ESTRO 2022 - Abstract Book

S157

Abstract book

ESTRO 2022

administered by systemic delivery, crossing the blood brain barrier and showing good tumour uptake and theranostic utility. Recent preclinical work in glioma has highlighted the potential of combing nanoparticles with other therapeutics including DNA damage inhibitors such as PARPi or ATMi and also targeting patients with mutations in DNA repair pathways. These combinatorial approaches have significant potential if optimal scheduling can be defined. New opportunities may also exist with a greater appreciation of the role of immune responses and their potential targeting and activation with metal-based nanoparticle. Despite the challenges, there is now significant opportunity for bespoke nanoparticle design based on an improved understanding of both physical and biological sensitisation mechanisms.

SP-0187 CRISPR-Cas combination therapy: What's in it for radiotherapy?

L. Marignol Ireland

Abstract Text The class of RNA-guided endonuclease known as Cas9 from the microbial adaptive immune system CRISPR (clustered regularly interspaced short palindromic repeats) is an increasingly examined tool that could assist the challenge of providing each cancer patients with the highest chance of disease control using radiation therapy. This transformative technology enables targeted editing of the genome and is being turned into effective cancer gene editing therapies. Selective gene editing can be achieved through the design of a researcher-defined 16bp guide RNA sequence unique to the chosen target gene. Once inside the target cell, the gRNA binds the target sequence and the Cas9 enzyme acts as a pair of “molecular scissors” that can cut the two strands of DNA at this chosen specific location within the genome. This talk will discuss the potential and limitations of CRISPR-Cas9 for the development of novel radiotherapy combination therapies.

Symposium: Large-scale collection of PROs for clinical use during follow-up

SP-0188 PRO for reporting radiation treatment outcome: How to select the right PROs?

I. Bhattacharya 1

1 Addenbrooke's Hospital, Oncology and Radiotherapy, CAMBRIDGE, United Kingdom

Abstract Text Systematic monitoring of late effects from radiotherapy is important in determining normal tissue effects and measuring dose response. Patient reported outcome (PRO) enable us to record patient perceptions of the impact of their cancer and the consequences of treatment. This talk will begin with a background on defining patient PRO and what is expected of a PRO tool. The differences between PRO describing the continuum of general and specific PRO tools and the requirement to use combinations to capture a range of PRO concepts will be discussed. The importance of collaborating with patients to tailor PRO which are most relevant to future patients will be highlighted using examples from breast radiotherapy trials. Finally, methods to optimise and streamline PRO using the most relevant questions and reduce missing data will be mentioned. SP-0189 Nation-wide app-based collection of PROs in early breast cancer patients treated with radiation therapy - The DBCG experience R. Zachariae 1 , B. Offersen 2 , N. Kroman 3 , H. Melgaard Nielsen 1 , T. Damsgaard 4 , J. Overgaard 1 , S. Lauritsen 5 , E. Eskildsen 6 , A. Bonde Jensen 1 , P. Christiansen 7 1 Aarhus University Hospital, Skejby, Oncology, Aarhus, Denmark; 2 Aarhus University Hospital, Skejby, Oncology, Aarhus , Denmark; 3 Copenhagen University Hospital, Rigshospitalet, Surgery, Copenhagen, Denmark; 4 Copenhagen University Hospital, Rigshospitalet, Surgery, Aarhus, Denmark; 5 Enversion Ltd., Life Sciences, Aarhus , Denmark; 6 Journl Ltd., IT, Aarhus, Denmark; 7 Aarhus University Hospital, Skejby, Surgery, Aarhus, Denmark Abstract Text Survival rates for breast cancer (BC) patients are increasing, but improved survival is often obtained at a cost, with more intense treatments resulting in persistent symptoms and late effects. These include treatment-specific loco-regional symptoms, e.g., surgery and radiotherapy-induced lymphedema and fibrosis, late effects after systemic treatments, e.g., chemotherapy-induced neuropathies and premature menopause, and general bio-behavioral late effects observed across cancer types and treatments, e.g., fatigue, pain, sleep disturbance, depression, fear of cancer recurrence, and cognitive impairment. While many BC patients experience improvements in these symptoms after completing primary treatment, substantial subgroups of BC survivors develop persistent or even exacerbated symptoms, severely affecting their daily physical, mental, and social functioning and well-being. The limitations of the available research in late effects include small samples of convenience, cross-sectional designs, and longitudinal studies, mainly capturing overall changes in symptom severity over time. We, therefore, only have limited knowledge about who is at heightened risk of developing persistent late effects, how their symptoms develop over time, the mechanisms driving such changes, and how best to prevent and treat them. The clinical implications are that patients are rarely asked about and seldom treated for their late effects. On this background, it has become increasingly clear that there is a need for systematically collected patient-reported outcome (PRO) data on symptoms and late effects across the cancer treatment and survivorship trajectory.