ESTRO 2024 - Abstract Book

S40 ESTRO 2024 terms of local control with the use of brachytherapy as boost technique compared with External Beam boost technique. However, the use of low-dose-rate (LDR) brachytherapy (linear sources) was correlated with high rate of toxicity especially in term of radio-necrosis and ulcers. Moreover, the brachytherapy approach had some issues: radio-protection issues, necessity of operating room / dedicated bunker, experienced brachytherapy team, hospitalization, and bleeding/infection risk. The recent innovations in the field of brachytherapy such as intensity modulated and image guided technique resulted in better outcome especially in term of toxicity. In order to stress the differences between the old technique and the new technique some authors started to call this therapy in different way: "interventional Radiotherapy”. The next frontiers about the treatment of anal canal cancer will be “personalized patient centric approach” and integrated therapies. Invited Speaker

3345

Hereditary cancer syndromes and genetic susceptibility affecting radiation decisions

Rinat Bernstein-Molho

Sheba Medical Center, Tel-Hashomer, Oncogenetics Unit, Institute of Genetics, Ramat Gan, Israel. Tel Aviv University, Faculty of Medicine, Tel Aviv, Israel

Abstract:

Cancer is a multifactorial disease, with dozens of environmental and genetic risk factors. All cancer cells contain mutations, some of them are drivers and others result from uncontrolled cell divisions. These are somatic mutations limited to the tumor tissue. These mutations are not heritable, in contrast to germline mutations that exist in all tissues – normal and tumoral. Hereditary predisposition to cancer can be found in 5-10% of all cancer cases. “Familial cancer” is found in approximately 15-20% of the patients with clustering of certain cancer types in families without identification of a single genetic cause. Radiation is a vital component of cancer therapy. Whether germline (as opposed to somatic) pathogenic mutations increase the excess risk of radiation-induced second malignancies or radiation-induced acute toxicity is a major focus of this session. I will discuss hereditary cancer syndromes, which can influence radiation decisions in several ways:

• Personalized treatment planning based on a patient's genetic susceptibility to cancer. • Increased susceptibility to radiation-induced secondary cancers. • Increased susceptibility to acute radiation toxicity in patients with rare recessive syndromes. • Patient counseling and informed consent.

Overall, integrating genetic information into radiation oncology practice allows for more personalized and informed decision-making, ultimately optimizing treatment outcomes for patients with hereditary cancer syndromes.

3346

How to balance the patient and clinician needs: Are we on the same side?

Michelle M Leech

Trinity College Dublin, Radiation Therapy, Dublin, Ireland. Trinity St. James's Cancer Institute, Dublin, Dublin, Ireland