Mixed-beam approach in locally advanced nasopharyngeal carcinoma: IMRT followed by proton therapy boost versus IMRT-only. Evaluation of toxicity and efficacy

Alterio, Daniela; D’Ippolito, Emma; Vischioni, Barbara; Fossati, Piero; Gandini, Sara; Bonora, Maria; Ronchi, Sara; Vitolo, Viviana; Mastella, Edoardo; Magro, Giuseppe; Franco, Pierfrancesco; Ricardi, Umberto; Krengli, Marco; Ivaldi, Giovanni; Ferrari, Annamaria; Fanetti, Giuseppi; Comi, Stefania; Tagliabue, Marta; Verri, Elena; Ricotti, Rosalinda; Ciardo, Delia; Jereczek-Fossa, Barbara Alicja; Valvo, Francesca; Orecchia, Roberto

doi:10.6084/m9.figshare.11889378.v1

ionc_a_1730001_sm4212.doc (46 kB)

Mixed-beam approach in locally advanced nasopharyngeal carcinoma: IMRT followed by proton therapy boost versus IMRT-only. Evaluation of toxicity and efficacy

journal contribution

posted on 2020-02-24, 06:33 authored by Daniela Alterio, Emma D’Ippolito, Barbara Vischioni, Piero Fossati, Sara Gandini, Maria Bonora, Sara Ronchi, Viviana Vitolo, Edoardo Mastella, Giuseppe Magro, Pierfrancesco Franco, Umberto Ricardi, Marco Krengli, Giovanni Ivaldi, Annamaria Ferrari, Giuseppi Fanetti, Stefania Comi, Marta Tagliabue, Elena Verri, Rosalinda Ricotti, Delia Ciardo, Barbara Alicja Jereczek-Fossa, Francesca Valvo, Roberto Orecchia

Objective: To compare radiation-induced toxicity and dosimetry parameters in patients with locally advanced nasopharyngeal cancer (LANPC) treated with a mixed-beam (MB) approach (IMRT followed by proton therapy boost) with an historic cohort of patients treated with a full course of IMRT-only.

Material and methods: Twenty-seven patients with LANPC treated with the MB approach were compared to a similar cohort of 17 patients treated with IMRT-only. The MB approach consisted in a first phase of IMRT up to 54–60 Gy followed by a second phase delivered with a proton therapy boost up to 70–74 Gy (RBE). The total dose for patients treated with IMRT-only was 69.96 Gy. Induction chemotherapy was administrated to 59 and 88% and concurrent chemoradiotherapy to 88 and 100% of the MB and IMRT-only patients, respectively. The worst toxicity occurring during the entire course of treatment (acute toxicity) and early-late toxicity were registered according to the Common Terminology Criteria Adverse Events V4.03.

Results: The two cohorts were comparable. Patients treated with MB received a significantly higher median total dose to target volumes (p = .02). Acute grade 3 mucositis was found in 11 and 76% (p = .0002) of patients treated with MB and IMRT-only approach, respectively, while grade 2 xerostomia was found in 7 and 35% (p = .02) of patients treated with MB and IMRT-only, respectively. There was no statistical difference in late toxicity. Local progression-free survival (PFS) and progression-free survival curves were similar between the two cohorts of patients (p = .17 and p = .40, respectively). Local control rate was 96% and 81% for patients treated with MB approach and IMRT-only, respectively.

Conclusions: Sequential MB approach for LANPC patients provides a significantly lower acute toxicity profile compared to full course of IMRT. There were no differences in early-late morbidities and disease-related outcomes (censored at two-years) but a longer follow-up is required to achieve conclusive results.