Optimizing survivorship Decreasing the burden of late adverse events in head and neck rhabdomyosarcoma survivors

Rhabdomyosarcomas (RMS) are the most prevalent soft tissue sarcoma in children, and up to 40% of RMS in children affect the head and neck (HN) area. Survival rates for HNRMS have increased significantly in past decades and continue to improve. However, this efficacy in most patients is achieved by combining systemic and local treatments which often lead to late, chronic adverse events (AEs) in survivors.
The central theme of this thesis is a clinical dilemma in treating pediatric HNRMS patients: how can overall survival be maintained, while lowering the burden of late adverse events resulting from local therapy. We conducted an international cross-sectional cohort study, including long-term HNRMS survivors treated according to any of the four internationally available local treatment strategies: external beam radiotherapy with photons, external beam radiotherapy with protons, surgical macroscopical resection combined with brachytherapy or surgical microscopical resection combined with external beam radiotherapy. Clinical data on the presence of a predefined list of known AEs were collected. Survivors were asked to fulfill a Patient Reported Outcome measure questionnaire. Dosimetric data were retracted from the original radiotherapy treatment plans of the survivors.
In this thesis we lay out a risk profile of factors influencing the burden of late AEs, provide recommendations to improve follow-up and propose pediatric radiotherapy dose constraints for ophthalmological and endocrine organs at risk (OAR) to avoid clinical toxicity. This information is important in order to make informed, shared, decisions on the most optimal treatment choice for future patients.