ESTRO 2023 - Abstract Book

S1271

Digital Posters

ESTRO 2023

With a median follow-up of 22.1 months, 6/21 (28.5%) patients had a progression of disease, 4 a distant progression (3 lung and 1 lung and abdomen), among these 1 had also a local progression. 2 patients had only local progression (in 1 case out filed recurrence in the other case patient was treated without RT). Overall, the local control rate was 85.7%. Conclusion In our experience, the integration between HT, radiotherapy and chemotherapy in patients affected by STS of trunk and extremities was feasible achieving a good local control. However, a larger number of patients and a long follow-up are needed to better estimate features of integration of HT radiotherapy and chemotherapy.

PO-1566 Low Rate of Function-Limiting Side Effects in High-Grade Soft Tissue Extremity Sarcomas

D. Koch 1 , M. van der Hoek 1 , D. Scafa 2 , C. Leitzen 2 , C. Schmeel 2 , A. Strauss 3 , S. Koob 4 , G. Feldmann 5 , F. Giordano 2

1 University Medical Center Bonn, Radiation Oncology, Bonn, Germany; 2 University Medical Center Bonn, Radiation Oncology , Bonn, Germany; 3 University Medical Center Bonn, Orthopaedics and Trauma Surgery, Bonn, Germany; 4 University Medical Center Bonn, Orthopaedics and Trauma Surgery , Bonn, Germany; 5 University Medical Center Bonn, Internal Medicine - Oncology / Hematology and Rheumatology, Bonn, Germany Purpose or Objective While the European Society for Medical Oncology guidelines take notice of a shift towards a neoadjuvant (neoadj.) RT approach, the American Society for Radiation Oncology’s guidelines clearly favour a neoadj. approach citing debilitating long-term adverse effects when RT is applied postoperatively. This study aims to examine these irradiation-associated adverse events for adjuvant (adj.) RT while also focusing on prognostic factors for disease outcome including local control. Materials and Methods In the course of this retrospective study, data of 106 patients with extremity soft-tissue sarcomas diagnosed between 1997 and 2021, of which 40 received adj. RT, was acquired from a high-volume sarcoma treatment centre’s clinical and radiological information systems. This data was then analysed for radiation-associated side effects, as well as predictive factors of overall survival (OS), disease-free survival (DSF), local control (LC) and surgery complications. Results For the 106 patients included, the median follow-up period was 26 months and the 1-, 2- and 5-year OS reached were 89%, 76.4% and 58.3%, respectively. 3.8% underwent neoadjuvant (neoadj.) RT and 37.7% received adjuvant (adj.) RT: the majority intensity-modulated radiation therapy (IMRT). Negative prognostic factors for OS were lymph node involvement, metastatic disease and tumour of ≥ 8cm, while surgery and a higher adj. total irradiation dose if having received adj. RT was found to be beneficial. 87.5% experienced side effects from RT, mainly radiation dermatitis for 67.5%, but only 40.0% had any adverse event ≥ 2nd grade according to CTCAE. Long-time function-limiting side effects like joint stiffness, oedema and tissue fibrosis occurred in 45.0% of patients; 10% for ≥ 2nd grade function-limiting adverse events. More time between surgery and adj. RT was found to be beneficial for the patients while joint infiltrating sarcomas were more likely to come with more severe long-time function-limiting events. 29.3% experienced surgery complications or a vacuum-assisted closure, most requiring a secondary invasive procedure. 7.5% experienced trouble with their wounds after having gone through adj. RT. Conclusion This study found a low rate of long-time function-limiting side effects with adj. RT even with high irradiation doses while at the same time attesting to the fact that RT is highly beneficial to local control. Recurrences can be avoided with high dose radiation, especially for high-grade G2- and G3-sarcomas even after complete R0-resection. Hence, adj. RT should be seriously considered when planning patients’ treatment, especially when treating patients presenting with high-grade sarcomas. For the majority of patients, RT involved IMRT which supports the idea that this has come to be the RT technique of choice. With the high benefit of specialised surgery, an interdisciplinary approach including complete resection and adj. RT should be further pursued and adverse events and patients’ quality of life further investigated.

Poster (Digital): Paediatric tumours

PO-1567 Health-related quality of life in survivors of childhood medulloblastoma: a systematic review

T. O'Donovan 1 , J. Delaney 2 , A. Devine 1 , P.M. Mc Entee 1 , P.A. Barry 1,3 , D.A. England 4

1 University College Cork, Medical Imaging and Radiation Therapy, Cork, Ireland; 2 Mater Private at Mid-Western Radiation Oncology Centre, Radiation Oncology, Limerick, Ireland; 3 Cork University Hospital, Radiation Oncology, Cork, Ireland; 4 University College Cork, Medical Imaging and Radiation Therapy, Co. Cork, Ireland Purpose or Objective Treatment-related side effects from paediatric medulloblastoma treatment are associated with a negative impact on survivors’ health-related quality of life (HR-QOL). Multiple factors are related to complications from treatment, including post-operative problems and radiation-induced side effects. The purpose of this study was to review the existing research to understand the impact of late effects of treatment on the HR-QOL for long-term survivors of childhood medulloblastoma.