Treatment Outcomes of Concurrent Nimotuzumab with Intensity Modulated Radiotherapy in Advanced Nasopharyngeal Carcinoma Patients Unfit for Concurrent Chemoradiotherapy: A Single Institute Experience

Abstract

To assess the safety and efficacy of intensity-modulated radiotherapy (IMRT) combined with nimotuzumab for patients with locally advanced nasopharyngeal carcinoma (LA-NPC) medically unfit to receive concomitant chemotherapy. From 2016.6 to 2020.9, 34 newly diagnosed patients with local-regional advanced NPC medically unfit for concurrent chemoradiation had undergone definitive radiotherapy and were retrospectively evaluated. All patients were treated with IMRT combined treatment modality of nimotuzumab with or without cisplatin-based induction chemotherapy. Nimotuzumab was administered concurrently with IMRT at a weekly dose of 200 mg. Acute and late radiation-related toxicities were evaluated based on the Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 during and after IMRT. The Kaplan-Meier method was used for survival analysis. Univariate and multivariate prognostic analyses were performed by using the Cox proportional hazard model. The median follow-up time for the entire group was 15 months (range 5 to 55 months). At the time of this analysis, a total of 2 cases developed loco-regional recurrence. In addition, 4 patients developed distant metastasis. There was a total of 5 deaths: 3 patients died from distant metastasis, 1 patient died from the progression of loco-regional disease after recurrence, and the causes of death for the additional 1 case was a nasopharyngeal ulcer and deadly bleeding. The 1-year OS rate of the whole cohort was 87.9%, and the 1-year LFFR, DFFR, and PFS rates were 100%, 91.0%, and 91.0%, respectively. During the period of concurrent nimotuzumab and IMRT, no grade 3-4 hematologic toxicities and dermatitis were observed. Grade 3-4 radiotherapy-related oral mucositis was reported in 7 patients (20.6%). No infusion reaction was observed. No acneiform eruptions were found among these patients. The most commonly observed late complication was xerostomia. The degree of dry mouth in most patients was mild-to-moderate at the time of the last follow-up. Finally, 7 patients developed either unilateral or bilateral hearing impairment. One female patient experienced a nasopharyngeal ulcer and deadly bleeding after 5 months of completion of radiotherapy. Concurrent nimotuzumab with IMRT for the treatment of LA-NPC was well tolerated, with encouraging survival data, and it could be an effective treatment alternative for patients with LA-NPC medically unfit for concomitant chemotherapy. Further clinical trials are needed to confirm these findings.