Phase III Non-Inferiority Trial of Proton Versus Photon Therapy for Nasopharyngeal Carcinoma

"This is the experimental arm intervention. Patients receive Intensity-Modulated Proton Therapy (IMPT) for primary nasopharyngeal carcinoma.~The subjects are patients with histologically confirmed, previously untreated, non-metastatic (M0) nasopharyngeal carcinoma.~Radiotherapy target volumes and doses: GTV (gross tumor volume of primary tumor and metastatic lymph nodes); CTV70Gy (GTVp + 0-5mm margin, GTVn + 0-3mm margin, reducible near organs at risk) at a dose of 69.6-70Gy; CTV50-54Gy (GTVp + 8-10mm margin + entire nasopharyngeal mucosa + adjacent high/intermediate risk structures and intermediate-risk subclinical lymph node regions) at a dose of 50-54Gy, delivered at 2Gy/(RBE) per fraction. The protocol notes that proton therapy does not use a PTV (Planning Target Volume).~The systemic therapy plan is formulated according to clinical guidelines."

"This is the control arm intervention. Patients receive Intensity-Modulated Radiotherapy (IMRT) for primary nasopharyngeal carcinoma; IMRT is one of the current standard and widely used treatment techniques.~The subjects are patients with histologically confirmed, previously untreated, non-metastatic (M0) nasopharyngeal carcinoma.~Radiotherapy target volumes and doses: GTV (gross tumor volume of primary tumor and metastatic lymph nodes); CTV70Gy (GTVp + 0-5mm margin, GTVn + 0-3mm margin); PTV70 (CTV70 + 3-5mm margin, reducible near organs at risk) at a dose of 70Gy; CTV50-54Gy (GTVp + 8-10mm margin + entire nasopharyngeal mucosa + adjacent high/intermediate risk structures and intermediate-risk subclinical lymph node regions); PTV50-54 (CTV50-54 + 3-5mm margin, reducible near organs at risk) at a dose of 50-54Gy, delivered at 2Gy/(RBE) per fraction.~The systemic therapy plan is formulated according to clinical guidelines."