ESTRO 2025 - Abstract Book

S46

Invited Speaker

ESTRO 2025

language. LGBTQI+ patients and carers can feel excluded, distressed, and have unmet needs when not represented in cancer education materials.

There is a pressing need to improve radiation therapy patient education to be LGBTIQ+ inclusive. This talk will therefore discuss:

1. The background of health care and oncology inequities for LGBTIQ+ patients 2. Some specific considerations for LGBTIQ+ patients undergoing radiation therapy 3. Strategies for inclusive communication and cultural sensitivity in patient information material, imagery and verbal communication 4. Ensuring psychosocial needs are met with positive onward referrals and access to community support 5. The importance of HCP education and recommendations for further resources for professional development

4724

Speaker Abstracts Focus on head and neck and skin Bruno Fionda Radiation Oncology Department, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy

Abstract:

Interventional radioimmunotherapy (RIT) is emerging as a transformative approach in oncology, particularly for head and neck cancers and skin malignancies. This paradigm shift redefines traditional radiation therapy principles, integrating precision immunomodulation to enhance therapeutic efficacy. This review explores key advancements in dose fractionation, target volumes, treatment timing, and histology-specific considerations, emphasizing the clinical relevance of novel radiation strategies in these anatomical contexts. Dose and Fractionation: A major evolution in RIT is the transition from the classical concept of radiation as an "invisible knife" to a "dose painting" strategy, where heterogeneous dose distribution optimally targets tumor subregions while preserving normal tissue. Volumes: This shift necessitates the redefinition of treatment volumes beyond traditional gross tumor volume (GTV) and organs at risk (OAR), incorporating new clinically relevant volumes such as immune-privileged regions or immune-responsive zones. Timing: Optimal timing for combining radiation therapy with immunotherapy remains an active area of investigation. Evidence suggests that radiation-induced immunogenic modulation is temporally dependent, with specific fractionation schemes and sequencing strategies potentially maximizing the synergy between radiotherapy and immune checkpoint blockade. Histologies: Biological and clinical heterogeneity across histological subtypes—including squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and melanoma—necessitates tailored RIT approaches. SCCs often present with high mutational burdens and immune infiltration, favoring immunotherapy combinations, whereas BCCs demonstrate unique responses due to aberrant Hedgehog signaling. Melanomas, inherently immunogenic, may benefit from radiation-enhanced antigen presentation. Anatomical Locations: For skin cancers and head and neck tumors, site-specific radiosensitivity and immune microenvironments dictate treatment personalization. Evidence supports differential responses in oropharyngeal, laryngeal, and cutaneous tumors, highlighting the importance of anatomical adaptation in RIT protocols.