323 Background: Clinical treatment pathway (CTP) tools have been incorporated into oncology practices to help standardize treatment, reduce care variation in cancer patients, and move towards value-based care. CTP tools incorporate the latest guidelines and are developed through multidisciplinary committees. Treatment decisions are prioritized by efficacy, toxicity, and cost to improve quality and value. This is especially important in cancer care which is associated with high drug costs. However, use and implementation of CTP tools has been met with mixed reviews and published data from academic medical centers are limited. Methods: Outpatient treatment decisions for patients across different cancer types, including colorectal, gastroesophageal, and breast cancers from July 2018 to March 2020 at an urban NCI-designated cancer center were evaluated. Every treatment decision was evaluated in relation to physician utilization of CTP tools. Treatment decisions were categorized as choosing a CTP recommended option ( pathways dependent), not choosing a CTP recommended option ( pathways independent), or not using the CTP tool at all ( non-pathways). Descriptive statistics and significance testing were used to explore CTP utilization over time, physician years in practice, cancer type, and cancer stage. Multinomial and binary logistic regression models were used to evaluate associated factors with CTP utilization. Results: During the study period, 1,007 treatment decisions were identified. Of these, 76% were pathways dependent, 13% were pathways independent, and 11% were non-pathways. CTP utilization was statistically significant in association with cancer type, cancer stage, physician years in practice, and year of encounter. In multinomial logistic regression models, physicians with more years in practice were more likely to be pathways independent and non-pathways than pathways dependent. Physicians treating colorectal or gastroesophageal cancer were more likely to be pathways independent [OR 3.27; 95% CI: 1.98-5.42 and OR 2.25; 95% CI: 1.12-4.49, respectively] or non-pathways [OR 2.98; 95% CI: 1.65-5.37 and OR 3.21; 95% CI: 1.58-6.54, respectively] than pathways dependent compared to physicians treating breast cancer. Treatment decisions for patients with either stage 2 and stage 4 cancers were more likely to be pathways independent than stage 1 cancers [OR 4.13; 95% CI: 1.44-11.84 and OR 4.37; 95% CI: 1.27-15.04, respectively]. Conclusions: This study found that a large proportion of treatment decisions for patients across different cancer types were made utilizing CTP tools, but utilization varies according to cancer type, stage, and physician years in practice. Further research is needed to better understand the physician decision making process and implementation of CTP tools to drive improvement in design, education, and training.