The primary aim of this study is evaluate the impact of hippocampal-sparing prophylactic cranial irradiation (HS-PCI) on survival status in patients with nodal-positive (locally advanced) adenocarcinoma by comparing overall survival rates of patients undergoing HS-PCI to that of patients without this intervention. In addition, this study aims to investigate whether HS-PCI is detrimental on neurocognitive function and to evaluate its impact on the patient's quality of life.