Background: As nodal surveillance is increasingly used for sentinel lymph node positive (SLN+) melanoma following the Second Multicenter Selective Lymphadenectomy Trial (MSLT-II), availability of high-quality nodal surveillance ultrasonography (U/S) has become a critical need. Based on MSLT-II, U/S criteria concerning for nodal recurrence should be evaluated to determine indication for lymph node (LN) biopsy. We previously demonstrated low utilization of MSLT-II criteria for reporting nodal U/S at our tertiary cancer center, diminishing the clinical utility of these reports. Working in an interdisciplinary team of surgeons and radiologists, we aimed to implement and evaluate a synoptic reporting template for melanoma nodal ultrasound at our institution. Methods: Patients undergoing melanoma nodal surveillance at a tertiary cancer center from July 2017 to June 2023 who received at least one nodal U/S were identified retrospectively. Reporting language from each U/S was analyzed for number of MSLT-II criteria reported and presence of clinically actionable recommendations for the referring surgical team (e.g. normal LN appearance or abnormal LN with recommendation for biopsy or observation). The synoptic report was designed collaboratively by a group of radiologists and surgical oncologists to include MSLT-II U/S criteria and thresholds for biopsy versus continued surveillance, with the institutional U/S dictation template revised accordingly. Dissemination to clinical teams was conducted and utilization was monitored in the course of clinical care. Following implementation of the synoptic template in January 2023, post-implementation adherence and outcomes were reviewed. Descriptive statistics and bivariate analysis were performed. Results: 337 nodal U/S studies were performed on 94 SLN+ melanoma patients, with a median of 2.5 U/S per patient (range 1 to 12). Forty-two U/S (12.5%) were performed in the post-implementation period and eligible for synoptic reporting; of these, 32 (76.0%) were reported with the synoptic template. The mean number of MSLT-II criteria reported was greater post-implementation (Pre 0.5 ± 0.8 vs Post 2.5 ± 1.0, p<0.001). Abnormal findings were reported in 73 U/S (21.7%), with a significant increase in the proportion of clinically actionable recommendations for abnormal findings reported in the Post versus Pre group (93.0% vs 64.0%, p=0.037). Conclusions: Following the implementation of a collaboratively designed synoptic reporting template for melanoma nodal U/S, reports were much more likely to have MSLT-II criteria reported in addition to an actionable recommendation. There was notable improvement when ultrasounds had abnormal findings, when the application of these reporting criteria is most crucial. Further iterative improvement to increase adherence to the synoptic report and dissemination to other cancer centers is ongoing.