR £526-2029 ($728-2,810)]. This cost could have been saved based on current guidelines recommending no routine surveillance for patients with no symptoms or clinical concerns. Conclusions: This data demonstrates that omission of routine post-treatment imaging surveillance, as per the recent UK guidelines, would result in a median DEC saving of £1,953 ($2,705) per patient at our institution. No local or distant relapses where identified within the follow-up period, in line with the existing literature suggesting BIA-ALCL has a very low risk of relapse and excellent prognosis. These findings provide a value-based analysis to further support the recommendation not to perform routine post-treatment imaging surveillance in patients with BIA-ALCL.