Event-free survival (EFS) defined as time to the first occurrence of disease progression, disease recurrence, second malignant neoplasm, or death from any cause Up to 5 years [clinicaltrials_resource:3cf797df4e74346d809e3eaa05695499]

Using Kaplan-Meier curves to estimate the observed EFS for the two randomization arms (post-radiation Maintenance arm and post-radiation Observation only arm). Log rank tests will be used to compare the observed EFS between the two randomization arms. Stratified log rank test will also be performed to examine the treatment difference with consideration and adjustment for the randomization groups.

Event-free survival (EFS) defined as time to the first occurrence of disease progression, disease recurrence, second malignant neoplasm, or death from any cause Up to 5 years [clinicaltrials_resource:3cf797df4e74346d809e3eaa05695499]

Using Kaplan-Meier curves to estimate the observed EFS for the two randomization arms (post-radiation Maintenance arm and post-radiation Observation only arm). Log rank tests will be used to compare the observed EFS between the two randomization arms. Stratified log rank test will also be performed to examine the treatment difference with consideration and adjustment for the randomization groups.