(ChemotherapyAdvisor) – Nearly 4 years after definitive intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC), patients experienced “excellent” outcomes and manageable oral toxicities, according to a multicenter prospective study in China, published in the Journal of Cancer Research and Clinical Oncology.

“IMRT for NPC patients achieved excellent long-term locoregional control and overall survival, with acceptable acute and late toxicities,” reported a team of Chinese researchers led by Rensheng Wang of the Department of Radiation Oncology at the First Affiliated Hospital of Guangxi Medical University.

“After the treatment, xerostomia was improved over time,” they noted.

All 300 study participants were treated from 2006 to 2008; they received definitive IMRT and cisplatin-based concurrent chemotherapy if their NPC was staged to III-IVb disease. At a median follow-up of 47.1 months (11–68 months), “the 4-year local control (LC), regional control (RC), distant metastasis-free survival (DMFS), and overall survival (OS) were 94.0, 95.1, 85.0, and 86.1%, respectively,” the authors reported.

Distant metastasis was the main cause of treatment failure, they noted: 42 patients experienced distant metastasis, 10 of whom suffered metastasis in more than one organ.

“More effective systemic therapy is demanding for reducing the risk of distant metastasis,” they concluded.

No grade 4 acute toxicities were noted. Most patients experienced acute grade 0-2 xerostomia (dry mouth; 286 patients; 95.3%), mucositis (n=200; 66.7%), and dermatitis (n=288; 96%). Grade 3 acute toxicities included mucositis (33.3%), dermatitis (4%), and xerostomia (4.7%), the authors reported.

Xerostomia was also a late toxicity, occurring after 3 months since IMRT, for 284 patients (94.7%).

“16.2% of patients had Grade 1, 73.6% had Grade 2, and 10.2% had Grade 3 xerostomia,” they reported. “However, the severity of xerostomia decreased over time. At 24 months, only 12.3% of patients had Grade 2 xerostomia, and none had Grade 3 or 4 xerostomia.”

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