Quality assurance in the EORTC phase III randomised 'boost vs. no boost' trial for breast conserving therapy: Comparison of the results of two individual case reviews performed early and late during the accrual period

The initial ICR has lead to the identification of a number of parameters, which needed a clarification in the protocol. These items have been corrected and the individual institutions have been made aware of the necessary adaptations. The evaluation at the end of the trial period showed that there was an improvement but also showed that continuous monitoring is necessary, especially for institutions which have the most deviations in the first ICR.