Childhood cancer treatment optimization: In rhabdomyosarcoma and supportive care

This thesis covers two subjects investigating optimization of cancer cure: prevention and treatment of central venous catheter related complications and improvement of local treatment in head and neck rhabdomyosarcoma survivors.
Central venous catheters are indispensable in the modern day treatment of children with cancer. However, these catheters also impose an increased risk of catheter-related infections or -thrombosis. In this thesis the results of two systematic Cochrane reviews are presented, investigating catheter-related complications. Furthermore, we present the results of the Aristocaths study: a randomized controlled multi-center trial investigating prophylactic 70% ethanol locks in pediatric oncology patients with central venous catheters. In a second chapter, the prevalence of asymptomatic and symptomatic venous thrombo-embolic events in the Aristocaths cohort are presented.
In the majority of head and neck rhabdomyosarcoma patients radiotherapy is needed to achieve and maintain local control. Radiotherapy, however, is known to cause damage to surrounding tissue and may cause growth abnormalities and impaired function. Therefore an innovative local treatment approach was developed in the Emma Children’s Hospital, aiming to reduce radiotherapy induced adverse events: Ablative surgery, MOld technique after loading brachytherapy, and surgical REconstruction (AMORE). In the first chapter the image-based response classification, qualifying for local treatment, is evaluated. In the following chapter we evaluate potential failure patterns of surgery and brachytherapy in patients treated for orbital rhabdomyosarcoma. In the last chapters adverse events following local treatment in head and neck rhabdomyosarcoma are described and a comparison is made between the AMORE approach and the international standard: external beam radiotherapy.