Mixed Photon and Carbon-Ion Beam Radiotherapy in the Management of Non-Metastatic Nasopharyngeal Carcinoma.

Jiyi Hu,Wenna Zhang,Xianxin Qiu,Xiyin Guan,Jing Yang,Qingting Huang,Jing Gao,Jiade J Lu,Weixu Hu,Lin Kong

doi:10.3389/fonc.2021.653050

Abstract

BackgroundCarbon-ion radiotherapy (CIRT) may further increase the therapeutic ratio for patients with newly diagnosed nasopharyngeal carcinoma (NPC). The purpose of the current study is to examine the effectiveness and toxicity profile of photon-based intensity-modulated radiotherapy (IMRT) plus CIRT boost in a relatively large cohort of NPC patients.MethodsIn the current study, non-metastatic NPC patients treated with IMRT plus CIRT boost at Shanghai Proton and Heavy Ion Center between June, 2015 and June, 2018 were included. Overall survival (OS), progression-free survival (PFS), local control, regional control, and distant control were calculated with Kaplan–Meier method. Acute and late toxicities were graded using CTCAE 4.03.ResultsA total of 69 patients were included in the analysis. Among those, 74% of the patients had locoregionally advanced (stage III/IV) disease, and 92.8% had cervical lymphadenopathy. With a median follow-up of 31.9 months, the 3-year OS, PFS, local control, regional control, and distant control rates were 94.9, 85.2, 96.9, 98.4, and 89.7%, respectively. Mixed treatment of IMRT with CIRT boost was well tolerated. Severe acute toxicities induced by radiation therapy were observed in only two patients (dermatitis). No severe radiation-induced late toxicity was observed at the time of analysis. Univariable analysis showed N2/3 disease was correlated with an inferior distant control (p = 0.040).ConclusionMixed treatment of IMRT plus CIRT boost provides an excellent disease control and a favorable toxicity profile for patients with non-metastatic NPC. Further follow-up is necessary to evaluate the long-term survivals and toxicities more accurately.

Highlights

Nasopharyngeal carcinoma (NPC) is one of the most commonly diagnosed head and neck cancers in Southeast Asia
Lewis et al demonstrated that intensitymodulated proton therapy (IMPT) could provide dosimetric advantages for NPC patients with lower dose delivered to the surrounding normal tissues as compared to intensity-modulated radiotherapy (IMRT) [13]
No significant difference was detected in the univariable analysis of local progression-free survival (89 vs 94%) and Progression-free survival (PFS) (69 vs 76%) at 2 years, mixed treatment of IMRT with proton boost was associated with significantly reduced severe acute toxicities (11 vs 76%, p < 0.001)

Summary

Introduction

Nasopharyngeal carcinoma (NPC) is one of the most commonly diagnosed head and neck cancers in Southeast Asia. [4] radiationrelated toxicities become a concern for patients with NPC who underwent IMRT, especially for long-term survivors. More precise and conformal radiation techniques are needed to further improve the toxicity profile of patients with NPC. [5] Our dosimetric study showed carbon-ion radiotherapy (CIRT) significantly reduces dose to surrounding organs (including brainstem and temporal lobes) for patients with recurrent nasopharyngeal carcinoma, compared to IMRT. [6] not investigated in newly diagnosed NPC patients, it is reasonable to speculate CIRT can provide similar improvement in dose distribution. Carbon-ion radiotherapy (CIRT) may further increase the therapeutic ratio for patients with newly diagnosed nasopharyngeal carcinoma (NPC). The purpose of the current study is to examine the effectiveness and toxicity profile of photon-based intensitymodulated radiotherapy (IMRT) plus CIRT boost in a relatively large cohort of NPC patients

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