e18035 Background: Definitive CRT is the standard of care for LA-HNSCC and associated with mucosal toxicity and treatment-related morbidity. Nutritional support via gastrostomy tube (G-tube) during CRT may reduce treatment-related complications. This study aims to identify factors associated with hospitalization in pts with LA-HNSCC treated with CRT. Methods: We conducted a medical record review of pts with LA-HNSCC treated with CRT between January 2010 and December 2019 at the VA San Diego Medical Center. Demographic and clinical factors were compared for pts based on hospitalization and G-tube placement. Logistic regression was used to identify associations with hospitalization and treatment interruptions. Results: Data on 100 pts (98% male) were analyzed. 21 pts were hospitalized, and 17 pts had radiation treatment (RT) interrupted. 72 pts had prophylactic G-tube (p-G-tube) placement, and 11 pts had reactive G-tube (r-G-tube) placement. Hospitalized and non-hospitalized pts did not differ by ethnicity, alcohol use status, or chemotherapy type. Hospitalized vs non-hospitalized pts were older (mean 67.6 vs 63.8, P = 0.043), more likely to lose more weight during CRT (-14.90% vs -10.60%, P = 0.009), less likely to complete CRT (71.4% vs 92.4%, P = 0.009), and more likely to have chemotherapy (42.9% vs 3.8%, P < 0.001) and RT interruptions (71.4% vs 2.5%, P < 0.001). Logistic regression used to predict hospitalization and RT interruption were significant (X2= 35.24, P = 0.002 and X2= 31.97, P = 0.007, respectively). The effect testing p-G-tube vs r-G-tube placement was the only factor significantly associated with lower likelihood of hospitalization during CRT (Wald = 4.61, P = 0.032) and RT interruption (Wald = 6.02, P = 0.014). Pts with r-G-tube placement lost more weight during CRT (-16.79% vs -10.82% with p-G-tube, -10.97% with no G-tube, P = 0.022), had higher hospitalization rates during CRT (72.7% vs 18.1% with p-G-tube, 0% with no G-tube, P < 0.001), had increased likelihood of RT interruption (63.6% vs 13.9% with p-G-tube, 0% with no G-tube, P < 0.001), and were more likely to receive weekly cisplatin (45.5% vs 9.7% with p-G-tube, 41.2% with no G-tube, P = 0.018). Prophylactic G-tube placement was associated with current smoking status (43.1% vs 9.1% with r-G-tube, 41.2% with no G-tube, P = 0.009), bolus cisplatin (52.8% vs 36.4% with r-G-tube, 35.3% with no G-tube, P = 0.018), and cetuximab (27.8% vs 9.1% with r-G-tube, 11.8% with no G-tube, P = 0.018). Conclusions: Prophylactic G-tube placement should be considered for pts with LA-HNSCC treated with CRT regardless of smoking history and chemotherapy choice to decrease treatment-related hospitalizations and RT interruptions. This may be more important for indigent pts since prior research has shown treatment interruptions occur at higher rates in this at-risk population.