ESTRO 2025 - Abstract Book

S80

Invited Speaker

ESTRO 2025

overall survival (P = .09). The grade ≥3 late toxicity rate was 12.1%.The GEC-ESTRO TAM score appears to be an important prognostic factor, assisting patients and physicians in the decision-making process.

In salvage BT, perioperative insertion of tubes can be a good option, to assure an optimal implant covering surgical bed and avoid a second procedure.

There are also some experiences for reirradiation with external radiotherapy. The NRG Oncology/Radiation Therapy Oncology Group 1014 published a phase 2, single-arm, prospective clinical trial of 3-dimensional, conformal, external reirradiation: 58 patients, follow-up of 5.5 years 5-year estimate of re-recurrence of breast cancer in the ipsilateral breast 5%. Late grade 3 treatment-related adverse events 7%, with no grade 4 or higher adverse events reported, and 5-year cumulative incidence of ipsilateral mastectomy 10%. The conclusion is that a second conservative treatment when a local relapse occurs is feasible, sure and safe with acceptable cosmetic outcomes. Brachytherapy is the technique with more follow-up and number of cases, but it can also be done with external RT.

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Speaker Abstracts Head and neck Luca Tagliaferri Radiation Oncology Unit, Fondazione Policlinico Universitario «Agostino Gemelli» IRCCS, Rome, Italy Abstract: Local recurrence of head and neck cancer after full-course radiotherapy remains a significant challenge, with recurrence rates varying widely and most relapses occurring within the field of radiotherapy. Surgical salvage is the primary option for resectable disease, although systemic agents and radiation are important means of locoregional control. However, their efficacy must be balanced with significant toxicity. Indeed, EBRT provides a non-invasive alternative but comes with its own spectrum of side effects, including tissue damage and functional impairment. Interventional radiotherapy (IRT), also known as brachytherapy, is increasingly being considered for its targeted approach. IRT can be offered exclusively or in combination with surgery in a peri-operative setting. Perioperative IRT involves the positioning of catheters during surgery. This approach aims to maximize the dose to the tumor bed while sparing surrounding healthy tissue. Results indicate good local control with manageable side effects. Thanks to innovations in the field of IRT, we have seen an improvement in side effects. Indeed, dose painting techniques, facilitated by image-guided and intensity-modulated radiotherapy, allow for precise targeting of tumor tissues. This method enhances the therapeutic ratio by delivering higher doses to the tumor while minimizing exposure to adjacent normal tissues. Moreover, thanks to cooperation with surgeons, this technique can also be offered using advanced approach, such as endoscopy-guided IRT. Finally, the integration of chemotherapy with interventional radiotherapy is being studied to enhance treatment efficacy. Preliminary results suggest that concomitant chemotherapy may improve outcomes, though further research is needed to fully understand the benefits and risks. • Michiels, S., Le Maître, A., Buyse, M., Burzykowski, T., Maillard, E., Bogaerts, J., Vermorken, J. B., Budach, W., Pajak, T. F., Ang, K. K., Bourhis, J., & Pignon, J. P.; MARCH and MACH-NC Collaborative Groups. (2009). Surrogate endpoints for overall survival in locally advanced head and neck cancer: meta-analyses of individual patient data. Lancet Oncol . • Janot, F., de Raucourt, D., Benhamou, E., et al. (2008). Randomized trial of postoperative reirradiation combined with chemotherapy after salvage surgery compared with salvage surgery alone in head and neck carcinoma. J Clin Oncol .