ESTRO 2024 - Abstract Book

S1362

Clinical - Head & neck

ESTRO 2024

1943

Digital Poster

Long-term results of the mixed beam approach for locally-advanced nasopharyngeal cancer

Daniela Alterio 1 , Stefania Volpe 1,2 , Emma D'Ippolito 3 , Riccardo Villa 1,2 , Riccardo Santamaria 1,2 , Maria Giulia Vincini 1 , Annamaria Ferrari 1 , Giulia Marvaso 1 , Pierfrancesco Franco 4,5 , Marco Krengli 6 , Umberto Ricardi 7 , Barbara Alicja Jereczek 1,2 , Ester Orlandi 8 , Roberto Orecchia 1 1 IEO, European Institute of Oncology, Division of Radiation oncology, Milan, Italy. 2 University of Milan, Department of Oncology and Hematology-Oncology, Milan, Italy. 3 Istituto Nazionale Tumori “Fondazione Pascale”, Division of Radiotherapy, Napoli, Italy. 4 Ospedale Maggiore della Carità, Division of Radiotherapy, Novara, Italy. 5 University of Eastern Piedmont, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy. 6 University of Padua, Division of Radiotherapy, Padua, Italy. 7 AO Città della Salute e della Scienza, Department of Oncology, Torino, Italy. 8 Centro Nazionale di Adroterapia Oncologica, Division of Clinical Radiotherapy, Pavia, Italy Aims Management of locally advanced nasopharyngeal cancer (LANPC) is challenging due to poor rates of both local and distant control. In this setting, the combination of photon and proton therapy (i.e. intensity modulated radiotherapy-IMRT- followed by intensity modulated proton therapy -IMPT-boost yields the promise of improving patients’ outcomes. While results on acute toxicities have already been reported, scope of the present work is to evaluate long-term radiation-related side effects and oncological outcomes, within a phase II study. Management of locally advanced nasopharyngeal cancer (LANPC) is challenging due to poor rates of both local and distant control. In this setting, the combination of photon and proton therapy (i.e. intensity modulated radiotherapy-IMRT- followed by intensity modulated proton therapy -IMPT- boost yields the promise of improving patients’ outcomes. While results on acute toxicities have already been reported, scope of the present work is to evaluate long-term radiation related side effects and oncological outcomes, within a phase II study. Purpose/Objective:

Material/Methods:

Methods Clinical and dosimetric data were collected per the following inclusion criteria: 1) histological diagnosis of either keratinizing/non-keratinizing/basaloid-squamous-cell primary LANPC (i.e., cT3 – T4 cN0 – N3 cM0), 2) availability of dosimetric data, 3) availability of oncological and toxicity follow-up data, and 4) availability of a written informed consent for the use of data for research purposes. Acute and late toxicities were evaluated according to Common Terminology Criteria Adverse Events (CTCAE) version 4.03, with toxicities of grade ≥3 being considered as severe. All proton-based sequential boosts were performed at a single center, while IMRTs were delivered at three other institutions. All patients received IMRT to a total dose of 54-60 Gy (2 Gy/die, 5 fractions a week) and subsequent boost with IMPT up to a total dose of 70-74 Gy [RBE] (2-3 Gy [RBE]/die, 5 fraction a week).

Results: