 The null hypothesis is that patients screened by PETCT will not have detection of disease recurrence any earlier than those screened by CT alone. The alternative hypothesis is that PETCT surveillance will lead to detection of disease recurrence 3 months earlier than CT surveillance. Furthermore, to reject the null hypothesis, earlier detection must be associated with a cause-specific survival improvement of 10. Primary endpoints will include time from the completion of definitive therapy to diagnosis of recurrent disease, and absolute survival within 3 years after completion of initial therapy. Duration of survival between diagnosis of recurrence and subsequent death will not be a primary endpoint because the investigators expect that PETCT will offer an opportunity for earlier recognition of recurrence and be subject to lead-time bias. Duration of survival will be measured from completion of primary treatment until death. Note: the presence of residual disease at surgical consolidation does not constitute a recurrence event. 