PURPOSE: A phase 3 trial assessing response-based therapy in intermediate-risk Hodgkin lymphoma mandated real-time central review of involved field radiation therapy (IFRT) and imaging records by a centralized review center to maximize protocol compliance. We report the impact of centralized radiation therapy review on protocol compliance.

METHODS AND MATERIALS: Review of simulation films, port films, and dosimetry records was required before and after treatment. Records were reviewed by study-affiliated or review center-affiliated radiation oncologists. A deviation of 6% to 10% from protocol-specified dose was scored as "minor"; a deviation of > 10% was "major." A volume deviation was scored as "minor" if margins were less than specified or "major" if fields transected disease-bearing areas. Interventional review and final compliance review scores were assigned to each radiation therapy case and compared.

RESULTS: Of 1712 patients enrolled, 1173 underwent IFRT at 256 institutions in 7 countries. An interventional review was performed in 88% of patients and a final review in 98%. Overall, minor and major deviations were found in 12% and 6% of patients, respectively. Among the cases for which > /=1 pre-IFRT modification was requested by the Quality Assurance Review Center and subsequently made by the treating institution, 100% were made compliant on final review. By contrast, among the cases for which > /=1 modification was requested but not made by the treating institution, 10% were deemed compliant on final review.

CONCLUSIONS: In a large trial with complex treatment pathways and heterogeneous radiation therapy fields, central review was performed in a large percentage of cases before IFRT and identified frequent potential deviations in a timely manner. When suggested modifications were performed by the institutions, deviations were almost eliminated.