Radiotherapy within the interdisciplinary treatment strategy for pediatric extracranial germ cell tumors

Abstract

<h3>Objectives</h3> Radiotherapy (RT) is not a standard modality in the treatment strategy for extracranial germ cell tumors (eGCT) of childhood due to the every young patient cohort and the risk to cause relevant late effects. However, it is used in individual cases to achieve local control. We want to evaluate the role of external beam radiotherapy for eGCT. <h3>Methods</h3> Recent protocols were systematically reviewed. Literature, results of the MAKEI-96 study and experiences from patients within the KiProReg study receiving proton irradiation (PT) were retrospectively evaluated for applied RT and tumor outcome. <h3>Results</h3> According to current protocols, RT is mainly considered for recurrent or residual disease after intensive multi-modal therapy. However, published data suggested that RT (≥ 45 Gy) seems to be beneficial to achieve local control (LC) [1]. Between 1983 and 2021, 41 patients (med. age 10.5 years; range, 0.1-18 years) were irradiated within the MAKEI-96-study or at our institution. Histological diagnoses were predominantly dysgerminomas and yolksac tumors at different sites. Patients were irradiated with various dose concepts applying total doses of 20-60 Gy and fraction doses of 1.5-4 Gy. PT was used in 14 out of the 41 patients. Follow-up time ranged from 1 to 147 months (mean: 58.8 months). During the observation period, LC was achieved in 32 of the 41 patients. <h3>Conclusion</h3> RT seems to be effective in achieving LC. Still, due to potential sequelae, RT has to be considered with caution and discussed individually by the multidisciplinary team, considering both risks and rewards. Strategies for standardized RT are lacking to allow prospective evaluation in near future.